Spinal News International Issue 51 – May 2019

May

Issue

19 51 Francis Lovecchio: Opioid consumption patterns

Page 10

Eric Lamoutte: The effects of day of surgery

Page 14

Cages in ACDF are associated with a higher non-union rate than allograft Investigators found a higher rate of non-union associated with intervertebral cages than with allograft in a recent retrospective analysis, which led to the conclusion that allograft may be superior to cages in anterior cervical discectomy and fusion (ACDF). This research, by Sean Pirkle (Department of Orthopaedic Surgery and Rehabilitation Medicine, University of Chicago Medical Center, Chicago, USA) and colleagues, was recently published in Spine.

T

he investigators note that in recent years, the use of an intervertebral cage in anterior discectomy and arthrodesis has gained popularity. Concurrently, attention has been given to the use of either bone graft or cages during this procedure, as well as the occurrence of non-union, which the authors mention can lead to “poor clinical outcome and the need for revision surgery, whether posterior or anterior, presenting an additional risk to the patient”.

Pirkle and colleagues remark that the increased prevalence of cage use, alongside the negative effects of non-union for the patient, make this a necessary and timely study.

The authors describe the research as a retrospective database review of 6,130 patients registered in the PearlDiver national database through Humana Insurance from 2007–2016. All ACDF patients with anterior plating who were active in the database for at least one year were included in the study. Pirkle and colleagues excluded patients with a fracture history within one year of intervention, past arthrosis of hand, foot, or ankle, or a planned posterior approach.

Patients were stratified by number of levels treated, tobacco use, and diabetic condition. Non-union rates

The non-resorbable nature of the intervertebral cage may represent a literal block for fusion formation. ”

Ronald Bartels:

Profile

Page 12

Advanced method of quantifying the cone of economy may allow practitioners to determine appropriate treatment options A new method to quantify the boundaries of Dubousset’s cone of economy, the centre of mass displacements, and the amount of sway within the cone of economy along with the energy expenditure for a specific patient, has been developed and evaluated by Ram Haddas and Isador Lieberman of the Texas Back Institute (Plano, USA).

of structural allograft and intervertebral cage groups after one year were then compared using Chi-squared analyses.

The investigators report that 4,063 patients were included in an allograft treatment group, while 2,067 were included in a cage treatment group. Overall, they found that non-union rates were “significantly higher” in the cage group (5.32%) than in the allograft group (1.97%) and when controlling for confounders, they observed increased rates of non-union in the cage group, achieving statistical significance in 25 of the 26 analyses.

Pirkle and colleagues comment: “Although the non-

LIEBERMAN RECENTLY PRESENTED the results of this study at the 19th Annual Conference of the International Society for the Advancement of Spine Surgery (ISASS; 3–5 April, Anaheim, USA).

Haddas and Lieberman set out to evaluate this method to quantify the dimensions of the cone of economy and the energy expenditure associated with maintaining a balanced posture within the cone of economy in adult degenerative scoliosis (ADS) patients compared to matched non-scoliotic controls.

They note that ADS patients exhibit a variety of postural changes within their cone of economy, involving the spine, pelvis and lower extremities, in their effort to compensate for the altered posture.

They defined balance as the ability of the human body to maintain its centre of mass within the base of support with minimal postural sway, and note that the cone of economy refers to the stable region of upright standing posture. In general, though, the brain, through the righting reflex, will sacrifice focal Continued Continued on page on page 2 2

Continued on page 2

2

May

Cages in ACDF are associated with a higher non-union rate than allograft Continued from page 1

Senior author Michael J Lee

resorbable nature of the cage may allow for stability as the fusion mass forms, it may also represent a literal mechanical block for fusion formation. Fusion mass cannot form in the space occupied by the synthetic cage.” With less endplate surface area and less intervertebral volume available for arthrodesis, the authors therefore hypothesised that the use of a cage in ACDF would be “significantly associated” with the development of a non-union.

According to the authors, existing literature consists

To date, this is the largest comparative study examining the fusion rates of ACDF using cages and structural bone graft. We hope that future studies [...] may be of value in further investigation. ”

Editors-in-chief:

Professor Gunnar Andersson (USA) Dr Alexis Kelekis (Greece) Professor Christopher Bono (USA)

Publisher:

Stephen Greenhalgh

Head of Publishing: Sadaf Kazi

Editor:

Jocelyn Hudson jocelyn@bibamedical.com

Editorial contribution:

Suzie Marshall, Dawn Powell and Jessica Thompson

Issue

19 51

Cervical spine

primarily of single-centre studies with inconsistent findings. The purpose of this study was therefore to analyse the rate of non-union in patients treated with structural allograft and intervertebral cages in ACDF in a larger patient cohort.

The investigators also note that their finding is in contrast with prior literature. To date, there have been five studies that compared union rates in ACDF using cages versus bone graft. However, “None of them were able to demonstrate a difference between the two techniques.” Pirkle and colleagues mention in particular that the sample size of these studies were low. “Even when the data from these five studies are pooled, there are only 122 patients in the bone graft ACDF group and 147 in the cage group. This low combined sample size precludes sufficient analysis and control for confounding variables, whereas our study allows for a larger stratified analysis.”

The investigators also mention some weaknesses of the present study. For example, they were unable to obtain radiographic evidence of non-union for individual patients and instead relied on the diagnosis codes for non-union, which they describe as “an important assumption we have made in this study”.

Furthermore, as this was an observational database study, the authors were unable to determine the constitution of each cage placed, whether that be polyetheretherketone (PEEK), titanium, mesh, or porous material.

Going forward, Pirkle and colleagues hope that future studies utilising other data sources with sufficient sample size may be of value in further investigation.

However, they also highlight the strength of their study, noting that the PearlDiver data have been widely utilised in peer-reviewed publications and also that, to date, this is the largest comparative study examining the fusion rates of ACDF using cages and structural bone graft.

They comment: “Our practice, like the majority of spine surgeons in North America, is to utilise structural bone graft in ACDF. These data suggest that allograft, when available, may be a superior option than the use of a cage in achieving arthrodesis in the cervical spine.”

However, they add: “ACDF cages may continue to have a role in cervical spine arthrodesis. In situations where structural allograft may not be readily available, cervical cages represent a reasonable alternative with a well-documented fusion rate, though perhaps not as high as allograft.”

Design:

David Reekie, Terry Hawes and Naomi Amorra

Advertising: Jade Keegan

jade@bibamedical.com

Subscriptions: Susan Couch

susan@bibamedical.com

Please contact the Spinal News International team with news or advertising queries Tel: +44 (0)20 7736 8788

linkedin.com/company/spinal-news-international/

Advanced method of quantifying the cone of economy may allow practitioners to determine appropriate treatment options Continued from page 1

alignment to optimise global balance within the cone of economy. They also mentioned that the underlying assumption is that deviating outside of a patient’s individual cone challenges the balance mechanisms and consumes more energy.

In this non-randomised, prospective, control cohort study, Haddas and Lieberman included 15 ADS patients and 15 non-scoliotic volunteers, all of whom performed a series of functional balance tests.

The investigators measured the dimensions of the cone of economy and the energy expenditure related to maintaining balance within the cone of economy using a human motion video capture system and dynamic surface electromyography.

The investigators describe how the ADS patients included in the study presented more centre of mass range of sway in the sagittal (ADS: 1.59cm vs. H: 0.61cm; p=0.049) and coronal (ADS: 2.84cm vs. H: 1.72cm; p=0.046) directions in comparison to the non-scoliotic controls. Additionally, they note that ADS patients presented with more centre of mass (ADS: 33.3cm vs. H: 19.13cm; p=0.039) and head (ADS: 31.06cm vs. H: 19.13cm; p=0.013) overall sway in comparison to the non-scoliotic controls.

Finally, scoliosis patients expended more muscle activity to maintain static standing, as manifest by increased muscle activity in their erector spinae (ADS: 37.16mV vs. H: 20.31mV; p=0.050), and gluteus maximus (ADS: 33.13mV vs. H: 12.09mV; p=0.001) muscles.

The strength of this study relates to the objective nature of this form of functional balance testing. ”

Published by: BIBA Medical, 526 Fulham Road, London, UK SW6 5NR

Write to us!

If you have comments on this issue or suggestions for upcoming editions write to jocelyn@bibamedical.com

Tel: +44 (0) 20 7736 8788 Fax: +44 (0) 20 7736 8283

Printed by: Buxton Press Reprint requests and all correspondence regarding the newspaper should be addressed to the editor at the above address. © BIBA Medical Ltd, 2019 All rights reserved.

facebook.com/spinalnews

www.spinalnewsinter national.com

Make sure you get your copy of

Next issue September 2019 @SpinalNewsInt

4

May

Effect of spinal decompression on back pain in lumbar spinal stenosis A recent study found that low back pain is significantly improved in 74% of patients immediately after surgery for lumbar spinal stenosis and that, at two years, over twothirds of patients continue to have significant relief of low back pain (LBP) symptoms.

Shreya Srinivas, senior fellow at Alder Hey Children’s Hospital (Liverpool, UK) recently presented these results at the 2019 meeting of the British Association of Spine Surgeons (BASS; 3–5 April, Brighton, UK).

S

Issue

19 51

Conference coverage

rinivas and colleagues (Canadian Spine Outcomes and Research Network [CSORN] investigators, Canadian Spine Society) found that various patient factors, including the absence of claims or compensation, baseline severity of LBP and the absence of narcotic usage, were associated with LBP improvement.

However, they found no significant correlation between the type of surgical procedure performed and LBP improvement.

Lumbar spinal stenosis is the most common indication for lumbar spine surgery in older adults. While the predominant presenting symptom is of neurogenic claudication, LBP is a common associated or coexisting presenting symptom that contributes to disability.

According to the authors, there is a substantial amount of quality evidence that surgical intervention results in good relief of leg pain, and therefore an improvement in functional and disability status. However, improvement

in back pain relief as a primary outcome measure has not been investigated.

The investigators describe the study as a multicentre, retrospective review of consecutive spine surgery patients enrolled

by CSORN between 2014 and 2017. The aim was to assess quality improvement Shreya Srinivas of LBP following surgical decompression for lumbar canal stenosis, and also to identify factors associated with a change in LBP. Patients undergoing surgical treatment for lumbar spinal stenosis without instability were included, with the surgical intervention (decompression either with or without fusion, conducted using either an open or minimally invasive approach) being left to the discretion of the treating surgeon.

Postoperatively, the investigators recorded patientreported outcome measures (PROMs), with baseline PROMs repeated for those waiting longer than six weeks prior to surgery. This information was collected in person, via post or by employing an online portal at baseline, three months, 12 months and 24 months.

Outcome measures included patient variables, specifically sociodemographic factors, medication and resource utilisation, comorbidities and symptoms.

Operative and postoperative variables, such as type of procedure, operating time, blood loss, adverse events and length of hospital stay, were also collected, as well as PROMs, from a disability scale, numerical rating scale (NRS) for back and leg pain, and the EuroQol EG5D and the SF-12 physical (PCS) and mental component summary (MCS). The investigators note that they considered a change in NRS of two points to count as a minimal clinically important difference.

For the 1,221 patients included in the CSORN registry

study, the mean score from the EQ-5D was 0.54 (-0.11 to -1). For 27 of the patients the duration of their back pain lasted between zero and three months, for 150 patients it lasted between three and 12 months, for 138 patients between one to two years, 325 patients for over two years and for 10 patients the duration of their back pain was not known.

Six hundred and seventeen patients (72%) were treated with either discectomy or decompression, 227 (26.6%) were treated with fusion with discectomy or decompression, and for eight patients the surgical procedure was unknown. In terms of surgical approach, 357 patients underwent minimally invasive surgery (MIS), while a majority of 495 patients underwent open surgery. The average surgical time was 117.64 minutes (30–800) and the average length of hospital stay was 3.9 days (0–371). Adverse events occurred intraoperatively in 70 patients (8.2%), perioperatively in 109 patients (13.2%) and postoperatively in 55 patients (10.6%).

The NRS mean for back pain improvement at baseline (n=1,133) was 8.83, at three months (n=926) it was -3.56, at 12 months (n=651) it was -3.37 and at 24 months (n=334), the figure was -3.23. The percentage of patients reaching MCID was 73.9 at three months, 68 at 12 months and 68.3 at 24 months.

Srinivas tells Spinal News International: “Improvement in back pain as a primary outcome measure has not been investigated so far. In fact, it is usually accepted that, despite adequate surgical treatment, residual back pain is the rule.”

“Prospectively collected data from CSORN allows us to report on care as actually provided, without rigid inclusion and exclusion criteria. The results of this study are thus representative of real-life clinical practice and complement data from randomised controlled trials and other observational studies.” She adds: “Ultimately this helps surgeons to manage patient expectations and counsel them about potential effects of surgical intervention on their symptoms.”

Study highlights the need for individualised thromboprophylaxis regimens for neurosurgical and orthopaedic spine surgery patients At the 2019 meeting of the International Society for the Advancement of Spine Surgery (ISASS; 3–5 April, Anaheim, USA), Erik Wang of NYU Langone Health (New York, USA) presented the results of a study reviewing the rates of hospital-acquired venous thromboembolism (HAVTE) and the prevalence of known risk factors in patients who developed HA-VTE among both neurosurgical and orthopaedic spine surgery patients. He concluded that, among those who sustained a VTE, neurosurgical patients had higher rates of active cancer and there were more patients over the age of 60 years, while orthopaedic patients had higher estimated blood loss and rates of anterior–posterior surgery.

ACCORDING TO LEAD author Charla R Fischer (NYU Langone Health, USA) and colleagues: “This highlights the different patient populations between the two departments and the need for individualised thromboprophylaxis regimens.” They suggest: “A multicentre study may further elucidate the reasons why certain procedures and diagnoses are more associated with HA-VTEs, as well as the difference between spine disciplines.”

Fischer and colleagues note that VTE is the number one preventable, hospital-acquired cause of morbidity and mortality in the USA, and estimates of total annual healthcare costs attributable to VTE range from US$7,594–16,644 per patient, up to US$10 billion annually.

The investigators found that the rate of HA-VTE was 0.61% (32/5,283) among orthopaedic patients compared to 1.87% for neurosurgery patients, giving an average rate of 0.94% (67/7,089)

among the whole patient population.

Additionally, among patients who developed a HA-VTE, orthopaedic patients had higher estimated blood loss (2,436ml vs. 1,176ml, p=0.006), higher rates of anterior–posterior surgery (22.58% vs. 0%, p=0.004) and more patients over the age of 60 (80% vs. 50%, p<0.001). Postoperative anticoagulation was found to be initiated sooner in neurosurgery patients (postoperative day: 1.26 vs. 3.19, p<0.001).

Fischer and colleagues note that significant independent patient risk factors for VTE included treatment in the neurosurgery department (odds ratio [OR] 3.521, 95% confidence interval [CI] 2.11–5.882, p<0.001), the cervical procedure level (OR 0.343, 95% CI 0.134–0.879, p=0.026) and fracture diagnosis (OR: 8.25, 95% CI 1.471– 46.26, p<0.001).

The investigators describe the study

as a retrospective chart review of all spine surgery patients at NYU Langone Health from 1 January 2013 to 31 July 2017, in which the rates of HA-VTE and the prevalence of known HA-VTE risk factors among these patients was evaluated. They define HA-VTE as either inpatient discharge that was diagnosed with a deep venous thrombosis (DVT) or pulmonary embolism (PE) not present

A multicentre study may further elucidate the reasons why certain procedures and diagnoses are more associated with HA-VTEs. ”

on admission, or a discharge that was readmitted within 30 days of index discharge with a principal diagnosis of DVT or PE. Furthermore, demographic data was collected for gender, age, ethnicity, BMI, length of hospital stay and number of spinal levels involved in surgery.

The prevalence of risk factors, surgical factors, procedure types, preoperative diagnoses and surgical diagnosisrelated groups (DRGs) was compared between patients with and without HA-VTE, between patients undergoing procedures with orthopaedic surgery and neurosurgery departments, and between patients at different hospital facilities at NYU Langone Health.

The investigators carried out a univariate analysis for categorical variables, an independent student’s t-test for continuous variables and a multivariate logistic regression to determine the independent of risk factors.

6

May

Issue

19 51

Spinal cord injury

Acute, severe spinal cord injury: Monitoring from the injury to improve outcome Marios Papadopoulos Samira Saadoun Comment & Analysis Marios Papadopoulos and Samira Saadoun talk to Spinal News International about the ISCoPE trial, which aimed to develop techniques to continuously monitor the pressure of the spinal cord at the injury site in the intensive care unit (ICU). They conclude that monitoring from the injury site provides clinically important information, and note that they are now in the process of setting up a randomised controlled trial to test whether, compared with bony decompression, expansion duroplasty improves functional outcome after severe spinal cord injury.

M

any spinal surgeons manage patients in the first few days after a severe spinal cord injury.

In general, surgeons fix the fracture using metalwork to eliminate instability and the risk of further cord damage. Nothing much can be done in the first few days to improve long-term neurological recovery.

About seven years ago, we set up a study termed ISCoPE (Injured Spinal COrd Pressure Evaluation) aiming to develop techniques to continuously monitor the pressure of the spinal cord at the injury site in the ICU. We call this pressure intraspinal pressure or ISP by analogy to intracranial pressure or ICP that we routinely measure in patients with severe brain injuries. The pressure probe is inserted intradurally during surgery and the ISP is monitored for up to a week and used to compute the spinal cord perfusion pressure (SCPP=mean arterial pressure minus ISP) by analogy to cerebral perfusion pressure for injured brain.1 More recently, we also started monitoring hourly the metabolism of the injured spinal cord (glucose, lactate, pyruvate, glutamate, glycerol) by placing a microdialysis catheter intradurally at the injury site next to the pressure probe.2 These measurements are displayed on the ICU monitors to help the intensivists optimise management to reduce secondary cord damage.

Inserting the two monitoring probes (pressure, microdialysis) intradurally, next to the injured cord and leaving them there for up to a week is safe.3 The ISP signal that is measured from the injured cord is pulsatile and is similar to the ICP signal that is measured from

observations that too low and too high SCPP are both detrimental, suggest that there must be an intermediate optimum SCPP. We developed a technique to compute the optimum SCPP in real-time and display this on the ICU monitor. A key finding is that the optimum SCPP varies between patients and with time in each patient, thus supporting the concept of individualised management, i.e. not applying the same MAP guidelines to each patient.5 Intervening to increase the SCPP allows more intravenously administered drugs to enter the injury site, which has important implications for the design of drug trials for spinal cord injury.2 In most patients with severe injuries (AIS grades A–C), the cord swells soon after the injury and becomes compressed against the surrounding dura. Such compression is evident on MRI as well as persistently high ISP despite the bony decompression. The concept that the dura is responsible for spinal cord compression after injury is not unappreciated, but has two important clinical implications. First, dural compression causes three compartments to form intrathecally, each with a different pressure: the cerebrospinal fluid compartment above the injury, the cerebrospinal fluid compartment below the injury and the injury site where the cord is compressed against the dura.

Because of this compartmentalisation, draining cerebrospinal fluid by placing

We conclude that monitoring from the injury site provides clinically important information. ” the injured brain. In most patients with a spinal cord injury, the ISP is high and the SCPP is low. ISP and SCPP are important physiological parameters; the chance of functional improvement at one year correlates with SCPP and inversely correlates with ISP (each averaged over the first week after injury).4 Too low SCPP appears to be detrimental and thus intervening to increase the SCPP improves spinal cord metabolism at the injury site and, in some patients, sensory and motor function below the injury.

Interestingly, increasing the SCPP too much also appears to be detrimental and worsens injury site metabolism. The

a lumbar catheter does not effectively reduce the ISP in most patients. Second, the dural cord compression raises the intriguing possibility of expansion duroplasty as a novel treatment to reduce the ISP after acute, severe spinal cord injury. The idea of performing expansion duroplasty to treat uncontrolled cord swelling is analogous to performing a decompressive craniectomy to treat uncontrolled brain swelling after a brain injury. We thus explored expansion duroplasty in patients with acute, severe spinal cord injuries in a phase II trial; our key findings are that the technique is not only safe, but also effectively reduces

the ISP and increases the SCPP.6 Based on these observations, we are now in the process of setting up a randomised controlled trial to test whether, compared with bony decompression, expansion duroplasty improves functional outcome after severe spinal cord injury.

Many patients with spinal cord injuries have fever in the first two weeks after injury. We noticed that during these periods of fever, the spinal cord metabolism at the injury site becomes very deranged.7 In patients with severe spinal cord injuries, fever burden appears to be an adverse prognostic factor independent of age and AIS grade on admission. These findings suggest that fever should be treated to reduce further spinal cord damage.

Our recent work focuses on monitoring spinal cord blood flow during surgery.8 We observed several novel phenomena including three different spinal cord blood flow patterns, which we term necrosis-penumbra (a core of low blood flow with regions of intermediate blood flow on either side), hyper-perfusion (very high blood flow throughout the injury site) and patchy-perfusion (irregular regions of low, intermediate and high blood flow), blood pressureinduced local steal (with increased blood pressure, blood flow increases in some regions but, decreases in other regions) and diastolic ischaemia (parts of the injury site only perfused in systole, but not diastole).

Based on our experience with ISCoPE over the last few years, we conclude that monitoring from the injury site provides clinically important information. We thus propose that injury site monitoring be employed in ICUs as standard of care to provide the basis to guide management aiming to improve neurological outcome.

References 1. Werndle MC, Saadoun S, Phang I, et al. Monitoring of spinal cord perfusion pressure in acute spinal cord injury. Crit Care Med 2014;42:646-55.

2. Phang I, Zoumprouli A, Papadopoulos MC, et al.

Microdialysis to optimize cord perfusion and drug delivery in spinal cord injury. Ann Neurol 2016;80:52231.

3. Phang I, Zoumprouli A, Saadoun S, et al. Safety profile and probe placement accuracy of intraspinal pressure monitoring for traumatic spinal cord injury. J Neurosurg Spine 2016;25:398-405.

4. Saadoun S, Chen S, Papadopoulos MC. Intraspinal pressure and spinal cord perfusion pressure predict neurological outcome after traumatic spinal cord injury.

J Neurol Neurosurg Psychiatry 2017;88:452-453.

5. Chen S, Smielewski P, Czosnyka M, et al. Continuous monitoring and visualization of optimum spinal cord perfusion pressure in patients with acute cord injury. J Neurotrauma 2017;34:2941-2949.

6. Phang I, Werndle MC, Saadoun S, et al. (2015).

Expansion duroplasty reduces intraspinal pressure and increases spinal cord perfusion pressure after traumatic spinal cord injury: J Neurotrauma 2015;32:865-74.

7. Gallagher MJ, Zoumprouli A, Phang I, et al. Markedly deranged injury site metabolism and impaired functional recovery in acute spinal cord injury patients with fever.

Crit Care Med 2018;46:1150-7.

8. Gallagher MJ, Hogg FRA, Zoumprouli A, et al. Spinal cord blood flow in patients with acute spinal cord injuries. J Neurotrauma 2018 [EPub]

Marios C Papadopoulos is a professor of neurosurgery at St George’s, University of London (London, UK) and a neurosurgeon at St George’s University Hospitals NHS Foundation Trust (London, UK). He has a specialist interest in complex spinal surgery and vascular neurosurgery.

Samira Saadoun is a senior lecturer in neuroscience at St George’s and has published a number of papers on spinal cord injury.

May

Issue

19 51

New results “strongly support” the safety of the ProDisc-C device

Conference coverage

7

At the annual meeting of the International Society for the Advancement of Spine Surgery (3–5 April, Anaheim, USA), Jack E Zigler (Texas Health Center for Diagnostics and Surgery, Texas Back Institute, Plano, USA) reported results which “strongly support” the safety of the ProDisc-C device (Centinel Spine). In a study of 504 consecutive patients, Zigler and colleagues found that no secondary surgeries were required for device failure, as well as a relatively low reoperation rate of 5.5%, including the learning curve for every participating surgeon.

THE INVESTIGATORS REPORT that secondary surgeries were required in 28/504 patients (5.5%).

More specifically, 20/28 of these were operations for adjacent segment degeneration, five of which were adjacent to fusion levels. Three patients had total disc replacement (TDR) removals and anterior cervical discectomy and fusion (ADCF), including one migration, one subsidence, and one spondylosis. In addition, the investigators report one repositioning of a TDR, one incision and drainage for a wound infection, one haematoma drainage, two spinal cord stimulator implantations for pain control and, “most significantly,” according to Zigler, there were no reoperations for device failure.

Zigler and colleagues describe how cervical TDR cases involving the ProDisc-C device were identified at a multi-site, multi-surgeon spine speciality centre. They began with the first investigational device exemption (IDE) case performed in 2003 and included only patients ≥2 years postoperative by December 2017. Consecutive series of the first 504 ProDisc-C patients were analysed, involving 463 (92%) patients with one level, 39 patients (8%) with two levels, and two patients with three levels.

The series included 112 hybrids.

The authors highlight two important factors in

evaluating the safety of an implant: the rate of subsequent reoperations and the reasons for that surgery, in particular reasons that are related to possible problems with the implant. Zigler and colleagues therefore sought to investigate the reoperation rate for a case series of cervical TDR patients for 15 consecutive years at a single-centre, involving the same device.

They reviewed the surgery log 2003–2017 to identify reoperations and for each one, recorded the reason, duration from index surgery and procedure type. The mean time from index operation to surgery log search for reoperations was 69.4 months (range of 24–169), they report.

During the presentation at ISASS 2019, Zigler described a repositioning case to demonstrate the safety of the ProDisc-C device. The patient he mentioned was discharged the day after surgery with some new right arm discomfort. The next day, he called reporting more severe right arm pain and tingling in his fingers. Imaging suggested foramenal encroachment, and the device was repositioned. Six months postoperatively, the patient reported 0/10 neck pain and 1.3/10 arm pain.

The authors note that one of the key strengths of the study was that its single-centre design eliminated many of the surgical and data collection variables that exist

Most significantly, there were no secondary operations for device failure.” in multicentre analyses. They also address important weaknesses. Firstly, they mention that although most of the surgeons at the centre involved in the study are experienced in anterior cervical surgery, for many of them, ProDisc-C was the first arthroplasty device they were exposed to. Additionally, Zigler and colleagues note that besides the IDE patients, reoperations could have been performed elsewhere without the investigators’ knowledge. However, the company would have been alerted to this and this did not occur in the present study.

Talking to Spinal News International, Zigler commented on the significance of the study: “This study represents the early learning curve in cervical arthroplasty for all surgeons involved.” He continued: “A very low operation rate, and no instance of device breakage were two positive findings of the study.”

8

May

Hospital and patient characteristics can predict extended length of stay in patients undergoing primary spine procedures A recent study conducted by Peter G Passias (NYU Langone Health, New York Spine Institute, New York, USA) and colleagues showed that male patients and patients with increased comorbidity severity experienced a greater length of hospital stay (LOS) after undergoing a primary spine procedure. Another factor that was found to increase LOS, as well as higher rates of hospital-acquired conditions (HACs), was treatment at large, metropolitan, government teaching hospitals. Overall, the investigators found that hospital characteristics and population density, independent of regional location, appear to play greater roles in predicting longer LOS and HACs compared to patient demographic factors.

AT THE 19TH Annual Conference of the International Society for the Advancement of Spinal Surgery in Anaheim, USA (ISASS; 3 –5 April), co-author Virginie Lafage (Hospital for Special Surgery, New York, USA) presented these results.

Passias and colleagues note that HACs have been the focus of recent policy initiatives by the Centers for Medicare and Medicaid Services in an effort to improve patient safety and outcomes. For example, subsection of the Affordable Care Act’s Pay-for-Performance Program, the Hospital-Acquired Reduction Program lowers patient reimbursement for hospitals with elevated rates of “reasonably preventable” complications.

As elective spine surgery continues to grow in popularity, the investigators note that “It is important to assess the most common postoperative conditions as they relate to invasive spine procedures.” The authors note that the goals of the study were to determine the rates of the three most common HACs that occur within 30 days postoperatively for spine surgeries and compare them to other common surgical procedures,

and to investigate the influence of patient and hospital characteristics on length of stay and never events.

Passias and colleagues found that of the 1,348,305 surgeries included in the study, the mean LOS was 4.04 days. The spinal procedures associated with the greatest LOS were any osteotomy (7.57 days), fusion (5.35 days), device insertions (3.4 days), and disc replacement (1.63 days). Additionally, the investigators mention that extended LOS was associated with greater hospital charges (US$143,985.57 vs. US$63,439.5, R: 0.631, p<0.001).

Significant demographic predictors of LOS were male sex, with an odds ratio (OR) of 1.1 (1.1–1.13), Hispanic ethnicity (OR: 1.15 [1.15–1.17]), and CCI (OR: 1.175 [1.174–1.175]). The types of hospitals which predicted the longest LOS were urban teaching hospitals (OR: 1.3 [1.3–1.31]), large hospitals (OR: 1.2 [1.19–1.23]), government-owned hospitals (OR: 1.28 [1.27–1.28]) and hospitals located in metropolitan areas (OR: 1.05 [1.05–1.06]).

The investigators report that 1.4% of the total number

CT scan prior to spine fusion surgery finds significant number of patients had undiagnosed osteoporosis A study at the Hospital for Special Surgery (HSS; New York, USA) found that a CT scan of the lumbar spine prior to surgery indicated that a significant number of patients had low bone density that was previously undiagnosed. If a patient is found to have low bone density prior to surgery, it could affect the treatment plan before, during and after the procedure.

A

lmost half of the nearly 300 patients tested were diagnosed with osteoporosis or its precursor, osteopenia for the first time. Some, but not all, had undergone a prior dual energy X-ray absorptiometry (DXA or DEXA) bone density scan. The research, titled, “Prevalence of osteopenia and osteoporosis diagnosed by quantitative computed tomography in 296 consecutive lumbar fusion patients” was presented at the 2019 American Academy of Orthopaedic Surgeons Annual Meeting (12–16 March, Las Vegas, USA).

“Metabolic bone disease is a major public health concern. In 2010, the US prevalence of low bone mineral density in adults 50 and older was 44%, and 10.3% had a diagnosis of osteoporosis,” says Alexander Hughes, an orthopaedic

Issue

19 51

Conference coverage

surgeon specialising in spine surgery at HSS and senior investigator. “Low bone density is a known risk factor for vertebral fractures, and there is a recent emphasis by spinal surgeons to evaluate

of patients included in the study experienced an HCA, or “never event.” Seven point nine per cent of patients who underwent an osteotomy experienced a never event, making it the procedure with the highest rate within this patient cohort. Out of the patients who underwent spinal fusion, 1.2% experienced a never event. The rate for patients undergoing a spinal device insertion was 0.9% and 0.7% of disc replacement patients.

CCI was the most significant predictor of a never event in this patient cohort, with an odds ratio of 1.28 (1.27–1.29). Another important factor was male sex (OR: 1.2 [1.1–1.2]). Hospital factors included midAtlantic hospitals (OR: 1.125 [1.068–1.186]), mountain region hospitals (OR: 1.263 [1.189–1.341]), teaching hospitals (OR: 1.752 [1.702–1.805]), government hospitals (OR: 1.335 [1.259–1.416]) and hospitals located in metropolitan areas (OR: 1.122 [1.077–1.17]).

Surgical predictors included osteotomy (OR: 5.7 [5.4–6.1]), spinal fusion (OR: 0.5 [0.5–0.6]), spinal device insertion (OR: 0.5 [0.4–0.5]), discectomy (OR: 0.3 [0.3–0.4]) and disc replacement (OR: 0.5 [0.4–0.6]).

Passias and colleagues describe that patients >18 years old who underwent elective spine surgery were identified in the American College of Surgeons’ National Surgical Quality Improvement Program (ACS-NSQIP) database from 2005–2013, and that primary spinal surgeries were isolated via ICD-9-CM codes.

In order to analyse LOS, the investigators used descriptive analysis and Pearson bivariate correlations to determine the mean LOS, LOS associated with specific spinal procedures, and total hospital charges associated with extended LOS (>75th percentile). They used Poisson regression models controlling for CCI, surgical invasiveness, patient and hospital characteristics to identify independent predictors of increased LOS. For HACs, a descriptive analysis determined the incidence of never events for the overall cohort and specific spinal procedures. Furthermore, binary logistic regression models controlling for CCI, surgical invasiveness, patient and hospital characteristics identified independent predictors of never events.

to measure lumbar spine bone density using quantitated computed tomography (QCT) and determine the prevalence of osteopenia or osteoporosis in patients undergoing lumbar spine fusions. We believe that QCT is more effective in screening patients because the DXA scan can overestimate bone density in the spine due to certain bone changes, a patient’s weight or physique, and other factors.”

If a patient is found to have osteoporosis or osteopenia prior to spinal fusion, the treatment plan may be modified, including the type of implants used. “We now have newer technologies in terms of the hardware we use in spinal fusion that are better suited to patients with low bone density,” Hughes explained. “Secondly, we are in a kind of renaissance as far as treating

Diagnosing osteoporosis or osteopenia prior to spine fusion could lead to a change in surgical planning and treatment. ” and treat this prior to elective spine fusion.”

“The literature reporting QCT-based lumbar spine bone density is scarce, and we believe our study is the first of its kind,” said Hughes. “The purpose was

metabolic bone disease. We now have a newer generation of medications that can improve bone health and bone biology. If someone is diagnosed with osteoporosis, we may start them on one of those medications either before or after

surgery.”

The study enrolled 296 patients undergoing lumbar spine fusion for a degenerative condition or spinal instability. Fifty-five percent were female, and the mean age was 63 years old, (21–89). All patients had preoperative QCT scans of their lumbar spine. Using American College of Radiology criteria, 44% of patients were diagnosed with osteopenia; 15% had osteoporosis; and 41% were diagnosed with normal bone density.

There were no differences in prevalence between gender or race, but patients over age 50 were much more likely to be diagnosed with low bone density. Of these patients, 49% were diagnosed with osteopenia and 18 percent had osteoporosis. In patients under age 50, no individuals were found to have osteoporosis, but 17% had osteopenia.

Within a subgroup of 212 patients with no prior history of low bone density, 39% were diagnosed with osteopenia and 10% had osteoporosis.

“Spine surgeons should be aware of the high prevalence of abnormal bone mineral density in lumbar spine patients and the possibility that those without a previous diagnosis may have osteopenia or osteoporosis,” Hughes said. “Diagnosing this prior to spine fusion could lead to a change in surgical planning and treatment, and we believe this would improve outcomes.”

10

May

Opioid consumption patterns after lumbar microdiscectomy or decompression Francis Lovecchio Comment & Analysis Francis Lovecchio (Hospital for Special Surgery [HSS], New York, USA) recently gave a presentation on opioid consumption patterns after lumbar microdiscectomy or decompression at the 19th Annual Conference of the International Society for the Advancement of Spine Surgery (ISASS; 3–5 April, Anaheim, USA). Here, for Spinal News International, he gives a summary of the talk.

I

Issue

19 51

Opioids

n an effort to ensure adequate pain control and a functional recovery, providers have tended to overprescribe narcotics in the post-discharge period.1,2 In turn, patients are often left with an excess of pills, which may become available for diversion or increase the risk of misuse. Excess pain medication in the home is a key driver of the current opioid crisis.3 In patients who become dependent on prescription opioids, spinal conditions are the most common diagnoses for the first prescription, putting spine surgeons on the frontlines of the opioid epidemic.4 While opioid prescribing guidelines have been shown to reduce overprescribing, there is a paucity of data on the amount of opioid to provide after spine surgery.5 Determining the “minimum necessary quantity” to provide after specific spine procedures is essential to create evidence-based, national prescribing guidelines. The purpose of the current study is to prospectively record daily opioid use and pain levels after one-level lumbar microdiscectomy or decompression at two high-volume spine centres.

Following approval from the respective institutional review boards, a prospective observational study was conducted at the Hospital for Special Surgery and at Midwest Orthopaedics at Rush (Chicago, USA) from September 2017–2018. During this time period, any adult patient undergoing a single-level decompression or microdiscectomy was prospectively enrolled with one of eight fellowship trained, participating surgeons, with anywhere from six to greater than 20 years of experience.

These two surgeries were chosen as they are often performed on an outpatient basis, leaving providers without any inpatient narcotic consumption data on which to base an estimate for a post-discharge prescription. In order to generate conclusions for a realistic spine

practice population, a selective exclusion criteria was used: non-English-speakers and those who had used opioids on a daily basis in the six months preceding surgery.

Data collection was performed using a Health Insurance Portability and Accountability Act (HIPAA) compliant automated SMS-based data collection platform, created and piloted by the first two authors specifically for use in this study. The platform sent daily queries to enrolled patients asking for 24-hour opioid consumption and average

Patients are often left with an excess of pills, which may become available for diversion or increase the risk of misuse.”

Numeric Rating Scale (NRS) pain score.

At six weeks, or after patients reported cessation of opioid use, the final survey questions were asked, including the number of pills remaining, method of disposal, and side effects. Prescription and refill data were taken from the electronic medical record and/or the state prescription registry. Surgeons were not asked to change their preoperative, intraoperative, or postoperative pain management protocols in any way.

Patients who completed at least 50% of the daily queries were included in the final statistical analysis.

Out of 104 patients approached, 89 patients enrolled, and 85 patients completed at least 50% of the daily

queries. The average age of the patient cohort was 50.5±14.6 years, and average body mass index was 28±5.5 kg/m2.

The majority of patients were male (68.2%). Fifty-seven patients (67.1%) underwent microdiscectomy and 28 (31.8%) underwent decompression.

Twenty patients (23.5%) had an inpatient or overnight stay in the hospital. Thirteen percent of patients had a history of psychiatric disorder, and 31.8% of patients had a history of intermittent opioid use, defined as non-daily opioid use in the last six months before surgery.

The most commonly prescribed opioid was oxycodone (with or without acetaminophen), and the second most commonly prescribed was tramadol (40% and 24.1%, respectively).

Daily opioid use and pain scores declined steadily through the initial postoperative period. On postoperative day (POD) one, the average amount of opioid consumed was 16.2 oral morphine equivalents (OME), which dropped to 7.6 OME by POD seven. On POD one, the median NRS pain score was five, which dropped to three by POD seven.

The average time of opioid cessation was between POD eight and nine. To further facilitate comparisons between patients who were prescribed different types of pain medication, opioid quantities were converted into oxycodone 5mg equivalents. A conversion ratio of 7.5 OME to one oxycodone 5mg “pill” was used. Total opioid consumption in the postoperative period was widely variable, ranging from 0–118 pills.

Median opioid consumption was 32 pills, while 75th percentile was 57 pills. Initial prescription size was equally variable.

The most common prescription ranges were between 70–80 pills (18.8%), 30–40 pills (17.6%), and 10–20 pills (17.6%). While only 22.4% of patients completed their initial prescription, just 9.4% of patients obtained a refill.

Out of the 77.6% of patients who had leftover medications, only approximately 1/5th reported appropriate methods of disposal (destroy/throw away or return to pharmacy/authorities), while the others reported they were either “unsure” of what they would do or would keep the medications.

The study had several strengths.

While recall bias was inherently present, the prospective design combined with automated daily data collection likely minimised such bias. Second, given the narrow exclusion criteria, the patient population was generalisable to a realworld spine surgery practice. Third, refill and prescription data were verified from the state registry for the majority of patients. However, there were also limitations. While a multivariate logistic regression was performed in an attempt to identify independent predictors of increased postoperative opioid use, the analysis was underpowered.

Second, the variations in prescription quantity possibly affected opioid use, that is, those who were given larger prescriptions may have subsequently utilised more opioids simply by virtue of having excess pills. Lastly, the variability within the surgical procedures could not

be quantified. However, any prescribing guideline must make assumptions of surgical consistency in order to be clinically applicable.

There are several crucial findings that can be taken from this study to influence the content of national, statewide, or institutional opioid prescribing guidelines. Fewer than half of the patients who finished their prescriptions obtained a refill, a pattern that has been seen before in similar research in other subspecialties.2 This suggests that the expected increase in refill requests by lowering initial prescription quantities is likely overestimated. Lowering initial prescription quantities will likely minimise the number of leftover medications without leading to an unreasonable increase in refill requests (a clinically important concern given the increased potential workload for surgeons and their staff). Thirty-two oxycodone 5mg pills (the median use) is likely a reasonable initial prescription quantity. While 57 pills, the 75th percentile of use, may lead to near zero refill requests, such a prescribing strategy will likely lead to very large number of leftover pills. This is a critical point considering that the majority of patients did not know what to do with their leftover pills, and by default are likely to keep them in the home, continuing the risk for diversion or misuse. Thus, patient education on proper disposal and access to pill disposal centres is a crucial area for improvement as we optimise opioid prescribing strategies in the future.

While the quantities provided by this study are helpful to reduce overprescribing, blind adherence to a quantitative prescribing quantity can be potentially harmful, especially considering that opioid consumption is difficult to predict and widely variable on an individual level. Thus, along with a quantitative recommendation, any opioid prescribing guideline must include large components of patient and provider education on responsible opioid prescribing, consumption, disposal, and follow up.

References 1. Kumar K, Gulotta LV, Dines JS, et al. Unused opioid pills after outpatient shoulder surgeries given current perioperative prescribing habits. Am J Sports Med 2017;45:636–41.

2. Wojahn R, Bogunovic L, Brophy R, et al. Opioid consumption after knee arthroscopy. J Bone Jt Surg Am 2018;100A:1629–36.

3. American Society of Addiction Medicine. Opioid Addiction 2016 Facts & Figures. Available at https:// www.asam.org/docs/default-source/advocacy/opioidaddiction-disease-facts-figures.pdf. 2016.

4. Schoenfeld AJ, Jiang W, Chaudhary MA, et al.

Sustained prescription opioid use among previously opioid-naïve patients insured through TRICARE (20062014). JAMA Surg. Epub ahead of print 2017. DOI: 10.1001/jamasurg.2017.2628.

5. Lovecchio F, Stepan JG, Premkumar A, et al. An institutional intervention to modify opioid prescribing practices after lumbar spine surgery. J Neurosurg Spine 2018;1–8.

Francis Lovecchio is currently a thirdyear orthopaedic surgery resident at HSS. He received his medical degree from the Northwestern University Feinberg School of Medicine (Chicago, USA).

His research interests include opioid prescription practices after orthopaedic procedures, bone turnover markers in spinal fusion, and proximal juntional kyphosis in adult spinal deformity.

12

May

Issue

19 51

Interview

Profile

Ronald Bartels

A clinical professor of neurosurgery, Ronald Bartels talks to Spinal News International about his career. From his days at medical school to his appointment as chair of the Department of Neurosurgery at Radboud University Medical Center, he discusses how he thinks the field of neurosurgery has changed over the years, and how it might develop in the near future.

Why did you decide to pursue a career in medicine?

I knew at young age that I would become a physician, but the reason why remains obscure to me. A romantic version is that I decided to become a medical doctor at the age of eight years, when I was walking after the hearse in which the coffin with my deceased grandfather, who died because of lung cancer, was placed.

What drew you to neurosurgery and later spinal surgery in particular?

The nervous system has always intrigued me. This is due to the embryology, anatomy and clinical syndromes associated with its pathology. Topological diagnosis is only possible in the nervous system. My interest in the nervous system was stimulated by excellent teachers in embryology, anatomy and neurology. Since I knew very early on in medical school that I should be surgically active, the choice for neurosurgery was obvious. Actually, I never considered another specialty as a career despite the very low chance of obtaining a residency in neurosurgery. During my residence and in my early years as a staff member, I was exposed as a primary surgeon to nearly all kinds of neurosurgical procedures. Spinal surgery attracted me more than other neurosurgical activities for several reasons. The approaches to the spine are very diverse and specific for each region within the spine. The combination of wide anatomical knowledge and the basics of general surgery are challenging. Biomechanics were not usual in neurosurgical training at that time. It is intriguing since it combines physics, anatomical knowledge, restoration of spinal imbalance and expectations regarding clinical results. The neural elements within the spine are very delicate, necessitating accurate and sensitive surgical handling. Intraoperative neuromonitoring might be useful in selected cases. Finally, the treatment of patients with signs and symptoms due to spinal diseases warrants consideration of the complete spine, including biomechanical alterations and their influence on the disease. Decompression of the neural tissue might not be the sole solution to a spinal problem.

Have you had important mentors throughout your career? What have they taught you?

I had several mentors who influenced me. I will name the ones who were most important to me. Dr van der Spek was an old fashioned neurosurgeon, who confirmed my idea that a patient may account for your attention 24 hours a day. Every detail of the patient should be known and considered in your judgement. A surgical treatment should not be offered without thorough consideration. Professor Grotenhuis stimulated further study of neuroanatomy. He was very innovative and prompted the careful introduction of new techniques. Professor Harms showed me also innovative techniques at that time like transforaminal lumbar interbody fusion and C1C2 fixation. Finally, Dr Donk acted not as a mentor but merely as a “a partner in crime”. He was an orthopaedic surgeon and experienced in spinal surgery. We collaborated extensively, and introduced new techniques that we carefully evaluated.

What is the main focus of your current research?

I ty to focus on demonstrating the clinical relevance of known techniques. The main problem with all reports in journals and meetings is that statistically significant results are emphasised without mentioning any clinical relevance. An example are the reports about cervical arthroplasty. Whereas many authors report statistically significant results in favour of arthroplasty, the clinical relevance is absent. This information is relevant to correctly inform the patient. It is also important from the viewpoint of costs, especially when your alternative is much cheaper. Recently, I recognised why this message is not really accepted in the USA. The alternative is anterior cervical discectomy and fusion (ACDF) with a plate. The costs for both methods are similar. I can imagine why American surgeons are in favour of an arthroplasty, a simpler technique with no chance of pseudoarthrosis and, therefore, preventing regular follow-ups with X-rays and eventually re-surgeries.

A situation that raised many questions regarding clinical relevance arose recently with the studies about restoration of global sagittal balance in all patients.

Another focus is recovery after spinal cord injury and autonomous robotic surgery.

What is the most interesting piece of research you have read recently?

I think that the following article should be read by every research minded spine surgeon: Ronald L Wasserstein & Nicole A Lazar (2016) The ASA’s statement on p-values: Context, process, and purpose, The American Statistician, 70(2):129–133, DOI: 10.1080/00031305.2016.1154108. It clearly states

The current reemphasis on the value and interpretation of RCTs is meaningful for clinical practice. ” the restrictions of the p-value. Furthermore, many interesting viewpoints in JAMA regarding this subject have been published. I recommend studying these to anyone who is really interested in implementing the results of studies into their clinical practice.

How have your research activities influenced your clinical practice, and vice versa?

Clinical practice has often been the source of a hypothesis and design of a study. The results of a study always influence my practice, either by continuing it or changing it. After publishing the results of a randomised controlled trial comparing simple decompression versus anterior subcutaneous transposition—the usual technique—of the ulnar nerve we only performed simple decompression. After we reported our result regarding the interspinous process device we stopped implanting it. The publication of the meta-analysis of cervical disc prostheses was the reason for ending our trial comparing disc prosthesis, ACDF with a cage and

anterior cervical discectomy. It was also the reason for stopping implanting it and it contributed to the decision that this kind of surgery was not reimbursed anymore in The Netherlands.

How has the field of spinal neurosurgery changed since you started your career?

Since the late nineties I have seen many implants being introduced. Some of them still are being used, others have been abandoned. The focus changed from the radiological result to the result reported by the patient. Fortunately, patients demand correct information in order to make a decision for a treatment together with the physician. The role of the patient has changed dramatically. When I started I was not expected to inform the patient. They accepted any

May

Issue

19 51

Interview meaningful. These developments might be promising for larger, less expensive studies with results that are meaningful for clinical practice. Finally, the development of autonomous robotics will start, or has already been started. The main advantage of an autonomous robotic system will be that a learning curve will eventually be absent, the quality will gradually be improved, and can be distributed worldwide with the same level of quality for the same costs. A functioning robotic system will not be available in 10 years but major developments in this direction will be achieved.

13

Fact File

What do you think are the main challenges in the field at the moment?

A major challenge is the selection of the patients that will benefit from a surgical procedure on the spine.

I think that, at this moment, too many are operated on. We focus on what are we capable of, without taking the characteristics of the complete patient into consideration. As we do not have a good insight into predictive factors, we do not discuss it with the patients. They are interested in relieving complaints at this moment, but would they chose the same treatment when the effect on the long term was known, given their specific characteristics?

What are the potential solutions?

Installation of national or worldwide registries would help to investigate predictive factors. It also would contribute to the outcomes as registered by the patient in the long term. People should also be informed about physical burden and pain accompany ageing. It is normal, but not everything can be fixed. This needs a mentality shift in the general population, and within spine surgeons.

You have been an active member of CSRS-Europe for some time. What did you achieve as president of the society 2016–2018?

Since I entered the board I was convinced that the length of the term for a board member should be restricted. In the beginning, not all board members were enthusiastic. During my presidency, I stated this again, and now we have a scheme for retiring in order to invite new, younger board members. I am aware that I have also been a board member for too long, so as soon as possible I will retire from the board. For good functioning of the board, a good mix of young blood and experience is needed. We also started with a more transparent rating system for the annual meetings. This is still developing. Now, I have made a proposal that is based on a rating similar to the GRADE statement, and secondly on a personal rating in order to evaluate the importance for the annual meeting of CSRS-Europe.

What advice would you give to someone wishing to start their career in spinal surgery? decision. Nowadays, this is not accepted anymore.

The availability of the internet has facilitated this development enormously.

In your opinion, what are the most exciting developments in spinal neurosurgery that we can expect in the next five to 10 years?

The ageing of the population will ask for our attention more and more. We will be confronted with more spinal cases, whereas the prevalence will remain nearly stable.

Extra effort is needed, necessitating the education of more spinal surgeons. In order to monitor the quality of our care, we need to introduce national registries.

This is the only way to investigate if the treatments are really clinical relevant. Additionally, the current re-emphasis on the value and the interpretation of RCTs is meaningful. Pragmatic designs are considered as

My advice to anyone interested in spinal surgery would be to focus. Spinal surgery should be your main activity.

Within the spine focus on a region and/or a group of pathologic conditions. It improves your surgical skills, your knowledge, and your scientific activities.

Furthermore, try to be unbiased. Financial disclosures contradict unbiasedness. You can only make the right decisions if you are not bound to any company. Your scientific results will be more easily accepted.

What are your interests and hobbies outside spine?

I like jogging, especially in the early morning when all the animals are awake. Apart from the health benefits, I need it for being relaxed during my daily professional activities. Another interest is reading. I like literature as well as comics. I have a collection of nearly 1,000 comics. I am also active in fine metal working. I am building a steam locomotive for my garden railroad, another hobby of mine.

Education and qualifications (selected)

2008 Certification epidemiologist B (SMBWO) 1999 Spinal surgery, Karlsbad Langensteinbach, Duitsland May 1996 Board certification neurosurgery 1993–1996 Radboud University Medical Center, Department of Neurosurgery, Nijmegen, The Netherlands 1980–1987 Catholic University Nijmegen (currently Radboud University Nijmegen), Medical faculty

Professional positions (selected)

2015–present Full clinical professor of neurosurgery, Radboud University Nijmegen 2010–present Chairman of the Department of Neurosurgery, Radboud University Medical Center 2011–2012 Temporary chairman of the Department of Plastic and Reconstructive Surgery, Radboud University Medical Center 1996–2010 Member of staff, Radboud University Medical Center, Department of Neurosurgery 2003–2005 Consultant Sint Maartens Hospital, spinal surgery

Editorial board (selected)

2018–present International advisory board, Neurosurgery 2018–present Associate editor, Froniters in Neurology 2010–present Editorial board, European Spine Journal 2013–2015 Guest editor, cervical spondylotic myelopathy supplement, European Spine Journal

Scientific publications (selected)

Donk RD, Verbeek ALM, Verhagen WIM, Groenewoud H, Hosman AJF, Bartels RHMA. What's the best surgical treatment for patients with cervical radiculopathy due to single-level degenerative disease? A randomised controlled trial. PLoS One 2017; 12 (8): e0183603.

Bartels RHMA, Brunner H, Hosman A, van Alfen N, Grotenhuis JA. The pathogenesis of idiopathic ventral herniation of the spinal cord: A hypothesis based on the review of the literature. Frontiers in Neurology 2017 Volume 8, Article 476 (1).

Martens J, de Jong G, Rovers M, Westert G, Bartels R. Importance and presence of high-quality evidence for clinical decisions in neurosurgery: International survey of neurosurgeons. Interact J Med Res 2018; 7 (2): e16.

14

May

Does day of surgery affect length of stay and hospital charges following lumbar decompression?

Eric Lamoutte Kern Singh Comment & Analysis Eric Lamoutte and Kern Singh (Department of Orthopaedic Surgery, Rush University Medical Center, Chicago, USA) discuss results of their recent study examining whether or not day of surgery affects length of stay and hospital charges following lumbar decompression.

While they found “no statistical significance” with respect to the scheduling of minimally invasive lumbar decompression, the authors believe it remains an important topic to investigate, as orthopaedic sub-specialities have found increases in length of stay and associated costs when surgery occurs later in the week.

I

n the current value-based healthcare climate, there is increasing focus on minimising medical expenditures without compromising the quality of care.5 However, in order to reform the delivery of care in a cost-effective manner, the factors that increase expenses must be identified and reduced. Although unnecessary tests and procedures may be seen as drivers in increasing medical expenditures, hospital length of stay has been recently identified as one of the leading factors contributing to the financial burden.1,2 Spine surgery has been determined to be one of the most expensive surgical interventions on a per-case basis.3,4 Surgeons continually strive to minimise the gap in costs between other sub-specialty procedures and spine surgery, while maintaining maximum efficiency and improving the quality of care. The switch from traditionally open procedures to the alternative minimally invasive approach has significantly minimised the length of stay and costs to the patient and hospital.6,7 However, specific surgical scheduling factors may also play a role in increased length of stay and ensuing costs, as demonstrated by studies evaluating hip fractures and total joint arthroplasties. In these investigations, the surgeries performed earlier in the week were associated with reduced lengths of stay and subsequent expenditures.8–11 The role of surgical scheduling on length of stay and associated costs has not been evaluated in spinal procedures such as minimally invasive lumbar decompression (MIS LD). Thus, the aim of our investigation is to determine whether there is an association between the day of surgery and length of stay and hospital costs after

Issue

19 51

Value and economics

a primary MIS LD. A prospectively-maintained surgical database was retrospectively reviewed for patients that underwent primary, 1–3 level MIS LD for degenerative pathology from 2008–2017. We classified lumbar decompression as any combination of laminectomies, facetectomies,

cohort and 297 (41.4%) were in the late surgery cohort.

The demographic and baseline characteristics included age, gender, body mass index, smoking status, and comorbidity index. Perioperative variables assessed included operative levels, operation time, estimated blood loss, and length of hospital stay. We determined discharge from the hospital by pain management, ability to ambulate, and voluntary bladder control. Direct hospital costs were obtained from our institution’s billing department and were expressed as total costs. Various factors contributed to the total costs, including surgical expenses, blood transfusions, and services from cardiology, emergency room (ER), radiology, laboratory, nursing unit, intensive care unit (ICU), pharmacy, rehabilitation (physical, occupational, or speech therapy), and other miscellaneous expenditures.

The results of this study demonstrated that patients undergoing an MIS LD early in the week have similar lengths of hospital stay compared to those undergoing surgery towards the end of the week. Direct hospital costs were also determined to be similar among patients with no differences in when they had their surgery in the week.

Furthermore, our cost breakdown analysis demonstrated no difference between cohorts in surgical fees, as well as laboratory, nursing, radiology, therapy, and medical sub-specialties fees.

Although this particular investigation demonstrated no statistical significance with respect to the scheduling of MIS LD, we believe it remains an important topic to investigate, as other orthopaedic sub-specialties have found increases in

In the current healthcare climate, there is increasing focus on minimising expenditures without compromising the quality of care. ” foraminotomies, and/or partial discectomies. All of the surgeries were performed by a single surgeon at a single academic medical centre. We grouped patients undergoing MIS LD according to the timing of their procedures: (1) early in the week (Monday/Tuesday) or (2) late in the week (Thursday/Friday).

A total of 717 patients were included in the analysis. Four hundred and twenty (58.6%) patients were in the early surgery

length of stay and associated costs when surgery occurs later in the week.

There are several possibilities that could explain why the scheduling of MIS LD during the week displayed minimal effect on length of stay and direct hospital costs. When compared to traditional open spine procedures, minimally invasive techniques are proven to have shorter operative time, less blood loss, and a quicker recovery.12 Due to

the minimally invasive nature of the procedure, patients undergoing MIS LD on average suffer drastically reduced pain and are less restricted in mobility in the early postoperative period, allowing for same-day ambulation in most cases. This could be an explanation for the lack of necessity for physical and occupational therapists in the immediate postoperative course. The main cost-driving factor in the total hospital charges is directly related to surgical services, which has little procedural variation in this investigation. Additionally, since MIS LD is mostly a same-day procedure, cohorts experience similar lengths of stay with minimal variation in postoperative hospital course. Therefore, there was no significant difference in costs associated with nursing, physical therapy, and other typical postoperative services. Thus, at this time, there are no recommended changes to scheduling during the week for patients undergoing MIS LD. There are some strengths and limitations to this study. All surgeries were performed by a single surgeon at a single academic medical centre, resulting in a consistency of care. However, the retrospective nature of this study may have introduced an element of selection bias. Additionally, the standard discharge protocol at our institution involves social work being contacted and discharge documents being completed in a timely manner before the weekend.

We understand that our discharge protocol may not be generalisable to other institutions. It is important that this study is replicated at other institutions, perhaps as a multi-institutional study, to further understand the effect that surgery scheduling has on length of stay and direct hospital costs for patients undergoing MIS LD. References 1. Newman JM, Szubski CR, Barsoum WK, et al. Day of surgery affects length of stay and charges in primary total hip and knee arthroplasty. J Arthroplasty 2017;32:11-5.

2. Lilly R, Siljander M, Koueiter DM, et al. Day of surgery affects length of hospitalization for patients undergoing total joint arthroplasty discharged to extended care facilities. Orthopedics 2018;41:82-6.

3. Missios S, Bekelis K. Hospitalization cost after spine surgery in the United States of America. J Clin Neurosci 2015;22:1632-7.

4. Kazberouk A, Sagy I, Novack V, et al. Understanding the extent and drivers of interphysician cost variation for spine procedures. Spine (Phila Pa 1976) 2016;41:11117.

5. Resnick DK, Tosteson AN, Groman RF, et al. Setting the equation: Establishing value in spine care. Spine (Phila Pa 1976) 2014;39:S43-50.

6. Al-Khouja LT, Baron EM, Johnson JP, et al. Costeffectiveness analysis in minimally invasive spine surgery. Neurosurg Focus 2014;36:E4.

7. Phan K, Hogan JA, Mobbs RJ. Cost-utility of minimally invasive versus open transforaminal lumbar interbody fusion: systematic review and economic evaluation. Eur Spine J 2015;24:2503-13.

8. Ricci WM, Brandt A, McAndrew C, et al. Factors affecting delay to surgery and length of stay for patients with hip fracture. J Orthop Trauma 2015;29:e109-14.

9. Keswani A, Beck C, Meier KM, et al. Day of surgery and surgical start time affect hospital length of stay after total hip arthroplasty. J Arthroplasty 2016;31:2426-31.

10. Muppavarapu RC, Chaurasia AR, Schwarzkopf R, et al. Total joint arthroplasty surgery: Does day of surgery matter? J Arthroplasty 2014;29:1943-5.

11. Malik AT, Khan S, Ali A, et al. Total knee arthroplasty: Does day of surgery matter? Clin Med Insights Arthritis Musculoskelet Disord 2018;11:1179544117754067.

12. Banczerowski P, Czigleczki G, Papp Z, et al. Minimally invasive spine surgery: Systematic review. Neurosurg Rev 2015;38:11-26; discussion

Kern Singh is a professor of Orthopaedic Surgery at Rush University Medical Center (Chicago, USA).

Eric Lamoutte is a research assistant for Kern Singh at Rush University Medical Center.

May

Issue

19 51

Outcomes

Outcomes of anterior cervical discectomy and fusion influenced by presurgical depressive symptoms A recent study found that patients who presented with presurgical depressive symptoms reported more severe symptoms preoperatively and postoperatively. However, despite residual symptoms, these patients may benefit more from surgery than those without depressive symptoms. The results were presented by Christopher K Kepler (Thomas Jefferson University Hospital, Philadelphia, USA) at the 46th annual meeting of the Cervical Spine Research Society (6–8 December 2018, Scottsdale, USA).

THE INVESTIGATORS, KEPLER and colleagues at Thomas Jefferson University Hospital, describe the relationship between the mental component score (MCS) of the Short Form 12 Survey and disability after an anterior cervical discectomy and fusion (ACDF) as “uncertain”. The purpose of the study, therefore, was to investigate whether presurgical depressive symptoms measured by the MCS influenced the clinical benefit of ACDF. Mean improvement in neck disability index was 16.8 points (95% confidence interval [CI]: -19.93, -13.72, p<0.001). Compared to the patients with an MCS >45.6, patients with an MCS <45.6 had higher neck disability index both preoperatively, 48.86 (95% CI: 25.04, 33.07) vs 22.01 (95% CI: 18.44, 25.58; p=0.01), but both groups demonstrated a “significant improvement” from baseline (p<0.0001). While the patients with an MCS <45.6 had more disability postoperatively, these patients demonstrated even greater benefit from surgery, as the improvement of the neck disability index was actually greater than patients with a higher MCS, -19.8 vs. -13.7. Kepler and colleagues included 264 patients in the study with a mean follow up of 19.8 (range 12–46.6) months. The

cohort included 135 patients with an SF-12 MCS of <45.6 and 129 with an SF-12 MCS >45.6. The mean age was 53.1 (range 18–84) years old, and the mean BMI was 29.6 (range 18.7–54.9).

Furthermore, mean improvement of PCS after

Prospective research would allow a more accurate evaluation of the role of depressive symptoms on clinical outcomes.”

ACDF was 7.78 (95% CI: 6.27, 7.3; p<0.001) and no significant difference in baseline PCS was found between patients with an MCS (32.87 [95% CI: 31.69, 34.06]) and those with an MCS >45.6 (33.54 [95% CI: 31.92, 35.16]). Both groups demonstrated “statistically significant” improvement from baseline, with the final

15

PCS scores of 39.06 (95% CI: 37.13, 40.99) in patients with an MCS <45.6 PCS (p=0.043). “Importantly,” the investigators found that while the final PCS score was lower in patients with an MCS <45.6, they reported more improvement compared to patients with an MCS >45.6.

The analysis comparing patients with and without depressive symptoms on the MCS who underwent an ACDF for a degenerative cause, evaluated outcomes including neck disability index, SF-12 PCS, visual analogue scale (VAS) arm pain, and VAS neck pain.

The authors note that patients with trauma, tumour infection, previous cervical spine surgery, or those with less than one year of clinical follow up were excluded.

The investigators used an MCS <45.6 as a diagnostic criterion of depressive symptoms.

Kepler and colleagues note that a number of studies have evaluated the impact of depression on outcomes after ACDF with mixed results. While one of these studies found no difference in patients with depressive symptoms, multiple others found worse outcomes, including, most recently, a 2017 study by Phan published in the Journal of Spine Surgery.

Commenting on the significance of the results, Kepler proposes: “Patients with depressive symptoms may have lower preoperative and postoperative function and worse disability, but have similar improvement after ACDF and should be given full consideration as surgical candidates.” However, he also notes that “The study is limited by its retrospective nature and questions about the suitability of MCS as a proxy for depressive symptoms”.

“There continues to be uncertainty about the impact of depression on outcome after spinal surgery,” Kepler adds. “Prospective research with patients who have been clinically diagnosed with depression and depression-spectrum disorders would allow a more accurate evaluation of the role of depressive symptoms on clinical outcome.”

16

May

“No further trials of vertebroplasty should be performed”, report concludes Current evidence does not support the routine use of vertebroplasty for the treatment of pain from vertebral fractures, concludes a recent taskforce report charged by the American Society for Bone and Mineral Research (ASBMR) aimed at examining the efficacy and safety of vertebral augmentation. Although lead author of the report, Peter R Ebeling (Monash University, Melbourne, Australia) and colleagues surmise that this conclusion is “also likely to apply to other augmentation procedures”, such as kyphoplasty, they maintain throughout the report that high-quality evidence from placebo-controlled trials remains absent. However, lead authors of the VAPOUR trial, which reported a benefit with the use of vertebroplasty in fractures of less than six weeksʼ duration, have published their concerns in the BMJ Evidence-Based Medicine regarding the statistical methodology underpinning the ASBMR report.

“THE RECOMMENDATIONS BY this task force are designed to help provide a foundation for advancing the research and clinical care of patients with painful acute vertebral fractures”, write the authors. They stress that clinicians will need to balance the “limited findings” on the safety and efficacy of other non-pharmacological interventions with good clinical judgement, when it comes to making quality, informed patient care decisions.

The rationale behind the commissioned report encompasses the lack of consensus amongst clinicians on whether to use percutaneous vertebroplasty or kyphoplasty to reduce pain in patients with vertebral fractures. This disparity in opinion, as well as the high prevalence of vertebral compression fractures in patients with osteoporosis, led the ASBMR to commission a task force to address the efficacy and safety of vertebral augmentation, as well as spinal bracing and exercise, for the treatment of pain after vertebral fractures.

Ebeling and colleagues explain that vertebral augmentation was introduced into practice before high-quality evidence establishing its efficacy and safety was published, yet remains—in some settings— part of standard routine care. Although the authors acknowledge that balloon kyphoplasty is currently more expensive and is performed almost three times more commonly than percutaneous vertebroplasty in the USA, they write: “No placebo-controlled trials of balloon kyphoplasty have been performed and the evidence of the value of this procedure is reliant on low-quality evidence from trials that have compared kyphoplasty with usual care or head-to-head comparisons with vertobroplasty”.

Ebeling and colleagues performed a systematic review of the existing literature and meta-analyses of an array of outcomes. Randomised controlled trials (RCTs) and quasi-randomised trials enrolled adults older than 40 years with acute nontraumatic vertebral fractures, directly comparing percutaneous vertebroplasty or balloon kyphoplasty with any treatment comparator group. In terms of nonsurgical interventions, Ebeling and colleagues included RCTs and quasi-randomised trials of bracing or exercise interventions with similar enrolment criteria.

The ASBMR task force first addresses the efficacy and relative effectiveness of vertebral augmentation and its ability to improve pain, posture, physical function and quality of life. Based on “moderate to high” quality evidence for percutaneous vertebroplasty from five randomised placebo-controlled trials, Ebeling and colleagues find that percutaneous vertebroplasty provides no demonstrable clinically important benefit when compared with placebo or sham. Moreover, they report that subgroup analyses in the updated Cochrane review indicate that the result did not differ according to duration of pain. However, the sensitivity analyses indicate that open trials comparing percutaneous vertebroplasty with

Issue

19 51

Vertebroplasty

standard medical care are likely to have overestimated any benefit of percutaneous vertebroplasty.

In terms of balloon kyphoplasty, Ebeling and colleagues write: “There is insufficient evidence to support kyphoplasty over nonsurgical management, percutaneous vertebroplasty, vertebral body stenting, or KIVA”. Although the authors find kyphoplasty to be associated with improved pain, back-related disability, and quality-of-life outcomes compared with nonsurgical management, they acknowledge that these results were derived almost solely from a single trial. Further, the investigators write: “Any apparent benefits of kyphoplasty over nonsurgical management appeared to decrease over time, and, based on available data, it was not possible to determine whether these between-group differences were clinically meaningful of the extent to which they were accounted for by sham effects or study bias.”

Ebeling and colleagues go on to address the potential harms and possible risk of new vertebral fractures with vertebral augmentation. Prior to the task force report, limited evidence was available on these risks. In relation to both percutaneous vertebroplasty and balloon kyphoplasty, the authors find that adverse events— including risk of death, incident vertebral fracture, cement leakage, adjacent fractures, vasovagal reactions, cord compression requiring decompression, hypoxia and respiratory failure—were rarely systematically reported.

According to the authors, compared with nonsurgical

There is insufficient evidence to support kyphoplasty over nonsurgical management.” management, kyphoplasty was not associated with a statistically significant increased risk of incident vertebral fracture, although it was associated with nearly twice the risk of any adverse event within 30 days of intervention. Yet, Ebeling et al allude to the high risk of bias present in the trials: “It is uncertain whether any benefits of kyphoplasty versus nonsurgical management of vertebral fracture outweigh potentials harms”.

Finally, the efficacy and safety of other nonpharmacologic treatments—spinal bracing and exercise interventions, was investigated. Based on the current evidence, Ebeling and colleagues report that for patients with painful vertebral fractures, there is low quality evidence that spinal bracing improves pain, trunk muscle strength, kyphosis, pulmonary volume and quality of life at six months. Furthermore, although the authors note that, following exercise interventions, the “magnitude of effects on mobility were small”, they

surmise that exercise interventions have significant positive effects on mobility and may improve pain, fear of falling, as well as back extensor strength or endurance.

Yet, the aforementioned study biases and methodological flaws present in the literature that Ebeling and colleagues acknowledge throughout the report led them to address these gaps in the literature.

The authors report on future research that is required to improve patient outcomes in managing osteoporotic vertebral fractures, in relation to both vertebral augmentation and other nonpharmacologic approaches.

While a rigorous trial design to minimise the potential for bias is recommended in order to examine all therapies, specific recommendations are also detailed.

“No further trials of vertebroplasty should be performed, unless they are adequately powered to alter the conclusions of the current body of evidence”, they write. If further trials are to commence, the authors state that patients, as well as ethics committees, should be fully informed about the current body of evidence. Regarding balloon kyphoplasty, the authors recommend that “further studies are needed to resolve whether kyphoplasty increases the risk of future vertebral fractures or adverse events, which should be systematically collected”, while “any future trials should carefully characterise the timing and severity of vertebral fracture among study participants [and] should have a placebo control group.”

Based on the findings outlined in the report, the ASBMR task force detailed guidelines for the clinical management of patients with vertebral fracture.

Maintaining that the optimal management of vertebral fracture remains uncertain, Ebeling and colleagues put forward that when vertebral augmentation is used, patients should be fully informed about the evidence.

In light of the findings, they conclude: “It is critical that anti-oseoporotic medications are started, continued or changed in patients with recent vertebral fracture”. Further, the task force highlights that while the use of bracing in reducing pain immediately after vertebral fracture was not supported by current evidence, exercise may improve mobility and may reduce pain and fear of falling.

Authors of the VAPOUR trial submit complaint about the Cochrane vertebroplasty review

Interventional radiologist William Clark (St George Private Hospital, Sydney, Austrialia) reached out to Spinal News International to say that a section of the ASBMR report takes its findings directly from the Cochrane review. Clark and fellow authors of the VAPOUR trial have submitted a complaint to the chief editor of the Cochrane Library about alleged irregularities in the Cochrane Vertebroplasty Review (CVR) of April 2018. They asked that the review be withdrawn from the Cochrane Library, writing “we believe that the report provides a biased analysis of the VAPOUR trial, contains inappropriate statistical analysis and errors in data presentation.”

CVR authors issued a new November 2018 version of CVR to correct errors in analysis 8.1/2, but according to its critics left the bulk of the review unchanged.

Clark and colleagues subsequently published their criticism of the CVR in the British Medical Journal of Evidence-Based Medicine. Their allegations against the CVR include bias against the VAPOUR trial, breach of protocol, improper use of meta-analysis and other methodological errors.

While the CVR authors conclude that the benefits from vertebroplasty in the VAPOUR trial are “clinically irrelevant and consistent with the negative results of their trials”, Clark and colleagues write that “this assertion is false”.

Indeed, Clark told Spinal News International that “The same criticisms of the Cochrane review apply directly to the ASBMR report, which draws its conclusions directly from the Cochrane review, which includes the flawed Cochrane meta-analyses”.

18

May

Response: The ASBMR taskforce report is “dangerous” and “shameful” Douglas Beall Comment & Analysis A recent taskforce report charged by the American Society for Bone and Mineral Research (ASBMR) concluded that current evidence does not support the routine use of vertebroplasty for the treatment of pain from vertebral fractures (see page 16). However, as someone who strongly believes the evidence supports the use of this procedure to alleviate pain, Douglas Beall has significant concerns about the impact this report will have on patient numbers.

This article published in the Journal of Bone and Mineral Research (JBMR) is dangerous and puts patients at an increased risk of morbid injury and death. The manuscript focuses on recommendations by a task force from the American Society for Bone and Mineral Research (ASBMR). Most of the taskforce do not even perform the procedure they are writing about (vertebral augmentation) and the ones that do it still do it after writing negative articles about it. I would never continue to do a surgery or procedure that I found to be ineffective, but it is well documented that authors of this trial do.

One can only conclude that either they do not believe their own recommendations, or that they perform the procedure for reasons other than clinical effectiveness.

I would also never write any article, especially a highly critical one about a technique that I did not personally do, but

the taskforce is filled with authors from the departments of Internal Medicine, Clinical Sciences, Epidemiology and Human Metabolism that have never seen the inside of an operating room in their current professional positions.

So what is dangerous about these recommendations? The task force says there is insufficient evidence to recommend vertebral augmentation. This will assuredly decrease the number of patients treated. This situation has been seen previously after two vertebroplasty versus sham trials were published in the New England Journal of Medicine (NEJM) in 2009. What happened afterwards was recently described by Kevin Ong (Philadelphia, USA) et al who documented the decreasing number of patients treated and estimated that 75,452 patients were at higher mortality risk and that 6,814 lives were lost due to the downward trend in treatment. The

Orthofix Medical recently announced the full two-year outcomes from its US Investigational Device Exemption (IDE) study of the M6-C artificial cervical disc.

Jack Zigler, of Texas Back Institute (Plano, USA) and an investigator in the study, presented the study results during the International Society for the Advancement of Spine Surgery annual meeting (3–5 April, Anaheim, California).

The data demonstrates that patients treated with the M6-C artificial cervical disc had significant improvements in neck and arm pain, function and quality of life scores. Additionally, these patients had a significant difference in the reduction of pain and opioid medications use when compared to anterior cervical discectomy

inevitable increase in patient morbidity and mortality is not even been addressed by the task force despite the fact that this has been studied by many authors from many countries in the USA, Europe and Asia. If the ASMBR taskforce has their way, they would like to ban a procedure that is demonstrably life-saving and life prolonging.

The taskforce states that there is “insufficient evidence to support kyphoplasty over non-surgical management, percutaneous vertebroplasty, vertebral body stenting or Kiva” but is apparently unaware of a large kyphoplasty randomised control trial (RCT), the Fracture Reduction Evaluation (FREE) trial published in 2009 provided Level 1 evidence supporting kyphoplasty over non-surgical management and a recent meta-analysis

by Ioannis Papanastassiou (Rimini, Greece) that showed prominent pain, function and quality of life improvements with vertebral augmentation. The metaanalysis examined 1,587 articles in the English language including 27 Level I or II articles compared to the task force’s five articles.

Why only five articles? They only examined the vertebroplasty versus sham trials. Despite this severely limited dataset this didn’t stop the taskforce from making recommendations about implant augmentation and kyphoplasty which has been shown to be highly effective. The taskforce incorrectly stated that “a sham procedure means that local anaesthetic was administered to the skin and the procedure was simulated”, which is only true for one of the positive trials, not the three negative ones. The negative studies use a sham that involved injecting anaesthetic onto the bone in the location of the medial branch of the dorsal ramus, a technique that has Level I evidence supporting its efficacy in significantly decreasing back pain. Not only is this not a sham, it is an active treatment that significantly decreases back pain. This

active treatment called a sham by the authors of VERTOS IV decreased the pain by a massive 4.75 points on the numerical rating scale. So how does this rate? If you accout for their calculations for significance, this is better than spine injections, radiofrequency ablations, cervical discectomy, total hip arthroplasty and virtually everything we do in medicine. Yes, even the gold standards in spine and orthopedic surgery—the cervical discectomy and fusion and the hip arthroplasty—are nowhere close to as good as the fake surgery for the authors of VERTOS IV. The fundamental problem is that by comparing mean pain scores, as was inadvisably done in VERTOS IV, the authors created an impossibly high benchmark for comparison that almost nothing significantly outperforms, except for, ironically, kyphoplasty. In the largest clinical trial ever done on kyphoplasty with 354 patients, the pain decreased by an average of 6.3. The world’s largest registry recently completed in the USA showed real world results on data collected from sites around the country and featured a mean pain score reduction of 6.7 points and a median pain reduction of 9 points. These two data sources are the largest real world post-market data sources in the world for vertebral augmentation but were not even mentioned by the ASBMR task force.

The bottom line is that we know better than to produce recommendations like this that are completely divorced from the reality of today’s treatment of vertebral compression fractures and we know better to recommend something that has been shown to result in increased morbid suffering and death. The best way I can describe these recommendations is that they are shameful.

Douglas Beall is the chief of Radiology Services at the Clinical Radiology of Oklahoma in Oklahoma City, USA. All references for this article are online at www.spinalnewsinternational.com.

Si-Bone announces publication of two-year iMIA randomised controlled trial results

Clinical News Positive two-year data released for the M6-C cervical disc

Issue

19 51

Vertebroplasty

and fusion (ACDF) patients. At 24 months, patients in the ACDF group who were still using pain medications had a seven times higher rate of opioid use than those in the M6-C disc group.

A prospective, non-randomised, concurrently controlled clinical trial, the M6-C IDE study was conducted at 23 sites in the USA with an average patient age of 44 years. The study evaluated the safety and effectiveness of the M6-C artificial cervical disc compared to ACDF for the treatment of single level symptomatic cervical radiculopathy with or without cord compression. The overall success rate for the protocol-specified primary endpoint for the M6-C disc patients was 86.8% at 24 months and 79.3% in the control group.

This data statistically demonstrates that cervical disc replacement with the M6-C disc is not inferior to treatment with ACDF.

Two-year results of a randomised controlled trial, published in the Journal of Bone and Joint Surgery (JBJS), suggest that minimally invasive sacroiliac joint arthrodesis with triangular titanium implants is safe and more effective throughout two years in improving pain, disability, and quality of life compared with conservative management.

The iMIA (iFuse implant system minimally invasive arthrodesis) trial is a Level 1 randomised controlled trial (RCT), conducted at nine hospitals in four countries in Europe, that assessed the safety and effectiveness of SI joint fusion (SIJF) with triangular iFuse implants (Si-Bone) compared to conservative management in patients with chronic SI joint dysfunction. iMIA two-year results were published in the JBJS, which has an impact factor of 4.84, the highest among orthopaedic journals.

Si-Bone iFuse implant system

In the iMIA study, 103 subjects were randomly assigned to CM (n=51) or SIJF (n=52) between 6 June 2013 and 15 May 2015. At two years, mean low back pain (as measured on the Visual Analog Scale, or VAS) improved by 45 points in the SIJF group and 11 points in the CM group (mean difference between groups 34 points, p<0.0001). Mean ODI improved by 26 points in the SIJF group and eight points in the CM group (mean difference 18 points, p<0.0001). Parallel improvements were seen in leg pain and several quality of life measures.

20

May

Product News among healthcare institutions and payors of the proven benefits of our technology and the importance of making it a covered treatment option for patients.”

ISASS bone grafting policy statement features i-FACTOR peptide enhanced bone graft

The International Society for the Advancement of Spine Surgery (ISASS) recently issued a new bone grafting policy that features iFACTOR peptide enhanced bone graft (Cerapedics) as one of only two drug–device combination products approved by the US Food & Drug Administration (FDA) through the Premarket Approval (PMA) process and supported by level 1 clinical data.

“We are very pleased that ISASS has issued this important policy update that differentiates our proprietary biomimetic small peptide (P-15) technology from other bone grafting products that have little or no clinical evidence,” said Glen Kashuba, chief executive officer of Cerapedics. “The ISASS statement notes that iFACTOR Peptide Enhanced Bone Graft is based on a well-established mechanism of action and carries extensive clinical data including level 1 human data that strongly supports its safety and efficacy.” iFACTOR Peptide Enhanced Bone Graft has a novel mechanism of action (attract, attach, and activate) that induces osteoblast cell proliferation and differentiation to accelerate new bone formation in patients with degenerative disk disease. Prior research indicates that iFACTOR Peptide Enhanced Bone Graft is superior to the historical “gold standard” autograft in overall clinical success. Cerapedics recently initiated a second investigational device exemption clinical trial to evaluate the safety and efficacy of the P-15 technology compared to autograft in transforaminal lumbar interbody fusion surgery.

“We are continually hearing about the development of new technologies to support bone regrowth and repair, but little about the supporting clinical evidence,” said Paul M Arnold, chairman, Department of Neurosurgery, Carle Illinois College of Medicine (Urbana, USA). “iFACTOR Peptide Enhanced Bone Graft has a wealth of clinical evidence supporting its use, as well as the potential to offer an economical alternative that aligns with the values of healthcare systems.”

“More than 300,000 people in the USA suffer from degenerative disk disease that leads to pain and nerve irritation and often requires surgery,” added Jeffrey Marx, president and chief operating officer of Cerapedics. “Increasingly, surgeons and hospitals are recognising the advantages of the iFACTOR Peptide Enhanced Bone Graft’s biomimetic small peptide technology in helping to improve safety and outcomes, and we hope this ISASS policy statement builds awareness

Issue

19 51

Market watch

Vertos Medical granted CE mark for spinal stenosis treatment

Vertos Medical said it has received CE mark approval for its lumbar spinal stenosis (LSS) treatment device kit.

According to a press release, the company’s Mild device kit “enables a minimally invasive procedure to remove the cause of stenosis through a portal the size of a baby aspirin”. The procedure requires no stitches, general anaesthesia, implants or overnight hospital stays, the company added.

The Mild spinal decompression procedure received broad coverage from the Centers for Medicare & Medicaid Services (CMS) via the Coverage with Evidence Development Program in 2016.

“Receiving the CE mark is an important step for the company to be able to offer the mild procedure outside of the United States,” said Vertos Medical president & CEO Eric Wichems in a prepared statement. “We are excited about the prospect of helping European patients who suffer from LSS to stand longer and walk farther with less pain.”

Data from a CMS-approved study published in 2018 demonstrated the long-term safety and efficacy of the Mild procedure at two years after it had been performed. Vertos raised US$23 million in 2013 and US$28 million in 2017 for its Mild treatment.

AC is the first expandable cervical IBFD on the market to offer adjustment to both height and lordosis to easily and predictably restore the spine to its more natural curvature (lordosis) and balanced sagittal alignment.

“It’s not just about fusion anymore. As studies and clinical evidence continue to show, the value of restoring lordosis and global sagittal balance to the cervical spine is becoming more widely recognised and prioritised by spine surgeons today. With implant options that can achieve as much as 20 degrees of angulation, HiJak’s expandable capability plays right into this surgical objective.

This kind of mechanical advantage was unavailable to surgeons prior to the introduction of HiJak,” said Matt Baynham, Atlas’ CEO. “HiJak truly represents a disruptive technology when it comes to both height and lordosis restoration, especially at the cervicothoracic junction. It has given surgeons the opportunity to improve their patients’ chin-brow angle much better than we were ever able to accomplish with non-expandable technology,” stated Kees Poelstra, director of the Spine Center of Excellence at Sacred Heart Hospital (Destin, USA).

OrthoPediatrics announces global launch of new BandLoc DUO

OrthoPediatrics has announced the launch of BandLoc DUO, the latest addition to the BandLoc 5.5/6.0mm system. BandLoc is a temporary implant for use in orthopaedic surgery, intended to provide stabilisation as a bone anchor during the development of solid bony fusion and aid in the repair of bone fractures. The system allows a pedicle-sparing, band passage technique for treating a wide variety of complex spinal pathologies, including spinal trauma, degenerative, and reconstructive surgeries, such as scoliosis.

The BandLoc DUO enables bilateral fixation with a single sublaminar passage of the band, making it a simpler and more efficient solution. The implant features a unique pre-assembled design which incorporates the company’s RESPONSE set screw technology, accepts multiple rod diameters in Cobalt Chrome or

Atlas Spine interbody fusion device

Atlas Spine launches expandable cervical interbody fusion device

Atlas Spine has announced the successful completion of its 50th surgical procedure and over 100 devices implanted with its new HiJak AC expandable cervical interbody fusion device. The company has now moved to its full product launch.

According to a press release, HiJak

Titanium, and includes innovative and ergonomic instrumentation. While BandLoc incorporates the Company’s RESPONSE Spine System, it is compatible with any 5.5mm or 6mm spinal correction system on the market and thus can be used in conjunction with competitive systems.

Jeff Smithey, OrthoPediatrics’ vice president of spine, commented, “We are excited about the release of

BandLoc DUO, which was developed with paediatric orthopaedic surgeons to provide another superior option for their paediatric patients in treating complex spinal deformities. Our dedication to improving the lives of children around the world continues to drive our stateof-the-art paediatric solutions. This innovative technology expands our scoliosis portfolio and further represents our commitment as the only company completely focused on providing comprehensive, high-quality solutions for paediatric orthopaedic patients.”

Paediatric orthopaedic surgeon, Mike Albert of Dayton Children’s Hospital (Dayton, USA) has championed the technology, stating, “The primary advantages of the new BandLoc DUO are related to increased patient safety and operating room efficiency. Any technology that reduces risks to children while making surgery simpler, with an improved process and instrumentation, is a win.”

Alphatec announces FDA clearance of automated SafeOp neuromonitoring system

It was announced recently that Alphatec has received 510(k) clearance from the US Food & Drug Administration (FDA) for its automated SafeOp neuromonitoring system for use in real-time intraoperative nerve location and health assessment.

According to a press release, the technology of the SafeOp system represents a “significant advancement” in two intraoperative neurophysiological monitoring (IONM) modalities: somatosensory evoked potential (SSEP), and electromyography (EMG). SSEP assesses the functional health of the spinal cord and nerves, while EMG enables surgeons to test nerves for their location, proximity, and conduction.

Alphatec remarks that the SafeOp automated SSEP technology has been successfully used in more than 1,000 surgeries to identify potential nerve injury from patient positioning, and has demonstrated reliability in monitoring peripheral nerves in spine surgery.

The current 510(k) clearance expands the system to include more advanced algorithms for EMG. Pat Miles, chairman and chief executive officer of Alphatec, commented: “Surgeons yearn for information to enable better surgery.

SafeOp not only provides actionable intraoperative information regarding nerve location during access but, for the first time, it also allows surgeons to monitor patient nerve health, in real-time, during surgery.”

The SafeOp system’s initial focus will be on resolving the “significant unmet clinical need” in minimally invasive lateral procedures, but it can and will be leveraged into multiple Alphatec surgical approaches.

“This technology will provide more surgeons with the confidence to perform lateral surgeries and will improve patient care,” said Luiz Pimenta, Alphatec’s chief medical officer.

May

Issue

19 51

Market insights

Study to assess wearable robotic devices for improving motor function in spinal cord injury The US Department of Defense, Congressionally Directed Medical Research Programs has given the Kessler Foundation—a US nonprofit organisation in the field of disability—a grant of US$500,000 to evaluate the use of the MyoPro wearable robotic device (Myomo) for improving upper extremity motor function in people with incomplete spinal cord injury. Ghaith J Androwis (Kessler Foundation, West Orange, USA) will be the principal investigator of the three-year study.

A PRESS RELEASE from the Kessler Foundation reports that knowledge gained from this clinical trial (entitled “Efficacy of wearable robotic orthosis on improving upper extremity motor function/ activities of daily living in persons with spinal cord injury”) will advance patient care as well as orthotic and prosthetic outcomes-related rehabilitation research among individuals with incomplete spinal cord injuries. It adds that the data obtained will also be used to help design next generation assistive devices to better aid upper extremity motor function and its recovery in spinal cord injury and beyond.

Androwis and colleagues plan to enrol 30 individuals with incomplete spinal cord injury in the study, which will consist of 18, one-hour interventions using the MyoPro device over a period of six weeks. Androwis comments: “Although restoration of upper extremity function in people with spinal cord injury is a high priority in rehabilitation research and assistive technology, few wearable robotic devices specifically address wrist and hand mobility. The MyoPro brace facilitates elbow, wrist, and hand function with built-in motors and sensors that are driven by the patients’ voluntary muscle activity.

This study will provide the data needed to expand the options for rehabilitation for veterans, and lay the foundation Ghaith J Androwis for the introduction of home-based strategies for improved recovery of hand and arm function in individuals with incomplete spinal cord injury.”

The MyoPro is already commercially available and is targeted towards patients with weakened or paralysed arms because of a cerebrovascular accident, brachial plexus injury, traumatic brain or spinal cord injury, motor neuron disease (known as amyotrophic lateral sclerosis [ALS] in the USA) or other neuromuscular diseases/injuries.

According to the press release, it works by sensing a patient’s own electromyography (EMG) signals through non-invasive sensors on

BIBA Briefings

21

the arm and aims to restore the patient’s ability to perform activities of daily living–including feeding themselves, carrying objects and doing household tasks. It is currently the only marketed device to have this ability. Paul R Gudonis, CEO of Myomo, comments: “We are grateful to the Department of Defense for empowering the Kessler Foundation to conduct research around our MyoPro line of powered orthoses. Myomo is committed to transforming the lives of veterans with neurological or neuromuscular disease or injury by restoring control and range of motion to their arms and hands, giving them back their independence and reducing their cost of healthcare. It is important to continue to research MyoPro to further document how it can change veteran’s lives.”

According to the Kessler Foundation, about 17,500 traumatic spinal cord injuries cases occur in the USA each year—with high prevalence among active military members and veterans.

BIBA Briefings is a new platform that provides in-depth analysis of the latest market intelligence from BIBA MedTech Insights, reviews the latest technology developments, and looks at pipeline developments.

For more information about BIBA Briefings or BIBA MedTech Insights, please contact sales@bibamedical.com

22

May

Industry News RTI Surgical completes acquisition of Paradigm Spine

RTI Surgical has announced it has completed the acquisition of Paradigm Spine.

Paradigm Spine’s primary product is the Coflex interlaminar stabilisation device. According to a press release, this is a “differentiated, minimally invasive motion-preserving stabilisation implant that is FDA PMA-approved for the treatment of moderate to severe lumbar spinal stenosis (LSS) in conjunction with decompression.” “[The acquisition of Paradigm] marks the second completed acquisition for RTI’s spine portfolio since the second half of 2017 when we initiated a strategic transformation to reduce complexity, drive operational excellence and accelerate growth for RTI,” said Camille Farhat, president and CEO, RTI Surgical.

Farhat added: “The addition of coflex allows RTI to provide surgeons who treat patients with moderate to severe LSS a PMA-approved device supported by more than 12 years of clinical data and

with expanding coverage from payors.

With RTI’s demand generation expertise, scale, and infrastructure, and the experience of key members of the legacy Paradigm Spine team joining RTI, we are well-positioned to grow coflex as the treatment of choice and standard of care for appropriate LSS patients.”

Piper Jaffray & Co. served as financial advisers to RTI, and Sidley Austin LLP and Holland & Knight LLP served as legal counsel on the transaction and financing, respectively. Dorsey & Whitney LLP served as legal counsel to Paradigm Spine.

Scott Gottlieb resigns as head of US FDA

The commissioner of the US Food and Drug Administration (FDA), Scott Gottlieb, has unexpectedly resigned after serving just shy of two years in the post.

Gottlieb announced his intention to stand down in a letter to Alex Azar II, the secretary of the Department of Health and Human Services, the FDA’s parent agency, on 5 March. Gottlieb says the decision is due to the fact that he wants to

spend more time with his family.

Speaking in an interview with The Washington Post, Gottlieb says: “It was a very hard decision,” calling this posting “the best job I will ever have. He continues: “I am leaving because I need to spend time with my family. I get home late Friday, work on weekends and come back to Washington on Sunday. I did the job 100%.”

Gottlieb took up the position in May 2017, and has presided over a number of important initiatives, including the development of the new 510(k) pathway for device clearances.

No successor has been named. A new commissioner must be approved by the US Senate.

“All of us at the Department of Health and Human Services [HHS] are proud of the remarkable work Commissioner Gottlieb has done at the FDA,” health and human services secretary Alex Azar comments in a statement. “He has been an exemplary public health leader, aggressive advocate for American patients, and passionate promoter of innovation. I will personally miss working with Scott on the important goals we share, and I know that is true for so many other members of the HHS family.

“Scott’s leadership inspired historic results from the FDA team, which

Scott Gottieb

delivered record approvals of both innovative treatments and affordable generic drugs, while advancing important policies to confront opioid addiction, tobacco and youth e-cigarette use, chronic disease, and more. The public health of our country is better off for the work Scott and the entire FDA team have done over the last two years.”

Calendar of events 1–4 May XVII Congresso De Brasileiro de Coluna, Pre-Congress: Surgery and Minimally Invasive Spine Procedures Sao Paulo, Brazil www.cbc2019.com.br

13 May NASS GSC Technological Advancements in Spinal Cord Stimulation Toronto, Canada www.gsc2019.org

14 May NASS GSC Endoscopic Solutions for Lumbar Disc Herniation and Basic and Advanced Endoscopic Techniques

2–3 May EUROSPINE Spring Speciality Meeting Frankfurt, Germany www.eurospinemeeting.org

3–4 May Contemporary Management of Spinal Tumors Burr Ridge, USA

www.gsc2019.org

15 May NASS GSC Present and Future of Intraoperative Navigation, Robotics and Minimally Invasive Spine Surgery Toronto, Canada www.gsc2019.org

15–18 May 8th Annual Global Spine Congress Toronto, Canada

22–24 May 35th Annual meeting CSRSEurope Rome, Italy www.csrs-europe-congress.com

24–25 May 12th Congress of Chinese Association of Orthopedic Surgeons Beijing, China

5–7 June 20th EFORT Congress Lisbon, Portugal www.congress.efort.org

21–22 June Lumbar Spinal Injections Burr Ridge, USA

www.caos-china.org

www.gsc2019.org

16 May NASS GSC Advanced Techniques in Complex Spine Surgery Toronto, Canada www.gsc2019.org

Issue

March

16 38

bar multiple lum Fusion of associated with segments joint pain sacroiliac App

res has been cral procedu d online in Spine, res. and lumbosa publishe these procedu in lumbar in a study s involved c joint pain back pain following of segment of sacroilia low incidence l cause of The number affect the a potentia shown to the symptom as g confirmin failure oting published five rates of between for lumbar and 30% al spinal fusion and lumbosacr well as the s, as procedure of these frequency increasing of researcher

N

: Chris Bono

Q&A

Page 16

lski: Marek Szpa

Profile

Page 12

joint fusion Sacroiliac

Feature

Page 14

ps Motion trum SS NA fusion at debate

s a team surgeries, Kousei Medical from the Akita Japan) performed Center (Akita, analysis of ive the spinal a retrospect to determine common ive patient data t of many of postoperat res designed The treatmen primary causes fusion pain. by procedu more joint Walters Kluwer) conditions motion or by the subject of multiple sacroiliac (E Unoki, joint pain asserted that to preserve fusion was the The team Annual with sacroiliac noted sacroiliac of 28 patients at the 30th sacrum is conventional authors have potential candidate when the Fusion levels of debates American Spine , fusion as a symptom a series pain of a lumbar joint pain of the North October, Chicago the authors of low back fused as part could be more Meeting al fusion, 14–17 for the cause hal of the joint , it is lumbosacr lumbar fusion. procedure joint pain that sacroiliac 201 Society (NASS;by Scott Blument following sacroiliac patients discovered from Plano, USA. likely that in 20 of the of multiple USA), chaired Using data lumbar or Institute, the fusion pain occurred patients (10%) “We related to Texas Back who had undergone at the Akita of the spine. multiple lumbar fusion 61 lumbosacral al fusion segments and of the fusion of lumbosacr June 2006 and eight Whilst this ierce D Nunley consider that restrict the motion (13.1%). centre between researchers al can patients bar the (Spine Institute segments of towards lumbosacr or thoracolum June 2009, did trend of Louisiana, d the incidence of the lumbar authors observed ly depending investigate associated . fusion, the , USA) and joint pain spine considerab difference Shreveport of involved sacroiliac of floating no significant es Abitbol incidence fixed and on the number consequently Jean-Jacqu ip with both at Spine Group, When comparing the relationsh spinal segments, at the sacroiliac among fusion (California segments fusion, and stress USA) the symptom authors number of increasing San Diego, levels, the surgery and between the ly more authors wrote. the task of different in the fusion joint,” the that significant were given of literature involved joint pain. body a fusion treatment discovered underwent Citing sacroiliac of load debating the the rate of (20% a transfer two-level and sixty-two patients who reporting by the Nunley of a case of more segments Two hundred not experienced segments Pierce D of of three or had onto lower at ≥4) developed cervical herniated either fused levels patients who sacroiliac joint pain at 3, 22.5% sacroiliac joint pain. straightening of ve segment Of nucleus pulposescervical ive preoperati case for in adjacent postoperat in the study. argued the the spine reviewed lumbar with an anterior fusion were included 201 underwent procedure.

The authors a and the fusion disease following speculate discectomy to determine than 60 these patients, and 61 also or with authors literature that behind Citing more results, fusion fusion, The similar to (ACF) procedure t. mechanism Two a floating potential replacemen years of good that sacrum fused. that a mechanism disease n of sacroiliacand for total disc a had their segment were fused the presentatio lumbar surgery he contended of adjacent The case involved following (±1.4) segments average. After lumbar fusion joint pain. male patient joint pain surgery. on it offers predictable following 30-year-old al fusion who sacroiliac fusion each patient herniated lumbosacr nt difference g 66 patients pain results. This could explain has has reported with a two-level C5–6, insignifica determinin however, literature and Given the of this low back lower procedure, A body of presence disc at C4–5 with of loads to d had developed through the between the ively been associated on the transfer straightening who had experience pain incidence postoperat of medical records, the including on a significant levels from in adjacent symptoms investigati segment the neck segments and physical, of adjacent arms fused used of of in both In the case the authors and imaging results he admits. years. The al pathology, segment disease.pain, loads might for over five neurologic radicudebate, joint which patients To win the sacroiliac from fused patient displayed failed to identify total disc had joint. this as a result he argues, also be transferred lopathy, and treatment.

The had developed t would onto the sacroiliac ive joint pain. the study replacemen segments non-operat note that something of sacroiliac sacroiliac block no The authors retrospective ard have to offer Imaging revealed on page 2 gold-stand by its Continued deformity. ed in patients is limited y with significant was administer sacroiliac joint particularl first, Abitbol ion design, Speaking with suspected was made in the identificat regards to pain. Diagnosis to the who had latent on page 2 according of patients ded Continued 28 patients criteria recommen diagnostic et al (J Orthop

by Murakami 74–80).

Sci. 2007;12:2 to lumbar and With regards

P

20%

with of patients fusion at threeped levels develo pain joint sacroiliac

Issue

19 51

Market watch

Spinal News International is a trusted, independent source of news and opinion in the spinal world.

Sign up for a free print subscription* and e-newsletter subscription**

www.spinalnewsinternational.com *Available for US and EU readers only ** Available worldwide