Neuroscience News Summer 2011 by South Denver Neurosurgery

Vol. 2, No. 2

Summer 2011

Is disc arthroscopy the right option for my patients?

With Ben Guiot, MD, Neurosurgeon, South Denver Neurosurgery

IN SI D E 2 A rthroplasty vs. Fusion for Lumbar Pain

4 U nknowns of

Disc Arthroplasty

A: Given the success of motion preservation devices in shoulder, hip and knee disease, it is certainly reasonable to consider the use of disc arthroplasty as a means of relieving pain from a degenerative disc. These devices have the distinct advantage of retaining motion through the affected joint, which may result in more favorable outcomes in spinal surgery. Ongoing research is required to confirm that there is a benefit to arthroplasty versus the more traditional spinal fusion procedure. This issue of Neuroscience News explores the current state of cervical and lumbar disc replacement and offers guidance in patient selection to improve outcomes.

5 Research Briefs :: M inimally invasive diskectomy shows no benefit :: C arotid stenting FDA approved :: L ittleton Hospital expands to Castle Rock

6 M eet Our Physicians

LUMBAR ARTHROPLASTY

CERVICAL DISC ARTHROPLASTY

Careful patient selection can improve lumbar arthroplasty outcomes

Cervical arthroplasty has yet to show benefit in prevention of adjacent-level disc degeneration

More than 200,000 spinal fusions are performed each year in the United States. With the growing popularity of disc replacement, it is anticipated that as many as 30% to 50% of these surgeries will be replaced with arthroplasty. Yet, according to most studies, only 40% to 60% of lumbar disc arthroplasties are successful. Careful patient selection is critical to improving these odds. Interesting to note is the finding that patient outcomes with arthroplasty are unambiguous —patients either improve significantly or not at all. Patients with disc arthroplasty who improve share these characteristics: O ne level of disease between L3-L4, L4-L5 or L5-S1. (It should be noted that Siepe et al found that postoperative �� continued on page 2

With the continued development and success of joint replacement surgery for hips and knees, interest has grown in the use of disc replacement as a means of treating neck pain while preserving motion and reducing degeneration in adjacent segments. The U.S. Food and Drug Administration approved use of cervical disc arthroplasty in 2007, and the clamor for this surgery continues to grow. The idea that an artificial disc can preserve motion of the neck and thus reduce progression of the degenerative process seems apparent. However, no studies have yet found that disc replacement is �� continued on page 4

Lumbar Arthroplasty from page 1

After headaches, low back pain is the most common neurological ailment in the United States, with cases continuing to increase as Americans age and become increasingly obese.

results deteriorated when replacement included the lumbosacral junction.)

Medical Management

T hose with degenerative disc disease or post-laminectomy syndrome diagnoses are the most successful candidates. Patients who have ankylosing spondylitis, low bone density, are pregnant, radiculopathy only, scoliosis, spine infections, spinal stenosis, or spondylothesis are not candidates for this surgery. C andidate is medically appropriate for surgery, with no upper age limit. Young adults still growing should not undergo this procedure.

After headaches, low back pain is the most common neurological ailment in the United States, with cases continuing to increase as Americans age and become increasingly obese. Low back pain is the most common cause of job-related disability and costs America at least $50 billion annually in direct health care costs and indirect expenses, such as lost work. Of course, most low back pain resolves itself in days or weeks. Of the patients who continue to suffer more than three months, upwards of 80 percent can be managed medically with medications (NSAIDs, painkillers, antidepressants), physical therapy, and/or cortisone injections. For the 20% of patients who do not respond after six months of medical treatment, surgery should be considered.

Fusion vs. Arthroplasty Spinal fusion surgery has become the gold standard for treatment of intractable lower back pain caused by degenerative disc disease, spinal stenosis, isthmic spondylolisthesis, fractures and tumors. Yet, various studies show that success rates for relieving pain generally fall in the The appeal of disc arthroplasty is its ability to preserve motion and potentially reduce degeneration in adjacent segments.

Neuroscience News | Summer 2011

66% to 80% range, with Bono and Lee reporting a 75% success rate in a study of 4,454 patients. Disc arthroplasty began being tested in the early to mid-20th century and became commonly used in the current form in the past 15 years, with the first devices formally approved by the U.S. Food and Drug Administration in 2004 and 2006. The driving hypothesis behind replacing the disc was a desire to preserve motion and reduce rates of degeneration of adjacent discs while also improving overall success rates beyond that of fusion surgery. However, multiple studies show that arthroplasty generally achieves success rates equivalent to fusion, and there is no evidence yet that it reduces degeneration of adjacent discs. Indeed, the most recent studies have found the following:

 “ Results suggest that (there are) no clinically relevant differences between the total disc replacement and fusion techniques. The overall success rates in both treatment groups were small. …High quality randomized controlled trials with relevant control group and long-term follow-up is needed to evaluate the effectiveness and safety of TDR.” (van den Eerenbeemt KD et al. 2010)

Photo: SPINE AboVE: ©iStockphoto.com/ EraxionEraxion

P reoperative Oswestry Disability Index (ODI) of 38-59. Higher levels almost universally result in postsurgical failure to relieve symptoms.

“there is little if any evidence to support the hypothesis that adjacent segment degeneration is an important clinical entity.” (Resnick DK et al. 2007)

 “ TDR does not show significant superiority for the treatment of lumbar (degenerative disc disease) compared with fusion. The benefits of motion preservation and the long-term complications are still unable to be concluded.” (Yajun W. et al. 2010)  “ Lumbar disc arthroplasty is highly successful in reducing lower-back pain in about two-thirds of patients. A significant one-third of patients do not respond to surgery.” (Deutsch, Harel. 2010)  “ No statistical differences were found in clinical outcomes between groups (of CHARITE artificial disc patients vs. anterior lumbar interbody fusion with BAK cages and iliac crest autograft). CHARITE patients reached a statistically greater rate of part- and full-time employment and a statistically lower rate of long-term disability, compared with BAK patients.” (Guyer RD et al. 2009)  “ There is no evidence to suggest that the use of disc arthroplasty results in better short- or long-term functional outcomes than fusion in properly selected patients. Furthermore, there is little if any evidence to support the hypothesis that adjacent segment degeneration is an important clinical entity.” (Resnick DK et al. 2007)  “ Despite the relatively good early clinical results of these (disc replacement) devices, questions remain about the long-term efficacy in pain relief and maintenance of motion, the results of randomized

comparative trials with fusion and the life span of the devices.” (Gamradt, Seth et al. 2005)

Patient Selection These conclusions point out that, at this time, it is not clear whether arthroplasty will replace fusion as the surgery of choice for intractable lower back pain. What is clear, however, is that careful patient selection is key to success. Both referring physicians and patients can help contribute to higher success rates by understanding key success factors and considering types of surgeries carefully. In addition to the patient selection criteria outlined in the beginning of this article, it should be noted that patients who do not fare well with arthroplasty surgery include: P atients with multisegmental degenerative disc disease (Although disc replacement is being tested on an off-label basis, this procedure lacks evidence of noninferiority when compared with fusion procedures in controlled, randomized trials. Siepe et al.) P atients with baseline ODI above 59. Although a high ODI by itself does not exclude a patient from consideration, caution should be used. (Deutsch) P atients with overlying psychosocial issues in general do not tend to get better with arthroplasty. (Carragee et al.)

Sources: Bono CM and Lee CK: The influence of subdiagnosis on radiographic and clinical outcomes after lumbar fusion for degenerative disc disorders; an analysis of the literature from two decades. Spine Jan 2005; 15:30(2):227-34 Carragee EJ et al.: Low-pressure positive discography in subjects asymptomatic in significant low back pain illness. Spine 2006: 31:505-509 Deutsch Harel: The predictive value of the baseline Oswestry Disability Index in lumbar disc arthroplasty. Neurosurgical Focus 2010: 28 (6): E7 Guyer RD et al.: Prospective, randomized, multicenter Food and Drug Administration investigational device exemption study of lumbar total disc replacement with the CHARITE artificial disc versus lumbar fusion: fiveyear follow-up. Spine 9 May 2009: (5): 374-86, 2009 Siepe Christoph J et al.: Total Lumbar Disc Replacement: Different Results for Different Levels. Spine 2007: 32(7): 782-790 Van Den Eerenbeemt KD et al.: Total disc replacement surgery for symptomatic degenerative lumbar disc disease: a systematic review of the literature. European Spine Journal 19 Aug 2010 (8): 1262-80 Yajun W et al.: A meta-analysis of artificial total disc replacement versus fusion for lumbar degenerative disc disease. European Spine Journal 19 Aug 2010 (8): 1250-61

Ben Guiot, M.D.

Ben Guiot. M.D., is a neurosurgeon specia He is board certified by the American Board o and Surgeons of Canada. Dr. Guiot received his medical degree from He completed his neurosurgical residency trai graduate training in spine. Dr. Guiot completed spinal deformity surgery in the Department of two in complex adult reconstructive surgery a Neurosurgery at the University of Florida. Befo spent two years in academic institutions in the surgery. Dr. Guiot’s expertise in spine has led him to him by his neurologic and orthopaedic colleag 30 articles in peer-reviewed journals as well as director or faculty for more than 40 courses b the Biomechanics Lab and was the director o South Florida. Dr. Guiot brings a unique skill set to spine su positions have allowed him to join a very select spine disorders.

Cervical Disc Arthroplasty from page 1 superior to arthrodesis (fusion) at reducing disease progression in adjacent segments. There are two fundamental and unresolved questions underlying the issue: It has not been proven whether disease progression to adjacent discs is caused or accelerated by fusion or is a result of natural progression of the degenerative process. If this phenomenon is a natural progression of disease, disc arthroplasty is unlikely to be more successful than fusion at preventing progression and needs to be evaluated on other risks and benefits. (Hilibrand et al.)

Given these unresolved issues — along with the fact that cervical disc arthroplasty is still relatively new — it is not surprising that no studies yet have found arthroplasty to be superior to fusion. Indeed, Botelho et al. reviewed 84 randomized clinical trials involving cervical arthroplasty and concluded that “adjacentlevel degeneration has not been adequately studied in a review of the available

alizing in spine procedures with South Denver Neurosurgery. of Neurological Surgeons and the Royal College of Physicians

m the University of Ottawa School of Medicine in Canada. ining at the University of Ottawa before embarking on postd three fellowships in spinal disorders: the first in pediatric Orthopaedics at McGill University in Montreal and the other and minimally invasive spine surgery in the Department of ore joining South Denver Neurosurgery in August 2008, he e United States, devoting himself to the practice of spinal

o undertake the most challenging of cases, often referred to gues. He has been an active participant in research, publishing s numerous book chapters. He also served as either course both nationally and internationally. In addition, Dr. Guiot directed of the spine fellowship program at the University of

urgery. The years of fellowship training and his academic t group of individuals that can truly address a broad spectrum of

randomized-controlled trials on this topic, and there is no clinical evidence of reduction in adjacent-level degeneration with the use of cervical arthroplasty.” Bartels et al. came to the same conclusion after reviewing records of 1,533 patients: “A clinical benefit for the cervical disk prosthesis is not proven.” This is not to say, however, that cervical arthroplasty should not be considered. Rather, this surgery should be evaluated based on risks and benefits other than the unproven belief that the procedure will reduce adjacent-level degeneration.

Patient Selection Criteria When evaluating fusion vs. arthroplasty, referring physicians and patients should consider the following: A lthough arthroplasty has not been proven to reduce progression of the disease, it does preserve neck motion, which is important for some patients (e.g., airline pilots) but not crucial for others. A rthroplasty avoids complications of bone graft that may be experienced with fusion. D isc replacement is not approved or recommended for multilevel disc degeneration, which is present in the majority of surgical candidates. F usion has proven over time to be highly predictable and largely effective, while long-term studies on the outcomes and viability of arthroplasty are still being conducted. SOURCES Baaj Ali et al. History of cervical disc arthroplasty. Neurosurgical Focus Sept. 2009: 27(3):E10 Bartels RH. No justification for cervical disk prostheses in clinical practice: a meta-analysis of randomized controlled trials. Neurosurgery. June 2010: 66(6): 1153-60. Botelho Ricardo Vieira et al. A systematic review of randomized trails on the effect of cervical disc arthroplasty on reducing adjacent-level degeneration. Neurosurgical Focus June 2010: 28(6):E5. Hilibrand, AS, Robbins M: Adjacent segment degeneration and adjacent segment disease: the consequences of spinal fusion? Spine J 4 2004: (6 Suppl): 190S-194S

SouthDenverNeurosurgery.org | Neuroscience News

Photo: SKULL: ©iStockphoto.com/ Raycat

Research also has not yet shown which type of device best mimics normal intervertebral kinematics. Current prostheses include constrained, unconstrained and semi-constrained types, which are then further segmented by materials, including metal-on-metal, metal-on-polymer, ceramic-on-polymer, polymer composite, or ceramic-on-ceramic. (Baaj et al.)

research briefs

Minimally invasive diskectomy not always superior, study shows Patients who underwent minimally invasive diskectomies did not experience any improvement in their outcomes compared with patients who had traditional “open” diskectomies, according to a new study in the July issue of the journal Neurosurgery. The study, conducted in the Netherlands, followed 328 patients for two years after surgery. Half had received minimally invasive tubular diskectomy, while the other half received conventional open microdiskectomy. Over the two years following surgery, patients reported similar levels of pain.

Fifteen percent of minimally invasive patients and 10% of microdiskectomy patients required repeat surgery within two years. “Despite many marketing claims about the universal benefits of minimally invasive surgery, no study has clearly shown an improvement in outcomes,” says J. Adair Prall, MD, neurosurgeon with South Denver Neurosurgery. “Patients and their primary care physicians need to understand that different clinical situations sometimes require open surgery and other times can benefit from minimally invasive surgery. It is critical to tailor the surgery to the individual patient.”

FDA approves carotid stenting Carotid artery stenting has been shown to be a viable alternative to surgery for treating cervical carotid stenosis, and has now been approved by the U.S. Food and Drug Administration (FDA) for treatment of both symptomatic and asymptomatic individuals with carotid stenosis. This approval by the FDA occurs about a year after results of the Carotid Revascularization Endarterectomy versus Stenting Trial (CREST) were published, and will likely make the minimally invasive treatment of carotid stenosis more widely available. CREST was the largest prospective randomized trial to date comparing these two interventions, enrolling 2,502 patients from 117 U.S. and Canadian centers. The study showed similar outcomes with carotid artery stenting (CAS) and carotid endarterectomy (CEA) for the treatment of carotid stenosis.

Castle Rock facility opens September 7 In September, the first phase of the $23.6 million Castle Rock Adventist Health Campus will open. This facility, a department of Littleton Adventist Hospital, will provide Castle Rock’s first full-service emergency department. The new ED will be open 24 hours a day, seven days a week, offering services including laboratory testing, diagnostic radiology, CT and MRI. The first-phase emergency department and imaging center of the project broke ground last summer. Additional development plans include construction of a medical office building and a full-service hospital, slated to open in two years. The campus is located in The Meadows at Historic Castle Rock, west of Interstate 25 on Meadows Boulevard.

For more information, go online to www.mylittletonhospital. org/castlerock, where you can see a live webcam of construction plus get complete information on plans and services. More information also can be obtained by calling 720-455-2500.

Neuroscience News | Summer 2011

(Left) A narrowed carotid artery before stenting. (Right) The artery is open after stenting.

Stenosis is estimated to cause approximately 10% of strokes, and those rates are increasing as the incidence of hypertension, diabetes and high cholesterol continue to go up. Although stenting was proven to be as effective as surgery, there are few qualified physicians who can perform this procedure. Currently, just four neurosurgery practices in Colorado, including South Denver Neurosurgery, offer carotid stenting. “The CREST results have shown that for asymptomatic and symptomatic patients, both procedures are safe and durable,” says Christopher Nichols, MD, a neurosurgeon with South Denver Neurosurgery who performs carotid stenting at Littleton Adventist Hospital.

About Us South Denver Neurosurgery provides state-ofthe-art diagnostic and treatment programs for a wide range of brain and spinal disorders. We partner with our patients and their physician teams to make individualized decisions and treatment plans. Our physicians are some of the most experienced in the Rocky Mountain region, offering the latest, most up-to-date procedures and treatment options to patients.

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Meet Our Physicians

Ben Guiot, MD Neurosurgeon, boardcertified by the American Board of Neurological Surgeons and the Royal College of Physicians and Surgeons of Canada. Specializing in all aspects of spine care including: :: Minimally invasive spine surgery :: Spinal deformity correction :: Reconstruction of complex spinal disorders

Christopher Nichols, MD Neurologist, specializing in stroke and vascular neurology and endovascular neurosurgery, including evaluation and treatment of: :: Brain aneurysms :: Arteriovenous malformations :: Dural arteriovenous fistulas :: Acute stroke and intracerebral hemorrhage :: Cervical and intracranial arterial disease :: Cerebral vasculopathy :: Cerebral venous thrombosis

J. Adair Prall, MD Neurosurgeon, specializing in: :: T rigeminal neuralgia :: S pinal disorders :: Neuro-oncology :: Minimally invasive and motion preserving spine surgery :: Stereotactic radiosurgery (Gamma Knife® and CyberKnife®)

David VanSickle, MD, PhD Neurosurgeon, PhD in bioengineering, specializing in: :: D eep brain stimulation (DBS) for Parkinson’s and Essential Tremor :: Epilepsy surgery :: Neuro-oncology :: Spinal cord stimulator implantation for pain :: Transphenoidal surgery (pituitary surgery) :: Minimally invasive and motion preserving spine surgery :: S tereotactic radiosurgery (Gamma Knife® and CyberKnife®)