ORTHOPEDIE

CENTRUM ORTHOPEDIE

ARTIKELS

ABSTRACT 1

An oblique fibular tunnel is recommended when reconstructing the ATFL and CFL.

5th International Congress of Foot & Ankle Minimally Invasive Surgery

Michels F

March 2019, Marrackech, Morocco

INTRODUCTION/BACKGROUND A bone tunnel is often used during the reconstruction of the anterior talofibular ligament (ATFL) and calcaneofibular ligament (CFL).

OBJECTIVE The purpose of this study is to compare proposed directions for drilling this fibular tunnel and to assess potential tunnel length, using a 5-mm diameter tunnel and surrounding bone.

MATERIALS/METHODS Anonymous DICOM data from spiral CT-scan images of the ankle were obtained from 12 Caucasian patients: 6 females and 6 males. Virtual tunnels were generated in a 3D bone model with angles of 30, 45, 60 and 90 degrees in relation to the fibular long axis. Several measurements were performed: distance from entrance to perforation of opposing cortex, shortening of the tunnel, distance from tunnel centre to bone surface.

RESULTS A tunnel in a perpendicular direction resulted in an average possible tunnel length of 16.8 (± 2.7) mm in the female group and 20.3 (± 3.4) mm in the male group. A tunnel directed at 30 degrees offered the longest length: 30.9 (± 2.5) mm in the female group and 34.4 (± 2.9) mm in the male group. The use of a 5-mm diameter tunnel in a perpendicular direction caused important shortening of the tunnel at the entrance in some cases. The perpendicular tunnel was very near to the digital fossa while the most obliquely directed tunnels avoided this region.

CONCLUSION An oblique tunnel allows for a longer tunnel and avoids the region of the digital fossa, thereby retaining more surrounding bone. In addition, absolute values of tunnel length are given, which can be useful when considering the use of certain implants. We recommend to drill an oblique fibular tunnel when reconstructing the ATFL and CFL. ABSTRACT 2

Does subtalar instability really exist? A systematic review.

Michels F, Van Der Bauwhede J, Stockmans F, et al. Foot Ankle Surgery, 2020, 26(2), 119-127

INTRODUCTION/BACKGROUND Subtalar joint instability (STI) is considered as a potential source of chronic lateral hindfoot instability. However, clinical diagnosis of STI is still challenging.

OBJECTIVE This systematic review was conducted to assess the consistency of the clinical entity "subtalar instability", to investigate the reliability of available diagnostic tools and to provide a critical overview of related studies.

MATERIALS/METHODS A systematic review of the Medline, Web of Sciences and EMBASE databases was performed for studies reporting on tests to investigate subtalar instability or lesions of the subtalar ligaments. To investigate the relation with chronic STI, studies focusing on sinus tarsi syndrome (STS) or acute lesions of the subtalar ligaments were also included in the search strategy and were assessed separately.

RESULTS This review identified 25 studies focusing on different topics: chronic STI (16), acute lesions of the subtalar ligaments (5) and STS (4). Twelve studies, assessing STI, demonstrated the existence of a subgroup with instability complaints related to abnormal increased subtalar motion (7) or abnormalities of the subtalar ligaments (6). We found insufficient evidence for measuring subtalar tilting using stress radiographs. MRI was able to assess abnormalities of the ligaments and stress-MRI detected abnormally increased motion.

CONCLUSION Complaints of instability can be related to subtalar ligaments injuries and an abnormally increased motion of the subtalar joint. Stress radiographs should be interpreted with caution and should not have the status of a reference test. Clinical diagnosis should rely on several parameters including MRI.

ABSTRACT 3

Endoscopic anatomic ligament reconstruction is a reliable option to treat chronic lateral ankle instability.

Cordier G, Ovigue J, Michels F, et al. Knee Surgery, Sports Traumatology, Arthroscopy, 2020, 28(1), 86-92

INTRODUCTION/BACKGROUND Anatomic reconstruction of the anterior talofibular ligament and calcaneofibular ligament is a valid treatment of chronic hindfoot instability.

OBJECTIVE The purpose of this study was to investigate the outcomes of this procedure performed by an all-inside endoscopic technique.

MATERIALS/METHODS This study is a retrospective evaluation of a prospective database. Subjects were all patients who underwent an endoscopic lateral ligament reconstruction between 2013 and 2016. All patients had symptoms of ankle instability with positive manual stress testing and failed nonoperative treatment during at least 6 months. At final follow-up the outcome was assessed using the visual analogue score (VAS), American Orthopaedic Foot and Ankle Society (AOFAS) score and Karlsson-Peterson scores.

RESULTS After an average follow-up of 31.5 ± 6.9 months, all patients reported significant improvement compared to their preoperative status. The preoperative AOFAS score improved from 76.4 ± 15 to 94.7 ± 11.7 postoperatively (p = 0.0001). The preoperative Karlsson-Peterson score increased from 73.0 ± 16.0 to 93.7 ± 10.6 postoperatively (p = 0.0001). The VAS score improved from 1.9 ± 2.5 to 0.8 ± 1.7 (p < 0.001). Two patients had complaints of recurrent instability.

CONCLUSION Endoscopic ligament reconstruction for chronic lateral ankle instability is a safe procedure and produces good clinical results with minimal complications. In addition, the endoscopic approach allows an assessment of the ankle joint and treatment of associated intra-articular lesions. ABSTRACT 4

The intrinsic subtalar ligaments have a consistent presence, location and morphology.

Michels F, Vanrietvelde F, Stockmans F, et al. Foot Ankle Surgery, 2020, Epub ahead of print, DOI: 10.1016/j.fas.2020.03.002

INTRODUCTION/BACKGROUND Chronic subtalar instability is a disabling complication after acute ankle sprains. Currently, the literature describing the anatomy of the intrinsic subtalar ligaments is limited and equivocal which causes difficulties in diagnosis and treatment of subtalar instability.

OBJECTIVE The purpose of this study is to assess the anatomical characteristics of the subtalar ligaments and to clarify some points of confusion.

MATERIALS/METHODS In 16 cadaveric feet, the dimensions and locations of the subtalar ankle ligaments were assessed and measured. CT-scans before dissection and after indication of the footprints with radio-opaque paint allowed to generate 3D models and assess the footprint characteristics.

RESULTS The cervical ligament (CL) had similar dimensions as the lateral ligaments: anterior length 13.9 ± 1.5 mm, posterior length 18.5 ± 2.9 mm, talar width 13.6 ± 2.2 mm, calcaneal width 15.8 ± 3.7 mm. The anterior capsular ligament (ACaL) and interosseous talocalcaneal ligament (ITCL) were found to be smaller structures with consistent dimensions and locations.

CONCLUSION This study identified consistent characteristics of the intrinsic subtalar ligaments and clarifies the local anatomical situation. The dimensions and footprints of the intrinsic ligaments of the subtalar joint suggest a more important role of the CL and ACaL in the stability of the subtalar joint. The results of this study are relevant to improve diagnostic tools and offer some guidelines when reconstructing the injured ligaments.

PRESENTATIES/ CONGRESSEN

ABSTRACT 1

Cone-beam CT as a fast and promising technique to assess the microstructure of distal radii in clinical practice.

25th Congress of the European Society of Biomechanics Mys K, Stockmans F, Vanovermeire O, et al. June 2019, Vienna, Austria

Er is geen abstract beschikbaar.

ABSTRACT 2

The anterior tibiotalar fat pad as a source of pain and inflammation in osteoarthritis of the ankle: anatomy, histology and imaging.

Osteoarthritis Research Society International (OARSI)

Clockaerts S

April 2019, Liverpool, United Kingdom

INTRODUCTION/BACKGROUND To gain a better insight in the pathophysiology of ankle osteoarthritis (OA), a pathology which is underrepresented in current and past research. The most important etiological factor in ankle OA is trauma (70-80% of cases), which can result in direct joint damage, malalignment, incongruency or instability. Despite successful conservative treatment or surgical intervention, many cases of ankle trauma evolve towards OA. Posttraumatic inflammation is hypothesized to be an important initiator of posttraumatic ankle OA. Pro-inflammatory mediators in the synovial fluid are elevated after injury, which may increase the imbalance between cartilage destruction and repair. In the knee, the infrapatellar fat pad is identified as an important source of inflammatory mediators. To date, the role of fatty tissues in the ankle joint has not been defined, although arthroscopic findings indicate the presence of adipose tissue anterior to the ankle joint.

MATERIALS/METHODS Three Tesla MRI scans (T1 and T2 sequences) were performed on 3 cadaveric human feet, which were obtained from the human body donation of the university. The anterior compartment of the ankle joint was dissected and the exact location of the anterior adipose tissue was documented. Histological analyses of the dissected fat pad were performed with hematoxyline eosine staining and immunohistochemistry for the inflammatory marker CD45 (leucocytes). The obtained histological sections were used to confirm structures seen during dissection and on MRI. To investigate the presence of inflammation in the anterior tibiotalar fat pad (ATTFP) of ankle joints, 30 ankle MRI scans of patients with chronic pain after trauma, OA, bone marrow oedema, persistent Achilles tendinopathy or fasciitis plantaris were scored for the presence of ankle pathology (including bone marrow oedema, effusion, synovitis, cartilage lesions, osteophytes, loose bodies). The presence of signal alteration in the adipose tissue on sagittal T2 sequences was scored as the number of slices showing signal alteration. Based on these scores, we categorized ankle pathology and signal alteration into: 0=no pathology, 1-2=mild, 3-5=moderate, >5=severe. Statistical analysis was performed with a Kruskal-Wallis test.

RESULTS We found adipose tissue to be present posterior to the extensor tendon sheaths, at the level of the ankle joint. It attaches to the periosteum of the tibia, 1 cm proximally to the joint line. It is mediolaterally delimited by the deltoid ligament and the anterior talofibular ligament. Anteromedially, it reaches as far as the neck of the talus. We defined it as the anterior tibiotalar fat pad (ATTFP). There is no joint capsule between the adipose tissue and the joint as determined macroscopically and microscopically. CD45+ cells were found in the ATTFP of cadaveric feet. On MRI, higher signal alterations were mainly present in the ATTFP in ankles with radiological presence of joint pathology, in particular in more severe cases (p=0.01).

CONCLUSION These results indicate that the ATTFP can be considered an active joint tissue in the ankle. The ATTFP should be investigated as a source of inflammation and pain.

ABSTRACT 3

Histologic characteristics of the arciform fibers (poster).

5th International Congress of Foot & Ankle Minimally Invasive Surgery Michels F, Batista J, Quintero D, et al. March 2019, Marrakech, Morocco

INTRODUCTION/BACKGROUND The arciform fibers are an expansion of the regular, colla-

genous and elastic dense connecting tissue, in the shape of a triangle or a semicircle, and an anteroinferior base, that connects the inferior band of the anterior talofibular ligament, and the calcaneofibular ligament, in a constant manner. These fibers play a critical role within the ankle’s lateral ligament complex.

OBJECTIVE The purpose of this study was to perform a study of the macroscopic and microscopic morphology of these arciform fibers.

MATERIALS/METHODS Ten lower leg cadaveric specimens were included in this study: 5 men, 5 women. Four specimens were fresh frozen, 6 embalmed. Anatomical dissection was performed to assess the presence of these arcuate fibers. After preparation, different histologic colourings were performed: Hematoxilin-eosin and Masson’s Trichrome.

RESULTS These are arciform fibers were present in all specimens. The histologic structure of these fibers was similar to the ligamentous structures, with an abundance of collagenous fibers, low adipose cell content, plus high vascular content.

CONCLUSION The arciform fibers have all characteristics of ligament tissue. This suggests an important mechanical function in the stability of the ankle.

ABSTRACT 4

How to drill the calcaneal tunnel in calcaneofibular ligament reconstruction?

5th International Congress of Foot & Ankle Minimally Invasive Surgery. Michels F, Wastyn H, Stockmans F, et al. March 2019, Marrakech, Morocco

INTRODUCTION/BACKGROUND Anatomical ankle ligament reconstruction has become a common procedure to treat chronic ankle instability. When performing an anatomical reconstruction of the calcaneofibular ligament(CFL), a graft is often fixed in bone tunnels. On the lateral side, the entrance should be at the normal anatomical insertion point. On the medial side, an transosseous bone tunnel should avoid the neurovascular bundle. The advent of new endoscopic and percutaneous techniques to perform this procedure increases the need for anatomical landmarks and guidelines.

OBJECTIVE The purpose of this study was to determine some guidelines for tunnel positioning based on external palpable anatomical landmarks.

MATERIALS/METHODS In ten lower leg cadaveric specimens a lateral and a medial procedure were performed. On the lateral side, a pin was drilled on the intersection of 2 lines based on external landmarks. The first line was parallel with the fibula passing through the posterior point of the lateral malleolus. The second line was placed at an angle of 45 degrees to the first one and passed through anteroinferior border of the fibula. During this procedure also a second pin was drilled(blinded to the earlier marked landmarks and pin) to assess the interobserver reliability. Dissection allowed to measure the distance to the anatomical foot print. The medial side was divided in four quadrants based on the upper posterior edge and the lower anterior edge of the tuber calcaneal tuberosity. Anatomical dissection was performed to assess the position of the neurovascular structures relative to the four quadrants.

RESULTS On the lateral side, the mean distance to the centre of the CFL footprint was 1.7 mm (0-11mm). The mean distance between both observers was 3.17 mm. The mean distance to the sural nerve was 1.7 mm. The mean distance to the peroneal tendons was 7.1 mm. On the medial side, a safe zone without important neurovascular structures was found and corresponded to the lower inner quadrant. The upper inner quadrant always contained the neurovascular bundle and thus should be avoided. In the upper outer and lower outer quadrants, sensory branches of the tibial nerve were found in a minority of the specimens.

CONCLUSION The described guidelines are useful when reconstructing the CFL using a less invasive technique. Lateral landmarks allowed to locate the CFL footprint. A medial safe zone could be determined to guide tunnel direction.

ABSTRACT 5

Distal metatarsal mini-invasive osteotomy (DMMO): a cadaveric study.

5th International Congress of Foot & Ankle Minimally Invasive Surgery Michels F, Clockaerts S, Stockmans F, et al. March 2019, Marrakech, Morocco

INTRODUCTION/BACKGROUND The distal metatarsal metaphyseal osteotomy (DMMO) is an extraarticular osteotomy performed using minimally invasive technique which may be a viable alternative to the weil osteotomy in treating metatarsalgia operatively.

OBJECTIVE The purpose of this study was to evaluate a percutaneous technique to perform an osteotomy of the central metatarsals.

MATERIALS/METHODS Ten lower extremity cadaveric specimens were used. An osteotomy of the second, third and fourth metatarsal was performed using a standardised technique. The technique was performed by a trained foot and ankle surgeon with experience in percutaneous foot surgery. The specimens were dissected to expose the local neurovascular structures. The specimens were assessed for macroscopic lesions of the digital nerves, the arteries and veins. In addition, the aspect of the osteotomy was assessed for completeness and orientation.

RESULTS In total 30 osteotomies were performed. The plantar and dorsal interdigital nerves were intact in all specimens. Digital arteries were exposed but no injuries were found. In 2 of the 10 specimens an injury of the dorsal veins were found. All osteotomies were complete and located in the metaphyseal area. The measured angle between the plane of the osteotomy and the metatarsal varied from 40 to 60 degrees.

CONCLUSION The described technique, which involves a percutaneous osteotomy of the central metatarsals is reproducible. The risk to macroscopic damage of the local neurovascular structures is low. ABSTRACT 6

Percutaneous treatment of a posterolateral calcaneal bump (Poster).

5th International Congress of Foot & Ankle Minimally Invasive Surgery

Michels F

March 2019, Marrakech, Morocco

INTRODUCTION/BACKGROUND Surgical treatment of exostoses of the heel is usually performed with open or endoscopic techniques. Endoscopic technique are valuable in case of a central prominence without damage of the achilles tendon. Open resection of the exostosis is related to wound healing problems and a longer rehabilitation period. Often the location of hyper pressure is limited to the lateral aspect of the heel.

OBJECTIVE The purpose of this study was to evaluate a percutaneous technique to perform a resection of a bump located on the posterolateral side of the calcaneum.

MATERIALS/METHODS Five patients with a bump located on the posterolateral side of the calcaneum were included in this study. All patients were resistant to non-surgical treatment(at least 6 months) which included shoe modification, orthosis, physiotherapy, and anti-inflammatory drugs. Pain was limited to the posterolateral border of the calcaneum without any signs of retrocalcaneal bursitis or achilles tendinopathy. The surgical management consisted of a percutaneous removal of the posterolateral bony ridge of the calcaneus. Using a Beaver blead and a periosteal elevator a working area was created. With burr (Wedge burr 3.1 x 13 mm) the bone of ridge was removed and washed out. The procedure was continued until a smooth surface is obtained.

RESULTS We treated 3 women and 2 men with an average age of 26. Surgery was performed between September 2014 and October 2017. All patients were followed up from 12 to 49 months (mean: 26 months). All surgery was performed in one day clinic under locoregional anaesthesia. Two days of rest and elevation was recommended. Normal walking was possible after 4 days. Local swelling continued until 5 weeks. No wound problems or other complications occurred. At final follow up all patients were without any complaints.

CONCLUSION Percutaneous resection of a posterolateral exostosis of the heel can be considered in patients with resisting pain limited to the posterolateral side of the heel.

ABSTRACT 7

Current concepts in the pathogenesis and diagnosis of subtalar instability.

5th International Congress of Foot & Ankle Minimally Invasive Surgery

Michels F

March 2019, Marrakech, Morocco

Er is geen abstract beschikbaar.

ABSTRACT 8

Postoperative treatment of toe deformities.

5th International Congress of Foot & Ankle Minimally Invasive Surgery

Michels F

March 2019, Marrakech, Morocco

Er is geen abstract beschikbaar.

ABSTRACT 9

Bunionette & quintus varus : results of a survey study.

5th International Congress of Foot & Ankle Minimally Invasive Surgery Michels F, Demeulenaere B March 2019, Marrakech, Morocco

Er is geen abstract beschikbaar.

ABSTRACT 10

Ankle instability: repair versus reconstruction.

5th International Congress of Foot & Ankle Minimally Invasive Surgery

Michels F

March 2019, Marrakech, Morocco

Er is geen abstract beschikbaar. ABSTRACT 11

How to optimize the fibular tunnel trajectory in a combined ATFL and CFL reconstruction.

5th International Congress of Foot & Ankle Minimally Invasive Surgery Michels F, Matricali G, Stockmans F March 2019, Marrakech, Morocco

Er is geen abstract beschikbaar.

ABSTRACT 12

Consensus in percutaneous bunionette correction.

5th International Congress of Foot & Ankle Minimally Invasive Surgery Michels F, Demeulenaere B March 2019, Marrakech, Morocco

INTRODUCTION/BACKGROUND The percutaneous treatment of bunionette deformity has been demonstrated as a reliable and satisfying technique with low risk of complications. However, there are some obvious variations in the surgical technique and perioperative protocol.

OBJECTIVE The purpose of this study is to analyze the currently used techniques and to look for some agreements. Hypothesis: There are some points of agreement in surgical technique and perioperative protocol when using a percutaneous technique to treat bunionette deformity.

MATERIALS/METHODS A survey was sent to 50 orthopedic surgeons with specific experience in percutaneous techniques. The questions were related to different aspects of the surgical bunionette procedure and the perioperative protocol.

RESULTS A response rate of 92.0 % was obtained. Several points of agreement were found. A condylectomy is rarely used while an osteotomy is performed in almost all procedures. This osteotomy is single (95.7%), complete (66.2-72.7%) and performed with a Shannon long burr (73.9%). The location of the osteotomy depends of the deformity (63.0%).

CONCLUSION This study demonstrates some consensus in the use of the surgical technique and the peri operative protocol. The per-

cutaneous oblique osteotomy is the preferred technique while a condylectomy is only rarely used.

ABSTRACT 13

An oblique fibular tunnel is recommended when reconstructing the ATFL and CFL.

5th International Congress of Foot & Ankle Minimally Invasive Surgery

Michels F

March 2019, Marrackech, Morocco

Het abstract is terug te vinden op pagina 55.

ABSTRACT 14

Postoperative treatment of toe deformities.

5th International Congress of Foot & Ankle Minimally Invasive Surgery

Michels F

March 2019, Marrakech, Morocco

INTRODUCTION/BACKGROUND In percutaneous surgery the bandage techniques are as important as the surgery. We should see them actually as a part of the surgical technique. For this reason, it is important that the surgeon himself(or herself) applies the bandage.

MATERIALS/METHODS There exist different bandage techniques. This allows you to choose the best technique depending of the situation. One should be aware of the preoperative situation and the performed corrections. Often the bandage techniques should be modified to the surgical technique, the deformity and obtained correction. I will present you some commonly used techniques.

RESULTS Elastic tapings using kinesiotape can be very helpful. Because of the stretching capacities they all can put stress on special areas which allows a secondary correction. Often the toes need to be hold in a bended position.

CONCLUSION The surgeon himself/or herself should apply the bandage and be able tot use different techniques. The bandage should be adapted to the corrected deformity.