Showing papers by "Victor Valderrabano published in 2013"
TL;DR: While the midterm to short-term results for patients managed with the STAR prosthesis have been encouraging at 3.7 years, the long-term survivorship of the same cohort was considerably inferior.
Abstract: The prosthesis discussed in this study was never made available in the U.S., and the manufacturer discontinued the use of this particular implant in favor of the titanium-spray design. This is discussed in an exchange between two of the authors and a reader in letters published as a data supplement attached to this article.
Background: The objective of this study was to determine the long-term survivorship and clinical and radiographic results of the Scandinavian Total Ankle Replacement (STAR).
Methods: From February 1996 to March 2000, seventy-seven ankles in seventy-two patients (thirty-seven female and thirty-five male patients, with an average age of fifty-six years) underwent total ankle replacement using the STAR prosthesis with a single coating of hydroxyapatite. Two patients were lost to follow-up, and twelve patients with thirteen ankle replacements died. The average duration of follow-up for the patients without revision was 12.4 years (range, 10.8 to 14.9 years). Sixty-two of the seventy-seven ankles were available for final follow-up.
Results: Twenty-nine (38%) of the seventy-seven ankles had a revision of at least one of the metallic components. The probability of implant survival was 70.7% at ten years and 45.6% at fourteen years. The main reasons for revision were aseptic loosening, subsidence of the talar component, and progressive cyst formation. Polyethylene insert fractures were observed in eleven ankles.
Conclusions: While the midterm to short-term results for patients managed with the STAR prosthesis have been encouraging at 3.7 years, the long-term survivorship of the same cohort was considerably inferior. The subjective and clinical results of the patients with retained prostheses are generally good and comparable with results reported in the current literature.
Level of Evidence: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.
173 citations
TL;DR: The modified AMIC procedure is safe for the treatment of OCLs in the ankle with overall good clinical and MRI results and normal signal intensity of the repair tissue compared with the adjacent native cartilage was seen.
Abstract: Background:Osteochondral lesions (OCLs) of the talus are a common entity in sports orthopaedics. There are several operative techniques with a good outcome on follow-up examinations. However, limitations such as sacrificing healthy cartilage (osteochondral autograft transfer system [OATS], mosaicplasty), multiple-stage operative procedures (matrix-induced autologous chondrocyte transplantation [MACI], autologous chondrocyte implantation [ACI]), high costs (ACI, allograft), and limited availability (allograft) do remain and reflect potential drawbacks of the currently used techniques.Purpose:To describe a novel operative technique for the treatment of OCLs of the talus in the form of an economically efficient, 1-step procedure combining OCL debridement, spongiosaplasty, and sealing of the OCL area with a collagen matrix.Study Design:Case series; Level of evidence, 4.Methods:Twenty-six patients underwent surgery receiving a modified autologous matrix-induced chondrogenesis (AMIC)–aided repair of OCLs of the...
155 citations
TL;DR: The onset and development of posttraumatic ankle OA is described, the most common form of OA in the tibiotalar joint, and various methods of clinical and radiographic assessment are described in detail.
Abstract: Osteoarthritis (OA) is defined as the syndrome of joint pain and dysfunction caused by substantial joint degeneration. In general, OA is the most common joint disease and is one of the most frequent and symptomatic health problems for middle-aged and older people: OA disables more than 10% of people who are older than 60 years. This article reviews the etiology of ankle OA, and describes the onset and development of posttraumatic ankle OA, the most common form of OA in the tibiotalar joint. Various methods of clinical and radiographic assessment are described in detail.
141 citations
TL;DR: A discreet number of YouTube videos on knee arthrocentesis appeared to be suitable for application in a Web-based format for medical students, fellows, and residents, but the low-average mean global score for overall educational value suggests an improvement of future video-based instructional materials on YouTube would be necessary before regular use for teaching could be recommended.
Abstract: BACKGROUND: Knee arthrocentesis is a commonly performed diagnostic and therapeutic procedure in rheumatology and orthopedic surgery. Classic teaching of arthrocentesis skills relies on hands-on practice under supervision. Video-based online teaching is an increasingly utilized educational tool in higher and clinical education. YouTube is a popular video-sharing Web site that can be accessed as a teaching source. OBJECTIVE: The objective of this study was to assess the educational value of YouTube videos on knee arthrocentesis posted by health professionals and institutions during the period from 2008 to 2012. METHODS: The YouTube video database was systematically searched using 5 search terms related to knee arthrocentesis. Two independent clinical reviewers assessed videos for procedural technique and educational value using a 5-point global score, ranging from 1 = poor quality to 5 = excellent educational quality. As validated international guidelines are lacking, we used the guidelines of the Swiss Society of Rheumatology as criterion standard for the procedure. RESULTS: Of more than thousand findings, 13 videos met the inclusion criteria. Of those, 2 contained additional animated video material: one was purely animated, and one was a check list. The average length was 3.31 +/- 2.28 minutes. The most popular video had 1388 hits per month. Our mean global score for educational value was 3.1 +/- 1.0. Eight videos (62 %) were considered useful for teaching purposes. Use of a "no-touch" procedure, meaning that once disinfected the skin remains untouched before needle penetration, was present in all videos. Six videos (46%) demonstrated full sterile conditions. There was no clear preference of a medial (n = 8) versus lateral (n = 5) approach. CONCLUSIONS: A discreet number of YouTube videos on knee arthrocentesis appeared to be suitable for application in a Web-based format for medical students, fellows, and residents. The low-average mean global score for over educational value suggests an improvement of future video-based instructional materials on YouTube would be necessary before regular use for teaching could be recommended.
108 citations
TL;DR: The current best evidence does not support the superiority of surgical intervention over conservative treatment in an acute patellar dislocation, but reconstruction of the medial patellofemoral ligament is the most effective treatment option and can be done safely, together with extensor realignment as needed.
Abstract: Purpose The purpose of this study was to comprehensively and systematically review the current evidence for orthopaedic treatment of immature and adolescent patients with acute and chronic patellar instability. Methods We searched the online databases PubMed, CINAHL, EMBASE, Cochrane Central Register of Controlled Trials, and Cochrane Database of Systematic Reviews for relevant publications on patellar instability. All dates and languages were included. Results Twenty articles reporting on a total of 456 knees in 425 patients (131 male patients, 294 female patients) followed-up for 56.7 ± 42.2 months on average were included in the analysis. Two studies focused specifically on conservative versus surgical treatment in acute dislocations and reported no difference in outcomes after 7 and 14 years, even in the face of slight trochlear dysplasia. For recurrent instability, we found consistent beneficial effects from surgical stabilization on clinical scores, postoperative stability, and radiographic assessment. There is no evidence for growth disturbance with surgical patellar stabilization in immature patients. Conclusions The current best evidence does not support the superiority of surgical intervention over conservative treatment in an acute patellar dislocation. However, anatomic variations and their effect on healing should be considered and included in decision making. In recurrent patellar instability in pediatric and adolescent patients with normal or restored knee anatomy, reconstruction of the medial patellofemoral ligament (MPFL) is the most effective treatment option and can be done safely, together with extensor realignment as needed. Level of Evidence Level IV, systematic review of mixed-level studies.
91 citations
TL;DR: Cross-sectional area and maximum calf circumference are cost-effective measurements and a good approximation of muscle volume and can thus be used in a clinical setting while clinical dorsiflexion should not be used.
Abstract: The best treatment for Achilles tendon (AT) ruptures remains controversial. Long-term follow-up with radiological and clinical measurements is needed. In this retrospective multicentre cohort study, patients (n = 52) were assessed at a mean of 91 months follow-up after unilateral AT rupture treated by open, percutaneous or conservative (non-surgical) treatment. Demographic parameters, time off work, maximum calf circumference and clinical scores (ATRS, Hannover, AOFAS) were evaluated. Muscle volume and cross-sectional area of the calf and AT length were measured on MR images and were compared between groups and to each patient’s healthy contralateral leg. Reduced muscle volume was found across all groups with a higher muscle volume in the conservative (729.9 ± 130.3 cm3) compared to the percutaneous group (675.9 ± 207.4 cm3, p = 0.04). AT length was longer in the affected leg (198.4 ± 24.1 vs. 180.6 ± 25.0 mm, p < 0.0001) without difference in subgroup analysis. Clinically measured ankle dorsiflexion showed poor correlation with AT length (R
2 = 0.07, p = 0.008). Muscle volume strongly correlated with the cross-sectional area (R
2 = 0.6, p < 0.0001) but showed a weak correlation with the Hannover score (R
2 = 0.08, p = 0.048). Maximum calf circumference correlated with muscle volume (R
2 = 0.42, p < 0.0001). No significant difference between the treatment groups was found in muscle volume, AT length, clinical measures or days off work. Cross-sectional area and maximum calf circumference are cost-effective measurements and a good approximation of muscle volume and can thus be used in a clinical setting while clinical dorsiflexion should not be used. III.
73 citations
TL;DR: The short- and midterm results following realignment surgery of the ankle joint are very promising with substantial pain relief and functional improvement observed post-operatively.
Abstract: Patients with varus or valgus hindfoot deformities usually present with asymmetric ankle osteoarthritis. In-vitro biomechanical studies have shown that varus or valgus hindfoot deformity may lead to altered load distribution in the tibiotalar joint which may result in medial (varus) or lateral (valgus) tibiotalar joint degeneration in the short or medium term. The treatment of asymmetric ankle osteoarthritis remains challenging, because more than half of the tibiotalar joint surface is usually preserved. Therefore, joint-sacrificing procedures like total ankle replacement or ankle arthrodesis may not be the most appropriate treatment options. The short- and midterm results following realignment surgery, are very promising with substantial pain relief and functional improvement observed post-operatively. In this review article we describe the indications, surgical techniques, and results from of realignment surgery of the ankle joint in the current literature.
70 citations
TL;DR: Evidence is produced that pegged glenoid components were associated with a lower revision risk compared with keeled components, which will therefore be most meaningful to high-volume shoulder arthroplasty centers.
Abstract: Background: The objective of this study was to conduct a meta-analysis and cost-effectiveness analysis of the effect of glenoid design on radiolucency, loosening, and revision after total shoulder arthroplasty.
Methods: We conducted a systematic review of PubMed, MEDLINE, Embase, the Cochrane Central Register of Controlled Trials, and CINAHL with use of a search for the terms arthroplasty AND shoulder AND (peg OR keel). Data on study design and on the end points of radiolucency, loosening, and revision were extracted independently and in duplicate. Random-effect models were used to calculate the pooled risk ratio and risk difference. The risk difference was used to estimate the number needed to treat (the number of individuals who would have to receive a pegged component to avoid one loosening or revision).
Results: Eight studies with a total of 1460 patients (mean age, sixty-seven years) were included. The mean study quality was 1.75 points (95% confidence interval [CI], 1.26 to 2.24) on the 3-point modified Jadad scale. There was no significant difference in the risk of any radiolucency (risk ratio, 0.42; 95% CI, 0.12 to 1.42) or in the risk of severe radiolucency (risk ratio, 0.65; 95% CI, 0.23 to 1.82) between pegged and keeled components. The pooled risk ratio for revision was 0.27 (95% CI, 0.08 to 0.88) in favor of pegged components (p = 0.028). At a cost-effectiveness threshold of $50,000 per quality-adjusted life year, pegged components can be between $2325 and $40,920 more expensive than keeled components and still be cost-effective.
Conclusions: Our study produced evidence that pegged glenoid components were associated with a lower revision risk compared with keeled components. However, the difference was rather small and will therefore be most meaningful to high-volume shoulder arthroplasty centers. Because of the similarity between primary and secondary costs, pegged glenoid designs were more cost-effective than keeled glenoid designs.
Level of Evidence: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.
66 citations
TL;DR: Evidence in support of a statistically significant effect of platelet concentrates in the treatment of Achilles tendon ruptures in vivo in animal models and human application, consistent with a medium to large sized effect is found.
63 citations
TL;DR: The results of the present review suggest that a solid intramedullary bolt provides reasonable fixation for realignment of the medial column in cases of Charcot neuroarthropathy.
Abstract: Charcot medial column and midfoot deformities are associated with rocker bottom foot, recurrent plantar ulceration, and consequent infection. The primary goal of surgical intervention is to realign and stabilize the plantar arch in a shoe-able, plantigrade alignment. Different fixation devices, including screws, plates, and external fixators, can be used to stabilize the Charcot foot; however, each of these methods has substantial disadvantages. To assess the effectiveness of rigid, minimally invasive fixation of the medial column and midfoot, 8 cases of solid intramedullary bolt fixation for symptomatic Charcot neuroarthropathy were reviewed. The patients included 6 males (75%) and 2 females (25%), with a mean age of 63 (range 46 to 80) years. The Charcot foot deformity was caused by diabetic neuropathy in 7 cases (87.5%) and alcoholic neuropathy in 1 (12.5%). The mean duration of postoperative follow-up period was 27 (range 12 to 44) months. The mean radiographic correction of the lateral talar–first metatarsal angle was 15° (range 3° to 19°), and the mean radiographic correction of the dorsal midfoot dislocation was 9 (range −4 to 23) mm. The mean loss of correction of the lateral talar–first metatarsal angle and midfoot dislocation after surgery was 7° (range 0° to 26°) and 1 (range 0 to 7) mm, respectively. No bolt breakage was observed, and no cases of recurrent or residual ulceration occurred during the observation period. Bolt removal was performed in 3 cases (37.5%), 2 (25%) because of axial migration of the bolt into the ankle joint and 1 (12.5%) because of infection. The results of the present review suggest that a solid intramedullary bolt provides reasonable fixation for realignment of the medial column in cases of Charcot neuroarthropathy.
54 citations
TL;DR: Chondrocyte death and Mankin Scores were significantly increased in the loaded joints, thereby linking muscular exercise of physiologic magnitude but excessive intensity to cartilage degeneration and cell death in the rabbit knee.
TL;DR: The current evidence strongly supports the use of static-progressive stretching 3 times 30 minutes per day in each direction as a first line of treatment in patients with post-traumatic and postsurgical elbow stiffness.
TL;DR: The authors' algorithm for the treatment of patients with asymmetric valgus ankle OA is described, which suggests joint-preserving realignment surgery to unload the degenerated lateral area and normalize joint biomechanics.
Abstract: Patients with posttraumatic ankle osteoarthritis (OA) typically present with asymmetric involvement of the tibiotalar joint, resulting in valgus or varus deformity of the ankle and hindfoot. Without appropriate treatment, patients with asymmetric ankle OA typically develop full end-stage ankle OA. Ankles with valgus deformities suffer from a lateral joint overload with subsequent lateral tibiotalar joint degeneration, which causes further lateral load shift. In these cases patients may benefit from joint-preserving realignment surgery to unload the degenerated lateral area and normalize joint biomechanics. This article describes the authors' algorithm for the treatment of patients with asymmetric valgus ankle OA.
TL;DR: The results suggest an equivalent incorporation of structural allografts as compared to autologous grafts in hindfoot arthrodeses and osteotomies in hind foot surgery.
Abstract: Structural and non-structural substitutes of autologous bone grafts are frequently used in hindfoot arthrodeses and osteotomies. However, their efficacy is unclear. The primary goal of this systematic review was to compare autologous bone grafts with structural and non-structural substitutes regarding the odds of union in hindfoot arthrodeses and osteotomies. The Medline and EMBASE and Cochrane databases were searched for relevant randomized and non-randomized prospective studies as well as retrospective comparative chart reviews. 10 studies which comprised 928 hindfoot arthrodeses and osteotomies met the inclusion criteria for this systematic review. The quality of the retrieved studies was low due to small samples sizes and confounding variables. The pooled random effect odds for union were 12.8 (95% CI 12.7 to 12.9) for structural allografts, 5.7 (95% CI 5.5 to 6.0) for cortical autologous grafts, 7.3 (95% CI 6.0 to 8.6) for cancellous allografts and 6.0 (95% CI 5.7 to 6.4) for cancellous autologous grafts. In individual studies, the odds of union in hindfoot arthrodeses achieved with cancellous autologous grafts was similar to those achieved with demineralised bone matrix or platelet derived growth factor augmented ceramic granules. Our results suggest an equivalent incorporation of structural allografts as compared to autologous grafts in hindfoot arthrodeses and osteotomies. There is a need for prospective randomized trials to further clarify the role of substitutes of autologous bone grafts in hindfoot surgery.
TL;DR: The commonly used methods for cartilage and osteochondral repair and new upcoming methods are discussed, plus the role of concomitant disorders of the ankle joint is discussed.
Abstract: Local cartilage or osteochondral degeneration of the ankle are common, painful posttraumatic conditions in young, sport-active patients. Conservative treatment of the acute initial stage of local cartilage or osteochondral damage might be indicated, but commonly fails in the presence of local or asymmetric osteoarthritic disease. Many surgical treatment methods are available for the orthopedic surgeon, which show satisfactory short-term to mid-term results. However, the scientific evidence for these procedures is weak. This article discusses the commonly used methods for cartilage and osteochondral repair and new upcoming methods, plus the role of concomitant disorders of the ankle joint.
TL;DR: In this study the indications for different forms of osteotomy are discussed and the surgical techniques are described.
Abstract: Bei der Behandlung osteochondraler Lasionen am oberen Sprunggelenk stehen sowohl arthroskopische als auch offene Therapieverfahren zur Verfugung. Die Osteotomien rund um das obere Sprunggelenk haben sich als Zugangserweiterung bei der Behandlung weiter posterior gelegener osteochondraler Lasionen fest etabliert. Bei den relativ haufig anzutreffenden osteochondralen Lasionen im Bereich der medialen Talusschulter wird die mediale, schrage, monoplanare Knochelosteotomie durchgefuhrt. Bei den weniger haufigen posterolateralen osteochondralen Lasionen kann die distale Fibulaosteotomie erfolgen. In der vorliegenden Arbeit werden die Indikationen fur einzelne Osteotomieverfahren diskutiert und deren chirurgische Techniken beschrieben.
TL;DR: Thorough understanding of the osteochondral unit of the ankle joint could be helpful for clinicians and researchers in the development of improved operative repair techniques for osteochondrals in elderly people, for example, in constructing specific tissue-engineered oste mitochondral plugs.
Abstract: Background:The specific morphological and biomechanical characteristics of the osteochondral unit of the ankle joint are not yet fully understood. This anatomical study aimed to map regional thickness of the articular hyaline uncalcified cartilage and its adjacent layers of mineralized cartilage and subchondral bone as well as to measure the regional indentation stiffness of human ankle joint cartilage.Materials and Methods:A total of 20 pairs of human cadaver ankle joints (median age: 78 years) were evaluated by histomorphometry and multidetector row double-contrast CT arthrography for cartilage thickness in 17 distinct anatomical regions. In addition, regional distribution of the subchondral bone plate and of the mineralized cartilage was scrutinized histologically. Cartilage indentation stiffness was measured using an arthroscopic handheld device (Artscan200), especially validated for use in thin cartilage. The correlation between the thickness of different components of the osteochondral unit and the ...
TL;DR: Dieser Artikel fokussiert auf die Atiologie and Biomechanik der Arthrose des oberen Sprunggelenks sowie den Beginn and das Fortschreiten speziell der posttraumatischen Arth rose vom oberenSprunggELenk – der haufigsten Entitat derArthrose im tibiotalaren Gelenk.
TL;DR: The literature addressing functional outcome and survivorship of prosthesis components is constantly growing, however, the data on thromboprophylaxis and thromBembolic complications in patients who underwent TAR are scarce.
Abstract: The literature addressing functional outcome and survivorship of prosthesis components is constantly growing. However, the data on thromboprophylaxis and thrombembolic complications in patients who underwent TAR are scarce. A total of 31 studies were included in the systemic literature review. The incidence of thrombembolic complications varied between 0.0 % and 9.8 %. Most commonly, low molecular weight heparin was used as thromboprophylaxis for 6 weeks postoperatively. The incidence of thrombembolic complications was comparable with that of symptomatic deep vein thrombosis in patients with total knee or hip replacement.
TL;DR: The short-term and mid-term results after realignment surgery are very promising with substantial pain relief and functional improvement observed postoperatively, and the experience with supramalleolar realignment Surgery in patients with asymmetric varus or valgus ankle osteoarthritis is described.
Abstract: Asymmetric ankle osteoarthritis (OA) may develop in patients with varus or valgus deformities. Pathologically altered load distribution in the tibiotalar joint leads to medial (varus) or lateral (valgus) tibiotalar joint degeneration. However, as more than half of the tibiotalar joint surface remains preserved, joint sacrificing procedures including total ankle replacement or ankle arthrodesis may not be the most appropriate treatment options. The short-term and mid-term results after realignment surgery, published in the current literature, are very promising with substantial pain relief and functional improvement observed postoperatively. Herein we describe our experience with supramalleolar realignment surgery in patients with asymmetric varus or valgus ankle osteoarthritis.
TL;DR: Overall implant subsidence was significantly increased for the two separate unicondylar tibial baseplates versus the new Transversal Support Tibial Plateau concept, which showed comparable levels to a conventional tibIAL baseplate.
TL;DR: The results of this study suggest that the increasing muscular forces are transferred through an increased contact area, thereby limiting the increase in average contact pressure.
08 Mar 2013
TL;DR: Für die Planung der Therapie sollten der Schweregrad der Gelenkveränderungen, die klinischen and radiologischen Befunde sowie the Gesamtzustand des Patienten berücksichtigt werden.
Abstract: Unter den Gelenkarthrosen nimmt die Arthrose des oberen Sprunggelenks (OSG) in gewisser Weise eine Sonderstellung ein: Denn anders als etwa die Gon- oder Coxarthrose ist die OSG-Arthrose am haufigsten Spatfolge eines vorangegangenen Traumas. Fur die Planung der Therapie sollten der Schweregrad der Gelenkveranderungen, die klinischen und radiologischen Befunde sowie der Gesamtzustand des Patienten berucksichtigt werden.
TL;DR: In this paper, a literaturreview with folgenden Fragestellungen durchgefuhrt: Thrombembolieprophylaxe und Inzidenz der postoperativen thrombose/Embolie nach endoprothetischem Ersatz des OSG.
Abstract: Einleitung
Der endoprothetische Ersatz des oberen Sprunggelenks (OSG) wird zunehmend als therapeutische Option bei Patienten mit fortgeschrittenen degenerativen Veranderungen des OSG angewendet. Es gibt jedoch wenige Angaben in der aktuellen Literatur uber die Inzidenz der thrombembolischen Komplikationen. Aus diesem Grund haben wir eine Literaturreview mit folgenden Fragestellungen durchgefuhrt: Thrombembolieprophylaxe und Inzidenz der postoperativen Thrombose/Embolie nach endoprothetischem Ersatz des OSG. Auserdem haben wir die Inzidenz thrombembolischer Komplikationen in unserem Patientenkollektiv evaluiert.
TL;DR: The most common cause of ankle osteoarthritis (OA) is posttraumatic, with around 80% of all cases, followed by primary and secondary ankle OA, and severe deformity of the pes planovalgus in patients with valgus OA or severe cavovarus deformity in patietns with varusOA is seen.
Abstract: Introduction: The most common cause of ankle osteoarthritis (OA) is posttraumatic, with around 80% of all cases, followed by primary and secondary ankle OA. Patients often present wit asymmetric involvement of the tibiotalar joint, resulting in valgus or varus deformity of the ankle and hindfoot. The etiology of asymmetric arthritic ankles can be divided into 2 main etiologic and morphologic groups. The primary form of asymmetric ankle OA is characterized by severe deformity of the pes planovalgus, with insufficiency of the medial ligaments and end-stage tibial tendon dysfunction (Grade IV using the Myerson classification) in patients with valgus OA or severe cavovarus deformity in patietns with varus OA. The second important etiologic category of asymmetric ankle OA is posttraumatic. Severe ankle fractures with valgus or varus impacted tibial plafond may end up in posttraumatic ankle OA. Furthermore, patients with malunited fibula fracture with shortened and externally rotated fibula may present with asymmetric valgus ankle OA.
TL;DR: Mit zunehmendem Einsatz dieser Therapieoption bei Patienten mit fortgeschrittener Arthrose des oberen Sprunggelenks steigt jedoch die Zahl von gescheiterten Endoprothesen.
TL;DR: Theoretisch veranderte Belastung ubertragt sich in das tibiotalare Gelenk und kann dort zu einer medialen (Varus-) oder lateralen (Valgus-) Degeneration fuhren.
TL;DR: In this article, the haufigste Atiologie der degenerativen Veranderungen des oberen Sprunggelenks is described.Zusammenfassung
01 Jan 2013
TL;DR: This data indicates that pre- and post-operative treatment with corticosteroids may improve the prognosis for knee and hip replacement in women with anterior cruciate ligament damage.
Abstract: Center for Advanced Orthopaedic Studies,Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, RN 115,Boston, MA 02215, USA* Corresponding authors. Orthopaedic Department, Osteoarthritis Research Center Basel,University Hospital of Basel, University of Basel, Spitalstrasse 21, Basel CH-4031, Switzerland.E-mail addresses: victor.valderrabano@usb.ch; alexej.barg@usb.ch