Stéphane Pelet

Novel Scaffold-Based BST-CarGel Treatment Results in Superior Cartilage Repair Compared with Microfracture in a Randomized Controlled Trial

BACKGROUND Microfracture, the standard of care, is recognized to be an incomplete solution for cartilage damage. BST-CarGel, a chitosan-based medical device, is mixed with autologous whole blood and is applied to a microfractured cartilage lesion in which it physically stabilizes the clot and guides and enhances marrow-derived repair. An international, multicenter, randomized controlled trial was conducted to evaluate BST-CarGel treatment compared with microfracture alone in the repair of cartilage lesions in the knee. METHODS Eighty patients between the ages of eighteen and fifty-five years with a single, symptomatic focal lesion on the femoral condyles were randomized to BST-CarGel and microfracture treatment (n = 41) or microfracture treatment alone (n = 39). The primary end points of repair tissue quantity and quality at twelve months were assessed by quantitative three-dimensional magnetic resonance imaging measuring the degree of lesion filling and T2 relaxation time with use of standardized one and twelve-month posttreatment scans. The secondary end point at twelve months was clinical benefit determined with the Western Ontario and McMaster Universities Osteoarthritis Index. The tertiary end point was quality of life determined by the Short Form-36. Safety was assessed through the recording of adverse events. RESULTS Patient baseline characteristics were similar in the two groups, although baseline lesion areas were slightly larger on quantitative magnetic resonance imaging for the BST-CarGel group compared with the microfracture group. Blinded quantitative magnetic resonance imaging analysis demonstrated that, at twelve months, when compared with microfracture treatment alone, BST-CarGel treatment met both primary end points by achieving statistical superiority for greater lesion filling (p = 0.011) and more hyaline cartilage-like T2 values (p = 0.033). The lesion filling values were 92.8% ± 2.0% for the BST-CarGel treatment group and 85.2% ± 2.1% for the microfracture treatment group, and the mean T2 values were 70.5 ± 4.5 ms for the BST-CarGel treatment group and 85.0 ± 4.9 ms for the microfracture treatment group. Western Ontario and McMaster Universities Osteoarthritis Index subscales for pain, stiffness, and function yielded equivalent improvement for both groups at twelve months, which were significant (p < 0.0001) from baseline. Treatment safety profiles were considered comparable. CONCLUSIONS At twelve months, BST-CarGel treatment resulted in greater lesion filling and superior repair tissue quality compared with microfracture treatment alone. Clinical benefit was equivalent between groups at twelve months, and safety was similar.

Aspirin versus low-molecular-weight heparin for extended venous thromboembolism prophylaxis after total hip arthroplasty: a randomized trial.

BACKGROUND The role of aspirin in thromboprophylaxis after total hip arthroplasty (THA) is controversial. OBJECTIVE To compare extended prophylaxis with aspirin and dalteparin for prevention of symptomatic venous thromboembolism (VTE) after THA. DESIGN Multicenter randomized, controlled trial with a noninferiority design based on a minimal clinically important difference of 2.0%. Randomization was electronically generated; patients were assigned to a treatment group through a Web-based program. Patients, physicians, study coordinators, health care team members, outcome adjudicators, and data analysts were blinded to interventions. (Current Controlled Trials: ISRCTN11902170). SETTING 12 tertiary care orthopedic referral centers in Canada. PATIENTS 778 patients who had elective unilateral THA between 2007 and 2010. INTERVENTION After an initial 10 days of dalteparin prophylaxis after elective THA, patients were randomly assigned to 28 days of dalteparin (n = 400) or aspirin (n = 386). MEASUREMENTS Symptomatic VTE confirmed by objective testing (primary efficacy outcome) and bleeding. RESULTS Five of 398 patients (1.3%) randomly assigned to dalteparin and 1 of 380 (0.3%) randomly assigned to aspirin had VTE (absolute difference, 1.0 percentage point [95% CI, -0.5 to 2.5 percentage points]). Aspirin was noninferior (P < 0.001) but not superior (P = 0.22) to dalteparin. Clinically significant bleeding occurred in 5 patients (1.3%) receiving dalteparin and 2 (0.5%) receiving aspirin. The absolute between-group difference in a composite of all VTE and clinically significant bleeding events was 1.7 percentage points (CI, -0.3 to 3.8 percentage points; P = 0.091) in favor of aspirin. LIMITATION The study was halted prematurely because of difficulty with patient recruitment. CONCLUSION Extended prophylaxis for 28 days with aspirin was noninferior to and as safe as dalteparin for the prevention of VTE after THA in patients who initially received dalteparin for 10 days. Given its low cost and greater convenience, aspirin may be considered a reasonable alternative for extended thromboprophylaxis after THA. PRIMARY FUNDING SOURCE Canadian Institutes of Health Research.

BST-CarGel® Treatment Maintains Cartilage Repair Superiority over Microfracture at 5 Years in a Multicenter Randomized Controlled Trial

Objective The efficacy and safety of BST-CarGel®, a chitosan scaffold for cartilage repair was compared with microfracture alone at 1 year during a multicenter randomized controlled trial in the knee. This report was undertaken to investigate 5-year structural and clinical outcomes. Design The international randomized controlled trial enrolled 80 patients, aged 18 to 55 years, with grade III or IV focal lesions on the femoral condyles. Patients were randomized to receive BST-CarGel® treatment or microfracture alone, and followed standardized 12-week rehabilitation. Co-primary endpoints of repair tissue quantity and quality were evaluated by 3-dimensional MRI quantification of the degree of lesion filling (%) and T2 relaxation times. Secondary endpoints were clinical benefit measured with WOMAC (Western Ontario and McMaster Universities Osteoarthritis Index) questionnaires and safety. General estimating equations were used for longitudinal statistical analysis of repeated measures. Results Blinded MRI analysis demonstrated that BST-CarGel®-treated patients showed a significantly greater treatment effect for lesion filling (P = 0.017) over 5 years compared with microfracture alone. A significantly greater treatment effect for BST-CarGel® was also found for repair tissue T2 relaxation times (P = 0.026), which were closer to native cartilage compared to the microfracture group. BST-CarGel® and microfracture groups showed highly significant improvement at 5 years from pretreatment baseline for each WOMAC subscale (P < 0.0001), and there were no differences between the treatment groups. Safety was comparable for both groups. Conclusions BST-CarGel® was shown to be an effective mid-term cartilage repair treatment. At 5 years, BST-CarGel® treatment resulted in sustained and significantly superior repair tissue quantity and quality over microfracture alone. Clinical benefit following BST-CarGel® and microfracture treatment were highly significant over baseline levels.

A prospective randomized multicenter trial comparing clinical outcomes of patients treated surgically with a static or dynamic implant for acute ankle syndesmosis rupture.

Objectives: To compare the clinical and radiographic outcome after stabilization of an acute syndesmosis rupture with either a static implant (a 3.5-mm metallic screw through 4 cortices) or a dynamic device (TightRope; Arthrex). Design: Multicenter randomized double-blind controlled trial. Settings: Study realized in 5 trauma centers (2 level 1 and 3 level 2) in 2 countries. Patients/Participants: Seventy subjects admitted for an acute ankle syndesmosis rupture entered the study and were randomized into 2 groups (dynamic fixation = 34 and static fixation = 36). The 2 groups were similar regarding demographic, social, and surgical data. Sixty-five patients (dynamic = 33 and static = 32) completed the study and were available for analysis. Intervention: Syndesmosis fixation in the static group was realized with a 4 cortices 3.5-mm cortical screw (Synthes) and in the dynamic group with 1 TightRope (Arthrex). Standardized rehabilitation process for the 2 groups: no weight bearing in a cast for 6 weeks and then rehabilitation without protection. Main Outcome Measurement: Olerud–Molander score. Results: Subjects with dynamic fixation achieved better clinical performances as described with the Olerud–Molander scores at 3 (68.8 vs. 60.2, P = 0.067), 6 (84.2 vs. 76.8, P = 0.082), and 12 months (93.3 vs. 87.6, P = 0.046). We also observed higher American Orthopaedic Foot and Ankle Society scores at 3 months (78.6 vs. 70.6, P = 0.016), but these were not significant at 6 (87.1 vs. 83.8, P = 0.26) or 12 months (93.1 vs. 89.9, P = 0.26). Implant failure was higher in the screw group (36.1% vs. 0%, P < 0.05). Loss of reduction was observed in 4 cases in the static screw group (11.1% vs. 0%, P = 0.06). Conclusions: Dynamic fixation of acute ankle syndesmosis rupture with a dynamic device seems to result in better clinical and radiographic outcomes. The implant offers adequate syndesmotic stabilization without failure or loss of reduction, and the reoperation rate is significantly lower than with conventional screw fixation. Level of Evidence: Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

The Incidence of Thromboembolic Events in Surgically Treated Ankle Fracture

BACKGROUND Thromboembolic events occur following musculoskeletal injury, and some have serious sequelae, including death. The purpose of this study was to determine the incidence of thromboembolic events and its relationship with risk factors in ambulatory patients with ankle fracture requiring open reduction and internal fixation. METHODS We conducted a retrospective chart review of 2478 patients who underwent open reduction and internal fixation of an ankle fracture at any one of three university hospitals between January 1, 1997, and April 30, 2005. One thousand five hundred and forty patients meeting the inclusion criteria and with complete records (minimum follow-up, six months) were identified. The median age of the patients at the time of surgery was forty-six years, and there was an equal proportion of male and female patients. Fracture types included 45% unimalleolar fractures, 31% bimalleolar, and 24% trimalleolar. Charts were reviewed to identify thromboembolic events, risk factors (neoplasia, hormone use, pregnancy, blood dyscrasia, history of a previous thromboembolic event, a current history of smoking, obesity, dyslipidemia, atherosclerotic vascular disease, or paralysis), and use of thromboprophylactic agents. A thromboembolic event was defined as symptomatic when deep venous thrombosis was confirmed with use of Doppler ultrasonography or when pulmonary embolism was confirmed with use of ventilation and perfusion scintigraphy or helical computed tomography. RESULTS The incidence of thromboembolic events was 2.99% (forty-six patients), with 2.66% (forty-one patients) involving a deep venous thrombosis and 0.32% (five patients) involving a nonfatal pulmonary embolism. There were no fatal pulmonary emboli recorded. The incidence did not differ among hospitals. Of the 1540 patients, 16.43% received thromboprophylaxis during their hospital stay and for six weeks (for the 10.78% taking low-molecular-weight heparin) or three months (for the 5.65% taking warfarin) after discharge without significantly modifying the incidence of thromboembolic events (2.56% vs. 2.37%, relative risk = 0.91). However patients with one or more risk factors had a greater risk of a thromboembolic event than did patients with no risk factors (3.59% vs. 2.38%, respectively; relative risk = 0.66). The use of thromboprophylaxis had no apparent impact on the occurrence of thromboembolic events in patients who did or did not have risk factors (3.68% vs. 3.55%, respectively; relative risk = 0.96). No significant correlation could be identified between the occurrence of thromboembolic events and fracture types, age, or sex. CONCLUSIONS Clinically detectable thromboembolic events after surgical treatment of ankle fractures are uncommon and do not appear to be influenced by the use of thromboprophylaxis. Patients with risk factors appear to be at higher risk for these events, but there is a need for prospective studies to determine the efficacy of thromboprophylaxis after surgical treatment of ankle fractures.

Functional impact of tibial malrotation following intramedullary nailing of tibial shaft fractures.

BACKGROUND Tibial malrotation is a complication that is seen in approximately 30% of patients following locked intramedullary nailing. In this cohort study, we evaluated the hypothesis that tibial malrotation would lead to impaired functional outcomes. METHODS Patients with a unilateral tibial shaft fracture who were managed with intramedullary nailing between 2003 and 2007 were identified with use of ICD-10 (International Classification of Diseases, 10th Revision) codes. After institutional review board approval and written informed consent had been obtained, specific assessment of eligible patients was achieved with use of computed tomography, functional measures (Lower Extremity Functional Scale, Olerud-Molander Score, six-minute walk test), and physical examination. Measures were compared between patients with and without tibial malrotation (defined as tibial rotation of ≥ 10°) on imaging studies. RESULTS Of the 288 patients who were identified, 100 were eligible for the study and seventy consented to participate. The mean duration of follow-up (and standard deviation) for these seventy patients was 58 ± 11 months. Twenty-nine patients (41%) had tibial malrotation. Lower Extremity Functional Scale scores were similar between the groups with and without malrotation (mean, 70.8 ± 8.6 points compared with 72.6 ± 8.7 points; p = 0.41). The results for the other functional tests were also similar. CONCLUSIONS Despite high rates of tibial malrotation following locked intramedullary nailing of isolated tibial diaphyseal fractures, this finding does not have a significant intermediate-term functional impact.

The Effect of Porous Tantalum Cones on Mechanical Alignment and Canal-Fill Ratio in Revision Total Knee Arthroplasty Performed with Uncemented Stems

In revision total knee arthroplasty (TKA), the internal diameter of metal cones may limit the ability of the stem to properly fill the medullary canal. We prospectively studied 115 patients who underwent revision TKA with uncemented stems to evaluate the effect of metal cones on mechanical alignment and stem positioning. Correction on the mechanical alignment was well achieved in all patients, regardless of whether a metal cone was used. The proportion of patients achieving restoration of neutral mechanical alignment was similar between groups, as were the mean canal fill ratio (CFR) and the proportion of patients achieving CFR ≥ 85%. The use of porous tantalum cones in revision TKA with uncemented stems is not an obstacle in achieving optimal mechanical alignment and stem positioning.

Osteochondroma of the Scapula with Accessory Nerve (XI) Compression

Osteochondroma is the most common benign bone tumor and is characterized as a cartilage-capped bony stalk. This lesion usually develops from the growth plate of long bones. Most osteochondromas are asymptomatic. Neurovascular compressions or cosmetic issues can occur in specific locations. Malignant transformation is extremely rare, and MRI can help evaluate these lesions. Symptomatic mass and malignancy features are the main surgical indications. Uncommonly, an osteochondroma can develop from flat bones. We present the case of a 25-year-old patient with a right scapula osteochondroma causing an accessory nerve compression. The mass was surgically removed, and the diagnosis was confirmed. The patient fully recovered at the latest 3-year follow-up visit.

Traumatic Rupture of an Intermediate Tendon in a Patient with Patellar Duplication

Patellar duplication is a rare asymptomatic condition. The diagnosis is often made following a traumatic event associated with an injury to the knee extensor mechanism. The treatment is often surgical and consists in removal of the smaller part of the patella with tendon reinsertion. The presence and rupture of an intermediate tendon between the two parts of the patella have not been reported in the modern literature. We present a traumatic rupture of an intermediate tendon in a patient with horizontal patellar duplication. The surgical management consisted of tenorrhaphy protected with a figure-of-eight tension band wire approximating the two parts of the patella. The patient recovered full knee range of motion and quadriceps strength at the last 8-month follow-up.