Hybrid total hip arthroplasty for multiple epiphyseal dysplasia.

BACKGROUND: Multiple Ephiphyseal Dysplasia (MED) is a rare autosomal dominant skeletal dysplasia that causes deformation of the epiphysis of the involved joints. The hips are invariably affected and symptoms due to incapacitating early onset degenerative hip disease often begin between the second and fourth decade of life. Literature regarding the clinical and radiographical outcomes after total hip arthroplasty in this young population are very scarce. Hypothesis in patients with multiple epiphyseal dysplasia and early onset degenerative hip disease, hybrid total hip arthroplasty is a safe and reliable procedure. PATIENTS AND METHODS: We followed 10 hybrid total hip arthroplasties in 6 patients with respect to the early and medium term complications. The average age at surgery was 32 years old (17 to 41). All stems were cemented polished straight tapered stems, all cups were porous coated uncemented cups. The mean duration of follow-up was 10.3 (7-14, SD2.8) years. Clinical outcomes were measured using the Charnley modification of the Merle d'Aubigné-Postel grading system and VAS-scores. RESULTS: No early complications and no revisions occurred and patients significantly improved for pain, function and mobility. The Charnley, Merle d'Aubigné and Postel hip scores significantly improved from 9.6 points pre-operatively (range: 8-11 points) to 17 points (range: 16-18 points) and the VAS-score significantly improved after surgery from respectively 7 at rest and 8.5 during activity preoperatively to 1 at rest and 1.5 during activity postoperatively. Radiographic evaluation showed no cases of radiolucency around the cemented femoral components. No migration or subsidence of the components was noted. With regard to the acetabular component, osteolysis was noted in 4 hips, but serial radiographs showed no progression or migration of the component and the patients were completely pain free. CONCLUSION: Hybrid total hip arthroplasty is a viable treatment option in multiple epiphyseal dysplasia patients, with excellent mid-term clinical and radiographical outcomes. LEVEL OF EVIDENCE: Level IV, retrospective study.

Predictors of outcome after manipulation under anaesthesia in patients with a stiff total knee arthroplasty.

PURPOSE: Flexion in a stiff total knee arthroplasty (TKA) can be improved by manipulation under anaesthesia (MUA). Although this intervention usually results in an improvement in range of motion, the expected result is not always achieved. The purpose of this study is to determine which factors affect range of motion after manipulation in patients with a stiff total knee. METHODS: After exclusion (n = 22), the data of 158 patients (138 knees) with a stiff knee after TKA who received a manipulation under anaesthesia between 2004 and 2014 were retrospectively analysed. Pre-, peri- and post-operative variables were identified and examined for their influence on flexion after the manipulation using Kruskal-Wallis and Mann-Whitney U tests and Spearman correlations. RESULTS: After MUA, a mean improvement in flexion of 30.3° was observed at the final follow-up. Preoperative TKA flexion, design of TKA and interval between TKA procedure and MUA were positive associated with an increase in flexion after MUA. MUA performed 12 weeks or more after TKA procedure deteriorated the outcome. CONCLUSIONS: Three factors, pre-TKA flexion type of prosthesis and interval between TKA procedure and manipulation under anaesthesia, were found to have impact on flexion after TKA and MUA were identified. Results are expected to be inferior in patients with low flexion before TKA procedure or with a long interval (>12 weeks) between the TKA procedure and the manipulation under anaesthesia. LEVEL OF EVIDENCE: IV.

Injuries in male versus female soccer players: epidemiology of a nationwide study.

The aim of this study is to analyse soccer injuries on a national scale over one decade and to compare injury rates by gender. Detailed injury data obtained from the Royal Belgian Football Association from seasons 1999-2000 and 2009-2010 were recorded and gender differences in incidences of injuries, type of injury, affected body part and timing of injury were compared. A significant decrease in injuries from 7.56 to 5.96 injuries per 100 players was seen (p<0.0001). Overall male players sustained more cont usions, fractures, joint dislocations and musculotendinous injuries than female players. Proportionally, females sustained more severe injuries than men (p<0.0001). Significantly more injuries where sustained during competition in both males and females. The number of injuries in male and female soccer players has decreased over the past decade. A higher injury rate was seen in men but proportionally, females sustained more severe injuries.

Post-cam mechanics and tibiofemoral kinematics: a dynamic in vitro analysis of eight posterior-stabilized total knee designs.

PURPOSE: Posterior cruciate ligament (PCL)-substituting total knee arthroplasty (TKA) designs were introduced to avoid paradoxical roll forward of the femur and to optimize knee kinematics. The aim of this in vitro study was to investigate post-cam function and contact mechanics and relate it to knee kinematics during squatting in eight contemporary posterior-stabilized TKA designs. METHODS: All prostheses were fixed on custom-designed metal fixtures and mounted in a knee rig and five sequential-loaded squats were performed between 30° and 130° of flexion. Contact pressure and contact area were measured using pressure-sensitive Tekscan sensors on the posterior face of the post. Kinematics was recorded with reflective markers and infrared light-capturing cameras. RESULTS: The post-cam mechanisms analyzed in this study are very variable in terms of design features. This leads to large variations in terms of the flexion angle at which the post and cam engage maximal contact force, contact pressure and contact area. We found that more functional post-cam mechanisms, which engage at lower flexion angle and have a similar behavior as normal PCL function, generally show more normal rollback and tibial rotation at the expense of higher contact forces and pressures. All designs show high contact forces. A positive correlation was found between contact force and initial contact angle. CONCLUSION: Post-cam contact mechanics and kinematics were documented in a standardized setting. Post-cam contact mechanics are correlated with post-cam function. Outcomes of this study can help to develop more functional designs in future. Nevertheless, a compromise will always be made between functional requirements and risk of failure. We assume that more normal knee kinematics leads to more patient satisfaction because of better mobility. Understanding of the post-cam mechanism, and knowing how this system really works, is maybe the clue in further development of new total knee designs.