Deficiency in the gluteus medius and minimus abductor muscles is a well-recognised cause of hip pain and considerable disability. These patients present a management challenge, with no established consensus for surgical intervention. Whiteside in 2012 described a surgical technique for gluteus maximus tendon transfer, with successful outcomes reported. This study is the largest known case series to date of patients undergoing gluteus maximus tendon transfer with clinical and patient reported outcomes measured. 13 consecutive patients were included in the study. All patients had clinical evidence of abductor dysfunction together with MRI evidence of gluteal atrophy and fat infiltration. All patients underwent gluteus maximus transfer with surgery performed according to the procedure described by Whiteside. Patients were followed up with both clinical assessment and patient questionnaires conducted. Mean age was 69 (range 54–82) with 9 patients (69%) having previous Hardinge approach to the affected hip. 6 patients (46%) reported they were satisfied overall with the procedure and 5 patients (38%) were unsatisfied. 7 patients (54%) had improvements in visual analogue scale of pain and 5 patients (54%) reported overall improvements in function. Mean Oxford Hip Score on follow up was 20/48 (range 5–48) and trendelenberg test was positive in 11 patients (85%). No differentiating variable could be identified between patients with positive and negative outcomes (Assessed Variables: Age, sex, BMI, aetiology and gluteus maximus muscle thickness). Clinical outcomes were varied following gluteus maximus tendon transfer for chronic hip abductor dysfunction. Results are considerably less promising than pre-existing studies would suggest

Introduction. The same cup orientation is classically applied to all cases of hip replacement (45° abduction, 20° anteversion). We hypothesize that this orientation must be adapted to the patient's hip range of motion. We tested this hypothesis by means of an experimental study with respect to hip range of motion, comparing the classical orientation (45° and 20°), and the orientation obtained with computer-assisted navigation. Material and Methods. The experimental model included a hemipelvis equipped with a femur whose mobility was controlled for three configurations: stiff (60°/0°, 15°/10°, 10°/10°), average (80°/10°, 35°/30°,35°/25°), mobile (130°/30°, 50°/50°, 45°/35°). The hemipelvis and the cup holder were equipped with an electromagnetic system (Fastrack ™) to measure cup orientation. The Pleos™ navigation system (equipping the hemipelvis, the femur, and the cup holder) guided the cup orientation by detecting the positions risking impingement through a kinematic study of the hip. Nine operators each performed 18 navigation-guided implantations (162 hip abduction, anteversion, and range of movement measurements) in two series scheduled 2 months apart. Results. The model used herein showed intra and interobserver reliability. Compared to the navigation-assisted surgery, the arbitrary orientation gave a mean anteversion error of only 1° ± 6° (−12 to +19°) but 5° ± 8° (−26° to +13°) for abduction. However, 16% of the errors were more than 10° in anteversion (1/2 in the mobile configuration) and 11% of the errors were more than 15° in abduction (for the most part in the mobile configuration). With arbitrary orientation, the errors consisted in excess anteversion and insufficient abduction. Discussion and Conclusion. The experimental model developed was reliable and can be used to evaluate different prosthetic configurations. This study emphasizes that the ideal arbitrary cup orientation cannot be applied to all hips. All the surgeons are very reproducible but the only way to integrate the range of motion in there ‘own way to do’ in vitro, is to use a navigation system witch can guide the surgeon so as to reduce the risk of impingement and instability

The purpose of this study was to assess the stability of a developmental pelvic reconstruction system which extends the concept of triangular osteosynthesis with fixation anterior to the lumbosacral pivot point. An unstable Tile type-C fracture, associated with a sacral transforaminal fracture, was created in synthetic pelves. The new concept was compared with three other constructs, including bilateral iliosacral screws, a tension band plate and a combined plate with screws. The pubic symphysis was plated in all cases. The pelvic ring was loaded to simulate single-stance posture in a cyclical manner until failure, defined as a displacement of 2 mm or 2°. The screws were the weakest construct, failing with a load of 50 N after 400 cycles, with maximal translation in the craniocaudal axis of 12 mm. A tension band plate resisted greater load but failure occurred at 100 N, with maximal rotational displacement around the mediolateral axis of 2.3°.

The combination of a plate and screws led to an improvement in stability at the 100 N load level, but rotational failure still occurred around the mediolateral axis. The pelvic reconstruction system was the most stable construct, with a maximal displacement of 2.1° of rotation around the mediolateral axis at a load of 500 N.