[Operative Treatment for Saddle-Shaped Femoral Heads]

PURPOSE OF THE STUDY A saddle-shaped deformity of the femoral head has a poor prognosis due to rapid development of secondary changes. A new method of treatment by intra-articular anteromedial wedge reduction osteotomy (AWRO) of the femoral head may preserve the hip for the future. This study was designed to ascertain that this invasive technique was safe and effective and to confirm our hypothesis that AWRO significantly improved functional and radiological parameters of the hip joint. MATERIAL AND METHODS Patients who underwent AWRO between 2010 and 2013 were enrolled in this study. The indication criteria for the procedure included Stulberg grade V hips on AP radiographs, hinged abduction with pain, limping and a limited range of movement. Values of the Stulberg grading, capital diaphyseal index, caput-collum-diaphyseal angle and Harris hip score were recorded before and after surgery and the results were statistically evaluated using the paired t-test. The AWRO procedure was performed from the anterolateral approach after subperiosteal protection of the vessels had been ensured. The central necrotic part of the femoral head was removed, and the medial segment was mobilised and fixed to the intact lateral segment. Either a hip spica cast or bed-rest for six weeks was indicated. Full weight bearing was allowed at 3 months after surgery. RESULTS Twelve patients with an average follow-up of 55 months were evaluated. There were eight boys and four girls with an average age of 14 years at the time of surgery. The average Harris hip score improved from 54.52 before to 73.58 after surgery. The post-operative outcomes according to the Stulberg classification included one grade II hip, seven grade III hips, three grade IV hips and one grade V hip. The average capital-diaphyseal index dropped from 1.56 (1.19-1.92) to 1.28 (0.95-1.67) and the average caput-collum-diaphyseal angle increased from 134 degrees (121-143) to 140 degrees (130-155) after surgery. Avascular necrosis developed in two patients. All the differences were statistically significant. DISCUSSION Reduction osteotomies of the femoral head reported in the literature differ from the AWRO procedure used in this study in both the approach and the performance. The results presented here are in agreement with those published in the relevant literature. They showed no significant deterioration in comparison with the outcomes of our short-term study reported earlier. The outcome of treatment is related to the disease aetiology, functional parameters and previous procedures involving the hip joint. CONCLUSIONS AWRO is a salvage procedure that prolongs the longevity of joints in incongruent hips with very high morbidity. This procedure gave significantly better results in years after surgery, which confirmed our hypothesis. Level of evidence IV Key words: hinge abduction, Perthes disease, Stulberg, femoral head reduction osteotomy, avascular necrosis, arteria circumflexa femoris medialis.