Surgical hip dislocation is more powerful than arthroscopy for achieving high degrees of acetabular correction in pincer type impingement

BACKGROUND: With the development of hip arthroscopy (HA), a shift away from surgical hip dislocation (SHD) is becoming a noticeable reality. It was the aim of this study to examine whether SHD provides a benefit over HA regarding its corrective power in the treatment of femoroacetabular impingement (FAI). HYPOTHESIS: It was hypothesized that SHD provides the more powerful tool for acetabular correction in FAI surgery compared to HA. METHOD: The examined cohort consisted of 85 hips of which 31 (36%) underwent a high degree of acetabular correction which was defined as a correction of >2 standard deviations from the population mean. A lateral center edge angle (LCE) correction>12° or an acetabular index (AI) correction>8° were therefore considered to high correction. A logistic regression model was applied to determine factors influencing high correction in FAI surgery. Subsequent adjustment was performed using a multivariate model. RESULTS: After adjusting for pre-operative acetabular orientation, SHD showed a pronounced influence on the likelihood of achieving the adequate degree of high acetabular correction (odds ratio (OR) 10.0 confidence interval (C.I) 2.3 to 44.0, p=0.002). On the other hand, SHD showed no influence on femoral correction (p=n.s). CONCLUSION: Surgical hip dislocation is a powerful modality for achieving high degrees of acetabular correction in the situation of a femoroactabular conflict, being defined as an LCE correction of>12° or AI correction of>8°. The reason for these results may be seen in the excellent exposure and the improved possibility of performing dynamic intra-operative examination to verify the results. The benefits are only limited to large acetabular correction. These findings should provide a helpful tool for decision making in clinical practise. LEVEL OF EVIDENCE: Level III retrospective cohort study.