The medial approach open reduction for developmental dysplasia of the hip: do the long-term outcomes validate this approach? A systematic review of the literature

INTRODUCTION Developmental dysplasia of the hip (DDH) is one of the most commonly diagnosed and treated paediatric orthopaedic conditions. OBJECTIVE To systematically identify, appraise and synthesise the best evidence for the long-term outcomes of the medial approach open reduction (MAOR) for DDH. METHODS MEDLINE, EMBASE and the Cochrane databases were searched up to July 2013. All study designs that reported on the long-term outcomes of the MAOR as the primary treatment modality for DDH were included. The risk of bias in each study was evaluated using the Cochrane risk of bias assessment tool with some modification to accommodate different study designs. RESULTS From the 162 citations screened, five retrospective observational studies that fulfilled the eligibility criteria were included. The mean age at surgery varied from 10 to 17 months with an average follow-up period of 16-25 years. Acetabular development, as defined by the Severin Classification, was reported as satisfactory (Severin I/II) in between 38 and 79 % of study cohorts. However these good and excellent outcomes were less promising when patients who had additional operations were considered as unsatisfactory results. Avascular necrosis, as predominantly defined by the Kalamchi criteria, varied from 5 to 43 %. Negative prognostic factors implicated were mean age at surgery >17 months, the absence of the ossific nucleus and eccentric posturing of the femoral head postoperatively. The rate of secondary operations reported varied from 11 to 50 %. There were no reported total hip replacements. CONCLUSION There is a paucity of robust evidence pertaining to the long-term outcomes of the MAOR for developmental dysplasia of the hip. The trends from observational studies suggest that the long-term outcomes are not as positive as short- to intermediate-term studies suggest. Further prospective, controlled and rigorously designed studies are required to validate this approach.