What Is the Impact of a Previous Femoral Osteotomy on THA? A Systematic Review

BACKGROUND: Femoral osteotomies have been widely used to treat a wide range of developmental and degenerative hip diseases. For this purpose, different types of proximal femur osteotomies were developed: at the neck as well as at the trochanteric, intertrochanteric, or subtrochanteric levels. Few studies have evaluated the impact of a previous femoral osteotomy on a THA; thus, whether and how a previous femoral osteotomy affects the outcome of THA remains controversial. QUESTIONS/PURPOSES: In this systematic review, we asked: (1) What are the most common complications after THA in patients who have undergone femoral osteotomy, and how frequently do those complications occur? (2) What is the survival of THA after previous femoral osteotomy? (3) Is the timing of hardware removal associated with THA complications and survivorship? METHODS: A systematic review was carried out on PubMed, the Cochrane Systematic Reviews Database, Scopus, and Embase databases with the following keywords: "THA", "total hip arthroplasty", and "total hip replacement" combined with at least one of "femoral osteotomy" or "intertrochanteric osteotomy" to achieve the maximum sensitivity of the search strategy. Identified studies were included if they met the following criteria: (1) reported data on THAs performed after femoral osteotomy; (2) recorded THA followup; (3) patients who underwent THA after femoral osteotomy constituted either the experimental group or a control group; (4) described the surgical and clinical complications and survivorship of the THA. The database search retrieved 383 studies, on which we performed a primary evaluation. After removing duplicates and completing a full-text evaluation for the inclusion criteria, 15 studies (seven historically controlled, eight case series) were included in the final review. Specific information was retrieved from each study included in the final analysis. The quality of each study was evaluated with the Methodological Index for Non-randomized Studies (MINORS) questionnaire. The mean MINORS score for the historically controlled studies was 14 of 24 (range, 10-17), whereas for the case series, it was 8.1 of 16 (range, 5-10). RESULTS: The proportion of patients who experienced intraoperative complications during THA ranged from 0% to 17%. The most common intraoperative complication was femoral fracture; other intraoperative complications were difficulties in hardware removal and nerve palsy; 15 studies reported on complications. The survivorship of THA after femoral osteotomy in the 13 studies that answered this question ranged from 43.7% to 100% in studies that had a range of followup from 2 to 20 years. The timing of hardware removal was described in five studies, three of which detailed more complications with hardware removal at the time of THA. CONCLUSIONS: This systematic review demonstrated that THA after femoral osteotomy is technically more demanding and may carry a higher risk of complications than one might expect after straightforward THA. Staged hardware removal may reduce the higher risk of intraoperative fracture and infection, but there is no clear evidence in support of this contention. Although survivorship of THA after femoral osteotomy was generally high, the studies that evaluated it were generally retrospective case series, with substantial biases, including selection bias and transfer bias (loss to followup), and so it is possible that survivorship of THA in the setting of prior femoral osteotomy may be lower than reported. LEVEL OF EVIDENCE: Level III, therapeutic study.