Does prior conservative surgery affect survivorship and functional outcome in total hip arthroplasty for congenital dislocation of the hip? A case-control study in 159 hips

IntroductionThe results of total hip arthroplasty (THA) in congenital dislocation of the hip (CDH) are well known, but such is not the case for the impact of prior conservative surgery on THA function and survivorship. The present study compared THA in CDH with prior conservative bone surgery (BS group) versus no prior bone surgery (NBS group), to (1) assess the impact of prior conservative surgery on function and survivorship after THA, and (2) determine whether a particular type of conservative surgery affected function or survivorship.HypothesisPrior conservative surgery for CDH does not affect function or survivorship of subsequent THA.Patients and methodsA multicenter retrospective case-control study analyzed 430 THAs in CDH patients (332 patients: 269 female, 63 male; mean age, 56 years [range, 17–80 years]) at a mean 13.2 ± 5.4 years’ follow-up (range, 1–29 years). The BS group included 159 hips (37%) (64 pelvic, 81 femoral and 14 combined pelvic and femoral osteotomies), and the NBS group 271 (63%). Groups were comparable for gender, age at surgery, Devane activity score, preoperative Postel Merle d’Aubigné (PMA) functional score and CDH radiographic type following Crowe.ResultsAt follow-up, PMA scores were comparable: BS, 16.8 ± 1.4 (11–18); NBS, 16.9 ± 1.5 (7–18). Fifteen-year survivorship censored for implant revision for whatever reason did not significantly differ: BS, 87% (95% CI: 83–91%); NBS, 89% (95% CI: 86–92%). Ten-year survivorship on the same criterion did not significantly differ according to type of prior surgery: hip shelf arthroplasty, 97% (95% CI: 95–99%); Chiari osteotomy, 100%; femoral osteotomy, 95% (95% CI: 92–98%); and Milch osteotomy 96% (95% CI: 93–99%).Discussion/ConclusionConservative surgery for CDH does not impair the functional results or survivorship of subsequent THA.Level of evidenceIII, case-control study.