Long-term outcomes of total hip arthroplasty in patients younger than 55 years: a systematic review of the contemporary literature

Background Total hip arthroplasty (THA) is increasingly performed in younger patients despite the lack of comprehensive assessment of long-term outcomes. We systematically reviewed the contemporary literature to assess the 1) indications, 2) implant selection and long-term survivorship, 3) complication and reoperation rates and 4) radiographic and functional outcomes of primary THA in patients younger than 55 years. Methods We searched the Embase and MEDLINE databases for English-language articles published between 2000 and 2018 that reported outcomes of primary THA in patients younger than 55 years with a minimum follow-up duration of 10 years. Results Thirty-two studies reporting on 3219 THA procedures performed in 2434 patients met our inclusion criteria. The most common preoperative diagnoses were avascular necrosis (1044 [32.4%]), osteoarthritis (870 [27.0%]) and developmental dysplasia of the hip (627 [19.5%]). Modular implants (3001 [93.2%]), cementless fixation (2214 [68.8%]) and metal-on-polyethylene bearings (1792 [55.7%]) were frequently used. The mean 5- and 10-year survival rates were 98.7% and 94.6%, respectively. Data on survival beyond 10 years were heterogeneous, with values of 27%-99.5% at 10-14 years, 59%-84% at 15-19 years, 70%-77% at 20-24 years and 60% at 25-30 years. Rates of dislocation, deep infection and reoperation for any reason were 2.4%, 1.2% and 16.3%, respectively. The mean Harris Hip Score improved from 43.6/100 to 91.0/100. Conclusion Total hip arthroplasty in patients younger than 55 years provides reliable outcomes at up to 10 years. Future studies should evaluate the outcomes of THA in this population at 15-20 years' follow-up.