Evolution of total hip arthroplasty in patients younger than 30 years of age: A systematic review and meta-analysis

Introduction While surgical technique and implant technology for total hip arthroplasty (THA) has improved over the years, it is unclear whether recent progress has translated to improved clinical outcomes for young patients. The goal of this study is to determine trends in (1) indications, (2) surgical technique (3) clinical and radiographic outcomes, and (4) survivorship for THA in patients younger than 30 years of age. Methods MedLine, Cochrane, EMBASE, and Google Scholar were searched using several key phrases for articles focusing on THA performed on patients younger than 30 years of age between 1971 and 2020. A total of 34 qualifying articles were identified and stratified into three groups according to operative years and compared to one another on the basis of (1) indications; (2) fixation technique; (3) implant design; (4) clinical and radiographic outcomes; and (7) survivorship. Results The mean patient age at index THA were 20.5 (9–30), 22.1 (11–30) and 21.5 (10–30) years, respectively, for each study group. Over time, patients underwent fewer THAs for JRA (Juvenile Rheumatoid Arthritis) ( p < 0.001) but more for post-treatment and iatrogenic avascular necrosis ( p < 0.001; p < 0.001). Early THAs primarily used metal on UHMWPE (Ultra high molecular weight polyethylene) (71.7%, p < 0.001), modern THA predominantly use ceramic on HXLPE (Highly cross-linked polyethylene) (42.5%, p < 0.001). Early fixation methods used cement (60.4%, p < 0.001), and modern fixation primarily use press fit technology (95.9%, p < 0.001). Prevalence of radiographic loosening decreased significantly ( p < 0.001) over time. There was no significant difference in clinical improvement on HHS. Lastly, fewer patients required THA revision in recent decades ( p < 0.001). Conclusions Advances in surgical technique and technology have served to improve implant longevity. Surprisingly, subjective clinical scores showed no significant improvement over time, suggesting that early iterations of THA were extremely successful.