Although total hip arthroplasty (THA) has become standard procedure to manag the symptoms of end-stage osteoarthritis (OA), there are multiple surgical approaches to acceE the hip joint. To date, there is limited information on the effect of surgical approach on muscle strength and performance-based measures of functional ability after THA.
The purpose of this study was to compare the effect of posterior or anterolateral surgical approaches on strength and function after THA. We hypothesized that individuals who underwent a posterior approach would have greater strength and performance-based measures of function than individuals who underwent an anterolateral approach one year after surgery. We also hypothesized that there would be no difference in pain or self-reported outcomes at follow-up.
63 subjects were tested two to four weeks prior to THA and then three months and 12 months after THA. Subjects were divided into a posterior approach and lateral approac groups. Patients completed functional testing, strength measures, as well as self-reported questionnaires at each time point. Repeated-measures analysis of variance (ANOVA) tests were performed to test the change between the pre-operative and one year time point. Descriptive data were reported for all three time points.
There was a significant interaction effect for hip abduction strength (p=0.025) and the lateral group was significantly weaker at one year (p=0.018). No other variable demonstrated a significant interaction effect; however, all other variables with the exception of hip abductor strength (p=0.883) and pain on the non-operated side (p=0.527) demonstrated a significant main effect of time (p≤0.01) in which there was significant improvement at 1 year.
The lateral surgical approaches result in weaker hip abduction one year after THA; however significant and clinically meaningful improvements in functional ability were seen for most subiects. regardless of surgical approach.