Hip strengthening exercise compared to standard rehabilitation after revision hip replacement: a multicenter randomized controlled trial

BACKGROUND: People undergoing revision total hip replacement (THR) typically experience slower recovery and greater functional limitations than those undergoing primary procedures. Rehabilitation practices following revision THR are inconsistent and often adapted from protocols for primary THR, despite limited specific evidence supporting their effectiveness. OBJECTIVES: To compare the effectiveness of an exercise intervention targeting hip strengthening (NEMEX-STR) on functional performance at 4 months with the standard community-based rehabilitation (Usual care) in participants undergoing revision THR. METHODS: This multicenter, randomized, controlled, parallel-group, assessor-blinded superiority trial included participants undergoing revision THR who were randomized to NEMEX-STR or Usual care. The NEMEX-STR group underwent a 16-week intervention targeting hip strengthening, while the Usual care group received standard rehabilitation. The primary outcome was the between-group difference in functional performance assessed by the 30-second Chair Stand Test (30s-CST), from baseline (ie, prior to surgery) to 4 months after the start of the intervention. Secondary outcomes included the Hip Disability and Osteoarthritis Outcome Score (HOOS), the 40-meter Fast-Paced Walk Test (40m-FPWT), the 9-step Timed Stair Climb Test (9-step TSCT), and unilateral leg extensor muscle power. RESULTS: A total of 84 participants were recruited between November 2022 and June 2024 and were allocated to either NEMEX-STR (n = 43) or Usual care (n = 41). The mean changes from baseline to 4-month follow-up in the 30s-CST were 1.9 (95 % CI 0.8 to 3.0) in NEMEX-STR and 1.2 (95 % CI 0.6 to 2.3) chair stands in Usual care, with a between-group difference of 0.7 (95 % CI -0.8 to 2.3). Secondary outcomes showed no clinically relevant between-group differences in change for HOOS subscales, 40m-FPWT, 9-step TSCT, or unilateral leg extensor muscle power. CONCLUSION: An exercise intervention targeting hip strengthening was not superior to standard community-based rehabilitation for improving functional performance at 4 months in participants undergoing revision THR. CLINICALTRIALS: GOV: NCT05657054.