10-Year Results of Metal-On-Metal Hip Resurfacing With Computer-Assisted Navigation.

Abstract

Hip resurfacing arthroplasty is a bone-conserving alternative to total hip arthroplasty for young, active men. Femoral component malalignment is a known contributor to early mechanical failure. Computer-assisted navigation improves femoral component positioning; however, its long-term clinical impact remains uncertain. This study compared survivorship, radiographic alignment, and patient-reported outcomes between navigation-assisted and conventional hip resurfacing. A retrospective cohort analysis was performed on 629 hip resurfacing arthroplasties (497 navigated; 132 conventional). Patient-reported outcome measures were collected preoperatively and at five and 10 years. Radiographic measures included stem-shaft angle, femoral component anteversion, and loosening based on established criteria. Survival was evaluated using Kaplan-Meier analysis under best-case and worst-case assumptions. Propensity score matching was performed using a 1:1 ratio. The 10-year all-cause survivorship was similar between groups (best-case: 96.7% navigation versus 97.0% conventional; P = 0.82). Excluding infection, survivorship remained comparable. Navigation resulted in fewer stem-shaft angle outliers (33 versus 48%, P = 0.007) and a lower rate of radiographic femoral loosening at 10 years (2.3 versus 12.7%, P = 0.005). Both groups demonstrated improvement in patient-reported outcomes (P < 0.001), with no differences at five or 10 years. Matched analyses confirmed similar functional outcomes. Navigation-assisted hip resurfacing arthroplasty demonstrated equivalent survivorship and patient-reported outcomes compared with conventional techniques while achieving more consistent femoral component alignment and a lower rate of radiographic femoral loosening at 10 years.