The effect of abduction differences between cup and contralateral acetabular angle on polyethylene component wear.

One hundred forty-two patients who underwent cemented or uncemented hip replacement were studied radiographically to determine acetabular component wear. Mean duration of follow-up was 58 months (range: 35-92 months). Average linear wear was 0.78 mm (range: 0-1.9 mm), and average wear rate was 0.16 mm/year (range: 0-0.45 mm/year). An increased wear rate per year correlated with a discrepancy >18.3 degrees between contralateral acetabular angle and acetabular cup inclination (P<.005). Statistical analysis revealed no significant correlation between cup inclination and polyethylene wear, which was studied without considering the contralateral hip (P>.3). There was no relationship between polyethylene wear and cup design, weight, and initial polyethylene thickness.