Large Femoral Heads With Small Acetabular Components: An Examination of 10-Year Polyethylene Wear.

Abstract

Highly cross-linked polyethylene (HXLPE) has improved polyethylene (PE) wear rates while decreasing osteolysis and aseptic loosening. However, concerns exist regarding the risk of mechanical failure with thin HXLPE liners in total hip arthroplasty (THA). Our purpose was to evaluate long-term outcomes and PE wear rates in primary THAs pairing large femoral heads with small acetabular components and thin HXLPE liners. We retrospectively reviewed 29 patients who underwent 33 primary THAs using large femoral heads (32 or 36 mm) with small acetabular components (48 or 50 mm) and thin HXLPE liners (3.9 or 5.9 mm) at minimum 10-year follow-up. PE liner wear was measured using a validated radiographic technique. Mean age was 66 years, 97% of the patients were women, and mean body mass index was 26.3 kg/m². Thirty hips (90.9%) had ceramic femoral heads, and 13 hips (39%) had 36-mm femoral heads with 3.9-mm HXLPE liners. All cases used a neutral PE design. Mean linear wear rate and volumetric wear rate were 0.04 mm/year and 39.6 mm³/year, respectively, at mean 10.9-year follow-up. There were no instances of liner fracture, liner dissociation, or revision. Mean Hip disability and Osteoarthritis Outcome Score for Joint Replacement (HOOS, JR) was 92.1. In the largest long-term study of primary THAs using large femoral heads with small acetabular components and thin HXLPE liners, we found low linear and volumetric wear rates and no cases of liner mechanical failures. Thin HXLPE liners are a safe and viable option for THA surgeons. [<i>Orthopedics</i>. 2024;47(2):118-122.].