Minimum Ten-Year Follow-Up of Patients 50 Years or Less Undergoing Total Hip Arthroplasty with Fourth-Generation Ceramic 32-mm Femoral Heads on Highly Cross-Linked Polyethylene.

Abstract

Total hip arthroplasty (THA) with third-generation alumina ceramic heads on highly cross-linked polyethylene liners (HXLPE) has demonstrated excellent outcomes in young patients. However, concerns of ceramic head fracture, squeaking, stripe wear, and limited sizing led to the development of a fourth-generation ceramic head. The purpose of our study was to report on survivorship, wear characteristics, and patient-reported outcomes of THA with a fourth-generation 32-mm ceramic femoral head and HXLPE liner in patients 50 years or younger at 10-year minimum follow-up. This was a retrospective study of 103 THAs with fourth-generation 32-mm ceramic femoral heads on HXPLE between December 2008 and December 2010. The mean age was 37 years (range, 13 to 50). All patients were 50 years or younger at index THA. The modified Harris Hip Score (mHHS), University of California, Los Angeles (UCLA) Activity Score, and Western Ontario and McMaster University Osteoarthritis Index (WOMAC) pain score were collected preoperatively and at each follow-up. Martell Hip Analysis was used for wear calculations. Survivorship from all-cause revision was 97.1% (95% confidence interval (CI), 93.8 to 100.0) at five years, 97.1% (95% CI, 93.8 to 100.0) at 10 years, and 95.4% (95% CI, 90.9 to 99.9) at 15 years. Survivorship from wear-related revision was 100% at 15 years. There were four hips (3.9%) that underwent revision at a mean of 5.1 years (range, 0.04 to 13.2) postoperatively. The mean linear wear rate was 0.0184 mm/year (standard deviation (SD) ± .043); the mean volumetric wear rate was 18.38 mm³/year (SD ± 22.55). Improvements were observed in the mHHS (48 ± 16 to 84 ± 22; P < 0.001), UCLA score (5.5 ± 2.3 to 6.2 ± 2.1; P = 0.031), and Western Ontario and McMaster Universities Arthritis Index (WOMAC) pain score (45 ± 21 to 86 ± 23; P < 0.001). Patient satisfaction scores were 73% "extremely satisfied" and 13% "very satisfied." The fourth-generation ceramic 32-mm femoral heads on HXLPE in THA for patients aged 50 years or younger demonstrate excellent survivorship, minimal wear, and high patient satisfaction at a 10-year minimum follow-up.