Reasons for Revision of First-Generation Highly Cross-Linked Polyethylenes

Over a 10-year period, we prospectively evaluated the reasons for revision of contemporary and highly cross-linked polyethylene formulations in a multicenter retrieval program. Two hundred twelve consecutive retrievals were classified as conventional gamma inert sterilized (n = 37), annealed (Crossfire [Stryker Orthopedics, Mahwah, NJ], n = 72), or remelted (Longevity [Zimmer ,Warsaw, Ind], XLPE [Smith and Nephew, Memphis, Tenn], Durasul [Zimmer, Warsaw, Ind], n = 103) liners. The most frequent reasons for revision were loosening (35%), instability (28%), and infection (21%) and were not related to polyethylene formulation (P = .17). Annealed and remelted liners had comparable linear penetration rates (0.03 and 0.04 mm/y, respectively, on average), and these were significantly lower than the rate in conventional retrievals (0.11 mm/y, P ≤ .0005). This retrieval study including first-generation highly cross-linked liners demonstrated lower wear than conventional polyethylene. Although loosening remained as the most prevalent reason for revision, we could not demonstrate a relationship between wear and loosening. The long-term clinical performance of first-generation highly cross-linked liners remains promising based on the midterm outcomes of the components documented in this study.