Thin highly cross-linked polyethylene liners combined with large femoral heads in primary total hip arthroplasty show excellent survival and low wear rates at a mean follow-up of 12.8 years

Abstract

Aims Several short- and mid-term studies have shown minimal liner wear of highly cross-linked polyethylene (HXLPE) in total hip arthroplasty (THA), but the safety of using thinner HXLPE liners to maximize femoral head size remains uncertain. The objective of this study was to analyze clinical survival and radiological wear rates of patients with HXLPE liners, a 36 mm femoral head, and a small acetabular component with a minimum of ten years’ follow-up. Methods We retrospectively identified 55 patients who underwent primary THA performed at a single centre, using HXLPE liners with 36 mm cobalt-chrome heads in acetabular components with an outer diameter of 52 mm or smaller. Patient demographic details, implant details, death, and all-cause revisions were recorded. Cox regression and Kaplan-Meier survival was used to determine all-cause and liner-specific revision. Of these 55 patients, 22 had a minimum radiological follow-up of seven years and were assessed radiologically for linear and volumetric wear. Results Overall survival rate for all-cause revision was 94.5% (95% confidence interval (CI) 81.7% to 97.2%) at a mean follow-up of 12.8 years (10.9 to 18.7). Three patients were revised, none for liner wear, fracture, or dissociation. A total of 22 patients were included in the radiological analysis (mean follow-up 9.9 years (7.5 to 13.7)). Mean linear liner wear was 0.085 mm (95% CI -0.086 to 0.257) and the volumetric wear rate was 11.097 mm3/year (95% CI -6.5 to 28.7). Conclusion Using HXLPE liners with 36 mm heads in 52 mm acetabular components or smaller is safe, with excellent survival and low rates of linear and volumetric wear at medium-term follow-up. Patients did not require revision surgery for liner complications such as fracture, dissociation, or wear. Our results suggest that the advantages of using larger heads outweigh the potential risks of using thin HXLPE liners. Cite this article: Bone Joint J 2023;105-B(1):29–34.

Ultra-High-Molecular-Weight Polyethylene in Hip and Knee Arthroplasties

“…In THA using sequentially irradiated and annealed HXLPE (X3; Stryker), the mean linear wear rate was 0.02 ± 0.03 mm/y with a mean follow-up of 10 years, and the all-cause survival rate was 92% [ 79 ]. Another study demonstrated that the mean linear wear rate was 0.085 mm, and the overall survival rate for all-cause revision was 95% at a mean follow-up of 13 years [ 80 ]. The long-term results were excellent, although in vivo oxidation has been reported [ 81 , 82 ].…”

Vitamin E-diffused liners show less head penetration than cross-linked polyethylene liners in total hip arthroplasty: a ten-year multi-arm randomized trial

“…This finding aligns with previous studies that demonstrated that total head penetration and wear rates are independent from femoral head size. [27][28][29] No patients experienced aseptic loosening, and only one underwent revision due to dislocation two days after surgery. Given that the THA lifespan is usually 20 years, 2,14 the sample size was small, and the wear rate was low, other revisions would have been unlikely.…”

Hip & Pelvis

“…This interesting single-centre study from a team in Vancouver (Canada) included only a few patients, but with radiological measures of linear and volumetric wear. 4 The authors identified 55 patients, all receiving a total hip arthroplasty using HXLPE liners combined with 36 mm cobalt-chrome heads in acetabular components with an outer diameter of 52 mm or smaller. Of the original 55 patients, 22 had a minimum radiological follow-up of seven years and were assessed radiologically for linear and volumetric wear.…”