Dual-taper modular stems: aseptic lymphocytic vasculitis-associated lesions (ALVAL): revision rates and outcome in a single hospital series.

Abstract

Dual-taper modular stems have been linked to implant failure due to aseptic lymphocytic vasculitis-associated lesions (ALVAL), yet data on revision outcomes remain limited. This study assessed the survival rate of modular stems revised for ALVAL and compared outcomes with a non-revised control group. A retrospective analysis of 233 total hip arthroplasties (THA) with ABGII dual-taper modular stems (2007-2011) was conducted, with follow-up until 2024. 39 THA (16.7%) underwent revision for ALVAL, confirmed by intraoperative histology. The control group included unrevised patients with ⩾1-year follow-up. Pre-revision assessments included Harris Hip Score (HHS), radiographs, MARS-MRI, and cobalt/chromium ion levels. Revision was indicated for disabling pain, cobalt >5 µg/L, or progressive effusion/pseudotumours. Outcomes included HHS, complications, and Kaplan-Meier survival analysis. Revisions for ALVAL (39 THA, 16.7%) were primarily due to groin pain (64.1%), MRI effusion (79.5%), and elevated cobalt levels (46.2%). The median time to revision was 4 years postoperatively, with a mean time to revision of 2.4 years. Of 21 unipolar revisions 10 hips (27.1%) had a had a dislocation, bipolar revisions (18 hips) had none (<i>p</i> <0.001).At 5, 10, and 15 years, overall revision-free survival was 88.8%, 80.3%, and 75.2%, respectively, while survival free from revision specifically due to ALVAL, confirmed by histological findings, was 91.4%, 83.7%, and 83.1%. 3 hips were re-revised for periprosthetic fractures. After ALVAL revision the HHS improved from 77.6 to 87.7 (<i>p</i> <0.001) but remained lower than in the non-revised controls (<i>p</i> = 0.002). 25.6% of the revised patients had persistent pain. ALVAL-related revisions led to improvement in the HHS but did not reach the levels of non-revied control. Revision with dual-mobility cups reduced the dislocation risk.