Clinical Outcomes and Risk Factors for Re-Revision Due to Trunnion Corrosion in Primary Metal-on-Polyethylene Total Hip Arthroplasty.

BACKGROUND:There is a paucity of literature regarding the mid-term (greater than 2 years) outcomes of revision for adverse local tissue reaction to metal debris due to corrosion at the head-neck junction (trunnionosis) in metal-on-polyethylene total hip arthroplasty (THA), and risk factors for re-revision remain largely unknown. We aimed to report the re-revision-free survival and functional outcomes for this patient population and to identify risk factors for re-revision. METHODS:A total of 80 hips (79 patients) with a metal-on-polyethylene THA who had undergone revision for trunnionosis at our institution were included. The mean study follow-up from index trunnionosis revision was 4.6 years (range, 2.0 to 9.4). Kaplan-Meier survival analysis was performed with all-cause re-revision as the end point, and multivariate logistic regression was used to identify risk factors for re-revision. RESULTS:We saw that twenty-one hips (26%) underwent re-revision at a mean of 8.0 months (range, 0.03 to 36.3) after the index trunnionosis revision, most commonly for instability and infection. The two- and five-year all-cause re-revision-free survival rates were 75.0 and 73.2%, respectively. The mean Oxford Hip Score was 33.7 (range, 11 to 48); 76% were satisfied, and 24% were dissatisfied with their hip. Multivariate analysis identified not undergoing a cup revision (odds ratio: 4.5; 95% confidence interval: 1.03 to 19.7) and time from primary THA to the index trunnionosis revision (odds ratio: 0.77; 95% confidence interval: 0.62 to 0.97) as risk factors for undergoing re-revision. CONCLUSIONS:The risk of early re-revision for these patients is high (26%), mostly due to infection and instability, and functional outcomes are fair. Not performing a cup revision appears to be a risk factor for re-revision, as is the shorter time from primary THA to trunnionosis revision. LEVEL OF EVIDENCE:III.