Cup centralization predicts revision risk in MAÏA trapeziometacarpal arthroplasty: a retrospective study of 217 cases

The aim of this study was to evaluate whether radiographic cup inclination and the degree of centralization affect complication rates or functional outcomes after MAÏA trapeziometacarpal joint (TMJ) arthroplasty.

This retrospective single-centre study included 217 MAÏA TMJ prostheses implanted in 194 patients with Eaton-Littler grade II-III osteoarthritis between 2015 and 2023. Clinical outcomes were assessed using the visual analogue scale for pain, thumb abduction, Kapandji score and QuickDASH. Radiographic evaluation of cup inclination and centralization was performed using standardized methods. The association between these parameters and complications or functional outcomes was analysed. Implant survival was estimated using Kaplan-Meier analysis.

The median follow-up was 3.6 years. The median cup inclination angle was 7.16°, and the median centralization index was 0.85. The overall complication rate was 9.7%, with 3.7% requiring revision owing to loosening or dislocation. No significant association was observed between cup inclination and complication rates (p = 0.675). However, poorly centralized cups were significantly associated with revision surgery (mean index 0.55 vs. 1.06, p = 0.019). No significant correlations were found between radiographic parameters and clinical scores. The 3-year implant survivorship was 96.4%.

Cup inclination does not appear to influence complications or functional outcomes in MAÏA TMJ arthroplasty. In contrast, poor centralization is significantly associated with an increased risk of revision. Accurate central placement of the trapezial cup may be a key factor in improving implant longevity and reducing complications.

IV (retrospective cohort study).