Implant migration and clinical outcomes with cemented vs cementless Motec cups in total trapeziometacarpal arthroplasty: a 10-year prospective RSA cohort study of 69 patients

BACKGROUND AND PURPOSE: Few clinical studies have assessed migration of trapeziometacarpal implants, and long-term outcomes are warranted. We aimed to evaluate 10-year migration, clinical outcomes, and revisions of cementless and cemented Motec cups. Additionally, early migration of revised and non-revised cups, and the association between clinical outcomes and cup revision were investigated. METHODS: Radiostereometric analysis (RSA) was performed after cast removal (baseline = 3 weeks), at 3 months, 1, 2, 5, and 10 years. Clinical outcomes and revisions were evaluated prospectively. RESULTS: 22 cementless Motec titanium-screw cups were inserted from 2009 to 2010, followed by 47 cemented Motec all-polyethylene cups inserted with Palacos bone cement from 2011 to 2012. At the 10-year follow-up, mean cup total translation (TT) was 0.79 mm (standard error [SE] 0.55) for cementless cups (n = 3) and 1.33 mm (SE 0.30) for cemented cups (n = 10), with cemented cups demonstrating 0.54 mm (CI -0.68 to 1.77) higher translation. 10 of 22 cementless cups and 15 of 47 cemented cups were revised, primarily due to aseptic loosening. There was a difference in TT between revised and non-revised cups of 1.75 mm (CI 0.45-3.05) for cementless cups at 1-year follow-up, and of 1.11 mm (CI 0.30-1.93) for cemented cups at 2-year follow-up. Increased pain in activity and Disabilities of the Arm, Shoulder, and Hand (QDASH) score was associated with revision. At 10 years, patients with retained cups reported high satisfaction and grip strength, pain, and QDASH improvement above the minimal clinically important difference compared with preoperatively. CONCLUSION: 10-year cup migration was similar between Motec cup groups. Revised cups migrated more than non-revised cups in both groups, and pain in activity and QDASH score were associated with revision. As such, decline in clinical outcomes, as well as progression in cup TT, seem to be useful predictors of cup revision.