Résultats de l’arthroplastie de type Ivory (r) dans le traitement de l’arthrose trapezométacarpienne avec un suivi d’au moins 10 ans – étude prospective cohorte d’un seul centre

Abstract

This study investigated the long-term functional outcome after total replacement of the trapeziometacarpal joint with the Ivory prosthesis (Stryker Corporate, Kalamazoo, Michigan, USA) for trapeziometcarpal joint osteoarthritis. In this prospective study, range of motion, overall function, pain and radiologic outcome of the trapeziometacarpal arthroplasty were analysed after a minimum of 10 years of follow-up. The opening of the first web space and metacarpophalangeal flexion and extension were graded. Opposition and retropulsion were graded by Kapandji scores. Key pinch, precision pinch and grip strength were measured using a calibrated hydraulic pinch gauge and a calibrated hydraulic hand dynamometer. To assess the overall function, the Quick Disabilities of the Arm, Shoulder and Hand score was used. Pain score was assessed with the Visual Analogue Scale. Radiologic outcome was evaluated using frontal and profile views as described by Kapandji and Eaton views with and without stress. A total of 26 Ivory arthroplasties was evaluated. Out of the 32 patients eligible, 24 patients were included in the study. Two patients had bilateral arthroplasties. The female to male ratio was 22–2 and the mean age was 71 (range 57–83) years. The mean follow-up period was 130 (range 120–142) months. Patient satisfaction was high, with 85 % of the patients willingly to repeat surgery. The mobility of the operated thumb was improved compared to the contralateral thumb, except for metacarpophalangeal extension (78 % less than contralateral). Key pinch deteriorated with 7 % compared to preoperatively, grip strength improved with 3 %. The overall function, according to the Quick Disabilities of the Arm, Shoulder and Hand score improved by 54 %. Pain decreased by 81 % with a mean Visual Analogue Scale score of 13/100 at a minimum of 10 years follow-up. Radiologic evaluation revealed polythene wear with secondary joint instability that needed revision in two patients, and a broken implant that needed revision in another male patient. Three patients had asymptomatic polythene wear that required no revision but remain in follow up. One patient had a failure of the prosthesis and was converted to a trapiezectomy. The 10 year overall survival of the prosthesis was 85 %. These long term results suggest that the Ivory arthroplasty is a reliable option for treating advanced trapeziometacarpal osteoarthritis, since it gives an important improvement in overall function and pain reduction. However, revision of the implant within 10 years after surgery is needed in 15 % of the cases.