Arthroplastie scapho-métacarpienne – À propos de 10 cas de révision d’arthroplastie trapézo-métacarpienne et de trapézectomie

Abstract

Trapezio-metacarpal (TM) prosthesis has show good results in the surgical treatment of rhizarthrosis. One of the main causes of failure is tapezium loosening. For the revision of a failed prosthesis, trapeziectomy can be a solution. Another possibility is to implant a cup into the distal extremity of the scaphoid, thus performing a scapho-metacarpal arthroplasty. This scapho-metacarpal arthroplasty can also be used in the event of failed trapeziectomies. The purpose of this study is to present preliminary results of 10 cases of scapho-metacarpal prosthesis. A retrospective multicentric study was carried out on 10 patients, 9 women and 1 man, with an average age of 74 years, who underwent surgery between 2009 and 2015. Four had revision surgery after trapezio-metacarpal arthroplasty, 5 after trapziectomy, one hade a revision of silicon implant. The prosthesis that has been used was MAIA ® Prosthesis, with long or extra-long neck. Assessment covered – Visual Analog Pain Scale, mobility, strength, Quick-DASH, satisfaction score, preoperative, postoperative and the most recent X-rays (Kapandji incidences). Results Nine patients were assessed with a mean follow-up of 34 months, 1 patient was lost during the follow-up. Out of these 9 patients, we had 1 who failed, due to an early scaphoid cup loosening. There are 4 out of 9 patients who underwent surgery on their dominant hand. Four patient said they were very satisfied with the outcome, 4 were satisfied and 1 was not very satisfied. The average pain score was 1.2/10 and the average Quick-DASH was 38.5. The mean mobility of the carpometacarpal joint was – 48° in abduction, 40° in antepulsion, opposition according to Kapandji was 8.6, retropulsion was 1.9. Tumb strength measurements were 3 kg for key pinch, and 13.6 kg for grip strength. Radiographic assessment showed only one scaphoid cup loosening, and measurement of the length of the thumb column showed a shortening of 0.2 cm after surgery. Other surgical procedures has shown good results for revision of failed prosthesis such as secondary trapeziectomy, but only with short follow-up. Surgical procedures for failed trapeziectomy are very limited. Scapho-metacarpal arthroplasty is a reliable medium-term solution for revision of the loosening of a trapezio-metacarpal prosthesis with trapezium damage, as well as for failed trapeziectomy.