[Surgical treatment of carpometacarpal joint osteoarthritis of the thumb by trapeziectomy-interposition-ligamentoplasty].

Introduction: Osteoarthritis of the carpometacarpal joint of the thumb is a common pathology. Several surgical methods exist, including trapeziectomy, arthrodesis, cemented or cementless prosthesis. Therefore, one must question the legitimacy of non prosthetic surgery. The authors have tried to answer this question.

Method: Surgery consisted in trapeziectomy and ligament reconstruction with tendon interposition arthroplasty (LRTI). Authors reviewed 47 cases with five years follow-up. Patients were evaluated using a functional score, including pain, professional and domestic activities, and leisure involving the hand. Objective data were also assessed: thumb opposition, radiographic scaphometacarpal mobility, key and tip pinch, grasp strength.

Results: Functional results ranged from good to excellent in 42 cases. Opposition was satisfactory in 46 cases. Scapho-metacarpal range of motion was 16 degrees. Pinch strength was 4.2 kg and grasp strength was 23 kg. There were no complications. Loss of pinch strength was 1 to 2 kg as compared to our reference group. Such a loss does not impair patients' daily life. Age and operated side do not influence results. Scores do not decrease with time. Radiographic staging seems to be linked with scoring. Reducing the trapezial space does not influence results. We had none of the complications described in other techniques: synovitis, ossifications, loosening and reflex sympathetic dystrophy.

Discussion: This study, as well as literature, confirms that trapeziectomy and ligament reconstruction with tendon interposition arthroplasty gives satisfactory functional results which are stable with time and without complication. For all these reasons, the authors prefer this technique in degenerative osteoarthritis.