Compression Arthrodesis of the Carpo-metacarpal Joint of the Thumb.

PURPOSE OF THE STUDY Arthrodesis of the carpometacarpal (CMC) joint of the thumb is an option for treatment of degenerative and post-traumatic conditions affecting the CMC thumb joint. This procedure is indicated most frequently in patients with primary or secondary stage III rhizarthritis (by the Eaton classification of basal joint arthritis) of idiopathic, rheumatic or post-traumatic etiology. Patients with multidirectional CMC instability, usually traumatic in origin, undergo this surgery only occasionally. In our institution, the treatment is based on the Carroll technique. MATERIAL AND METHODS Between 1990 and 2005 a total of 14 arthrodeses of the CMC joint of the thumb were performed in 12 patients. The Carroll technique used in all cases involved a conical shaping of the first metacarpal base and a corresponding shaping of the trapezium articular surface, their subsequent set-up and fixation with Kirschner's wires. The patients were assessed for the presence of pain, changes in mobility and muscle strength before and after surgery. The comprehensive evaluation of the whole group was carried out by means of the Cooney score. RESULTS Arthrodesis resulted in complete union of the CMC joint of the thumb in all cases. The patients were followed up for 5 years on average. The initial painful hand grip subsided in most of them. The initial restriction of motion remained, but was painless in almost all cases. However, broad grip strength improved on average by 35 %. The comprehensive Cooney score showed 64 % of excellent and very good results. DISCUSSION All characteristics of the patient group and the results achieved by this technique, including the Cooney score evaluation, are discussed. It is concluded that this technique is indicated particularly in middle-aged male patients with stage III rhizarthritis (Eaton classification) who do hard manual work, and in whom rhizarthritis of the other thumb joints can be excluded. Also, unstable CMC joints are indicated for this treatment. The resulting position of arthrodesis and methods of joint fixation are discussed. Different methods of osteosynthesis and their advantages are described. From a comparison with the relevant literature results it appears that the absence of postoperative pseudoarthrosis, a marked reduction of grip pain, improvement of grip strength and the values of Cooney score are encouraging results of arthrodesis for the CMC thumb joint performed by the Carroll method. CONCLUSIONS It is concluded that the Carroll arthrodesis is an effective technique which, if correctly indicated, alleviates pain, restores the axis of the thumb and, consequently, its stability necessary for thumb function in achieving a hand grip.