Functional Assessment of Basal Joint Fusion of the Thumb

Abstract

In the present study radiological and functional assessment of 24 cases of basal joint fusion for degenerative arthrosis of the carpo-metacarpal joint of the thumb is presented. Solid fusion occurred in 21 cases whereas 3 cases showed fibrous union. Secondary arthrosis in adjacent joints were uncommon. Compensatory motion in the greater multangular—navicular joint did not occur, while hyperextension of the metacarpo-phalangeal joint was a common finding and was considered to be secondary to the reduction of web space span caused by the basal joint fusion. Relief of pain at rest was obtained in all but 2 cases and 8 patients had no complaints. In 6 cases pain occurred after heavy work and was referred to the metacarpo-phalangeal joint in those cases with marked hyperextension, and to the base of the thumb in cases with a rigid and protruding first metacarpal. The positioning of the thumb was found to be of major importance for good results, 30° of palmar abduction and 10° of radial abduction being the optimal angle between the first and second metacarpal bones. Impairment of precision handling was found in most cases but generally accepted as a low price for pain relief and stability.