Description and Clinical Assessment of the Bone Block Tendon Interposition Technique for the Management of Thumb Carpometacarpal Joint Osteoarthritis.

Background: Pellegrini's surgical technique is the most useful for thumb carpometacarpal joint osteoarthritis. The purpose of this paper is to describe the technique of a modified version using a bone block in the tunnel through which the flexor carpi radialis tendon is passed (BBTI).

Methods: Case series of patients diagnosed with osteoarthritis of the thumb carpometacarpal joint, in stage II or higher based on Eaton's classification, that were intervened using the BBTI technique for a 2-year period. Grip and pinch strength, range of motion, and 1-2 metacarpal angle were evaluated. Pain and function were measured using the visual analogue scale and the Disabilities of the Arm, Shoulder and Hand (DASH) scale.

Results: The study included 16 cases in 14 patients (11 women and 3 men), with an average age of 55.7 ± 7.1 years. Encouraging results were obtained, with an average DASH score of 24.3 ± 17.9 and a minimum VAS pain score. A total of 58% showed a grip strength of over 80% and the postoperative movement was equivalent to the contralateral limb. No cases of infection were reported, and only two minor complications were observed.

Conclusions: The BBTI technique is a surgical option that incorporates an interference screw, offering good functional results for managing osteoarthritis of the thumb carpometacarpal joint, with a similar complication rate to that of the original technique.