The extensor sling procedure for an unstable carpometacarpal joint.

An unstable carpometacarpal joint of the thumb may present with pain and interfere significantly with normal function. Weakness of the intermetacarpal ligament may result in partial or complete dislocation. A procedure that reinforces this ligament more accurately than those previously published is described. A sling is made by routing part of the extensor carpi radialis longus tendon through the interspace between the second and third metacarpals and around the base of the first metacarpal. The ligament returns to its point of entry where it is sutured to itself. The entire ligament is situated deep to the adductor pollicis longus and restores stability without interfering with the first metacarpal excursion. All 10 patients who had this procedure had full metacarpal excursion and could oppose to the base of the small finger.