Addition-subtraction osteotomy with ligamentoplasty for symptomatic trapezial dysplasia with metacarpal instability.

Trapeziometacarpal instability with trapezial dysplasia is a disabling condition long before the radiological changes of osteoarthritis appear. In dysplastic joints surgical soft tissue correction fails to prevent the instability, requiring a correction of the bony anatomy. We combined two techniques described in the past, an abduction osteotomy of the first metacarpal and an opening wedge osteotomy of the trapezium, to which we added a ligament reconstruction. The combination of both osteotomy techniques restores the anatomy and centres the forces acting across the joint. We have done this procedure 21 times since 2003 in 18 patients. Seventeen thumbs were reviewed prospectively with a mean follow-up of 39 (range 16-65) months. Mean QuickDASH improved by 33.9 points, the key pinch improved by 1.8 kg and the grip strength improved by 8.7 kg. The visual analogue scale for pain improved from 7.9 preoperatively to 2 postoperatively. This technique preserves the trapeziometacarpal joint, allowing other techniques to be used if painful arthritis should develop in the middle to long term.