[Addition-subtraction osteotomy combined with ligamentoplasty for symptomatic trapezial dysplasia with instability]

Trapezometacarpal instability with trapezial dysplasia is an incapacitating condition long before radiological changes appear. Most of the patients are young and demanding. Treatment is often conservative. Surgical treatment options are relatively classic, starting with a ligamentoplasty of the base of the first metacarpal or a tenotomy of the transarticular accessory slip of the abductor pollicis longus. Other options such as arthrodesis and arthroplasty have not been so successful in this situation.

The idea arose to combine two techniques described previously. In 1973 Wilson published his technique of abduction osteotomy of the first metacarpal as a treatment for basal osteoarthritis of the thumb. In 2002, Kapandji and Heim published their opening wedge osteotomy of the trapezium in order to correct the slope of a dysplastic trapezium. The combination of both of these techniques avoids closing of the first web by utilising the abduction osteotomy of the first metacarpal. Moreover, the opening wedge osteotomy corrects the dysplastic lateral rim of the trapezium by correcting its slope.

We have been performing this technique since 2001 and 2005 in six patients. The preliminary results are encouraging, 5 of them were able to resume their work. A fair result was achieved in a young patient.

The described technique is relatively easy and has the advantage of preserving the trapezometacarpal joint. In addition, it leaves the door open for other techniques if it eventually should fail in the long term.