gms | German Medical Science

Objectives/Interrogation: Symptomatic trapezial dysplasia with metacarpal instability can lead to a disabling condition, which is characterized by pain, decrease in mobility and strength. Radiographic changes are initially often absent. Different techniques have been described based on soft tissue balancing or osteotomies around the joint. In dysplastic joints a bony correction is required, because soft tissue correction is insufficient to stabilize the trapeziometacarpal joint.

Methods: We combined two techniques described in the past, an abduction/extension osteotomy of the first metacarpal and an opening wedge osteotomy of the trapezium, to which we added a ligament reconstruction with the hemi Flexor Carpi Radialis. This combination corrects the anatomy and the forces acting across the joint. Between 2003 and 2007 we have done this procedure 21 times in 18 patients. The operation was only done when conservative treatment was unsuccessful (night splinting and nonsteroidal anti-inflammatory medication). Seventeen thumbs were reviewed prospectively with a mean follow-up of 12,2 (+/-0,94) years (range: 10,9 - 14,4). 3 patients were lost to follow-up.

Results and Conclusions: In our results we found very good mobility, strength, pain relief, function and radiographic evolution. There was an improvement of the key pinch with 1,1 kg (+/-1,8) (range: -2 - 5) and of grip strength with 4,5 kg (+/-7,4) (range: -6 - 18) after 10 year follow-up. Key pinch of the operated thumb is similar to the preoperative situation. The QuickDASH improved by 43,9 points (+/- 19,1) (range: -5 - 68,1). Radiographic evaluation showed a significant correction of the so called Dévers angle (slope of the trapezium), with a mean correction of 9,1° (+/-6,7) (range: 2 - 22). When comparing the postoperative radiographs with those made more than 10 years ago, there was a stable Dévers' angle. One patient had a trapeziometacarpal arthroplasty one year after the previous operation. One other patient had to be operated on twice more for pseudarthrosis due to entrapment of the ligament into the osteotomy. There was no damage to the articular surface due to iatrogenic fracture or other perforation into the joint. Even in this long-term follow-up no complications were observed.

This technique has a positive long-term effect on symptomatic trapezial dysplasia with metacarpal instability. It protects the trapeziometacarpal joint from further wear and allows other techniques to be used if painful arthritis develops in the long term.