gms | German Medical Science

Objectives/Interrogation: Ligament reconstruction of the basal joint of the thumb after trapeziectomy is a common technique in patients with osteoarthrosis. For this procedure different donor tendons and techniques are described. However, there is no exact report about the best borehole direction in the basis of the first metacarpal bone to avoid proximalization and beware mobility. In this study we investigated an optimized borehole direction for ligament reconstruction.

Methods: In 32 cadaver hands trapeziectomy and ligament reconstruction described by Epping with splitted tendon of the flexor carpi radialis muscle was performed. In each first metacarpal bone we used two different borehole directions through the basis: "standard" and "Vogt". Radiological measurements were performed after trapeziectomy with and without ligament reconstruction through the two drill channels.

Results and Conclusions: The distance between the first metacarpal bone and the scaphoid after trapeziectomy and ligament reconstruction was 9.3 ± 2.7 mm when using the standard drill hole and 10.4 ± 2.7 mm when using the Vogt drill hole (p<0.01), respectively. The relative proximalization compared to preoperatively was 4 mm with the standard drill hole and 3 mm with the Vogt drill hole (p<0.01). The distance between the first and second metacarpal bone in anterior-posterior radiographs was 7.9 ± 2.9 mm when using standard drill hole and was 6.2 ± 2.1 mm when using the Vogt drill hole (p=0.001), respectively.

In ligament reconstruction after trapeziectomy using the splitted tendon of the flexor carpi radialis muscle described by Epping proximalization can be reduced using a special drill hole in the basis of the first metacarpal bone.