A biomechanical study of extensor tendon repair methods: introduction to the running-interlocking horizontal mattress extensor tendon repair technique.

PURPOSE: Extensor tendon injuries are common; however, relatively few studies have evaluated extensor tendon repair methods. The purpose of this study was to investigate the properties of the running-interlocking horizontal mattress repair method with regard to tendon shortening, stiffness, strength, and time needed to perform the repair, compared with the modified Bunnell method and the augmented Becker method.

METHODS

Twenty-four extensor tendons from 8 fresh-frozen cadaveric hands were harvested from zone 6. The harvested tendons were randomly assigned into 1 of 3 repair groups: augmented Becker, modified Bunnell, and running-interlocking horizontal mattress repair methods. The running-interlocking horizontal mattress repair combines a running suture with an interlocking horizontal mattress suture. Each repaired tendon was measured for length before and after repair and tested for stiffness, ultimate load to failure, and time required to perform the repair.

RESULTS

The running-interlocking horizontal mattress repair was significantly stiffer (8,506 N/m) than the augmented Becker (5,971 N/m) and the modified Bunnell (6,719 N/m) repairs. The running-interlocking horizontal mattress repair resulted in significantly less shortening (1.7 mm) than the augmented Becker (6.2 mm) and modified Bunnell (6.3 mm) repairs. The running-interlocking horizontal mattress repair took significantly less time to perform without a significant difference in the ultimate load to failure (running-interlocking horizontal mattress repair, 51 N; augmented Becker, 53 N; modified Bunnell, 48 N).

CONCLUSIONS

The running-interlocking horizontal mattress repair is significantly stiffer and faster to perform than either the augmented Becker or the modified Bunnell repairs, and it results in less shortening than either of these methods. The running-interlocking horizontal mattress repair should be strong enough to withstand some early motion.