Biomechanical characteristics of extensor tendon suture techniques

Despite their ease of exposure, extensor tendons can be difficult to handle and suture well. Compared with flexor repair, little is known about the various factors that affect the suturing of extensor tendons. The present study was designed to investigate several biomechanical parameters involved in extensor repair. All techniques studied shortened the tendon considerably and produced significant losses of flexion at the metacarpophalangeal and proximal interphalangeal joints. In addition, repairs achieved with all suture techniques were considerably weaker than those achieved when comparable techniques were used on flexor tendons. However, the Kleinert modification of the Bunnell technique provided the strongest sutures in extensor tendons, produced no gapping, caused the least worrisome loss of metacarpophalangeal and proximal interphalangeal flexion, and best approximated the results found in an idealized tendon-shortening model.