The Effects of A1 Pulley Release after Flexor Tendon Repair in a Cadaveric Model

Abstract

Decreasing rupture rates after flexor tendon repair is accomplished by increasing the strength of the repair and by decreasing the forces across tendons during rehabilitation. The authors sought to determine whether A1 pulley release affects work of flexion after a zone 2 flexor tendon repair. Four fresh-frozen cadaveric hands were thawed to room temperature. The flexor digitorum profundus and flexor pollicis longus tendons were tested in a tensile testing machine. In hands 1 and 2, work of flexion of uninjured tendons was evaluated through the sequential division of the A1 pulley, starting with either the proximal 50 percent or the distal 50 percent of the pulley. In hands 3 and 4, zone 2 flexor digitorum profundus lacerations were created and repaired using a modified Kessler technique; then, sequential division of the A1 pulley was performed. Force-excursion curves were generated and used to calculate work of flexion. Analysis of variance was performed for multigroup comparisons, and t tests were performed for pairwise comparisons. Values of p < 0.05 were considered statistically significant. In uninjured tendons, work of flexion decreased with sequential division of the A1 pulley. After tendon repair, work of flexion increased significantly from baseline in all digits. A1 pulley release after flexor tendon repair produced significant decreases in work of flexion in all digits. A1 pulley release effectively decreases work of flexion after flexor tendon repair. Release performed at the time of tendon repair may decrease the forces across tendons in the postoperative period.