Feasibility of a New Pulley Repair: A Cadaver Study

Abstract

Purpose: In this study, the feasibility of a new pulley reconstruction in which the tendon graft is pulled through a tunnel in the proximal phalanx, was evaluated using a cadaver model, with particular attention paid to the weakening of the bone structure by the drill hole.

Methods: Nine fingers from 6 cadaver hands with intact pulley systems were compared with 9 fingers from 6 cadaver hands with missing A2 to A4 pulleys but that included a repair using the new surgical technique. Each finger was fixed to an isokinetic loading device. The forces in the flexor tendons were recorded in each finger using a force transducer.

Results: The forces recorded in the flexor tendons of the control group were significantly higher than in the reconstructed fingers. The most common event in the reconstructed fingers was graft failure. A fracture of the bone due to the drill hole was not observed.

Conclusions: The new pulley reconstruction could represent an alternative to existing reconstructive techniques. The cause for the higher forces recorded in the control group could be attributed to sutures used in the operated fingers.

Clinical relevance: The new pulley reconstruction method may enable reduced extensor tendon irritation because it avoids contact with the extensor hood and could possibly prohibit cortical bone loss, a serious side effect in the "one and one-half loop" technique.

Keywords: Bone strength; cadaver study; climbing; operation technique; pulley rupture.