Feasibility of partial A2 and A4 pulley excision: effect on finger flexor tendon biomechanics.

We investigated the effect of partial excision of the A2 and A4 digital pulleys, separately and in combination, on finger angular rotation and the energy for finger flexion. Statistically significant decreases in angular rotation resulted only after 50% and 75% excision of A2, A4, or A2 and A4 in combination. Work of flexion trends were weak and none of the changes were statistically significant. Although optimal finger function relies on the integrity of the A2 and A4 pulleys to maintain the efficiency of the digital flexor system, these data suggest that the A2 and A4 pulleys can be excised up to 25%, either separately or in combination, without significant effects on angular rotation. Decreases in total angular range of motion after 50% and 75% pulley excision were small, even for combined pulley excision (9 degrees +/- 3 degrees and 15 degrees +/- 5 degrees [mean +/- SD], respectively), and may be clinically acceptable.