The mechanical effect of partial resection of the digital fibrous flexor sheath

In the context of primary flexor tendon repair, a study has been made to determine how much of the flexor sheath may be opened without causing mechanical disadvantage to the finger. In five cadaver hands, measurement of profundus tendon excursion, distance from nail to distal palmar crease, profundus flexion force, and tendon bow-stringing, showed that there was no material change of these parameters when up to four contiguous pulleys were divided. Along with other individual pulleys, A2 and A4 cannot be regarded as inviolate.