Flexor digitorum profundus tendon excursions during controlled motion after flexor tendon repair in zone II: a prospective clinical study.

Intratendinous metal markers were used to study flexor digitorum profundus tendon excursions during early controlled motion with dynamic flexion traction and to evaluate their significance for results after flexor tendon repair in zone II. The mean excursion was 1 mm along the middle phalanx and 5.6 mm along the proximal phalanx. This corresponded to a mean excursion per 10 degrees of controlled distal and proximal interphalangeal joint motion of 0.3 and 1.2 mm, respectively. Compared to active motion, controlled motion of the distal interphalangeal joint mobilized the tendon with an efficiency of 36% and controlled motion of the proximal interphalangeal joint mobilized the tendon with an efficiency of 90%. Controlled-motion excursions induced by the distal interphalangeal joint along the middle phalanx had little influence on subsequent active range of motion in the distal interphalangeal joint, whereas excursions along the proximal phalanx (for which the proximal interphalangeal joint was largely responsible) did have a significant influence on subsequent total active interphalangeal range of motion.