An experimental model for the study of canine flexor tendon adhesions.

An experimental model for the study of canine flexor tendon adhesions was designed using a standardized crush-abrasion injury, meticulous sheath closure, and three-week limb immobilization. Ten animals in the experimental protocol were evaluated for visible adhesion formation. With use of a flexor tendon adhesion rating scale, consistent adhesion formation was documented with an average score of 10.4 +/- 2.1 (range, 0 to 12). Five additional animals had biomechanical testing. Applying an increasing load to the proximally divided profundus tendon (0 to 10 Newtons), it was found that the angle of distal interphalangeal joint motion and the displacement of the toe were significantly decreased, and the work generated significantly increased in the experimental versus control digits (p less than 0.05). The consistent production of visible adhesions thus correlates with biomechanical impairments in toe motion and work. The study of agents aimed at diminishing flexor tendon adhesions will thus be facilitated by this reliable model. Systemic or intrasheath administration of agents will be possible.