Cyclic stress testing after in vivo healing of canine flexor tendon lacerations

This study evaluated the effects of cyclic tension applied to lacerated and repaired canine flexor tendons after various periods of in vivo healing for up to 30 days. Final gaps obtained after cyclic stress testing were found to increase from a baseline of 0.75 +/- 0.17 mm (zero time controls) to a maximum of 1.14 +/- 0.24 mm at 3 days after repair, before returning to baseline at 10 days (0.63 +/- 0.27 mm). Cap formation at 30 days after repair (0.65 +/- 0.27 mm) was similar to that of control tendons. This canine study suggests that continued protection of flexor tendons from strong repetitive tensile, stress should extend at least through 30 days after repair.