[Biomechanical study of flexor tendon repair in an in vivo curvature model]

To compare the biomechanical characteristics of 2 different repair methods:Modified Kessler and Tsuge.

Eighty-four profound flexor tendons of 3(rd) toe of Sanhuang chicken were severed and repaired by either Modified Kessler or Tsuge method randomly. Six repaired tendons for each repair method were harvested at 0, 1, 4, 7, 10, 14, 21 days after operation and tested in an Instron 1185 biomechanical testing machine. An elongation force-elongation distance curve was obtained, and biomechanical meters (including rupture force and rupture work) were calculated from this curve.

Rupture force: rupture force significantly decreased at 10(th) and 14(th) day in both repair groups, and returned to immediate level at 21(st) day in Modified Kessler group but not in Tsuge group; Tsuge method was significantly higher than Modified Kessler group at time-points immediately and 7 days after operation. Rupture work: this work significantly decreased at 10(th) (65.17 mJ) and 14(th) (40.0 mJ) day and resumed to immediate level at 21(st) day in Modified Kessler group; While in Tsuge group, it decreased significantly at 14(th) and 21(st) day. Tsuge method was significantly higher than Modified Kessler group only at time 0.

The biomechanical properties decrease significantly after 10(th) day at both repair method groups. It resumes to immediate level at 21(st) day in Modified Kessler group. There is no significant difference after 10(th) day between both repair methods.