Characterization of the tensile properties and histologic/biochemical changes in normal chicken tendon at the site of suture insertion.

The hypothesis of this study is that inserting a grasping suture into tendon tissue causes adverse changes at the suture-to-tendon interface and thus compromises the outcome of tendon repair. This study characterized the histologic, biomechanical, and biochemical effects that 2 types of grasping sutures, Kessler and Savage, produced on normal chicken flexor tendon in the digital flexor sheath. Variables caused by a healing response were avoided by not cutting the tendon. Findings included a reduction in ultimate tensile strength beginning soon after the suture was inserted, cell proliferation, lysis of types I and III collagen by collagenase, and presence of gelatinase. No histologic or biochemical differences were detected between the 2 suture patterns. These findings are presumed to be adverse and suggest an additional reason why the ultimate tensile strength of repaired tendon may be too low to allow patients to move tendons actively without a high risk for causing gap formation or rupture in the early weeks of healing.