Experimental study of the optimal time for tenolysis.

We have attempted to define the optimal time for tenolysis by evaluating the blood supply, the rupture rate, and the tensile strength of tenolysed and control tendons. In 128 chickens tenolysis was performed 1, 3, 6, 12, 16, and 24 weeks after primary tendon repair. Tenolysis at 1 and 3 weeks resulted in devascularization, weak tendons, and high rupture rates. Tenolysis at 6 weeks after the primary repair had mixed effects on the blood supply but weakened the tendon. Tenolysis at 12 weeks after the tendon repair did not weaken the tendon and resulted in an increased blood supply. Tenolysis at 16 and 24 weeks did not weaken the tendon, but had varied effects on the blood supply. We recommend an interval of 12 weeks between primary tendon repair and tenolysis.