Abstract

The purpose of this study was to test the hypothesis that healing of a stable tear in the avascular region of the meniscus occurs when a horizontal conduit, extending from the periphery to the defect, is filled with an exogenous fibrin clot. In 6 sheep a full-thickness laceration was made in the lateral meniscus, and autologous blood clot was then injected into the conduit. Three animals in the control group received identical meniscal tears but no additional treatment. Casting and a harness prevented weight-bearing and maintained the knee in a flexed position. Twelve weeks after the operation histologic examination revealed only partial healing in one animal. In both the experimental and control groups increased numbers of dividing chondrocytes on either side of the tear were seen. We conclude that an in-substance conduit in combination with the injection of a blood clot is not sufficient to facilitate complete healing of a tear within the avascular region of the lateral meniscus of the sheep when the knee is immobilized only with a harness.