QUANTITATIVE COMPARISON OF SOFT TISSUE-BONE INTERFACE AT CHONDRAL LIGAMENT INSERTIONS IN THE RABBIT KNEE-JOINT

At chondral ligament insertions the calcified fibrocartilage interdigi tates deeply with the lamellar bone. The shape of this interface is fo rmed under physiological loading conditions. For the purpose of morpho logical comparison between different ligament entheses in the rabbit k nee, the number and frequency of interdigitations and thickness of cal cified fibrocartilage were quantitated at the femoral insertion of the medial collateral ligament, both insertions of the cruciate ligaments , and the tibial insertion of the patellar ligament. Among the inserti ons, the femoral insertion of the medial collateral ligament showed th e lowest frequency and depth of interdigitations at the soft tissue-bo ne interface, but had the thickest zone of calcified fibrocartilage. A n inverse relationship was found at the insertion interface of the cru ciate and patellar ligaments. The frequency and depth of interdigation s at the bone-soft tissue interface at different chondral entheses see m to be related to the mechanical strength of the respective ligament; meanwhile it may be hypothesised that the thickness of the calcified fibrocartilage might be more related to the amount of motion which tak es place at an insertion.