Biomechanical analysis of human ligament grafts used in knee-ligament repairs and reconstructions

Abstract

The aim of this study was to determine the mechanical characteristics of collegenous grafts in the knee in young adult donors. Cadaveric ligament specimens from a range of locations in and around the knee were assessed in terms of their tensile strength and lengthening characteristics. These were compared to similar anterior cruciate ligament specimens. Reduced graft strength was observed in specimens containing prepatellar retinacular tissues or specimens taken from the distal iliotibial tract or fascia lata, although the width of these grafts was directly proportional to the tensile strength. Grafts taken from the gracilis or semitendinosus tendons were stronger, although still not at the same level as the anterior cruciate ligament. The greatest tensile strength was observed in bone-patellar tendon-bone specimens, which was approximately 65 % greater than that of the anterior cruciate ligament graft. Semitendinosus and gracilis tendon grafts possessed similar stiffnesses to anterior cruciate ligament grafts, whereas that of the patellar tendon-bone grafts was three to four times higher than the anterior cruciate ligament.