Bone-ligament interaction in patellar tendon reconstruction of the ACL

Abstract

The bone-ligament junction is one of the most complex biological tissues. Its key function is distribution of mechanical loads applied to the ligament in such a way as to diminish the concentration of stresses or shearing at the interface. This paper reports an experimental assessment of the extent to which a nearly normal junction is formed following reconstruction of the anterior cruciate ligament (ACL) with patellar tendon in 20 New Zealand white rabbits sacrificed after 2-38 weeks. A histological comparison was also made with cadaver ACLs. After 5 weeks the new ligament was still separate from the tunnel wall, inflammation was no longer present, and there was no junction tissue. A thin fibrocartilage layer was observed between the bone and the ligament after 12 weeks and was thicker 6 weeks later. After 28 weeks, there was a substantial layer of fibrocartilage. The new junction was virtually "physiological" by the 38th week, with all four layers present. Many fibrocartilaginous cells were also visible between the collagen fibres. The bone-ligament insertion was almost normal. These findings indicate that tendon reconstruction results in the formation of a structure very similar to a physiological junction, and thus ensures better load distribution over a greater ligament insertion area.

Effects of hyperbaric oxygen treatment on tendon graft and tendon‐bone integration in bone tunnel: Biochemical and histological analysis in rabbits

“…Remodeling processes of tendon grafts depend upon numerous factors. 16,20,22,23 Anderson et al 24 and Rodeo et al 20 demonstrated that adding osteoinductive growth factors, such as bone morphogenetic protein (BMP), improves tendon healing in a bone tunnel. Other studies have also shown that parathyroid hormone, HBO, and physical factors such as continuous passive motion (CPM) accelerate the healing of joint tissues, including bone and cartilage.…”

“…Other studies have also shown that parathyroid hormone, HBO, and physical factors such as continuous passive motion (CPM) accelerate the healing of joint tissues, including bone and cartilage. 3,5,22,25,26 This study employed intra-articular tendon transplantation mimicking ACL reconstruction under physiological knee loading similar to that in clinical applications. Experimental results demonstrated that HBO treatment significantly increased the amount of trabecular bone around the tendon graft, increased the incorporation of tendon and bone, and enhanced the graft tensile strength.…”

The biology of integration of the anterior cruciate ligament

“…It is only by 38 weeks after implantation of a bone-patellar tendon model that the four layers of graftbone integration were apparent. 42 Hamstring autograft. The use of hamstring autograft is becoming increasingly popular.…”

Kinematic outcomes following ACL reconstruction

“…This graft has the advantage of bone to bone healing in tunnels that has been shown to incorporate much earlier than tendon to bone healing, thereby allowing for more rapid rehabilitation after surgery [55,56]. Various other properties of the bone-patellarbone construct may affect the performance of the graft.…”