ANTERIOR CRUCIATE LIGAMENT ALLOGRAFT TRANSPLANTATION

A multiplicity of surgical operations have been developed in an attemp t to achieve satisfactory function after ACL repair. None of these pro cedures have been able to duplicate the fiber organization, attachment site anatomy, vascularity, or function of the ACL. 29 foxhounds recei ved a deep frozen bone-ACL-bone allograft and a ligament augmentation device (LAD). Biomechanical, microvascular, and histological changes w ere evaluated 3, 6 and 12 months following implantation. The maximum l oad of the allograft/LADs were 34.3% (387.2 N) after 3 months, 49.3% ( 556.6 N) after 6 months and 61.1% (689.8 N) after a year. The maximal load was 69.1% (780 N). In general, after 6 months the allografts show ed a normal collagen orientation. The allografts demonstrated no evide nce of infection or immune reaction. No bone ingrowth into the LAD was observed. Polarized light microscopy and PAS-staining showed that the new bone/ligament substance interface had intact fiber orientation at the area of ligament insertion. Microvascular examination using Spalt eholtz-technique revealed neovascularization and the importance of inf rapatellar fat pad for the nourishment of the ACL-allografts.