PATELLAR TENDON AND INFRAPATELLAR FAT PAD HEALING AFTER HARVEST OF ANACL GRAFT

Clinical studies have documented proliferation of the host patellar te ndon and fibrosis extending into adjacent tissues after reconstruction of the injured anterior cruciate ligament (ACL) using the central one -third of the patellar tendon (PT) as the graft. Such generalized arth rofibrosis has been implicated in knee locking and as possible source of anterior knee pain. However, it is not clinically feasible to measu re changes in tendon morphology and mechanical properties and degenera tion of peripheral tissues over time following graft harvest. In a rab bit experimental model proliferative changes in the tendon and the inf rapatellar fat pad have been documented following harvest of a central third tendon graft without ACL reconstruction. Studies in larger anim als have shown significant reductions in the strength and stiffness of the healing patellar tendon, but without assessment of the peripheral tissue response. In the current study an ACL reconstruction was perfo rmed in a goat model using an autogenous patellar tendon graft. Extens ive tendon and fat pad proliferation were observed along with signific ant reductions in the biomechanical properties of the host tendon. Sig nificant fat pad fibrosis was documented using biochemical methods. Th e current data confirm that harvest of an autogenous PT graft for reco nstruction of the ACL results in significant changes in the PT and adj acent tissues. These data may help explain some of the clinical compli cations documented in the reconstructed joint. (C) 1998 Academic Press .