VIABILITY OF FIBROBLAST-SEEDED LIGAMENT ANALOGS AFTER AUTOGENOUS IMPLANTATION

Fibroblast-seeded collagen scaffolds or ligament analogs are potential ly useful for reconstruction of the anterior cruciate ligament of the knee. To provide lasting benefits, the seeded cells must survive impla ntation within the harsh synovial environment of the knee joint. Our o bjective was to determine the in vivo fate of autogenous fibroblast-se eded ligament analogs as a function of fibroblast source (anterior cru ciate ligament or skin), implantation site (knee joint or subcutaneous space), and time after implantation (1, 2, 4, 6, or 8 weeks). Before implantation, fibroblasts were labeled with PKH26-GL, a fluorescent me mbrane dye. Immediately after retrieval of the implant, the viability of the labeled seeded cells was assessed under a fluorescent microscop e. Viable seeded fibroblasts remained attached to the collagen fibers within the ligament analogs for at least 4 weeks (skin fibroblasts) or 6 weeks (anterior cruciate ligament fibroblasts) after implantation. A larger number of viable seeded cells were consistently observed in t he subcutaneous space than in the knee joint. Scaffold resorption prev ented observation at the 8-week time period. Fibroblast-seeded ligamen t analogs remained viable for prolonged periods in the knee joint and therefore have the potential to influence the formation and remodeling of neoligament tissue after reconstruction of the anterior cruciate l igament.