High intrinsic healing potential of human anterior cruciate ligament. Organ culture experiments.

We studied the intrinsic healing capacity of human semitendinosus tendon specimens, comparing them to human anterior cruciate ligament specimens collected at the time of ligament reconstructions, and using an organ culture model. On the day after cultivation, migration of cells and synthesis of collagen fibers were observed in the ligament group with preserved synovium (PS), the ligament group with resected synovium (RS), and the semitendinosus tendon group (ST). Migrating cells and newly-formed collagen fibers were most prominent in the PS group, followed by the RS, and ST groups. When the area occupied by the migrating cells and newly-formed collagen fibers in the prepared hole was measured, no differences were observed between the groups at week 2. However, differences were noted between the ST and PS or RS groups at weeks 4 and 6. Our findings indicate that the human anterior cruciate ligament possesses a high intrinsic healing capacity. It is also suggested that the synovium plays an important role in enhancing ligament healing capacity.