Repair of three-month-old experimental meniscal lesions in rabbits

Repair of three-month-old longitudinal meniscal lesions in the central avascular portion of the knee joint was investigated in 18 rabbits. Three months after a longitudinal incision was made in the avascular portion of the meniscus, no healing was observed. At that time a full-thickness radial cut from the lesion to the joint capsule, without using synovial flaps or implants, was performed in ten of the 18 rabbits. Three months later, nine of the ten menisci had healed mainly with cartilaginous tissue, although the repaired areas were different from the normal fibrocartilage both histologically and at gross inspection. Synovitis with hyperplasia of the lining cells, which was present in all cases at the time of repair, may play an important role in the healing process.