Arthroscopic observations of autogeneic quadriceps and patellar tendon grafts after anterior cruciate ligament reconstruction of the knee.

Fifty-six arthroscopic observations on 53 knees at various periods after anterior cruciate ligament (ACL) reconstruction using the autogeneic quadriceps and patellar tendon were analyzed to clarify the morphologic maturation process of such grafts in human patients. Arthroscopic observations of the grafts were divided into four types, excluding one rerupture case. Type I was observed in three knees less than six months after ACL reconstruction and in one knee six to 12 months after; Type II, in seven knees six to 12 months after; Type III, in six knees six to 12 months after, in 13 knees 12-18 months after, and in five knees more than 18 months after; and Type IV, in eight knees 12-18 months after and in 12 knees more than 18 months after. The types and the intervals after reconstruction were correlated with four phases of healing, including the maturation process of the implanted autogeneic grafts: (1) synovial envelopment, (2) fibrous tissue ingrowth, (3) transformation into ligamentlike tissue, and (4) hypertrophy or maturation of striated ligamentlike structure.