Purpose: Evaluate outcome after isolated intra-articular ACL graft in patients aged 40 to 60 years using patellar bone-tendon and gracilis grafts.

Material and methods: This retrospective comparative study included 30 consecutive patients who underwent arthroscopic surgery between September 1996 and September 1999 performed by the same operator: 14 patellar bone-tendon grafts and 16 gracilis grafts. The indication for surgery was knee instability in everyday or sports activities. Exclusion criteria were associated peripheral ligament plasty or bone procedures. The two populations were strictly identical except for gender and follow-up: patellar bone-tendon group: mean age 49 years, 12 men, follow-up 46 months, 6 associated menisectomies; gracilis series: mean age 48 years, 13 women, mean follow-up 30 months, 6 associated menisectomies. The IKDC score, laximetry (KT 2000), x-rays (AP, single stance lateral, 30° flexion) were used by two operators different from the operating surgeon to assess outcome.

Results: At last follow-up, there was a significant difference between functional and anatomic outcome in the two groups. 83% of the patients were classed IKDC A or B. Subjectively, 90% of the patients were satisfied or very satisfied. The pivot test was negative in 24 (80%), doubtful in 5 and positive in 1. 86% of the patients had a differential laxity less than 3 mm. In the gracilis group, two patients developed chronic hamstring pain. In the patellar bone-tendon group, two patients developed persistent patellar pain. Two patients underwent a second procedure for meniscectomy. At last follow-up the x-rays demonstrated early signs of degeneration in 20% of the patients and signs of medial femorotibial degeneration in 10%.

Discussion: Gracilis and patellar bone-tendon grafts provide strictly identical results; residual pain is not more prevalent after patellar graft; control of laxity is not less satisfactory after hamstring graft. In our series, ACL graft in patients over 40 years of age provided functional, laximet-ric, and radiographic results comparable to those in patients undergoing ACL grafts before the age of 40 years.

Conclusion: 1) ACL graft can be indicated after the age of 40 years for patients with knee instability bothersome for everyday or sports activities. 2) Functional and anatomic results are identical with those obtained in younger subjects. 3) Irrespective of the graft used, patellar or hamstring, outcome is satisfactory and morbidity is not different.