To evaluate the incidence and risk factors associated with osteoarthritis after a reconstruction of the anterior cruciate ligament (ACL) using a patellar tendon autograft after an average follow-up period of more than 10 years.

The study examined 56 cases that were selected from 118 cases who underwent an arthroscopic reconstruction of the ACL using a patella tendon autograft a minimum of 8 years ago and were available for follow up. The mean age at the time of the reconstruction was 31.3 years (19-58 years), and the average follow up period was 10.6 years (8.6-13.8 years). At the last follow up, the presence of osteoarthritis on the weight-bearing antero-posterior and lateral, and Merchant's radiographs, was assessed using the Kellgren and Laurence classification. The correlation between the development of osteoarthritis and the clinical results (Lysholm knee score, Lachman test, Pivot-shift test, return to preinjury activity), the radiological results (anterior laxity, persistent anterior subluxation), the interval from injury to the reconstruction, the patient age at the time of the reconstruction, the presence of an accompanying meniscal injury, and the patient's gender were examined.

Among the 56 cases, osteoarthritis was detected in 23 (41%) (grade II, 18 cases; grade III, 5 cases), and in regard to the lesion sites, the medial compartment was detected in all cases, the lateral compartment in 12 cases and the patello-femoral compartment in 11 cases. Among them, 19 cases were accompanied with a meniscal injury (OR, 10.336; p = 0.001), and a significant increase in osteoarthritis was detected in those cases with a interval from the injury to the reconstruction of more than 6 months (OR, 4.611; p=0.030), and in those aged more than 26 years at the time of the reconstruction (OR, 5.038; p=0.023). However, there was no correlation between the development of osteoarthritis and the clinical outcome, radiological anterior laxity and continuous anterior subluxation, and genders (p>0.05).

Osteoarthritis developed in 41% of cases, and developed more frequently in those cases with an accompanying meniscal injury, older patients at the time of the reconstruction, or in those with a longer interval from the injury to reconstruction.