Knee Function and Prevalence of Knee Osteoarthritis after Anterior Cruciate Ligament Reconstruction

Background Few prospective long-term studies of more than 10 years have reported changes in knee function and radiologic outcomes after anterior cruciate ligament (ACL) reconstruction. Purpose To examine changes in knee function from 6 months to 10 to 15 years after ACL reconstruction and to compare knee function outcomes over time for subjects with isolated ACL injury with those with combined ACL and meniscal injury and/or chondral lesion. Furthermore, the aim was to compare the prevalence of radiographic and symptomatic radiographic knee osteoarthritis between subjects with isolated ACL injuries and those with combined ACL and meniscal and/or chondral lesions 10 to 15 years after ACL reconstruction. Study Design Cohort study; Level of evidence, 2. Methods Follow-up evaluations were performed on 221 subjects at 6 months, 1 year, 2 years, and 10 to 15 years after ACL reconstruction with bone-patellar tendon-bone autograft. Outcome measurements were KT-1000 arthrometer, Lachman and pivot shift tests, Cincinnati knee score, isokinetic muscle strength tests, hop tests, visual analog scale for pain, Tegner activity scale, and the Kellgren and Lawrence classification. Results One hundred eighty-one subjects (82%) were evaluated at the 10- to 15-year follow-up. A significant improvement over time was revealed for all prospective outcomes of knee function. No significant differences in knee function over time were detected between the isolated and combined injury groups. Subjects with combined injury had significantly higher prevalence of radiographic knee osteoarthritis compared with those with isolated injury (80% and 62%, P = .008), but no significant group differences were shown for symptomatic radiographic knee osteoarthritis (46% and 32%, P = .053). Conclusion An overall improvement in knee function outcomes was detected from 6 months to 10 to 15 years after ACL reconstruction for both those with isolated and combined ACL injury, but significantly higher prevalence of radiographic knee osteoarthritis was found for those with combined injuries.