KOOS pain as a marker for significant knee pain two and six years after primary ACL reconstruction: a Multicenter Orthopaedic Outcomes Network (MOON) prospective longitudinal cohort study
Anterior Cruciate Ligament (ACL) reconstruction (ACLR) is the most effective and reproducible treatment for ACL injured patients who want to return to cutting and pivoting sports. More than half of the patients undergoing ACLR will have concomitant pathology, including injuries to the articular cartilage in more than 20%, lateral meniscal tears in up to 46% and medial meniscal tears in 38%.
An ACL tear is a known risk factor for the development of osteoarthritis (OA). Intermediate and long-term follow-up of ACLR patients has demonstrated a high prevalence of radiographic findings consistent with post-traumatic OA. Which factors, including concomitant pathology, the original injury, surgical techniques, or other as yet unidentified factors, are most responsible for the development of radiographic changes is unknown. A systematic review of studies including patients 5- to 10-years after ACLR, found radiographic joint space narrowing in 13% of patients with intact menisci, and 21-48% in those who had undergone either meniscectomy or repair. The meniscal status was also demonstrated to be important in a systematic review of non-reconstructed ACL injured patients. Most studies, however, are limited by poor follow-up and significant heterogeneity in the classification systems utilized to describe radiographic OA.