Osteoarthritis in patients with anterior cruciate ligament rupture: a review of risk factors.

The risk factors for the development of osteoarthritis (OA) in patients who have had an anterior cruciate ligament (ACL) rupture are reviewed. Although the principle arthrogenic factor is the increased anterior tibial displacement that is associated with the rupture, other direct and indirect factors contribute. Meniscal and chondral injuries can be present before, during, and develop after the index injury, making assessment of the relative importance of each difficult. Most studies concentrate on the radiological changes following ACL rupture and reconstruction. However the rate of significant symptomatic OA needing major surgical intervention is lower. This needs to be considered when advising patients on the management of their ruptured ACL. The long-term outcome in patients who are symptomatically stable following an ACL rupture is uncertain, although in a small cohort of elite athletes all had degenerative changes by 35 years and eight out of 19 (42%) had undergone total knee replacement. At 20 years follow-up the reported risk of developing osteoarthritis is lower after ACL reconstruction (14%-26% with a normal medial meniscus, 37% with meniscectomy) to untreated ruptures (60%-100%).