The stimulation of healing of the anterior cruciate ligament: Research and clinical relevance

Abstract

Anterior cruciate ligament (ACL) injuries do not heal, and even with modern surgical treatments, long-term problems remain. Current estimates suggest an incidence of approximately 1 in 3,000 for ACL tears, and approximately 120,000 patients undergo treatment for ACL defects annually in the USA alone [12, 24]. Tears of the ACL cause pain and instability and predispose patients to osteoarthritis in long term. Hence, all treatment options in the management of the torn ACL need to be evaluated both in light of their short-term effectiveness (as measured by pain, mechanical stability, and range of motion), as well as their ability to prevent osteoarthritis in the long term. The current gold standard in ACL treatment is reconstruction using either the middle third of the patellar ligament with patellar and tibial bone on either side or hamstring or quadriceps tendon. Allografts from cadavers are also available for use in multiple countries; however, availability is often limited, and there remains a small but real potential of disease transmission from the donor. Synthetic grafts are continuously being developed and tested; however, to date, most have failed in long-term trials due to inflammatory reactions to the synthetic material and eventual frank failure of the synthetic structure. Modern techniques of ACL reconstruction have consistently produced satisfactory results as far as restoring gross joint stability and relieving pain. However, recent studies have presented evidence of relatively high rates of osteoarthritis despite ACL reconstruction, even after controlling for other intra-articular damages caused by the initial trauma [10, 25, 45, 50].