How can practitioners decide when to reconstruct a torn anterior cruciate ligament?

Abstract

Anterior cruciate ligament (ACL) injuries are a common problem with 80,000 ACL injuries in the athletic population and 200,000 in the general population annually in the USA [1,2]. With growth in youth sports and activities, ACL injuries are a problem in the active adolescent population [3]. ACL reconstruction techniques designed to restore knee stability and protect the menisci and cartilage from damage are popular, but the decision of in whom to perform a reconstruction is not as clear as simply identifying a torn ACL on MRI. Some patients can develop functional stability with conservative treatment, while others require operative reconstruction to provide stability. Age, activity level, patient expectations, knee stability, mechanical alignment and cartilage status each play an important role in deciding who will maximally benefit from a surgical intervention versus nonoperative rehabilitation and/or bracing. In addition, one must consider the risk of joint degeneration and osteoarthritis (OA) to the knee with and without a functional ACL. The kinematics and contact mechanics of the knee with and without an ACL or an ACL reconstruction have been studied to provide greater insights into the role of the ACL in joint contact stresses and potentially OA [4]. Patients have a variable ability to function with ACL def iciency based on anatomic differences, activity level and expectations. Noyes et al. proposed a ‘rule of thirds’ in the 1980s [5]. ‘Copers’ are the one third of patients that resume activities and manage well without reconstruction, ‘adapters’ manage by modifying activities and ‘noncopers’ have recurrent instability with activities and require ACL reconstruction to restore functional stability. Very few studies have successfully addressed how to identify the potential copers from the noncopers and thereby focus ACL reconstructive surgery on those patients who will derive maximal benefit. Copers have been shown to have movement patterns consistent with knee stability [6] with significantly less anterior laxity, fewer incidences of instability or episodes Moira M McCarthy*, Suzanne Maher, Asheesh Bedi & Russell F Warren Editorial