The biology of anterior cruciate ligament healing after reconstruction

Anterior cruciate ligament (ACL) reconstruction is a common orthopaedic sports medicine procedure. Our understanding of ACL graft healing has evolved over time, and can guide our approach in rehabilitating patients after ACL reconstruction. This chapter reviews the native biology of the ACL tendon and our current understanding of the timeline of healing after ACL reconstruction, noting differences between autograft and allograft tissue. We discuss the effect of biomechanical loading on the graft and other factors than can positively or negatively influence graft healing. Greater understanding of the ACL graft healing process can ideally translate into better surgical techniques, optimized rehabilitative treatment of post-operative patients, and ultimately improved patient outcomes.