Management of ACL Tears in the Osteoarthritic Knee
Anterior cruciate ligament (ACL) injuries in patients with established degenerative joint disease present a unique set of challenges that go beyond solely the soft tissue structure management. Global care of the knee encompasses an evaluation of the mechanical alignment of the joint and the chondral surfaces and may require an additional intervention concurrently or staged with an ACL reconstruction (ACLR) to ensure optimal outcomes. Despite advances in technique and instrumentation, studies have shown ACLR to fail or have a poor outcome in 11.9% of cases on average, with some studies citing as high as 27%. Many of these poor outcomes can be attributed to the inadequate management of the contributing mechanical and chondral factors. In these specific cases, the addition of osteotomies and/or concomitant chondral procedures has been used to address some of the factors that may lead to long-term failures or dissatisfaction with ACL reconstruction. Typically, osteotomies have been performed to address varus or valgus malalignment that has led to isolated medial or lateral osteoarthritis (OA) by redistributing the joint forces and offloading the diseased compartment; however, the recent re-emphasis on posterior slope of the tibia and its effect on ACL graft forces has introduced additional osteotomy considerations into surgical planning. Chondral injuries due to trauma or malalignment can also be addressed at the time of ACL reconstruction or in subsequent procedures and have been shown to provide improved pain and functionality equal to that of an ACLR alone, despite worse pre-operative metrics [1, 2]. This chapter focuses on the management of ACL tears in osteoarthritic knees, with a focus on additional osseous and chondral considerations.
