Is patellofemoral joint osteoarthritis an under-recognised outcome of anterior cruciate ligament reconstruction? A narrative literature review

Patellofemoral joint (PFJ) osteoarthritis (OA) is a prevalent disease capable of being a potent source of knee symptoms. Although anterior cruciate ligament (ACL) injury and reconstruction (ACLR) are well-established risk factors for the development of tibiofemoral joint OA, PFJ OA after ACL reconstruction has gone largely unrecognised. This is despite the high prevalence of anterior knee pain after ACLR, which can reduce the capacity for physical activity and quality of life. The susceptibility of the PFJ to degenerative change after ACLR may have implications for current rehabilitation strategies. This review summarises the evidence describing the prevalence of PFJ OA after ACLR and examines why this compartment may be at increased risk of early onset OA after ACLR. Strategies that address the modifiable factors for risk of PFJ OA may aid in alleviating joint loads and symptoms for people after ACLR.