Fat pad syndrome following anterior cruciate ligament reconstruction in female athletes: A narrative review of biomechanical, hormonal, and rehabilitation factors

ABSTRACT Anterior cruciate ligament reconstruction (ACLR) remains the gold standard for restoring knee stability following ACL rupture. Despite advancements in surgical techniques, anterior knee pain persists as a common postoperative complaint, with infrapatellar fat pad syndrome (FPIS) emerging as a notable but often underdiagnosed contributor. Female athletes appear disproportionately affected, potentially due to anatomical, hormonal, and biomechanical differences that also predispose them to primary ACL injuries. This narrative review explores the hypothesis that FPIS is more prevalent in female patients post-ACLR. The literature highlights a higher incidence of ACL injuries in females, influenced by factors such as a greater Q-angle, estrogen fluctuations, altered neuromuscular control, and forefoot-dominant landing patterns. These variables can contribute to anterior tibial translation and fat pad impingement, particularly during terminal extension and early gait retraining. Improper load distribution during rehabilitation may exacerbate this risk. Hormonal effects on ligament laxity and proprioception further compound the likelihood of FPIS in this population. Early diagnosis, MRI confirmation, and sex-specific neuromuscular interventions—including landing mechanics retraining and targeted strength programming—are critical to improving outcomes and reducing chronic complications in female athletes undergoing ACLR.