Fabella Syndrome of Bilateral Knee with Common Peroneal Nerve Compression Neuropathy

Fabella syndrome is a rare, often underdiagnosed cause of recurrent posterolateral knee pain. It can disrupt the common peroneal nerve because of its anatomical location at the lateral head of the gastrocnemius at the lateral femoral condyle, where the nerve typically passes. Far East Asians have been shown to have a higher prevalence of fabella syndrome attributed to their genetic predisposition combined with mechanical causes. Failure to adequately identify a common peroneal nerve neuropathy associated with fabella syndrome can lead to recurrent visits, unnecessary examinations, and surgical procedures. Here, we present a case of a patient presenting with recurrent posterolateral knee pain and a slapping gait. Therefore, a high index of suspicion for fabella syndrome is warranted by a physician to diagnose this condition for the best outcome for the patient.