“…It is commonly associated with gonarthrosis in older patients [ 14 ] and can be an evasive cause of pain after a total knee replacement [ 15 ]. It is rarely reported in younger patients, being either “idiopathic” [ 12 , 14 ] or attributed to injury, repetitive trauma, or overuse [ 16 ]. As in other PTFJ pathologies, pain is usually lateral, but can also be anterior or posterior as in our case.…”