A 32-year-old man underwent arthroscopic anterior cruciate ligament reconstruction (ACLR) using hamstring autograft. He complained of persistent posterior knee pain in the postoperative period and at 4 weeks postsurgery developed foot drop and intense posterior knee pain. On clinicoradiological evaluation, a popliteal pseudoaneurysm (PSA) was diagnosed. The patient underwent surgical exploration, excision of the PSA, and primary repair of the popliteal artery. The foot drop recovered at 3 months post–second surgery follow-up.
Persistent posterior knee pain and popliteal fossa swelling in a patient after ACLR should raise a suspicion of popliteal PSA. Identifying these lesions early can prevent further complications such as common peroneal nerve palsy.