A Diagnostic Challenge in Acute Leg Swelling: Ruptured Popliteal Artery Aneurysm Mimicking Deep Vein Thrombosis

Popliteal artery aneurysms (PAAs) are the second most common type of arterial aneurysm after abdominal aortic aneurysms. True popliteal aneurysms are typically clinically silent and are primarily degenerative in nature, often associated with repeated flexion movements of the knee. We describe a case of spontaneous rupture of a PAA in an elderly female patient with a known history of type II diabetes mellitus, hypertension, and Stage V chronic kidney disease on maintenance hemodialysis. She was admitted for generalized weakness and poor oral intake over the past month, with complaints of difficulty breathing for the last 3 days. She was also experiencing progressively worsening pain in her left calf, accompanied by noticeable swelling of the leg. On examination, she presented with swelling and erythema of the left leg, which, upon further evaluation, was diagnosed as a ruptured silent aneurysm of the popliteal artery. In conclusion, silent compartment syndrome of the leg in patients presenting with lower limb swelling can be diagnosed by maintaining a high index of suspicion and conducting a thorough clinical assessment along with appropriate imaging. To the best of our knowledge, such a case has not been reported in the existing literature.