Abstract
Rupture of a Baker's cyst is an under-recognized condition that may closely mimic deep vein thrombosis, often leading to diagnostic uncertainty and delayed management. Although popliteal cysts are common findings associated with degenerative or inflammatory knee disorders, their rupture represents an uncommon but clinically significant complication. Ruptured cysts typically present with acute calf swelling and pain due to extravasation of synovial fluid into the intermuscular planes. The condition may mimic venous thrombosis (pseudo-thrombophlebitis), making diagnostic accuracy essential. Duplex ultrasonography is the first-line modality, primarily to exclude deep vein thrombosis, while musculoskeletal ultrasound and MRI help identify fluid dissection and residual cyst anatomy. Most cases are self-limiting and respond well to conservative treatment, including rest, ice, compression, elevation, and anti-inflammatory medication. Image-guided aspiration, corticosteroid injection, and ultrasound-guided fenestration may be considered in persistent or recurrent cases. Surgical management, most commonly arthroscopic treatment of intra-articular pathology with cyst decompression, is reserved for refractory symptoms or when the underlying joint lesion requires correction. Rare complications, such as compartment syndrome, necessitate prompt recognition and intervention. This review aims to synthesize current evidence on the clinical presentation, diagnostic challenges, imaging strategies, and management options for ruptured Baker's cysts.