Baker's cysts develop complications such as rupturing, hemorrhage and trapped calcified bodies, according to Patient. Neglected cysts worsen the symptoms and may extend into the calf muscles, notes the Better Health Channel. Baker's cysts, also known as popliteal cysts, may cause severe pain, related injuries and prolonged swelling, says Healthline.
In most cases, the fluid in a Baker's cyst dissects into the proximal gastrocnemius muscle, a condition that creates the clinical picture of a pseudothrombophlebitis syndrome, says Patient. Ruptured and non-ruptured Baker's cysts may cause the compartment syndrome, although the condition is not common. Hemorrhage into a cyst may occur in cases in which there is concomitant bleeding diathesis. Baker's cysts may cause infection or exert pressure on the common tibial and peroneal nerves.
Baker's cysts may trap loose calcified bodies if the patient has arthropathy, trauma or synovial osteochondromatosis, explains Patient. Burst cysts leak fluid that causes bruising on the affected leg, especially on the ankle, according to the Better Health Channel. The leaked synovial fluid may enter into the calf region, causing the calf to swell, notes the Mayo Clinic. Consequently, a sharp pain develops on the knee, and the calf may turn reddish. However, redness and swelling of the calf may result from other ailments.