Why does a popliteal cyst (Baker's cyst) recur after aspiration?

Doctor’s answer

In adults, popliteal cysts are mostly not isolated primary conditions but rather 'one-way valve' overflow manifestations of intra-articular knee pathology (often secondary to posterior meniscus tears, synovitis, or cartilage degeneration causing significant joint effusion). Simple aspiration cannot close the internal opening; only arthroscopic surgery to repair the torn meniscus, clean inflammatory synovium, and enlarge the cyst's one-way valve opening can fundamentally address the effusion source and prevent recurrence.

This content is for education. Diagnosis, treatment, and rehabilitation require an individual assessment by a sports medicine specialist.