Arthroscopic treatment of popliteal cyst and visualization of its cavity through the posterior portal of the knee.

In regard to arthroscopic treatment of popliteal cysts, we explored the refuted pathology for popliteal cysts proposed by others. Here we introduce an arthroscopic technique using posterior portals to treat a popliteal cyst based on our observation that the opening of the cyst in the joint is a slit-like structure in the posterior wall of the capsule. By disrupting this slit-like structure with our procedure, the popliteal cyst ceased to be palpable and was no longer symptomatic. This technique also provides excellent arthroscopic visualization of the cavity of the popliteal cyst through the knee joint approach. After completion of the resection of the opening, we can easily insert an arthroscope into the cavity of the popliteal cyst from the posteromedial portal through the resected opening. Arthroscopic visualization of the cavity of the cyst showed that the inside wall of the cavity was smooth and had no synovitis. We believe that to disrupt this slit structure is the most pathologically reasonable procedure to treat popliteal cysts surgically.