Arthroscopic Debridement of Loose Bodies From a Popliteal Cyst

To our knowledge, arthroscopic removal of loose bodies from a popliteal cyst has never been reported in the medical literature. This article describes our technique for removing loose bodies from a popliteal cyst and verifies that the procedure can be performed safely and effectively. A 52-year-old man had progressively worsening right knee pain and swelling of 3 years' duration that had been treated conservatively for 6 months. On physical examination, there was boggy swelling, a palpable popliteal cyst, crepitus with range of motion, and diffuse discomfort and tenderness about the knee. Magnetic resonance imaging showed synovitis of unclear etiology. Arthroscopic intervention was performed after conservative measures failed. An accessory posteromedial portal was used to gain access into the popliteal cyst through the posterior joint capsule. An electrocautery device was used to penetrate into the cyst through the posterior capsule after identifying the correct location of the cyst by passing a needle percutaneously through the posterior aspect of the cyst into the joint. Multiple loose bodies along with a large cartilaginous mass were identified in the popliteal cyst and removed. The patient remained symptom free at 2-year follow-up. As long as the instruments are kept in view and medial to the midline of the knee joint, the neurovascular structures lateral to the cyst are safe. Keeping the shaver suction on low during debridement will avoid pulling in any unvisualized tissue. To avoid injury to the superficial saphenous vein and nerve when making the posterior portal, the surgeon should incise through skin only, then use blunt dissection and a blunt obturator to enter into the joint. Simple decompression of large popliteal cysts can be accomplished in a similar manner.