Meniscal cysts.

Meniscal cysts are cysts that occur as a direct extension, or within the substance of the meniscus. The incidence varies in reports from 1% to 20% and are much more common laterally. They usually present as joint-line pain, swelling, or both in young adult men, and are often associated with meniscal tears. The exact etiology of meniscal cysts is unknown. A myxoid degenerative process is identified histologically. There is often a history of precedent trauma. Diagnosis is often suspected clinically and can be confirmed by arthrogram, CT, or MRI when necessary. Conservative treatment in the patient with few symptoms is recommended. Should the cyst become significantly symptomatic, it is necessary to treat the meniscal pathology to prevent a cyst recurrence. At the present time it is our recommendation that this be done by arthroscopically resecting the meniscus back to normal meniscus and either aspirating and injecting the cyst with steroid or local cyst excision if the aspiration and injection fails. If no meniscal tear is documented at arthroscopy, exploration and excision of the cyst are recommended.