Arthroscopic Treatment of Popliteal Cysts

Popliteal cysts, often referred to as Baker's cysts, are a common occurrence in the adult knee. Although controversy exists as to the exact indications for treatment, these structures can cause extreme discomfort and morbidity, including pain from rupture and symptoms from neurovascular compromise. Prior to the development of the arthroscope, open treatment of popliteal cysts was not uncommon. Complications such as poor wound healing, cyst recurrence, and knee flexion contractures were reported after such treatment. Owing to the presence of a valve-type structure, also called the posterior transverse synovial infold, there is 1-way flow of synovial fluid into the cyst. Although seldom described, there is a reproducible and relatively straightforward arthroscopic treatment for this pathology. This technical report will describe the arthroscopic treatment of popliteal cysts and clarify the posterior knee anatomy that gives the surgeon the landmarks to perform safe and effective arthroscopic treatment of popliteal cysts.