Compression syndromes of the popliteal neurovascular bundle due to Baker cyst.

BACKGROUND: The purpose of this study was to perform a comprehensive search of the literature for all studies, case reports, and series describing Baker cyst compression of the neurovascular bundle in the popliteal fossa and index their findings according to the structures compressed. METHOD: Case reports and series obtained after a thorough MEDLINE search were indexed according to compressed structures. Patient demographics, main findings, method of diagnosis, cyst size, outcomes, and follow-up were recorded for each publication. RESULTS: Signs and symptoms related to popliteal vein and tibial nerve compression were the most frequent presentation of symptomatic Baker cysts, due to the anatomic vulnerability of these structures within the popliteal fossa and their relative sensitivity to compression. Patients with tibial nerve entrapment demonstrated gastrocnemius muscle atrophy, paresthesias, and pain. Those with popliteal vein compression experienced swelling, pain, and rarely, venous thromboembolism. Isolated arterial compression, presenting with intermittent claudication, is a rare occurrence because it is a relatively stiff-walled vessel, has a higher pressure, and is located deep in the popliteal fossa. Combinations of these compression syndromes are most frequently encountered in the context of cyst rupture and resulting compartment syndrome. CONCLUSIONS: Baker cyst is an important pathology for the differential diagnosis of popliteal neurovascular compression phenomena. It has a wide spectrum of presentation, therefore requiring accurate diagnosis for proper patient management. Because Baker cyst is by definition a chronic disorder, long-term follow-up is necessary to monitor patient recovery and prevent recurrence.