The surgical management of lumbar synovial cysts that have extruded into the spinal canal remains controversial (e.g. decompression with/without fusion).
The neurological presentation, anatomy, pathophysiology, and surgical challenges posed by synovial cysts in the lumbar spine are well known. Neurological complaints typically include unilateral or, more rarely, bilateral radicular complaints, and/or cauda equina syndromes. Anatomically, synovial cysts constitute cystic dilatations of synovial sheaths that directly extrude from facet joints into the spinal canal. Pathophysiologically, these cysts reflect disruption of the facet joints often with accompanying instability, and potentially compromise both the cephalad and caudad nerve roots.
Aspiration of lumbar synovial cysts, which are typically gelatinous and non-aspirable, and typically performed by “pain specialists” (e.g. pain management, rehabilitation, radiologists, others) utilizing fluoroscopy or CT-guided aspiration, is associated with 50–100% failure rates. Surgical decompression with/without fusion (as the issue regarding fusion remains unsettled) results in the resolution of back and radicular pain in 91.6–92.5% and 91.1–91.9% of cases, respectively.
After a thorough review of the literature, it appears that the treatment with the best outcome for patients with synovial cysts is cyst removal utilizing surgical decompression; the need for attendant fusion remains unsettled. The use of an alternative treatment, percutaneous aspiration of cysts, appears to have a much higher recurrence and failure rate, but may be followed by surgery if warranted.