Endoscopic Transforaminal Approach for Extraforaminal Lumbosacral Synovial Cyst Resection: A Systematic Review and Operative Footage of a Unique Case

Introduction: Synovial cysts are associated with facet arthropathy and/or hypertrophy as well as underlying instability. The most common location is in the lower lumbar spine, predominantly in the lateral recesses. Extraforaminal locations of synovial cyst are rarely reported. Surgical intervention can be indicated when nonoperative management fails. We systematically reviewed the literature to better characterize these lesions and explore the various management/treatment options.

Methods: Following PRISMA guidelines, four databases were queried to identify cases of extraforaminal synovial cysts from 1989 to present.

Results: Of the 17 cases of extraforaminal cysts identified in the literature, all were located at either L4-L5 or L5-S1, with the exception of one case being located at L3-L4. 16 patients underwent surgical intervention. Six patients required a partial facetectomy while another six patients underwent total facetectomies. Four patients underwent decompression and resection of the cyst using an endoscopic approach, with one of these patients undergoing partial facetectomy as well. All patients improved symptomatically postoperatively. We also present operative footage highlighting surgical planning, key procedural steps, and technical nuances of a case of intractable lumbar radiculopathy and motor weakness caused by a synovial cyst located in the L5-S1 extraforaminal area. We performed an endoscopic transforaminal approach for resection of the extraforaminal lumbosacral synovial cyst. Postoperatively, the patient had complete elimination of radiculopathy and weakness.

Conclusion : Symptomatic juxtafacet synovial cysts are uncommon lesions that should be considered part of the differential diagnosis of extraforaminal space-occupying lesions. The endoscopic transforaminal approach is being presented as a viable alternative carrying low risk with good outcomes when compared to other forms of traditional or minimally invasive approaches that may require facetectomy and/or fusion in the setting of isolated radiculopathy, as highlighted in our review.