Endoscopic Resection of Symptomatic Cervical Facet Cyst in Ankylosing Spondylitis.

Background: Extradural benign cysts located in close proximity to the facet joints are called juxtafacetal cysts. Only about 3.5% of such cysts occur in the cervical spine. To our knowledge, there has been no published article on the endoscopic resection of a cervical facet cyst, and this is the first report.

Case Description: A 48-year-old male presented with a chief complaint of severe axial neck pain (visual analog scale score 9) and right scapular pain. The patient had no related radiculopathy or myelopathy, and neurologic status was intact. There was severe limitation of cervical spine movements. Plain radiographs indicated age-related degenerative changes with typical features of ankylosing spondylitis with a bamboo spine appearance and gross fusion of all the vertebrae. The only mobile cervical spinal level was C6-C7. Axial magnetic resonance imaging revealed a right-sided juxtafacetal lesion at C6-C7 level that was hyperintense on T2 and hypointense on T1 imaging. A percutaneous endoscopic posterior cervical foraminotomy at right-sided C7-T1 was performed under general anesthesia. The cyst was removed, and adequate decompression of the C7 root was achieved. Postoperative magnetic resonance imaging and computed tomography scan showed adequate foraminotomy and decompression of the neural structures. The patient had gross relief of neck pain (visual analog scale score 2).

Conclusions: The findings suggest that ankylosing spondylitis may cause formation of a juxtafacetal cyst at the mobile levels in a relatively less mobile cervical spine. The endoscopic resection of such cysts is a minimally invasive novel procedure that can cure such patients successfully without unwanted fusion surgery.