summary Synovial facet cysts are degenerative lesions of the lumbar spine that can lead to lumbar spinal stenosis, resulting in low back pain and radicular symptoms Diagnosis is made with MRI of the lumbar spine Treatment is a trial of nonoperative management with NSAIDs and physical therapy. Surgical management is indicated for progressive disabling pain that has failed nonoperative management and/or the presence of progressive neurological deficits Epidemiology Incidence rare Anatomic location usually in the lumbar spine 60-89% occur at L4-5 (most mobile segment) ~14% occur at L3-4 ~12% occur at L5-S1 Etiology Pathophysiology possible etiologies trauma (controversial) microinstability of the facet joint, leading to: login to view 3 more bullets cyst composition login to view 5 more bullets Associated conditions degenerative spondylolisthesis Presentation Symptoms mechanical back pain radicular symptoms (leg pain) rapid onset or sudden deterioration suggest a facet cyst hematoma neurogenic claudication (buttock/leg pain with walking) Physical exam neurovascular may have nerve root deficits at associated spinal levels Imaging Radiographs recommended views AP, lateral, flexion, and extension findings usually normal look for segmental instability MRI indications significant leg pain views best seen on axial and sagittal T2-weighted images traditionally hyperintense centers with hypointense rims on T2 and hypointense inner cores on T1 sequences login to view 1 more bullet improved detection rate with positional MRI login to view 3 more bullets high-signal intensity on T2-weighted images login to view 2 more bullets low-signal intensity on T2-weighted images login to view 2 more bullets Treatment Nonoperative NSAIDs, rest, immobilization, physical therapy, and epidural steroid injections indications login to view 3 more bullets outcomes login to view 1 more bullet CT-guided cyst rupture, facet steroid injection, and cyst injection indications login to view 2 more bullets outcomes login to view 2 more bullets Operative laminectomy with decompression and cyst excision indications login to view 3 more bullets outcomes login to view 3 more bullets facetectomy and instrumented fusion indications login to view 6 more bullets outcomes login to view 2 more bullets Techniques NSAIDs, rest, immobilization, physical therapy, and epidural steroid injections technique recommended for 6-8 weeks prior to proceeding with surgical treatment or CT-guided rupture CT-guided cyst rupture, facet steroid injection, and cyst injection technique fluoroscopic guidance login to view 2 more bullets CT guidance login to view 2 more bullets laminectomy with decompression and cyst excision approach posterior approach to the spine technique unilateral laminotomy and medial facetectomy with a high-speed burr create a plane between the dura and cyst grab cyst with Allis clamp or forceps and apply gentle traction separate cyst from the underlying dura with Epstein curet or Woodson elevator facetectomy and instrumented fusion approach posterior approach to the spine technique place pedicle screws at the intersection of the superior border of the transverse process and midline of the superior articular process perform decompressive laminectomy and facetectomy excise cyst after developing an interval between cyst and dura login to view 1 more bullet Complications Cyst recurrence incidence high recurrence rate with resection alone treatment new studies favor facetectomy and fusion as first-line operative treatment Iatrogenic spondylolisthesis risk factors decompressive laminectomy without fusion treatment posterior instrumented fusion +/- spondylolisthesis reduction Dural tear incidence risk factors revision surgery cyst adherent to the dura login to view 3 more bullets