(Kiosk 2) Lumbar Radiculopathy Secondary to Bilateral Facet Synovial Cysts: A Case Report

Case Diagnosis: 50-year-old male with history of chronic right back pain now presenting with worsening left-sided back and leg pain.

Case Description: The patient presented to PM&R sports medicine clinic with left-sided lower back pain radiating to the lateral left leg over the past two to three months, noting moderate weakness in the leg. For his current pain, oral steroids, gabapentin, pregabalin, NSAIDs, and physical therapy were utilized with no significant relief. Lidocaine trigger point injections were successful in palliating his pain, but lasted only two days. Physical exam was significant for positive slump sit and straight leg raise tests along the left lower extremity in the L4 distribution. Moderate pain on hip flexion and extension was similarly noted, with ROM and strength otherwise intact.

Discussion: Facet synovial cysts are an uncommon cause of lumbar radiculopathy typically arising from the L4/5 spinal level. While the exact pathogenesis of synovial cysts remains uncertain, clear association exists with degenerative spinal arthropathy. Clinical presentation is dependent upon cyst size, location, and interaction with other local structures. First-line treatment is typically conservative via anti-inflammatories, epidural/intra-articular steroid injections, and cyst aspiration; surgical excision is considered if otherwise refractory.

Setting: Outpatient Musculoskeletal/Sports Medicine Clinic

Assessment/Results: MRI of the spine was notable for large left-sided and small right-sided lumbar facet synovial cysts with central canal stenosis thought to be causing his radiculopathic symptoms. Imaging was similarly notable for facet arthropathy worse at L4/5 and L5/S1. The patient was subsequently referred to interventional radiology for synovial cyst rupture and left transforaminal epidural steroid injection at L4 with improvement in his symptoms.

Conclusion: Facet synovial cysts should be considered in the differential of lumbar radiculopathy and may require additional management in addition to typical treatments for lumbar radiculopathy, including facet cyst aspiration/rupture or even surgery.