Case 101: Lumbar Facet Synovial Cyst

History An 82-year-old woman in otherwise good health experienced gradually increasing low back pain of 15 years duration that was caused by degenerative scoliosis. Bending or twisting worsened her pain, but it was generally well man-aged with exercise, an orthosis, and nonsteroidal antiin-flammatory drugs. Recently, however, she began to experience bilateral leg pain. She underwent magnetic resonance (MR) imaging of the lumbar spine. On the basis of the MR findings, she returned to the clinic a few weeks later to undergo epidural steroid (0.5 mL betamethasone [6 mg/mL]) and facet joint (0.5 mL 1% xylocaine) injections with computed tomographic (CT) guidance. This re-sulted in the temporary resolution of bilateral leg pain. Approximately 2 months later, however, she returned to the clinic with low back pain radiating bilaterally to the legs. She subsequently underwent surgery.