19 year-old male status post left S1 tumor resection. Osteoblastoma. Lumbar spine:Since the previous examination there are new postoperative changes including bilateral pedicular fusion of the L5 vertebrae and trans-sacral alar fusion at the S1 level. There is no evidence of hardware complication including loosening or fracture of the osseous structures or hardware components. There is 1-2 mm of extracortical extension of the screw tip of the left S1 hardware component.Alignment of the lumbar spine is within normal limits. Attenuation and morphology of the vertebral bodies and intervertebral disk spaces is within normal limits. The pre-and paravertebral soft tissues are within normal limits. Limited intra-abdominal imaging is within normal limits.L1-2: within normal limits without central or neuroforaminal narrowing.L2-3: within normal limits without central or neuroforaminal narrowing.L3-4: within normal limits without central or neuroforaminal narrowing.L4-5: within normal limits without central or neuroforaminal narrowing. Left-sided L5 and S1 laminectomies. L5-S1: within normal limits without central or neuroforaminal narrowing. Mottled and expansile appearance of the left S1 facet with left-sided neuroforaminal narrowing from bony encroachment. Expansile and lytic/sclerotic appearance of the left S1 facet extends to the dorsal aspect of the body of S1 and minimally into the left transverse process, most likely representing postsurgical change. Soft tissues within the surgical site and within the intracanalicular space cannot be evaluated on this examination secondary to lack of contrast. If there is further need for soft tissue evaluation an MRI with contrast may be considered.
1. Postoperative changes including bilateral pedicular fusion at L5-S1 without gross hardware complication.2. Postoperative change including left-sided L5 and S1 laminectomies with mottled and expansile appearance of the left S1 facet joint, body of S1 and left transverse process as described above.