Bone SPECT of the back after lumbar surgery

Purpose: It may be difficult to evaluate back pain in patients who have und ergone spinal surgery, because symptoms may be secondary to all the possibl e abnormalities in patients who have not had surgery plus postoperative com plications, including infection, unstable fusion sites, or transfer of biom echanical stresses to other regions. Materials and Methods: Sixty-three patients with back pain and a history of lumbar spinal surgery had bone SPECT examinations. Twenty-eight patients h ad laminectomies, 10 had laminectomies with fusion, 10 had laminectomies wi th fusion and metallic stabilization devices (3 of which were removed), 7 h ad fusion without laminectomy, 7 had discectomies, and 1 had a fusion with metallic stabilization but no laminectomy. Eighty-seven percent of the fusi ons were posterior. The results of SPECT scanning were correlated with surg ery, clinical information, and diagnostic radiologic studies. Results: Patients with fusions tended to be scanned further out from the ti me of surgery than were patients with laminectomy alone or especially disce ctomy. Bone SPECT excluded bony abnormalities in the operative site in 7 of 63 patients. One hundred thirty-two lesions were uncovered, with facet abn ormalities (n = 51) the most common followed by disc space-centered conditi ons (n = 29), pseudarthrosis (n = 20), sacroiliac joint (n = 18), vertebral body lesions (n = 9), and miscellaneous sites in = 5). Sixty percent of th e abnormalities located in the facets, disc spaces, and vertebral bodies we re located in the operative field, whereas 29% were above and 11% were belo w it. Conclusion: Bone SPECT was useful in evaluating these patients to exclude b ony lesions or to identify pseudarthrosis, abnormal facets, disc space-cent ered lesions, and sacroilitis.