Subchondral marrow changes after laser diskectomy in the lumbar spine: MR imaging findings and clinical correlation.

OBJECTIVE: We examined MR imaging findings and determined the clinical significance of subchondral bone marrow changes in the lumbar spine of holdium:yttrium aluminum garnet laser diskectomy patients.
MATERIALS AND METHODS: We retrospectively reviewed the pre- and postoperative MR images of 109 patients with recurrent radiculopathy, lower back pain, or both 1 year after laser diskectomy of 178 disks. From this group of patients, MR images were also obtained in 11 patients with subchondral marrow changes 5-7 years after surgery. These patients were interviewed regarding residual lower back pain. Thirteen asymptomatic laser diskectomy patients also underwent follow-up MR imaging within 1 year of surgery.
RESULTS: After surgery, subchondral marrow abnormalities were identified in 41 of 109 laser diskectomy patients. The remaining 68 patients had no postoperative subchondral bone marrow changes. Postoperative subchondral marrow changes were not associated with inflammation of the adjacent disk space and did not affect surgical outcome. Bone marrow changes decreased in size in the 11 patients examined 5-7 years after laser diskectomy, and eight of these patients described their lower back pain as improved. In 13 asymptomatic laser diskectomy patients, one new subchondral marrow abnormality was identified.
CONCLUSION: Subchondral marrow abnormalities may occur in the vertebral end plates after holmium:yttrium aluminum garnet laser diskectomy. However, these changes probably do not affect surgical outcomes and appear to resolve over time.