Low back pain after lumbar discectomy in patients showing endplate modic type 1 change.

STUDY DESIGN: Prospective cohort study.

OBJECTIVE: To examine the relationship between low back pain after discectomy for disc herniation and Modic type 1 change.

SUMMARY OF BACKGROUND DATA: Lumbar vertebral bone marrow change is divided into Modic types. Some reports indicate that Modic type 1 is related to low back pain, but the reliability of this assertion is unclear. The current study examines changes in low back pain in patients with lumbar disc herniation and Modic type 1 change after lumbar discectomy without fusion surgery.

METHODS: Forty-five patients with lumbar disc herniation showing normal or Modic type 1 signals in their bone marrow were selected (mean age 35 years). All patients suffered low back and leg pain because of lumbar disc herniation, and underwent a discectomy without fusion. We evaluated change in low back pain [Visual analogue scale (VAS) score, Japanese Orthopedic Association score (JOAS), and Oswestry Disability Index (ODI)] before, 12 and 24 months after surgery.

RESULTS: Twenty-three patients showed Modic type 1 signals and 22 patients showed normal intensity before surgery. VAS score, JOAS, and ODI were not significantly different between the normal and Modic type 1 groups. VAS score, JOAS, and ODI improved after surgery in both groups (P>0.05). Low back pain after surgery evaluated from the 3 scores was not significantly different in the 2 groups 12 or 24 months after surgery (P>0.05).

CONCLUSION: Discectomy improved low back pain in patients suffering from lumbar disc herniation. Patients with or without Modic type 1 change showed a similar improvement of low back pain score. Low back pain in patients with disc herniation appears to mainly originate from disc or nerve root compression, and decompression surgery without fusion is an option for these patients, even those with Modic type 1 changes.