Modic Change and Clinical Assessment Scores in Patients Undergoing Lumbar Surgery for Disk Herniation

Study design: Retrospective cohort study.

Objective: To examine the relationship between preoperative Modic change (MC) and postoperative clinical assessment scores for patients receiving lumbar discectomy or transforaminal lumbar interbody fusion for lumbar disk herniation.

Summary of background data: Lumbar disk herniation is a risk factor for MC development. MC on spinal magnetic resonance imaging (MRI) has been associated with worse preoperative and postoperative clinical assessment scores.

Materials and methods: We reviewed data for 285 primary single-level surgeries. Preoperative and 12-month postoperative assessment scores were recorded using the visual analog scale leg pain, Oswestry Disability Index, and Short Form-36 Physical Component Summary. MC subgroup on preoperative MRI was recorded by a single neuroradiologist.

Results: One hundred seventy-nine patients (female, 56%; age-53±13 y) with preoperative MRI were included. Age and sex were similar across MC subgroups. The sample prevalence of MC on preoperative MRI was 62%, and MC2 was the most common subgroup (35%). No differences in preoperative assessment scores were identified, regardless of presence or absence of MC. For the overall cohort, improvement in assessment scores were observed: Short Form-36 improved an average of 8.2 points [95% CI (95% CI), 5.8-10.7], Oswestry Disability Index by 11.3 points (95% CI, 8.7-14.0), and visual analog scale by 2.8 points (95% CI, 2.1-3.5). In nearly all cases, MCID values were met, even when stratifying by MC subgroup. Few differences in postoperative assessment scores were identified when comparing across MC1, MC2, or no MC groups.

Conclusions: Statistically and clinically significant improvement in postoperative clinical assessment scores was observed for both lumbar discectomy and transforaminal lumbar interbody fusion groups. MC on preoperative MRI was not associated with worse preoperative or postoperative clinical assessment scores.

Level of evidence: Level III.