Impact of Preoperative Intramedullary T2 Signal Intensity Changes on Surgical Outcomes in Cervical Spondylotic Myelopathy: A Multicenter Prospective Study.

STUDY DESIGN: Multicenter prospective cohort study. OBJECTIVE: To evaluate the impact of preoperative intramedullary T2 signal intensity (SI) changes on surgical outcomes in patients with cervical spondylotic myelopathy (CSM). SUMMARY OF BACKGROUND DATA: Intramedullary SI on T2-weighted MRI has been considered a predictor of poor outcomes in CSM; however, its prognostic value remains controversial. METHODS: We prospectively analyzed 721 patients with CSM who underwent surgical decompression at 10 institutions between 2019 and 2022. Patients were classified into SI (+) and SI (-) groups based on preoperative T2-weighted MRI. Outcomes were assessed preoperatively and at 2 years using the Japanese Orthopaedic Association (JOA) score, visual analog scale (VAS), JOA Cervical Myelopathy Evaluation Questionnaire (JOACMEQ), and Short Form-36 (SF-36). Multivariable analyses were adjusted for age, sex, symptom duration, preoperative C2-7 angle, cervical range of motion, diabetes mellitus, and smoking history. RESULTS: Of the 721 patients, 554 (76.8%) were SI (+) and 167 (23.2%) were SI (-). Although preoperative upper extremity pain/numbness on VAS was significantly higher in the SI (+) group (64.7 vs. 58.9, P=0.037), this difference was not significant at 2 years. No significant between-group differences were found in preoperative or postoperative JOA score, JOA recovery rate, ΔJOA, SF-36, JOACMEQ effectiveness rates, or perioperative complications. SI was not independently associated with improvement in any JOACMEQ domain. Only the preoperative C2-7 angle was independently associated with the presence of SI (odds ratio, 1.02; P=0.023). CONCLUSION: Preoperative intramedullary T2 SI was associated with greater preoperative upper extremity pain/numbness, and with a greater preoperative C2-7 angle. However, after adjustment for confounders, the binary presence of intramedullary T2 SI was not statistically significantly associated with worse 2-year neurological, functional, or patient-reported outcomes. LEVEL OF EVIDENCE: Level II.