Long-Term Results After Surgery for Degenerative Cervical Myelopathy

Abstract

BACKGROUND AND OBJECTIVES: Degenerative cervical myelopathy (DCM) is a frequent cause of spinal cord dysfunction, and surgical treatment is considered safe and effective. Long-term results after surgery are limited. This study investigated long-term clinical outcomes through data from the Norwegian registry for spine surgery. METHODS: Patients operated at the university hospitals serving Central and Northern Norway were approached for long-term follow-up after 3 to 8 years. The primary outcome was change in the Neck Disability Index, and the secondary outcomes were changes in the European Myelopathy Scale score, quality of life (EuroQoL EQ-5D); numeric rating scales (NRS) for headache, neck pain, and arm pain; and perceived benefit of surgery assessed by the Global Perceived Effect scale from 1 year to long-term follow-up. RESULTS: We included 144 patients operated between January 2013 and June 2018. In total, 123 participants (85.4%) provided patient-reported outcome measures (PROMs) at long-term follow-up. There was no significant change in PROMs from 1 year to long-term follow-up, including Neck Disability Index (mean 1.0, 95% CI −2.1-4.1, P = .53), European Myelopathy Scale score (mean −0.3, 95% CI −0.7-0.1, P = .09), EQ-5D index score (mean −0.02, 95% CI −0.09-0.05, P = .51), NRS neck pain (mean 0.3 95% CI −0.2-0.9, P = .22), NRS arm pain (mean −0.1, 95% CI −0.8-0.5, P = .70), and NRS headache (mean 0.4, 95% CI −0.1-0.9, P = .11). According to Global Perceived Effect assessments, 106/121 patients (87.6%) reported to be stable or improved (“complete recovery,” “much better,” “slightly better,” or “unchanged”) at long-term follow-up compared with 88.1% at 1 year. Dichotomizing the outcome data based on severity of DCM did not demonstrate significant changes either. CONCLUSION: Long-term follow-up of patients undergoing surgery for DCM demonstrates persistence of statistically significant and clinically meaningful improvement across a wide range of PROMs.