Study design: National population-based cohort study.

Objective: To compare the reoperation rates between cervical spondylotic radiculopathy and myelopathy in a national population of patients.

Summary of background data: There is an inherently low incidence of reoperation after surgery for cervical degenerative disease. Therefore, it is difficult to sufficiently power studies to detect differences between reoperation rates of different cervical diagnoses. National population-based databases provide large, longitudinally followed cohorts that may help overcome this challenge.

Methods: We used the Korean Health Insurance Review and Assessment Service national database to select our study population. We included patients with the diagnosis of cervical spondylotic radiculopathy or myelopathy who underwent anterior cervical discectomy and fusion from January 2009 to June 2014. We separated patients into two groups based on diagnosis codes: cervical spondylotic radiculopathy or cervical spondylotic myelopathy. Age, sex, presence of diabetes, osteoporosis, associated comorbidities, number of operated cervical disc levels, and hospital types were considered potential confounding factors.

Results: The overall reoperation rate was 2.45%. The reoperation rate was significantly higher in patients with cervical spondylotic myelopathy than in patients with cervical radiculopathy (myelopathy: P = 0.0293, hazard ratio = 1.433, 95% confidence interval 1.037-1.981). Male sex, presence of diabetes or associated comorbidities, and hospital type were noted to be risk factors for reoperation.

Conclusion: The reoperation rate after anterior cervical discectomy and fusion was higher for cervical spondylotic myelopathy than for cervical spondylotic radiculopathy in a national population of patients.

Level of evidence: 3.