International Variations in the Clinical Presentation and Management of Cervical Spondylotic Myelopathy: One-Year Outcomes of the AOSpine Multicenter Prospective CSM-I Study

INTRODUCTION: : While cervical spondylotic myelopathy (CSM) is the most common cause of spinal cord impairment worldwide, little is known regarding international variations in clinical presentation, management and outcomes of this condition. To address this key issue, we undertook a prospective multicenter study of CSM patients undergoing surgical treatment. METHODS: : 486 patients with clinically symptomatic CSM were enrolled in 16 sites in Europe, Asia, North and South America. The following outcomes were assessed: modified Japanese Orthopaedic Assessment scale (mJOA), Nurick Score, Neck Disability Index (NDI), short form 36v2, and complications. Data were analyzed using multivariate techniques (SAS 9.2) adjusting for baseline differences in patient populations (age, gender, surgical approach, number of spinal levels and baseline outcome parameter value). RESULTS: : To date, 389 patients have completed the 1-year follow-up. Thirty-five percent were females with an average age of 56.2 yrs (SD 12.4). Patients underwent anterior (58%), posterior (40%) or circumferential (2%) surgery. There were significant differences in the age at presentation and baseline neurological status among the regions, with Asian and Latin American patients being significantly younger and with less neurological impairment. With surgical treatment, there was a significant (P < 0.001) improvement from baseline values to 12 months in all outcome parameters assessed. The amount of improvement varied across the international regions with patients from Asia-Pacific and Latin America reporting comparatively better SF36 PCS and MCS scores for comparatively similar outcomes on the Nurick and mJOA assessments. CONCLUSION: : This large prospective global clinical study shows that surgical treatment for CSM is associated with significant improvements in generic and patient-specific outcome measures at one-year. Interestingly, there are significant variations in clinical presentation and in patient perceptions of the impact of these improvements on their perceptions of quality of life.