Risk factors for development of cervical spondylotic myelopathy: results of a systematic review

Study design: Systematic review. Study rationale: Cervical spondylotic myelopathy (CSM) is a common cause of spinal cord dysfunction that may be asymptomatic or may present with severe symptoms. Since CSM has an insidious manifestation, identification of risk factors associated with this condition may aid clinicians in monitoring high-risk patients and implementing appropriate management strategies. Objective: To assess sociodemographic, clinical, radiographic, and genetic risk factors associated with presence of CSM in patients 18 years or older. Methods: A systematic review of the literature was performed using PubMed, the National Guideline Clearinghouse Databases, and bibliographies of key articles to assess risk factors associated with CSM. Articles were reviewed by two independent reviewers based on predetermined inclusion and exclusion criteria. Each article was evaluated using a predefined quality-rating scheme. Results: From 486 citations, eight articles met all inclusion and exclusion criteria. Larger vertebral body and smaller spinal canal and Torg/Pavlov ratio were associated with CSM diagnosis, while gender was not associated with a CSM diagnosis across multiple studies. There were inconsistent reports with respect to increased age as a risk factor for CSM diagnosis. Conclusion: The limited data available suggests that inherent anatomical features that may contribute to congenital cervical stenosis may be associated with CSM. This systematic review is limited by the small number of high-quality studies evaluating prognostic factors for CSM. The overall strength of evidence for all risk factors evaluated is low.