Dynamic Mri of the Cervical Spine – An Important Tool in Planning Surgical Treatment of Cervical Compressive Myelopathy

Cervical compressive myelopathy (CM) remains a common entity in the practice of spine surgery. Though MRI is the diagnostic modality for CM, there are a subset of patients whose clinical features are suggestive of multilevel compression caused by dynamic factors, which however cannot be detected by a static MRI study. The causes include buckling of ligamentum flavum, collapse of disc height and changes in posterior longitudinal ligaments at the level of compression. These changes can only be detected on dynamic MRI. The application of Dynamic MRI can reveal not just additional levels of compression but even the site of maximum pressure, thus playing a vital role in surgical planning. It is also seen that adjaent level disease, commonly thought to be secondary to Cervical fusion was actually pre-existing and could have been picked up if dynamic MRI were used. We thus planned a prospective cohort of 24 patients of multilevel cervical compessive myelopathy who were studied with dynamic MRI at the Sakra Spine centre in Bangalore India. The clinical symptoms were correlated to the dynamic changes in MRI and were considered for planning appropriate treatment. Of the 24 patients in our study, 17 patients had a change in the original plan of treatment, either between conservative therapy and surgery, or the approach (Anterior vs. Posterior) of surgery. It was also noted that additional levels of compression discovered on the dynamic MRI were instrumental in changing the treatment protocol. Thus Flexion and Extension MRI is an important tool in planning the appropriate management in cervical compressive myelopathy