Research On The Relationship Between The Change Of Bone Mineral Density Of Patients With Cervical Spondylotic Myelopathy And Vertebral Deformation And Clinical Manifestation

Objective: By using a case-control study method, the ratios of sagittal diameters of vertebral canals and bodies, the vertebral body deformation indexes and clinical manifestations of patients with cervical spondylotic myelopathy in lower bone mineral density group and normal bone mineral density group are compared and analyzed, to investigate the relationship between the osteoporosis and cervical spondylotic myelopathy, and provide new ideas for clinical prevention and treatment of cervical spondylotic myelopathy.Methods: Based on lumbar spine bone mineral density measurements, all patients with cervical spondylotic myelopathy were divided into two groups: the normal group, including 27 cases of patients with cervical spondylotic myelopathy, whose lumbar spine bone mineral densities are normal and the average age is 47 years; the lower group, including 24 cases of patients with the cervical spondylotic myelopathy, whose lumbar spine bone mineral densities are lower and the average age is 59 years. The superior, middle and inferior sagittal diameters, the heights of anterior and posterior vertebral bodies, the upper, middle and lower sagittal diameters of the spinal canals behind the vertebral bodies were measured on lateral view of each C3-C6 vertebral body in all cases and the average values were calculated. The ratios of sagittal diameters of vertebral canals and bodies and the vertebral body deformation index values are calculated. And a comparison was made between the two groups to find whether there are differences between the ratios of sagittal diameters of vertebral canals and bodies and the vertebral body deformation in two groups. Compare the clinical manifestations in two groups (dizziness, numbness, walking instability and improved Hoffman sign test, neck hyperextension /hyperinflexion test, lower limb muscle tension) to find whether there are differences between the two groups.Results: Comparing the two groups, the ratios of the sagittal diameters of vertebral canals and bodies in lower bone mineral density group (C3 0.788±0.107, C4 0.757±0.119, C5 0.724±0.0703, C6 0.692±0.052) are significantly lower (P <0.05 or P <0.01), compared with those in the normal bone mineral density group (C3 0.996±0.081, C4 0.930±0.118, C5 0.955±0.0917, C6 1.0013±0.282), while there was no significant difference between the vertebral deformation indexes of the cervical spine (C3 C4 C5 C6) in two groups (P> 0.05). At the same time, clinical manifestations are compared: the percentages of positive cases in lower bone mineral density group (dizziness in 22 cases (91.6%), numbness in 20 cases (83.3%), walking instability in 19 cases and improved Hoffman sign test in 23 cases (95.8%), neck hyperextension /hyperinflexion tests in 18 cases (75%), lower limb muscle in 18 cases (75%)) were significantly higher than those in normal bone mineral density group (dizziness in 16 cases (60%), numbness in 14 cases (51.8%), walking instability in 15 cases (55.5%), improved Hoffman sign test in 18 cases (66.7%), neck hyperextension/hyperinflexion test in 13 cases (48.1%), lower limb muscular tension in 12 cases(44.4%)), P <0.05.Conclusion: Low bone mineral density of patients with cervical spondylotic myelopathy can cause morphological changes in cervical vertebral bodies, hyperosteogeny of vertebral body and vertebral canal stenosis. Clinical manifestations of patients with lower bone mineral density are more obvious than those of patients with normal bone mineral density.