Influence of intramedullary stress on cervical spondylotic myelopathy

Abstract

Study design: A cross-sectional analysis. Objective: To examine whether intramedullary stress is related to the appearance of symptoms in cervical spondylotic myelopathy (CSM). Setting: Japan. Methods: Thirty-three consecutive patients with CSM and 30 consecutive patients without CSM were enrolled. A total of 99 disc levels from C3 to C6 in 33 patients with CSM were divided into two groups: 33 disc levels with high signal intensity (HSI) on T2-weighted magnetic resonance image (HSI group) and 66 disc levels without HSI (Non-HSI group). Ninety disc levels from C3 to C6 in patients without CSM were set up in a control group. Intramedullary stress value at each level was analyzed using the finite element method. Stress was compared among the three groups. A cutoff value of stress to present HSI was investigated from receiver operator characteristics (ROC) curve. Results: In all the patients with CSM, the disc level with HSI presented the highest stress among the three disc levels evaluated. The stress was 3.16 ± 0.86 kPa (mean ± s.d.) in the HSI group, 1.81 ± 0.72 kPa in the Non-HSI group and 1.01 ± 0.37 kPa in the control group. The stress differed significantly among the three groups (Po0.0001). The qualified cutoff value derived from the ROC curve was 2.30 kPa (sensitivity 78.8%, specificity 91.9%). None of the disc levels in the control group exceeded 2.30 kPa. Conclusion: HSI was strongly associated with intramedullary stress. Threshold of intramedullary stress to present HSI that related closely to the symptoms of myelopathy was revealed.

Anterior cervical discectomy and fusion may be more effective than anterior cervical corpectomy and fusion for the treatment of cervical spondylotic myelopathy

“…CSM is the predominant reason of spinal cord injury and neurological dysfunction especially among industrialized countries, which may lead to disability as a life-long event, posing a great social and economic burden [ 4 , 5 ]. It has been highlighted that the compromise of spinal canal as well as the compression of spinal cord were the main pathology of CSM, and the etiology of CSM was suggested to be the age-related degenerative spondylosis [ 6 , 7 ]. At present, patients diagnosed with symptomatic CSM were often recommended to receive anterior cervical decompression and fusion for patients diagnosed with CSM [ 8 , 9 ].…”

Stress analysis of the cervical spinal cord: Impact of the morphology of spinal cord segments on stress

“…25 30 Takahashi et al reported on the relationship between high signal intensity on MRI and FEM model. 31 The above papers evaluated the stress distribution and thus provide valuable background information for understanding the injury mechanism of spinal cord. However, the pathology of the gray matter and white matter that caused the symptoms was not evaluated.…”

Ti-24Nb-4Zr-8Sn Alloy Pedicle Screw Improves Internal Vertebral Fixation by Reducing Stress-Shielding Effects in a Porcine Model

“…Theoretically, lumbar dynamic stability system reduces adjacent segment degeneration and the stress on the intervertebral bone graft and promotes bone healing and spine recovery. However, high-level stress will cause spinal cord compression and induce nerve tissue damage [ 31 ]. Lumbar Ti-24Nb-4Zr-8Sn fixation system is a dynamic stability system made of titanium alloy and polyether ether ketone (PEEK) materials [ 32 ].…”