Comparison of clinical outcomes between sequestered cervical disk herniation and non-sequestered cervical disk herniation after anterior cervical decompression and fusion: a cohort study

BACKGROUND

The advantages of anterior cervical decompression and fusion (ACDF) were well published, while research on postoperative results in different subtypes of cervical disk herniation (CDH) still remains blank. This study aimed to explore the surgical outcome between sequestration and other types in CDH.

METHODS

This retrospective cohort study enrolled 108 patients treated with ACDF in our hospital. The participants were divided into two groups according to the existence of a sequestered disk. The Visual analog scale score, the Japanese Orthopedics Association (JOA) score and the Neck disability index score were used to evaluate postoperative outcome.

RESULTS

Significant improvements were observed in both groups at every viewpoint (P < 0.001). The mean JOA was 15.04 ± 1.26 in the sequestered disk group and 14.45 ± 1.43 in the non-sequestered disk group two months after the operation (P = 0.026 < 0.05). The improvement in JOA at two months after ACDF showed a significant difference: 46.58% ± 39.17% in the sequestered disk group and 33.39% ± 28.82% in the non-sequestered disk group (P = 0.047 < 0.05). Thirty-two patients in the sequestered disk group (64%) and 19 patients in the non-sequestered disk group (32.76%) presented with high signal intensity of the spinal cord on preoperative cervical T2-weighted MRI (P < 0.001).

CONCLUSIONS

Patients with sequestered cervical disks seemed to have a higher degree of symptom improvement two months after ACDF. CDH with a sequestered disk appears to be more likely to cause high signal intensity changes in the compressed cervical spine on T2-weighted MRI. We prefer early positive surgery in patients with sequestered cervical disks from the clinical point of view.

Clinical and Radiologic Features of Degenerative Cervical Myelopathy Depending on the Presence of Cord Signal Change

BACKGROUND

Cord signal change (CSC) on magnetic resonance (MR) imaging is an important radiologic feature of degenerative cervical myelopathy (DCM). Occasionally, DCMs correlate with clinical symptoms with no CSC. The aim of this study was to evaluate clinical and radiologic features, depending on the presence of CSC in DCM.

METHODS

This retrospective study included 73 patients who underwent cervical laminoplasty for DCM. They were divided into 2 groups based on the presence of CSC on static MR imaging (positive CSC in group A and negative CSC in group B). Preoperative radiologic parameters on lateral radiographs and the severity of canal stenosis on MR imaging were analyzed. The functional outcomes were evaluated using the modified Japanese Orthopedic Association score and Nurick grade.

RESULTS

Group A showed more deteriorated canal stenosis (P < 0.001) and kyphotic change than did group B. C2-7 sagittal vertical axis (P = 0.003) of group A and C2-7 range of motion (C27ROM; P < 0.001) of group B were greater than in the opposite groups, respectively. In a multivariate analysis, greater width of the cervical canal (P = 0.002) and increased C27ROM (P = 0.002) were statistically significant radiologic parameters related to negative CSC. Group B showed better functional outcomes until 6 months postoperatively, with statistical significance.

CONCLUSIONS

DCM with negative CSC can be caused by a well-preserved cervical ROM, even with less deteriorated canal stenosis and kyphosis. C27ROM may be a helpful radiologic parameter in diagnosing DCM before CSC appears.