Radiographic Parameters in Cervical Myelopathy: Review of Current Literature

Comparison of efficacy between endoscope-assisted anterior cervical discectomy and fusion (ACDF) and open ACDF in the treatment of single-segment cervical spondylotic myelopathy

BACKGROUND

In this study, we compared the clinical efficacy of endoscope-assisted anterior cervical discectomy and fusion (ACDF) with open ACDF in the treatment of single-segment cervical spondylotic myelopathy.

METHODS

A retrospective analysis was performed on 52 patients with single-segment cervical spondylotic myelopathy between June 2021 and February 2022, including 33 males and 19 females, with a mean age of 58.42 ± 9.26) years. Among them, 28 patients were treated with endoscope-assisted ACDF (Group A), including 2 cases of C4/5 segment, 16 cases of C5/6 segment, and 10 cases of C6/7 segment; 24 patients were treated with open ACDF (Group B), including 4 cases of C4/5 segment, 11 cases of C5/6 segment, and 9 cases of C6/7 segment. The operation time, intraoperative blood loss, hospital stay, and complications were recorded and compared between the two groups. The Visual Analogue Scale (VAS) and the Japanese Orthopaedic Association (JOA) score were used for clinical evaluation during the follow-up in the 1st month and 3rd month after surgery, and at the final follow-up.

RESULTS

The 52 patients were followed up on average for 13.04 months (12-17 months). The operation time in Group A and Group B was (105.18 + 8.66) minutes and (81.88 + 6.05) minutes, the intraoperative blood loss was (84.29 + 13.45) mL and (112.92 + 17.81) mL, and the hospital stay was (6.75 + 1.29) days and (7.63 + 1.41) days, respectively. The difference between the two groups was statistically significant (P < 0.05). The VAS and JOA scores in the 1st month and the 3rd month after surgery and the last follow-up significantly improved in both groups compared with those before surgery (P < 0.05). The VAS and JOA scores of Group A in the 1st month, 3rd month after surgery, and the last follow-up were better than those in Group B (P < 0.05). The complication rate in Group A was 7% (2/28), which was not significantly different from the 17% (4/24) in Group B (P > 0.05).

CONCLUSION

Both endoscope-assisted ACDF and open ACDF can achieve satisfactory clinical efficacy in the treatment of single-segment cervical spondylotic myelopathy. Although the operation time of endoscope-assisted ACDF is prolonged, it has the advantages of clear vision, thorough decompression, less blood loss, and reduced risk of nerve damage, and is worthy of clinical promotion and application.

A novel classification that defines the normal cervical spine: an analysis based on 632 asymptomatic Chinese volunteers

PURPOSE

The "normal" cervical spine may be non-lordotic shapes and the cervical spine alignment targets are less well established. So, the study was to propose novel classification for cervical spine morphologies with Chinese asymptomatic subjects, and to address cervical balance status based on the classification.

METHOD

An overall 632 asymptomatic individuals on cervical spine were selected from January 2020 to December 2022, with six age groups from 20-30 year to 70 plus group. Cervical alignment contained C2-7 cervical lordosis (C2-7 CL) and T1 slope (T1S), together with C1-2 CL, C2-4 CL, C5-7 CL, C2S, cervical sagittal vertical axis (CSVA), thoracic inlet angle (TIA) and neck tilt (NT). C2-7 cervical lordosis was regarded as primary outcomes. To identify groups with similar cervical alignment parameters, a 2-step cluster analysis was performed.

RESULTS

C2-7 CL, T1S, CSVA, TIA and NT increased by age and mean value of them were larger in male than female group. Four unique clusters of female lordotic cluster, female kyphotic cluster, male lordotic cluster and male kyphotic cluster were classified mainly based on gender and C2-C7 CL. T1S was the independent influencing factor for C2-7 CL in all individuals and C2-7 CL = -28.65 + 0.57 × TIA, which varied from clusters. Although interactions among cervical parameters, it showed the alignment was more coordinated in lordotic groups.

CONCLUSIONS

The cervical sagittal profile varied with age and gender. Four clusters were naturally classified based on C2-7 CL and gender. The cervical balance status was addressed by C2-7 CL =  - 28.65 + 0.57 × TIA.

Cervical alignment and clinical outcome of anterior cervical discectomy and fusion vs. anterior cervical corpectomy and fusion in local kyphotic cervical spondylotic myelopathy

Background

Cervical local kyphosis (CLK) is a common degenerative disorder with a potentially debilitating and intractable condition. Currently, there is still debate on the optimal treatment of local kyphotic cervical spondylotic myelopathy (LKCSM) via different anterior approaches.

Objective

The objective of this study was to evaluate the surgical efficacy of anterior cervical discectomy and fusion (ACDF) vs. anterior cervical corpectomy and fusion (ACCF) for the treatment of LKCSM. In addition, the cervical sagittal alignment parameters and axial symptoms (AS) severity after CLK correction were analyzed.

Materials and methods

From January 2016 and December 2020, 104 patients who suffered LKCSM were retrospectively reviewed. These patients underwent ACDF (n = 53) and ACCF (n = 51). Pre- and postoperatively, cervical sagittal alignment parameters were measured on the lateral X-rays, including local kyphotic angles (LKA), C2-7 Cobb angle, T1 slope, and C2-7 sagittal vertical axis (C2-7 SVA). The neurological recovery rate was calculated according to the Japanese Orthopedic Association (JOA) score. The AS severity was evaluated using Neck Disability Index (NDI).

Results

Significant differences (P < 0.05) were demonstrated between ACDF and ACCF groups regarding LKA, LKA correction, C2-7 Cobb angle, T1 slope, C2-7 SVA, NDI, NDI recovery and NDI ranking system. However, no significant differences (P > 0.05) existed in JOA score, recovery rate, and neurological recovery rate grade. In both groups, significant differences (P < 0.05) were demonstrated between pre- and postoperative LKA, T1 slope, C2-7 Cobb angle, C2-7 SVA, JOA score, and NDI. LKA correction showed the positive correlations with the recovery rate (r = 0.48, P < 0.001), and with the NDI recovery in ACDF group (r = 0.49, P < 0.001) and in ACCF group (r = 0.55, P < 0.001).

Conclusions

LKCSM with ≤3 segments of spinal cord compression can be improved with either ACDF or ACCF, resulting in satisfactory neurological outcomes. CLK correction can significantly improve the neurological function and AS, and increase the T1 slope and C2-7 SVA. However, ACDF was more favorable than ACCF in the CLK correction.