Analysis of Cervical Spine Alignment Change after Modified Kurokawa Cervical Laminoplasty in the Patients with Cervical Myelopathy and Straight Cervical Spine

The clinical efficacy of laminectomy fusion fixation and posterior single open-door laminoplasty in the treatment of multilevel cervical ossification of the posterior longitudinal ligament (OPLL): a retrospective study

BACKGROUND

To compared the clinical efficacy of two surgical methods, posterior laminectomy fusion fixation, and posterior single open-door laminoplasty, in treating multilevel cervical ossification of the posterior longitudinal ligament (OPLL).

METHODS

The study retrospectively included 102 patients treated between December 2016 and December 2020. The patients were included into an observation group (56 cases) treated with total laminectomy and lateral screw fixation, and a control group (46 cases) treated with single open-door laminoplasty.

RESULTS

After 24 months, both groups showed significant improvement in Japanese Orthopaedic Association (JOA) scores and Visual Analogue Scale (VAS) scores, indicating better clinical symptoms and functional recovery. There was no significant difference in preoperative JOA and VAS scores between the two groups (P > 0.05). At 24 months after surgery, there was no significant difference in JOA and VAS scores between the two groups (P > 0.05). However, the observation group had a significantly higher cervical curvature index (CCI) and lower range of motion (ROM) of the cervical spine compared to the control group (P < 0.05). The CCI in control group was lower than before surgery, while the CCI in observation group was higher than before surgery, and CCI in the control group was considerably lower than that in the observation group (P < 0.05). The complication rate was lower in the control group, with fewer cases of axial symptoms, fifth cervical nerve root palsy, and overall complications. The overall complication rate was 25.0% (14/56) in the observation group and 10.8% (5/46) in the control group (P < 0.05).

CONCLUSIONS

Both posterior laminectomy fusion fixation and posterior single open-door laminoplasty yield positive outcomes in improving clinical neurological function, cervical curvature, range of motion of the cervical spine, and cervical sagittal balance. Although open-door laminoplasty is less effective than total laminectomy in maintaining CCI and sagittal balance, it excels in preserving cervical range of motion, less surgical trauma and complications. Thus, open-door laminoplasty may be a suitable first-choice treatment for multi-segmental cervical OPLL, especially for patients with lordotic cervical spine physiological curvature.

Preoperative Range of Motion in Extension May Influence Postoperative Cervical Kyphosis After Laminoplasty

STUDY DESIGN

Retrospective observational study.

OBJECTIVE

The objective of this study was to investigate factors associated with cervical kyphosis after laminoplasty.

SUMMARY OF BACKGROUND DATA

Many factors are reportedly associated with the deterioration of cervical curvature after laminoplasty, including cervical lordosis angle, cervical spine range of motion (ROM), T1 slope, and C2-C7 sagittal vertical axis. Postlaminoplasty kyphosis or deterioration of cervical curvature is likely caused by multiple factors. There is currently no consensus on these issues.

MATERIALS AND METHODS

Data of patients treated with laminoplasty for degenerative cervical myelopathy at our institution during 2008-2018 were reviewed. The following variables were collected for each patient: age and sex; follow-up time; surgery involving C3 (yes or no); surgery involving C7 (yes or no); distribution of segments operated on; number of laminae operated on; flexion, extension, and total ROM; cervical lordotic angle; longitudinal distance index; curvature index; C2-C7 sagittal vertical axis; and T1 slope. Logistic regression analysis was used to assess possible risk factors for postoperative kyphosis. Receiver operating characteristic curves were constructed to determine the cutoff values of risk factors.

RESULTS

The study cohort comprised 151 patients. Logistic regression analysis indicated that sex, number of laminae operated on, and preoperative extension ROM were significantly associated with postoperative cervical kyphosis ( P <0.05). There was significantly greater postoperative kyphosis in women than in men; the more segments operated on, the greater the risk of postoperative kyphosis, and the larger the preoperative extension ROM, the lower the risk of postlaminoplasty kyphosis. Receiver operating characteristic curve analysis showed that the cutoff value for preoperative extension ROM is 22.1°.

CONCLUSIONS

Preoperative extension ROM may be associated with the development of postoperative kyphosis. The cutoff value of preoperative extension ROM that suggested the prospect of postoperative kyphosis in our sample was 22.1°.

Cervical alignment and clinical outcome of open-door laminoplasty vs. laminectomy and instrumentation in kyphotic multilevel cervical degenerative myelopathy

INTRODUCTION

The aim of this study was to determine whether the sagittal lordotic alignment, clinical outcomes and axial symptoms (AS) could be improved by kyphotic correction through the posterior approach for the treatment of multilevel cervical degenerative myelopathy (CDM) and to further analyze the changes of cervical spinal alignment parameters after correction of kyphosis. The hypothesis was that correction of kyphosis can improve the severity of AS and neurological recovery.

MATERIALS AND METHODS

We retrospectively reviewed 109 patients who suffered from multilevel CDM combined with kyphosis. The patients had undergone open-door laminoplasty (Group LP, 53 patients) and laminectomy with instrumentation (Group LI, 56 patients) between January 2014 and December 2018. Cervical spinal alignment parameters, including curvature index (CI), T1 slope, C2-7 Cobb angle, C2-7 SVA, were measured on the pre- and postoperative lateral radiographs. The recovery rate was calculated based on the Japanese Orthopedic Association (JOA) score. AS severity was quantified using Neck Disability Index (NDI). A P value less than 0.05 was considered to be significant.

RESULTS

Analyses of postoperative follow-up data showed significant differences (P < 0.001) in CI, correction of CI, C2-7 Cobb angle, T1 slope, C2-7 SVA and NDI between Group LP and LI, but no significant differences in JOA score (P = 0.23) and recovery rate (P = 0.13). There were significant differences (P < 0.001) in CI, T1 slope, C2-7 Cobb angle, C2-7 SVA, JOA score, and NDI between pre- and postoperative follow-up in both groups. Correction of CI showed negative correlation with AS severity (r = -0.51, P < 0.001), and no association with recovery rate (r = 0.14, P = 0.15).

CONCLUSIONS

Satisfied neurological improvement was achieved by LP and LI for multilevel CDM combined with kyphosis. Cervical kyphotic correction produced significant improvement of AS and increase of T1 slope and C2-7 SVA. However, the kyphotic correction may not be associated with better neurological recovery in the short-term postoperative period.