OBJECTIVE: The use of biomodels in the laboratory for studying and training cervical laminoplasty has not yet been reported. We propose the use of a cervical spine biomodel for surgical laminoplasty training.
METHODS: This is an experimental study. Ten 3D identical cervical spine biomodels were printed based on CT and MRI scans of a patient diagnosed with spondylotic cervical myelopathy. The additive manufacturing method employed fused deposition modeling (FDM) and polylactic acid (PLA) and selected as the raw material. The sample was divided into two groups: control (n = 5; the biomodels were submitted to CT scanning) and open-door (n = 5; the biomodels were submitted to open-door laminoplasty and postoperative CT). The area and anteroposterior diameter of the vertebral canal were measured on CT scans.
RESULTS: Printing each piece took twelve hours. During the surgical procedure, there was sufficient support from the biomodels to keep them immobilized. Using the drill was feasible; however continuous irrigation was mandatory to prevent plastic material overheating. The raw material made the biomodel CT study possible. The vertebral canal dimensions increased 24.80% (0.62 cm2) in the area and 24.88% (3.12 mm) in the anteroposterior diameter.
CONCLUSIONS: The cervical spine biomodels can be used for laminoplasty training, even by using thermosensitive material such as PLA. The use of continuous irrigation is essential while drilling.

OBJECTIVE: Laminoplasty (LP) combined with C3 laminectomy (LN) can effectively achieve spinal cord decompression while maintaining the integrity of the posterior ligament-muscle complex, thereby minimizing cervical muscle damage. However, its necessity and safety remain controversial. This study aimed to compare the safety and efficacy of LP and LP combined with C3 LN in the treatment of patients with multilevel degenerative cervical spondylotic myelopathy (DCM).
METHODS: A systematic review and meta-analysis of the literature was performed. A search of PubMed, Web of Science, Embase, and the Cochrane Library databases was conducted from inception through December 2023 and updated in February 2024. Search terms included laminoplasty, laminectomy, C3 and degenerative cervical spondylosis. The literature search yielded 14 studies that met our inclusion criteria. Outcomes included radiographic results, neck pain, neurologic function, surgical parameters, and postoperative complications. We also assessed methodologic quality, publication bias, and quality of evidence.
RESULTS: Fourteen studies were identified, including 590 patients who underwent LP combined with C3 LN (modified group, MG) compared to 669 patients who underwent LP (traditional group, TG). The results of the study indicated a statistically significant improvement in cervical range of motion (WMD = 3.62, 95% CI: 0.39 to 6.85) and cervical sagittal angle (WMD = 2.07, 95% CI: 0.40 to 3.74) in the MG compared to the TG at the last follow-up (very low-level evidence). The TG had a higher number of patients with complications, especially C2-3 bone fusion. There was no significant difference found in improvement of neck pain, JOA, NDI, cSVA, T1 slope at latest follow-up.
CONCLUSIONS: LP combined with C3 LN is an effective and necessary surgical method for multilevel DCM patients to maintain cervical sagittal balance. However, due to the low quality of evidence in existing studies, more and higher quality research on the technology is needed in the future.

OBJECTIVE: This study aims to investigate the potential of preoperative blood supply condition measured by dynamic susceptibility contract (DSC) MRI in prediction of postoperative outcomes for patients with cervical spondylotic myelopathy (CSM).
METHODS: Thirty-nine patients (Age: 61 ± 7, male: 23, female: 16) with CSM who underwent laminoplasty were enrolled. All patients received DSC MRI before the operation. Five parameters include Enhance, rEnhance, full width at half maxima (FWHM), Slope1 and Slope2 in DSC MRI, were calculated at all the compressed spinal cord segments. Clinical outcomes were evaluated by modified Japanese Orthopaedic Association (mJOA) scores. Patients were divided into two groups based on mJOA recovery rate of 5 years: good recovery (> 50%) or poor recovery (≤ 50%). The difference between two groups were compared. The value of DSC MRI to CSM was evaluated by logistic and receiver operating characteristic (ROC) curve analysis.
RESULTS: There were 26 patients in good recovery group and 13 patients in poor recovery group. The baseline characteristics, including age, gender, preoperative mJOA score, and smoking status showed no significant difference between the two groups (all p > 0.05). The FWHM was significantly higher in the poor recovery group (9.77 ± 2.78) compared to the good recovery group (6.64 ± 1.65) (p = 0.002). Logistic regression analysis indicated that an increased FWHM was a significant risk factor for poor prognosis recovery (p = 0.013, OR = 0.392, 95%CI: 0.187-0.822). The AUC of FWHM for ROC was 0.843 (95% CI: 0.710-0.975) with a p value of 0.001. In addition, an FWHM greater than 5.87, with a sensitivity of 92.3% and specificity of 69.2%, was found to be an independent risk factor for poor postoperative recovery in patients with CSM.
CONCLUSIONS: In this study, we successfully quantified the spinal cord blood supply condition by DSC MRI technique. We found that an increase in FWHM was an independent risk factor for poor postoperative recovery in CSM patients. Specifically, patients with FWHM > 5.87 have a poor postoperative recovery.

METHODS: Retrospective cohort study.
OBJECTIVE: This study aimed to investigate the long-term outcomes of laminoplasty-alone (LP) and combined procedure (CP), consisting of laminoplasty and single-level anterior cervical discectomy and fusion, in comparable patients who had multilevel degenerative cervical myelopathy (MDCM) with concomitant anterior and posterior compression (CAPC).
METHODS: Consecutive MDCM patients with CAPC underwent LP or CP between 2012 and 2015 from a same surgical group were enrolled and followed up for a minimum of 8 years. Preoperative demographic, radiological, and clinical variables were collected. Propensity score matching (PSM) analysis was performed to match patients with comparable conditions. The outcomes were evaluated by postoperative Japanese Orthopedic Association (JOA) score improvement, JOA recovery rate (JOARR) and complications.
RESULTS: A total of 230 patients were included, of whom 146 underwent LP and 84 underwent CP. After PSM, 84 pairs of comparable patients were matched. The matched groups presented fair comparability in preoperative conditions. The CP group had significantly prolonged surgery time and greater blood loss. At the final follow-up, the postoperative JOA scores of LP and CP groups were 14.51 ± 1.79 and 15.47 ± 1.81 (P < 0.001) and the JOARR were 42.5% ± 53.3% and 68.5% ± 35.4%, respectively (P < 0.001). Three (3.6%) patients in the LP group underwent reoperations because of recurrent symptoms (P = 0.081).
CONCLUSIONS: Both LP and CP demonstrated considerable long-term neurological recovery in patients with CAPC. The CP showed a significantly higher JOA improvement and JOARR. The combined decompression might be a safe and effective alternative in treating MDCM with CAPC in experienced hands.

BACKGROUND: How to quickly read and interpret intraoperative ultrasound (IOUS) images of patients with degenerative cervical myelopathy (DCM) to obtain meaningful information? Few studies have systematically explored this topic.
OBJECTIVE: To systematically and comprehensively explore the IOUS characteristics of patients with DCM.
METHODS: This single-center study retrospectively included patients with DCM who underwent French-door laminoplasty (FDL) with IOUS guidance from October 2019 to March 2022. One-way ANOVA and Pearson\'s /Spearman\'s correlation analysis were used to analyze the correlations between the cross-sectional area of the spinal cord (SC) and individual characteristics; the relationships between the morphology, echogenicity, pulsation, decompression statuses, compression types of SC, location of the spinal cord central echo complex (SCCEC) and the disease severity (the preoperative Japanese Orthopedic Association score, preJOA score); the difference of the spinal cord pulsation amplitude(SCPA) and the SCCEC forward movement rate (FMR) between the compressed areas(CAs) and the non-compressed areas (NCAs).
RESULTS: A total of 38 patients were successfully enrolled (30 males and 8 females), and the mean age was 57.05 ± 10.29 (27-75) years. The cross-sectional area of the SC was negatively correlated with age (r = - 0.441, p = 0.006). The preJOA score was significantly lower in the heterogeneous group than in the homogeneous group (P < 0.05, p = 0.005). The hyperechoic area (HEA) was negatively while the SCCEC FMR was positively correlated with the preJOA score (r = - 0.334, p = 0.020; r = 0.286, p = 0.041). The SCCEC FMR and SCPA in CAs were significantly greater than those in NCAs (p < 0.05, p = 0.007; P < 0.001, P = 0.000).
CONCLUSIONS: The cross-sectional area of the SC decreases with age in adults. More changes in intramedullary echogenicity and less moving forward of the SCCEC often indicate poor SC status, and the SCCEC FMR and SCPA are more pronounced in CAs.

OBJECTIVE: The purpose of this study is to compare radiological and clinical outcomes between alternate levels (C4 and C6) and all levels mini-plate fixation in C3-6 unilateral open-door laminoplasty.
METHODS: Ninety-six patients who underwent C3-6 unilateral open-door laminoplasty with alternate levels mini-plate fixation (54 patients in group A) or all levels mini-plate fixation (42 patients in group B) between September 2014 and September 2019 were reviewed in this study. Radiologic and clinical outcomes were assessed. Clinical results included Visual Analogue Scale (VAS) of axial neck pain and Japanese Orthopedic Association (JOA) score. Radiographic results included cervical range of motion (ROM), cervical curvature index (CCI), and the spinal canal expansive parameters including open angle, anteroposterior diameter (APD), and Pavlov`s ratio.
RESULTS: There was no significant difference in VAS, JOA score, ROM, and CCI between two groups. There was no significant difference in canal expansion postoperatively between two groups. However, open angle, APD, and Pavlov`s ratio in group A decreased significantly during the follow-up. In group B, APD, Pavlov`s ratio, and open angle were maintained until the final follow-up. There was no hardware failure or lamina reclosure occurred in both groups during the follow-up. The mean cost of group B was higher than that of group A.
CONCLUSIONS: Despite the differences in the maintenance of canal expansion, alternate levels mini-plate fixation can achieve similar clinical outcomes as all levels mini-plate fixation in C3-6 unilateral open-door laminoplasty. As evidenced in this study, we believe C3-6 laminoplasty with alternate levels (C4 and C6) mini-plate fixation is an economical, effective, and safe treatment method.

OBJECTIVE: To evaluate C2 muscle preservation effect and the radiological and clinical outcomes after C2 recapping laminoplasty.
METHODS: Fourteen consecutive patients who underwent C2 recapping laminoplasty around C1-2 level were enrolled. To evaluate muscle preservation effect, the authors conducted a morphological measurement of extensor muscles between the operated and nonoperated side. Two surgeons measured the cross-sectional area (CSA) of obliquus capitis inferior (OCI) and semispinalis cervicis (SSC) muscle before and after surgery to determine atrophy rates (ARs). Additionally, we examined range of motion (ROM), sagittal vertical axis (SVA), neck visual analogue scale (VAS), Neck Disability Index (NDI), and Japanese Orthopaedic Association (JOA) score to assess potential changes in alignment and consequent clinical outcomes following posterior cervical surgery.
RESULTS: We measured the CSA of OCI and SSC before surgery, and at 6 and 12 months postoperatively. Based on these measurements, the AR of the nonoperated SSC was 0.1% ± 8.5%, the AR of the operated OCI was 2.0% ± 7.2%, and the AR of the nonoperated OCI was -0.7% ± 5.1% at the 12 months after surgery. However, the AR of the operated side\'s SSC was 11.2% ± 12.5%, which is a relatively higher value than other measurements. Despite the atrophic change of SSC on the operated side, there were no prominent changes observed in SVA, C0-2 ROM, and C2-7 ROM between preoperative and 12 months postoperative measurements, which were 11.8 ± 10.9 mm, 16.3° ± 5.9°, and 48.7° ± 7.7° preoperatively, and 14.1 ± 11.6 mm, 16.1° ± 7.2°, and 44.0° ± 10.3° at 12 months postoperative, respectively. Improvement was also noted in VAS, NDI, and JOA scores after surgery with JOA recovery rate of 77.3% ± 29.6%.
CONCLUSIONS: C2 recapping laminoplasty could be a useful tool for addressing pathologies around the upper cervical spine, potentially mitigating muscle atrophy and reducing postoperative neck pain, while maintaining sagittal alignment and ROM.

BACKGROUND: Cervical spine range of motion (ROM) is a critical factor in changes in cervical sagittal alignment (CSA) and clinical outcomes after cervical laminoplasty (LMP). However, the impact of postoperative cervical ROM on CSA after cervical LMP is still unclear.
OBJECTIVE: Evaluating the imaging and symptomatic data from patients with cervical spondylotic myelopathy (CSM) to identify the influence of postoperative cervical ROM on post-LMP CSA and surgical outcomes.
METHODS: Retrospective study.
METHODS: Eighty-six patients undergoing LMP due to multilevel CSM OUTCOME MEASURES: Radiographic parameters were measured before surgery and at follow-up: cervical lordosis (CL), T1 slope (T1S), cervical sagittal vertical axis (cSVA), CL in flexion (Flex CL), CL in extension (Ext CL), total cervical spine range of motion (ROM), cervical spine range of flexion (Flex ROM), and cervical spine range of extension (Ext ROM). Japanese Orthopedic Association (JOA) and visual analog score (VAS) were used to assessed clinical outcomes. Other parameters included age, gender, body mass index (BMI), follow-up time, number of surgical segments, proximal level, distalis level, and collar wear time.
METHODS: We divided patients according to the changes in CSA (loss of cervical lordosis (LCL)>10°, or ≤10°; an increase in cervical sagittal vertical axis (I-cSVA) >10mm, or ≤10mm). A receiver-operating characteristic curve (ROC) analysis was constructed to identify the optimal cut-off value to discriminate the patients with and without postoperative deterioration of CSA.
RESULTS: The postoperative total and Flex ROM were significantly lower in the LCL>10° and I-cSVA>10mm groups. Multivariate logistic regression analysis showed that low post-Flex ROM was significant risk factor for postoperative deterioration of CSA. ROC showed that the cut-off value for postoperative Flex ROM was 15.60°. Improvements in JOA recovery rate and neck pain were more significant in the flexibility group (post-Flex ROM ≥15.6°) after surgery. Patients in the stiffness group (post-Flex ROM <15.6°) wore a collar longer.
CONCLUSIONS: The preservation of cervical flexibility can maintain CSA after cervical LMP. Postoperative cervical stiffness is related to poor surgical outcomes because significant cervical kyphotic change and sagittal imbalance are likely to occur after surgery. Prolonged wearing of cervical collar is correlated with cervical stiffness following cervical LMP.

Background/Objectives: There exists limited data guiding open-door laminoplasty. The objective of this study is to determine if open-door laminoplasty affects radiographic decompression or arm pain outcomes. Methods: Adult patients who underwent unilateral open-door laminoplasty cervical myelopathy were included. The side opened was dependent on surgeon discretion. We recorded preoperative side of symptoms, side of radiographic compression, arm pain scores, and canal diameter. Patients with open-side ipsilateral or contralateral to dominant symptoms or compression were compared to determine any effect on arm pain outcomes or spinal canal diameter. If the symptoms were equal bilaterally, patients were neutral. Results: A total of 167 patients were included, with an average age of 64 ± 11 years and average follow-up time of 64.5 ± 72 weeks. The average preoperative arm pain visual analog score (VAS) was 2.13 ± 2.86, and the average arm VAS after 6 months was 1.52 ± 2.68. For dominant symptoms, the ipsilateral, contralateral, and neutral groups had a significant improvement in arm VAS at >6 months postoperatively. For dominant compression, the ipsilateral and contralateral groups had a significant improvement in both arm VASs and canal diameter at >6 months postoperatively. No differences were seen between groups for either. We observed a significant correlation between size of plate and change in canal diameter; however, no differences were noted for arm pain. Conclusions: Laminoplasty may be effective in addressing radicular arm pain by increasing the spinal canal\'s diameter and space available for the cord. The laterality of open-door laminoplasty did not affect arm pain improvement or canal expansion.

UNASSIGNED: Spinal schwannomas are the most common intradural extramedullary tumors, and their complete removal is recommended to avoid tumor recurrence. Although laminoplasty provides a sufficient window for tumor resection, this approach may increase tissue trauma and cause postoperative instability compared with unilateral hemilaminectomy. This study aimed to compare the efficacy and clinical outcomes of the two approaches.
UNASSIGNED: We included 100 consecutive patients who underwent unilateral hemilaminectomy or laminoplasty for resection of spinal schwannomas between January 2015 and February 2023. The patients\' baseline characteristics, including sex, age, tumor location, percentage of tumor occupying the intradural space, operative time, postoperative length of hospital stay, intraoperative bleeding volume, visual analog scale score, and neurologic results, were retrospectively analyzed.
UNASSIGNED: Hemilaminectomy patients who underwent unilateral hemilaminectomy had smaller intraoperative bleeding (p = 0.020) volume, shorter operative time (p = 0.012), and shorter postoperative length of hospital stay (p = 0.044). The mean VAS scores at the last follow-up were similar between the two groups (p = 0.658). Although the postoperative McCormick and Karnofsky Performance scores were not significantly different between the laminoplasty and unilateral hemilaminectomy groups (p = 0.687 and p = 0.649, respectively), there was a statistically significant improvement based on postoperative neurological results compared to preoperative neurological results for both groups. The incidence of postoperative complications was 5% and 11.7% in the unilateral hemilaminectomy and laminoplasty groups, respectively (p = 0.308).
UNASSIGNED: For spinal schwannoma resection, unilateral hemilaminectomy has more advantages than laminoplasty, including a shorter postoperative hospital stay, faster procedure, and less intraoperative blood loss while achieving the same desired result.