Jmjd3 Mediates Neuropathic Pain by Inducing Macrophage Infiltration and Activation in Lumbar Spinal Stenosis Animal Model.

Lumbar spinal stenosis (LSS) is a major cause of chronic neuropathic back and/or leg pain. Recently, we demonstrated that a significant number of macrophages infiltrated into the cauda equina after compression injury, causing neuroinflammation, and consequently mediating neuropathic pain development and/or maintenance. However, the molecular mechanisms underlying macrophage infiltration and activation have not been elucidated. Here, we demonstrated the critical role of histone H3K27 demethylase Jmjd3 in blood-nerve barrier dysfunction following macrophage infiltration and activation in LSS rats. The LSS rat model was induced by cauda equina compression using a silicone block within the epidural spaces of the L5-L6 vertebrae with neuropathic pain developing 4 weeks after compression. We found that Jmjd3 was induced in the blood vessels and infiltrated macrophages in a rat model of neuropathic pain. The blood-nerve barrier permeability in the cauda equina was increased after compression and significantly attenuated by the Jmjd3 demethylase inhibitor, GSK-J4. GSK-J4 also inhibited the expression and activation of MMP-2 and MMP-9 and significantly alleviated the loss of tight junction proteins and macrophage infiltration. Furthermore, the activation of a macrophage cell line, RAW 264.7, by LPS was significantly alleviated by GSK-J4. Finally, GSK-J4 and a potential Jmjd3 inhibitor, gallic acid, significantly inhibited mechanical allodynia in LSS rats. Thus, our findings suggest that Jmjd3 mediates neuropathic pain development and maintenance by inducing macrophage infiltration and activation after cauda equina compression and thus may serve as a potential therapeutic target for LSS-induced neuropathic pain.

A New Indicator Predicting the Degree of Cord Shift After Posterior Decompression of Cervical Ossification of the Posterior Longitudinal Ligament Extended to the C2 Level and Its Clinical Usefulness.

AIM: To evaluate the usefulness of the rostral line (R-line) as a new index for determining the degree of C2 lamina decompression in the context of ossification of the posterior longitudinal ligament (OPLL) extending to the C2 level. MATERIAL AND METHODS: The R-line was devised based on the mechanism by which the cord is shifted backward following cervical posterior decompression. According to their R-line status, 36 patients with cervical OPLL extending to the C2 level were divided into two groups of R-line (+) and R-line (?) cases, where the R-line touched the upper half of the posterior C2 lamina in the R-line (+) group and the inferior half of the posterior C2 lamina in the R-line (?) group, respectively. RESULTS: Eighteen patients were classified as R-line (+) and 18 patients were classified as R-line (?). Total laminectomy of the C2 lamina was more common in the R-line (+) group, while dome-shape C2 laminectomy was more common in the R-line (?) group. All patients requiring reoperation were included in the R-line (+) group. Only the operation type showed a statistically significant difference according to the need for reoperation in the R-line (+) group; specifically, all patients who underwent reoperation in the R-line (+) group had dome-shape C2 laminectomy. It was determined that the risk factor for reoperation in the R-line (+) group was a history of dome-shape C2 laminectomy. CONCLUSION: If the R-line touches the upper half of the posterior C2 lamina, total decompression of the C2 lamina should be performed.

The R-line: A New Imaging Index for Decision Making Regarding C2 Lamina Decompression in Cervical Ossification of the Posterior Longitudinal Ligament.

OBJECTIVE: The optimal treatment modality for cervical ossification of the posterior longitudinal ligament (OPLL) including the C2 level remains controversial. Cervical laminoplasty is a widely accepted considering of advantages such as development of few postoperative complications, including kyphosis or neck pain. We encountered seven patients with postoperative disabilities resulting from incomplete decompression after undercutting of the C2 lamina. Based on this experience, we developed a new index to determine the degree of decompression in cervical OPLL-the rostral line (R-line). METHODS: Total of 79 consecutive patients who underwent posterior decompression of cervical OPLL were included in this study. Mean age at the time of operation, the C2-C7 cervical lordotic angle and OPLL thickness at the most stenotic level of the spinal canal, and preoperative/postoperative Japanese Orthopedic Association score was checked in these group. We compared the correspondence between the degree of C2 lamina decompression using the R-line and actual degree of decompression. RESULTS: In all patients, the R-line touched the upper half of the C2 lamina on preoperative magnetic resonance imaging (MRI). The C2-C3 local segment lordotic angle and maximal degree of spinal cord compression by OPLL were independently correlated to postoperative C2 cord shifting. This result indicates that the R-line is a valid indicator to determine the degree of C2 lamina decompression in OPLL extending to the C2 level. CONCLUSION: The results showed that undercutting the C2 lamina can result in incomplete spinal cord decompression and poor clinical outcome if the R-line touches the upper half of the C2 lamina on preoperative MRI.

Comparison of the Accuracy of C1 Pedicle Screw Fixation Using Fluoroscopy and Free-Hand Techniques in Patients With Posterior Arch Thickness of Less Than 4 mm.

BACKGROUND: C1 pedicle screw insertion is not easy, and more fluoroscopy can be required for safe insertion. Fluoroscopy is time consuming and increases patient radiation exposure. There have been no studies comparing the accuracy of C1 pedicle screw insertion using the fluoroscopy and free-hand techniques. OBJECTIVE: To describe a free-hand C1 pedicle screw insertion method in patients with the posterior arch thickness of less than 4 mm in the thinnest part of the groove, and to compare the clinical and radiological outcomes of C1 pedicle screw insertion using fluoroscopy vs using the free-hand technique. METHODS: A total of 25 patients who had atlantoaxial instability with a C1 posterior arch <4 mm and were treated with C1 pedicle screw insertion were included. In 10 patients, fluoroscopy was used for C1 pedicle screw insertion, and 15 patients underwent the free-hand technique. We compared the radiologic and clinical outcomes between the 2 groups. RESULTS: In patients who underwent the free-hand technique, 96.5% of screws were rated as safe (grade A or B), and 80.0% of screws in the fluoroscopy group were rated as safe. Postoperative occipital neuralgia occurred in one patient in the fluoroscopy group and did not occur in the free-hand technique group. There was no significant difference in the improvement of Nurick grade between the 2 groups. CONCLUSION: C1 pedicle screw insertion using the free-hand technique is feasible and safe in patients with a C1 posterior arch <4 mm.

Posterior Cervical Muscle-Preserving Interspinous Process Approach and Decompression: More Minimally Invasive and Modified Shiraishi's Selective Laminectomy.

OBJECTIVE: The cervical extensor musculature is important in cases of neck pain and loss of cervical lordosis after laminoplasty. Therefore, various surgical methods have been developed to preserve the muscle during laminoplasty. We have developed a posterior cervical muscle-preserving interspinous process (MIS) approach and decompression method. We have described the operation details and clinical outcomes of selected patients who have undergone this procedure. METHODS: The MIS approach and decompression method were performed in 20 consecutive patients who had only required central decompression for cervical stenosis. This procedure includes an approach to the interspinous space that is similar to Shiraishi's method but includes decompression without fracturing the spina bifida. RESULTS: The patients had no complications and did not require conversion to conventional laminoplasty. The mean operative time and mean blood loss was 53.0 minutes and 63.0 mL per level, respectively, and the mean hospital stay was 4.0 days. The mean preoperative and 3-month postoperative modified Japanese Orthopedic Association scores were 12.6 and 16.2, and the mean preoperative and 3-month postoperative neck disability index scores were 15.4 and 2.5, respectively. The postoperative neck visual analog scale score was 0.8. The mean preoperative and postoperative sagittal vertical axis was 1.6 and 1.8 cm, respectively. The mean loss of lordosis was 1.0°, and the mean cervical range of motion did not change from preoperatively to postoperatively. CONCLUSIONS: The MIS approach and decompression method was less invasive than both conventional laminoplasty and Shiraishi's selective laminectomy. It is a safe and effective minimally invasive technique for central stenosis caused by cervical spondylotic myelopathy.

Surgical Treatment of Lumbar Spinal Discal Cyst: Is It Enough to Remove the Cyst Only without Following Discectomy?

Discal cysts are a rare cause of low back pain and radiculopathy with unknown pathophysiologic mechanism. Associated symptoms are difficult to distinguish from those caused by extruded discs and other spinal canal lesions. Most discal cysts are treated surgically, but it is unclear whether the corresponding intervertebral disc should be excised along with cyst. We conducted a retrospective clinical review of 27 patients who underwent discal cyst excision at our institution between 2000 and 2017. The mean follow-up period was 63.6 months. We recorded symptoms, radiographs, operative findings, postoperative complications, and short- and long-term outcomes. Structured outcome assessment was based on Numeric Rating Scale (NRS) for pain intensity, Oswestry disability index, and Macnab classification. All patients underwent partial hemilaminectomy and microscopic cyst resection without discectomy. All patients had preoperative back or leg pain. Other preoperative clinical features included motor weakness, neurogenic intermittent claudication, and cauda equina syndrome. After surgery, NRS scores of back and leg pain decreased. The other symptoms also improved. During long-term follow-up, patients reported no restrictions on daily life activities, and were satisfied with our intervention. There were no cases of cyst recurrence. We conducted a review of the literature on lumbar discal cysts published before January, 2018. Including our cases, 126 patients were described. We compared two surgical modalities-cystectomy with and without discectomy-to elucidate both effectiveness and long-term complications. We found that microsurgical cystectomy without corresponding discectomy is an effective surgical treatment for lumbar discal cysts, and is associated with a low recurrence rate.

Anterior Odontoid Screw Fixation for the Treatment of Type 2 Odontoid Fracture with a Kyphotic Angulation or an Anterior Down-slope: A Technical Note.

Anterior odontoid screw fixation (AOSF) is difficult and challenging to perform in patients with type 2 odontoid fracture with a kyphotic angulation or an anterior down-slope. To demonstrate two surgical techniques to resolve kyphotic angulation or difficult fracture direction issues. Anterior odontoid screw fixation was performed in two patients with type 2 odontoid fracture with a kyphotic angulation or an anterior down-slope. This technique can avoid sternal blocking using a percutaneous vertebroplasty puncture needle, and can reduce the kyphotic angle using a Cobb elevator in patients with type 2 odontoid fractures with a kyphotic angulation or an anterior down-sloped fracture. In both the patients, AOSF was successfully performed and a successful clinical outcome was achieved. The screws were well-maintained with reduced fracture segment and well-preserved, corrected kyphotic angles were achieved, as observed on cervical X-ray 6 months postoperatively. Our technique is a safe and effective method for the treatment of type 2 odontoid fracture with a kyphotic angulation or an anterior down-slope.

Clinically significant radiographic parameter for thoracic myelopathy caused by ossification of the ligamentum flavum.

PURPOSE: To investigate radiographic parameters to improve the accuracy of radiologic diagnosis for ossification of ligamentum flavum (OLF)-induced thoracic myelopathy and thereby establish a useful diagnostic method for identifying the responsible segment. METHODS: We classified 101 patients who underwent surgical treatment for OLF-induced thoracic myelopathy as the myelopathy group and 102 patients who had incidental OLF and were hospitalized with compression fracture as the non-myelopathy group between January 2009 and December 2016. We measured the thickness of OLF (TOLF), cross-sectional area of OLF (AOLF), anteroposterior canal diameter, and the ratio of each of these parameters. RESULTS: Most OLF cases with lateral-type axial morphology were in the non-myelopathy group and most with fused and tuberous type in the myelopathy group. Most grade-I and grade-II cases were also in the non-myelopathy group, whereas grade-IV cases were mostly observed in the myelopathy group. The AOLF ratio was found to be the best radiologic parameter. The optimal cutoff point of the AOLF ratio was 33.00%, with 87.1% sensitivity and 87.3% specificity. The AOLF ratio was significantly correlated with preoperative neurological status. CONCLUSIONS: An AOLF ratio greater than 33% is the most accurate diagnostic indicator of OLF-induced thoracic myelopathy. In cases of multiple-segment OLF, confirmation of cord signal change on MRI and an AOLF measurement will help determine the responsible segment. AOLF measurement will also improve the accuracy of diagnosis of OLF-induced thoracic myelopathy in cases of grade III or extended-type axial morphology. These slides can be retrieved under Electronic Supplementary Material.

Importance of the preoperative cross-sectional area of the semispinalis cervicis as a risk factor for loss of lordosis after laminoplasty in patients with cervical spondylotic myelopathy.

PURPOSE: To investigate the effect of the preoperative cross-sectional area (CSA) of the semispinalis cervicis on postoperative loss of cervical lordosis (LCL) after laminoplasty. METHODS: A total of 144 patients who met the inclusion criteria between January 1999 and December 2015 were enrolled. Radiographic assessments were performed to evaluate the T1 slope, C2-7 sagittal vertical axis (SVA), cephalad vertebral level undergoing laminoplasty (CVLL), preoperative C2-7 Cobb angle, and preoperative CSA of the semispinalis cervicis. RESULTS: The T1 slope and the summation of the CSAs (SCSA) at each level of the semispinalis cervicis correlated with LCL, whereas the C2-7 SVA, CVLL, and preoperative C2-7 Cobb angle did not. Multiple regression analysis demonstrated that a high T1 slope and a low SCSA of the semispinalis cervicis were associated with LCL after laminoplasty in patients with cervical spondylotic myelopathy (CSM). The CSA of the semispinalis cervicis at the C6 level had the greatest association with LCL, which suddenly decreased with a LCL of 10°. The best cutoff point of the CSA of the semispinalis cervicis at the C6 level, which predicts LCL > 10°, was 154.5 mm2 (sensitivity 74.3%; specificity 71.6%; area under the curve 0.828; 95% confidence interval 0.761-0.895). CONCLUSION: Preoperative SCSA of the semispinalis cervicis was a risk factor for LCL after laminoplasty. Spine surgeons should evaluate semispinalis cervicis muscularity at the C6 level when planning laminoplasty for patients with CSM. These slides can be retrieved under Electronic Supplementary Material.

Clinical analysis of C5 palsy after cervical decompression surgery: relationship between recovery duration and clinical and radiological factors.

BACKGROUND: Postoperative C5 palsy is a widely known complication of cervical decompression surgery. Many studies have focused on its etiology and factors affecting it. However, no study to date has evaluated the association between the clinical outcome and recovery duration of post-operative C5 palsy. We evaluated this in our current report. METHODS: A retrospective analysis was conducted for 710 consecutive degenerative cervical spine decompression surgeries performed in a single institution. We included all patients who underwent any type of surgical procedure for cervical spinal stenosis, ossification of posterior longitudinal ligament (OPLL), or cervical spondylotic myelopathy (CSM). Demographic, radiologic, clinical information was recorded. Finally, correlation analysis was conducted to identify demographic, radiologic, or clinical factors related with recovery duration (within or after 6 months). RESULTS: The incident rate of postoperative C5 palsy was 5.1 % (36/710 cases). Analysis of recovery duration revealed that 18 patients had recovered within 6 months and 33 (91.7 %) within 2 years, whilst 3 individuals (8.3 %) had not fully recovered within the follow-up period. Factors related to longer recovery (>6 months) included motor grade ≤2 (p < 0.001), presence of multi-segment paresis involving more than the C5 root (p = 0.002), loss of somatic sensation with pain (p = 0.008), and the degree of posterior spinal cord shifting (p = 0.040). Furthermore, multivariate analysis revealed that motor grade ≤2 (p = 0.010) had a significant effect on a recovery duration beyond 6 months. CONCLUSIONS: A motor grade ≤2, the presence of multi-segment paresis involving more than the C5 root, the loss of somatic sensation with pain, and the degree of posterior spinal cord shifting significantly influence whether the duration of recovery from postoperative C5 palsy will take longer than 6 months.

Progression of lumbar spinal stenosis is influenced by polymorphism of thrombospondin 2 gene in the Korean population.

PURPOSE: The aim of this study is to determine the contribution of thrombospondin 2 (THBS2) polymorphisms to the development and progression of lumbar spinal stenosis (LSS) in the Korean population. METHODS: We studied 148 symptomatic patients with radiographically proven LSS and 157 volunteers with no history of back problems from our institution. Magnetic resonance images were obtained for all the patients and controls. Quantitative image evaluation for LSS was performed to evaluate the severity of LSS. All patients and controls were genotyped for THBS2 allele variations using a polymerase chain reaction-based technique. RESULTS: We found no causal single nucleotide polymorphism (SNPs) in THBS2 that were significantly associated with LSS. Two SNPs (rs6422747, rs6422748) were over-represented in controls [P = 0.042, odds ratio [OR] = 0.55 and P = 0.042, OR = 0.55, respectively]. Haplotype analysis showed that the ''AGAGACG'' haplotype (HAP4) and ''AAGGACG'' haplotype (HAP5) were over-represented in severe LSS patients (P = 0.0147, OR = 2.02 and P = 0.0137, OR = 2.48, respectively). In addition, the ''AAAGGGG'' haplotype (HAP1) was over-represented in controls (P = 0.0068, OR = 0.30). CONCLUSIONS: Although no SNPs in THBS2 were associated with LSS, haplotypes (HAP4 and HAP5) were significantly associated with progression of LSS in the Korean population, whereas another haplotype (HAP1) may play a protective role against LSS development.

Effects of transforaminal balloon treatment in patients with lumbar foraminal stenosis: a randomized, controlled, double-blind trial.

BACKGROUND: Lumbar spinal stenosis is a common condition in the elderly. Although balloon treatment is a well-known therapeutic method in specific pain conditions, applying the balloon treatment in patients with lumbar spinal stenosis is not yet well established. OBJECTIVES: We tested the therapeutic effect of transforaminal balloon treatment with a Fogarty balloon catheter on body pain and functional performance in patients with severe lumbar spinal stenosis. STUDY DESIGN: Prospective, randomized, double-blinded, active control trial. SETTING: A tertiary, interventional pain management practice, specialty referral center. METHODS: Sixty-two patients with refractory unilateral radiculopathy aggravated by walking were enrolled and randomly assigned to receive transforaminal steroid injection after transforaminal balloon treatment using a 3 Fr balloon catheter (n = 32) or the same procedure without balloon treatment (n = 30). The patients were prohibited from making any alterations to their medications during the 12 weeks of their follow-up period. After the first 12 weeks, the patients who had persistent symptoms or unbearable pain were allowed to increase the dose of analgesics or to receive additional interventional treatment. OUTCOME ASSESSMENT: Visual analogue scale (VAS) pain scores for the leg and lower back, Oswestry disability index (ODI), and claudication distance were measured at 2, 4, 8, and 12 weeks post procedure. During the 52 weeks of the overall follow-up period, the patients achieving ≥ 50% leg pain relief without additional treatment or increasing the dose of analgesics were evaluated. RESULTS: Significant improvement occurred compared to baseline in VAS (P < 0.001), ODI (P < 0.001), and claudication distance (P < 0.001) in the balloon group during the overall follow-up period, whereas the improvement in ODI (P < 0.05) and claudication distance (P < 0.05) in the control group persisted for 8 weeks. The balloon group showed better improvement in leg VAS (P < 0.05), ODI (P < 0.05), and claudication distance (P < 0.05) than the control group at all post-procedure assessment points. Kaplan-Meier analysis of the duration of the patients achieving ≥ 50% leg pain relief without additional treatment or increasing the dose of analgesics showed a significant intergroup difference between the balloon and control (P = 0.003) groups. Six patients (18.8%) in balloon group maintained ≥ 50% pain relief for 52 weeks whereas no patient (0%) did in control group. LIMITATIONS: Our study is an active-controlled randomized design with a relatively small number of patients. CONCLUSION: Transforaminal balloon treatment leads to both significant pain relief and functional improvement in a subset of patients with refractory spinal stenosis. INSTITUTIONAL REVIEW: This study was approved by the Institutional Review Board of the Asan Medical Center.

A haplotype at the COL9A2 gene locus contributes to the genetic risk for lumbar spinal stenosis in the Korean population.

STUDY DESIGN: We conducted a cross-sectional, genotyping study in patients with lumbar spinal stenosis (LSS) and controls. OBJECTIVE: To determine the contribution of COL9A2 polymorphisms to LSS development in the Korean population. SUMMARY OF BACKGROUND DATA: Because congenital spinal stenosis is typically associated with chondrodysplasias, which are genetic disorders, genetic factors may also play a role in degenerative LSS. A recent Finnish study reported a splice site mutation in COL9A2, leading to premature translation termination. However, a few studies on the genetic association of single nucleotide polymorphisms (SNPs) or haplotypes with LSS have appeared. METHODS: We studied 205 symptomatic patients with radiographically proven LSS and 101 volunteers with no history of back problems from our institution. Magnetic resonance images were obtained for all the patients and controls. Quantitative image evaluation for LSS was performed to evaluate the severity of LSS. All patients and controls were genotyped for COL9A2 allele variations, using a polymerase chain reaction-based technique. RESULTS: We found no causal SNPs in COL9A2 that were significantly associated with LSS, even after phenotypic subgrouping. Haplotype analysis showed that the "GCAGCG" haplotype (HAP2) was overrepresented in LSS patients (P = 0.023, odds ratio [OR] = 1.86), especially in those with severe stenosis (P = 0.018, OR = 1.98). In addition, the "TCAGCG" haplotype (HAP4) was overrepresented in controls (P = 0.042, OR = 0.52). CONCLUSION: Although no SNPs in COL9A2 were associated with LSS, a COL9A2 haplotype (HAP2) was significantly associated with LSS in the Korean population, whereas another haplotype (HAP4) may play a protective role against LSS development. However, the genetic functions of COL9A2 haplotypes in LSS remain to be determined.

Spinal radiosurgical treatment for thoracic epidural cavernous hemangioma presenting as radiculomyelopathy: technical case report.

OBJECTIVE: Image-guided stereotactic radiosurgery (SRS) was applied to a case of spinal epidural cavernous hemangioma in the thoracic spine. This report demonstrates the potential for spinal SRS in treating diseases that have previously required extensive invasive surgery. CLINICAL PRESENTATION: A 27-year-old woman with gait disturbance and shoulder pain radiating into the right upper arm and back presented for clinical evaluation. Magnetic resonance imaging revealed an extraforaminal epidural mass compressing the spinal cord at the T1-T2 and T2-T3 levels of the intervertebral foramen. The patient had previously undergone a decompressive laminectomy and open biopsy. Several months after this surgery, her radiculomyelopathy had not improved and appeared to be progressing. INTERVENTION: Intensity-modulated hypofractionated radiosurgery was performed on the lesion. The patient's radicular pain was remarkably improved within days, and associated neurological symptoms had largely disappeared within a few months. Subsequent follow-up magnetic resonance imaging at 12 and 36 months showed that the tumor mass was greatly reduced. No evidence of any complications associated with irradiation was apparent, and the patient continued to demonstrate a positive prognosis. CONCLUSION: A thoracic epidural cavernous hemangioma of proven pathology was successfully treated using state-of-the-art, spinal image-guided SRS. Based on our experience with other types of tumors, we determined that an effective treatment modality for this pathology would be a hypofractionated dose of 32 Gy in 4 fractions. This treatment protocol delivered rapid clinical benefits and long-term tumor control demonstrating the viability of SRS in the treatment of this difficult and rare condition.

Postlaminoplasty cervical range of motion: early results.

OBJECT: The authors studied cervical range of motion (ROM) before and after cervical laminoplasty to determine factors associated with cervical ROM in patients with cervical myelopathy. METHODS: Between July 2003 and August 2005, 20 patients underwent a modified Hirabayashi-type unilateral open-door laminoplasty to treat multilevel cervical spondylosis or ossification of the posterior longitudinal ligament (OPLL). Clinically, the authors assessed Japanese Orthopaedic Association (JOA) score, duration of symptoms, disease entity, and the age and sex of patients to ascertain the relation of these factors to ROM before and after cervical laminoplasty. Intraoperative findings such as ligament detachment from the C-2 spinous process and cervicothoracic junction involvement were noted. Radiological and imaging findings such as the length of the lesion, cervical axial canal area, anteroposterior (AP) diameter of the cervical canal, angle of the opened lamina after surgery, cervical sagittal angles, cervical curvature index (CCI), and signal change of the cord on magnetic resonance imaging were evaluated. The mean follow-up period was 19.45 months (range 13-38 months). The preoperative average ROM in 18 patients (after excluding two patients with trauma) was 36.73 +/- 15.73 degrees; postoperatively it was 25.24 +/- 16.06 degrees. Thus, ROM decreased by 9.64 +/- 10.09 degrees (31.80%) after surgery (p = 0.002), reflecting the mean in the same 18 patients. Preoperative ROM was related to the age of patients, CCI, preoperative JOA score, and AP diameter of the cervical canal. In cases of OPLL the ROM was lower than that in cases of spondylosis. Postoperative cervical ROM was related to preoperative ROM, postoperative AP diameter of the cervical canal, laminar angle, patient age, and follow-up duration. None of the studied parameters, however, correlated with a decreased cervical ROM. CONCLUSIONS: Cervical ROM was reduced after cervical laminoplasty. Postlaminoplasty cervical ROM had a positive correlation with extended motion; however, gradually it became reduced. In this study, no correlative factor was associated with a reduction in cervical ROM. Further study is also needed.