Risk factors for development of myelopathy in patients with cervical spondylotic cord compression

Importance of gap evaluation in the ossification of posterior longitudinal ligament lesions using three-dimensional computed tomography

BACKGROUND CONTEXT

Evaluating the gaps within the ossification of the posterior longitudinal ligament (OPLL) lesions, which may contribute to neurological symptoms, using conventional imaging techniques is challenging.

OBJECTIVE

This study aimed to investigate the importance of evaluating gaps using three-dimensional computed tomography (3D-CT) and their association with the occurrence of magnetic resonance imaging (MRI) T2 high intensity in the spinal cord.

STUDY DESIGN/SETTING

Retrospective cohort study.

PATIENT SAMPLE

Retrospective analysis of 116 patients diagnosed with cervical OPLL.

OUTCOME MEASURES

Presence of gaps in OPLL, presence of T2 high intensity in the cervical spinal cord, and OPLL thickness were evaluated.

METHODS

Lateral X-ray, CT, and reconstructed 3D-CT images were reviewed to assess lesion characteristics and the presence of gaps. MRI was used to evaluate the change in spinal cord signal intensity. The relationship among gap presence, lesion morphology, and MRI T2 high intensity in the spinal cord was examined.

RESULTS

A significant difference in gap detection accuracy was observed between CT and 3D-CT (p = 0.0054). CT demonstrated false-positive results in the detection of gaps as compared with 3D-CT. The presence of gaps was significantly associated with an increased likelihood of MRI T2 high intensity in the spinal cord (p = 0.037). Patients with thicker lesions and smaller space available for the spinal cord (SAC) were more likely to exhibit T2 high intensity. Meanwhile, patients with gaps co-occurring with T2 high intensity exhibited significantly thinner lesions (p = 0.011) and larger SACs (p = 0.0002). Patients with gaps had a significantly lower JOA scores (p = 0.0035), which indicates that patient with gaps are likely to exhibit more severe clinical neurological symptoms.

CONCLUSION

3D-CT showed superiority in accurately identifying gaps within OPLL lesions, while CT demonstrated false-positive results in the detection of gaps. Furthermore, the gap presence was a risk factor for MRI T2 high intensity in the spinal cord, independent of lesion thickness. In addition, gaps are related to more severe clinical symptoms. This study highlighted the importance of evaluating gaps within OPLL lesions using 3D-CT to clarify neurological pathogenesis.

Age is Associated with Level of First-Time Anterior Cervical Discectomy and Fusion: An Ordinal Analysis of Factors Influencing Timing of Cervical Degeneration

BACKGROUND

Symptomatic cervical spondylosis is often treated with anterior cervical discectomy and fusion (ACDF). However, few factors can predict which cervical level will degenerate and require intervention. This analysis evaluates preprocedural factors associated with level of first-time single-level ACDF.

METHODS

We performed a retrospective analysis of patients who underwent single-level ACDF without prior history of spine surgery. Mann Whitney U-tests and Spearman rank-order correlation were performed for analyses of associations between variables of interest and ACDF level. Adjusted odds-ratios were calculated by proportional-odds logistic regression, with age, sex, body mass index, current tobacco use, history of neck trauma, preoperative radicular symptoms, and preoperative myelopathic symptoms as covariates.

RESULTS

One hundred forty-one patients met inclusion criteria, and age demonstrated a negative correlation with ACDF level, such that younger patients tended to have ACDF performed at inferior subaxial levels (P = 0.0006, rho = -0.31, moderately strong relationship). Patients with preoperative radicular symptoms and myelopathic symptoms were more likely to have ACDF performed at inferior (P = 0.0001) and superior (P < 0.0001) levels, respectively. Patient sex, body mass index, current tobacco use, and history of neck trauma were not predictive of ACDF level. When adjusting for the above variables in a proportional-odds ordinal logistic regression model, a one-year increase in age conferred a 4% increase in the odds of requiring an ACDF at a given superior level compared to the adjacent inferior level.

CONCLUSIONS

Age is correlated with level of first-time single level ACDF. Individual subaxial levels may have unique biomechanical properties that influence degeneration.

Network pharmacology analysis and animal experiment validation of neuroinflammation inhibition by total ginsenoside in treating CSM

BACKGROUND

Cervical spondylotic myelopathy (CSM) is a degenerative pathology that affects both upper and lower extremity mobility and sensory function, causing significant pressure on patients and society. Prior research has suggested that ginsenosides may have neuroprotective properties in central nervous system diseases. However, the efficacy and mechanism of ginsenosides for CSM have yet to be investigated.

PURPOSE

This study aims to analyze the composition of ginsenosides using UPLC-MS, identify the underlying mechanism of ginsenosides in treating CSM using network pharmacology, and subsequently confirm the efficacy and mechanism of ginsenosides in rats with chronic spinal cord compression.

METHODS

UPLC-Q-TOF-MS was utilized to obtain mass spectrum data of ginsenoside samples. The chemical constituents of the samples were analyzed by consulting literature reports and relevant databases. Ginsenoside and CSM targets were obtained from the TCMSP, OMIM, and GeneCards databases. GO and KEGG analyses were conducted, and a visualization network of ginsenosides-compounds-key targets-pathways-CSM was constructed, along with molecular docking of key bioactive compounds and targets, to identify the signaling pathways and proteins associated with the therapeutic effects of ginsenosides on CSM. Chronic spinal cord compression rats were intraperitoneally injected with ginsenosides (50 mg/kg and 150 mg/kg) and methylprednisolone for 28 days, and motor function was assessed to investigate the therapeutic efficacy of ginsenosides for CSM. The expression of proteins associated with TNF, IL-17, TLR4/MyD88/NF-κB, and NLRP3 signaling pathways was assessed by immunofluorescence staining and western blotting.

RESULTS

Using UPLC-Q-TOF-MS, 37 compounds were identified from ginsenoside samples. Furthermore, ginsenosides-compounds-key targets-pathways-CSM visualization network indicated that ginsenosides may modulate the PI3K-Akt signaling pathway, TNF signaling pathway, MAPK signaling pathway, IL-17 signaling pathway, Toll-like receptor signaling pathway and Apoptosis by targeting AKT1, TNF, MAPK1, CASP3, IL6, and IL1B, exerting a therapeutic effect on CSM. By attenuating neuroinflammation through the TNF, IL-17, TLR4/MyD88/NF-κB, and MAPK signaling pathways, ginsenosides restored the motor function of rats with CSM, and ginsenosides 150 mg/kg showed better effect. This was achieved by reducing the phosphorylation of NF-κB and the activation of the NLRP3 inflammasome.

CONCLUSIONS

The results of network pharmacology indicate that ginsenosides can inhibit neuroinflammation resulting from spinal cord compression through multiple pathways and targets. This finding was validated through in vivo tests, which demonstrated that ginsenosides can reduce neuroinflammation by inhibiting NLRP3 inflammasomes via multiple signaling pathways, additionally, it should be noted that 150 mg/kg was a relatively superior dose. This study is the first to verify the intrinsic molecular mechanism of ginsenosides in treating CSM by combining pharmacokinetics, network pharmacology, and animal experiments. The findings can provide evidence for subsequent clinical research and drug development.

Assessment of Cervical Myelopathy Risk in Ossification of the Posterior Longitudinal Ligament Patients With Spinal Cord Compression Based on Segmental Dynamic Versus Static Factors

OBJECTIVE

Using segmental dynamic and static factors, we aimed to elucidate the pathogenesis and relationship between ossification of the posterior longitudinal ligament (OPLL) and the severity of cervical myelopathy.

METHODS

Retrospective analysis of 163 OPLL patients' 815 segments. Imaging was used to evaluate each segmental space available for the spinal cord (SAC), OPLL diameter, type, bone space, K-line, the C2-7 Cobb angle, each segmental range of motion (ROM), and total ROM. Magnetic resonance imaging was used to evaluate spinal cord signal intensity. Patients were divided into the myelopathy group (M group) and the without myelopathy group (WM group).

RESULTS

Minimal SAC (p = 0.043), (C2-7) Cobb angle (p = 0.004), total ROM (p = 0.013), and local ROM (p = 0.022) were evaluated as an independent predictor of myelopathy in OPLL. Different from the previous report, the M group had a straighter whole cervical spine (p < 0.001) and poorer cervical mobility (p < 0.001) compared to the WM group. Total ROM was not always a risk factor for myelopathy, as its impact depended on SAC, when SAC > 5 mm, the incidence rate of myelopathy decreased with the increase of total ROM. Lower cervical spine (C5-6, C6-7) showing increased "Bridge-Formation," along with spinal canal stenosis and segmental instability (C2-3, C3-4) in the upper cervical spine, could cause myelopathy in M group (p < 0.05).

CONCLUSION

Cervical myelopathy is linked to the OPLL's narrowest segment and its segmental motion. The hypermobility of the C2-3 and C3-4, contributes significantly to the development of myelopathy in OPLL.

Effects of cervical rotatory manipulation on the cervical spinal cord complex with ossification of the posterior longitudinal ligament in the vertebral canal: A finite element study

Background: There are few studies focusing on biomechanism of spinal cord injury according to the ossification of the posterior longitudinal ligament (OPLL) during cervical rotatory manipulation (CRM). This study aimed to explore the biomechanical effects of CRM on the spinal cord, dura matter and nerve roots with OPLL in the cervical vertebral canal. Methods: Three validated FE models of the craniocervical spine and spinal cord complex were constructed by adding mild, moderate, and severe OPLL to the healthy FE model, respectively. We simulated the static compression of the spinal cord by OPLL and the dynamic compression during CRM in the flexion position. The stress distribution of the spinal cord complex was investigated. Results: The cervical spinal cord experienced higher von Mises stress under static compression by the severe OPLL. A higher von Mises stress was observed on the spinal cord in the moderate and severe OPLL models during CRM. The dura matter and nerve roots had a higher von Mises stress in all three models during CRM. Conclusion: The results show a high risk in performing CRM in the flexion position on patients with OPLL, in that different occupying ratios in the vertebral canal due to OPLL could significantly increase the stress on the spinal cord complex.

Comparing the Bridge-Type Zero-Profile Anchored Spacer (ROI-C) Interbody Fusion Cage System and Anterior Cervical Discectomy and Fusion (ACDF) with Plating and Cage System in Cervical Spondylotic Myelopathy

OBJECTIVE

To compare the clinical efficacy and radioactivity of the bridge-type zero-profile anchored spacer (ROI-C) interbody fusion cage and anterior cervical discectomy and fusion with plating and cage system (ACDF) for cervical spondylotic myelopathy (CSM).

METHODS

This is a retrospective contrastive study. We recruited 35 patients who received ROI-C (ROI-C group) and 34 patients who received ACDF (ACDF group), between January 2014 to January 2019, at our treatment center. The ROI-C group comprised of 11 males and 24 females with a mean age of 61.59 ± 8.21 years (range, 51-71 years). The ACDF group comprised of 12 males and 22 females with a mean age of 60.15 ± 7.52 years (range, 52-74 years). Neck Disability Index (NDI), Japanese Orthopaedic Association score (JOA), Odom's score, cervical Cobb angle, fusion rate, adjoining ossification, and dysphagia.

RESULTS

A total of 69 patients met the inclusion criteria, and these patients received more than two years of follow-up. There were significant differences in surgical duration (101 ± 22 min vs. 118 ± 29 min) and blood loss (102 ± 46 ml vs. 145 ± 58 ml) between two groups (P < 0.05). The JOA and NDI of these two groups of patients significantly improved, when compared with those before the operation (P < 0.05). Twenty-nine of 35 patients in the ROI-C group and 27 of 34 patients in ACDF group achieved good or excellent outcomes according to Odom's criteria. The cervical lordosis of both two groups significantly increased, when compared with those before the operation (P < 0.05). In the ROI-C group, the postoperative fusion rate was 85.7% at the 3-month follow-up and 100% at the final follow-up. In the ACDF group, the postoperative fusion rate was 82.4% at the 3-month follow-up and 100% at the final follow-up. The dysphagia incidence of the ACDF group was higher than that of the ROI-C group postoperatively and at the one month after surgery (P < 0.05), but no significant difference was found in the incidence of dysphagia at final follow-up (P > 0.05).

CONCLUSION

Both ROI-C and ACDF achieved good therapeutic effects. However, ROI-C can reduce the operation time and postoperative complications.

The influence of carotid atherosclerosis on surgical outcomes of patients with cervical spondylotic myelopathy: A retrospective study

The appearance of atherosclerosis in the carotid artery may be suggest the possibility of atherosclerosis in the spinal cord artery, which can cause spinal cord ischemia and further lead to neural element damage.According to the inclusion and exclude standard, there are 137 patients with cervical spondylotic myelopathy (CSM) incorporating retrospective analysis. These patients were consecutively admitted into The Second Hospital- Cheeloo College of Medicine-Shandong University from January 2016 to December 2018 and have accepted surgical treatment. All patients were examined by color Doppler ultrasound to detect carotid atherosclerosis before surgery. All patients were divided into 2 groups according to the presence or absence of carotid atherosclerosis: carotid atherosclerosis group (n = 88) and noncarotid atherosclerosis group (n = 49). All patients were followed up for at least 12 months after surgery. Demographic and surgery-related data were collected and analyzed to identify potential factors that affect the surgical outcomes in CSM.The average age of carotid atherosclerosis group (51 males and 37 females), and noncarotid atherosclerosis group (24 males and 25 females) were 62.02 ± 10.34 years (range, 38-85 years) and 49.61 ± 10.28 years (range, 26-67 years), respectively.In carotid atherosclerosis group: pre and postoperative modify Japanese Orthopedic Association Scores (mJOA score) were 11.58 ± 1.82 and 14.36 ± 1.64; the recovery rate of mJOA score was 45.57% ± 13.28%. In noncarotid atherosclerosis group: pre and postoperative mJOA score were 12.00 ± 2.11 and 15.04 ± 1.70; the recovery rate of mJOA score was 53.90% ± 13.22%. Univariate logistic regression analysis demonstrated that gender (P = .004), age ≥65 years (P = .001), duration of symptoms ≥12 months (P = .040), smoking history (P < .001), preoperative mJOA score ≤11 (P = .007) and carotid atherosclerosis (P = .004) were related to poor surgical outcomes. Multivariate logistic regression analysis showed significant correlations between poor surgical outcomes and age ≥65 years (P = .047), smoking history (P = .010), preoperative mJOA score ≤11 (P = .008) or carotid atherosclerosis (P = .047).Carotid atherosclerosis may be a risk factor for poor surgical outcomes in CSM.

Risk factors for the development of degenerative cervical myelopathy: a review of the literature

Degenerative cervical myelopathy (DCM) encompasses various pathological conditions causing spinal cord (SC) impairment, including spondylosis (multiple level degeneration), degenerative disc disease (DDD), ossification of the posterior longitudinal ligament (OPLL), and ossification of the ligamentum flavum (OLF). It is considered the most common cause of SC dysfunction among the adult population. The degenerative phenomena of DDD, spondylosis, OPLL and OLF, is likely due to both inter-related and distinct factors. Age, cervical alignment, and range of motion, as well as congenital factors such as cervical cord-canal mismatch due to congenital stenosis, Klippel-Feil, Ehler-Danlos, and Down syndromes have been previously reported as potential factors of risk for DCM. The correlation between some comorbidities, such as rheumatoid arthritis and movement disorders (Parkinson disease and cervical dystonia) and DCM, has also been reported; however, the literature remains scare. Other patient-specific factors including smoking, participation in contact sports, regular heavy load carrying on the head, and occupation (e.g. astronauts) have also been suggested as potential risk of myelopathy development. Most of the identified DCM risk factors remain poorly studied however. Further researches will be necessary to strengthen the current knowledge on the subject, especially concerning physical labors in order to identify patients at risk and to develop an effective treatment strategy for preventing this increasing prevalent disorder.

Comparison of Clinical Outcomes Following Anterior Cervical Discectomy and Fusion with Zero-Profile Anchored Spacer-ROI-C-Fixation and Combined Intervertebral Cage and Anterior Cervical Discectomy and Fusion: A Retrospective Study from a Single Center

Background

The aim of this study was to compare the outcomes following anterior cervical discectomy and fusion with zero-profile anchored spacer-ROI-C-fixation (ROI-C) vs combined intervertebral cage and anterior cervical discectomy and fusion (ACDF).

Material/Methods

We retrospectively analyzed 87 patients who underwent operations between January 2015 and January 2019, including 42 patients that underwent ROI-C treatment (group A) and 45 that were treated by the ACDF approach (group B). Operative duration, blood loss, dysphagia, Neck Disability Index scores (NDI), Japanese Orthopaedic Association scores (JOA), and other complications were compared between these groups. In addition, implant settlement, fusion, and cervical Cobb angle were assessed via imaging analyses.

Results

Patients in group A and group B were followed for 22.6±3.3 months and 27.1±3.5 months, respectively (range: 13–30 months). Relative to preoperative values, JOA scores were increased and NDI scores were reduced in both groups following treatment (P<0.05), with comparable outcomes between groups (P>0.05). However, operative duration, intraoperative blood loss, and postoperative complications did differ significantly between these groups (P<0.05). Specifically, rates of short-term dysphagia were lower and recovery time was faster in group A relative to group B (P<0.05).

Conclusions

The findings from this study showed that ROI-C fixation achieved satisfactory outcomes, improved cervical curvature, restored intervertebral height, and was associated with shorter operative duration, reduced blood loss, and less dysphagia.

Clinical impact and imaging results after a modified procedure of ACDF: a prospective case-controlled study based on ninety cases with two-year follow-up

Study design

This is a prospective case-controlled study.

Background

To analyze the postoperative axial pain and cage subsidence of patients presenting with cervical spondylotic myelopathy (CSM) after a modified procedure of ACDF (mACDF).

Methods

Ninety patients with CSM were prospectively collected from 2014 to 2018. The patients were divided into spread group and non-spread group (48:42 ratio) according to the cage placement with or without releasing the Caspar cervical retractor after decompression. Spread group received conventional ACDF and non-spread group received mACDF. Patients were followed-up for at least 24 months after surgery. Radiologic data, including height of intervertebral space and Cobb Angle, were collected. Nervous system function was obtained using JOA scores, and level of pain was assessed using VAS scores.

Results

A total of 90 patients were enrolled and the patients were divided into spread group (n = 48) and none-spread group(n = 42). Cage subsidence of (spread group vs none-spread group) was (0.82 ± 0.68 vs 0.58 ± 0.81) mm, (0.64 ± 0.77 vs 0.34 ± 0.46) mm, (0.48 ± 0.43 vs 0.25 ± 0.28) mm, and (0.45 ± 0.47 vs 0.17 ± 0.32) mm at 3 months, 6 months, 12 months and 24 months, respectively. The period exhibiting the most decrease of the height of intervertebral space was 3 months postoperatively. However, there was no statistical difference in the height of intervertebral space, JOA or VAS scores at the final follow-up between the two groups.

Conclusions

The mACDF can avoid excessive distraction by releasing the Caspar Cervical retractor, restore the “natural height” of cervical vertebra, relieve immediate pain after surgery, and prevent rapid Cage subsidence and the loss of cervical curvature.

Surgical outcomes in rigid versus flexible cervical deformities

OBJECTIVE

Cervical deformity (CD) patients have severe disability and poor health status. However, little is known about how patients with rigid CD compare with those with flexible CD. The main objectives of this study were to 1) assess whether patients with rigid CD have worse baseline alignment and therefore require more aggressive surgical corrections and 2) determine whether patients with rigid CD have similar postoperative outcomes as those with flexible CD.

METHODS

This is a retrospective review of a prospective, multicenter CD database. Rigid CD was defined as cervical lordosis (CL) change < 10° between flexion and extension radiographs, and flexible CD was defined as a CL change ≥ 10°. Patients with rigid CD were compared with those with flexible CD in terms of cervical alignment and health-related quality of life (HRQOL) at baseline and at multiple postoperative time points. The patients were also compared in terms of surgical and intraoperative factors such as operative time, blood loss, and number of levels fused.

RESULTS

A total of 127 patients met inclusion criteria (32 with rigid and 95 with flexible CD, 63.4% of whom were females; mean age 60.8 years; mean BMI 27.4); 47.2% of cases were revisions. Rigid CD was associated with worse preoperative alignment in terms of T1 slope minus CL, T1 slope, C2-7 sagittal vertical axis (cSVA), and C2 slope (C2S; all p < 0.05). Postoperatively, patients with rigid CD had an increased mean C2S (29.1° vs 22.2°) at 3 months and increased cSVA (47.1 mm vs 37.5 mm) at 1 year (p < 0.05) compared with those with flexible CD. Patients with rigid CD had more posterior levels fused (9.5 vs 6.3), fewer anterior levels fused (1 vs 2.0), greater blood loss (1036.7 mL vs 698.5 mL), more 3-column osteotomies (40.6% vs 12.6%), greater total osteotomy grade (6.5 vs 4.5), and mean osteotomy grade per level (3.3 vs 2.1) (p < 0.05 for all). There were no significant differences in baseline HRQOL scores, the rate of distal junctional kyphosis, or major/minor complications between patients with rigid and flexible CD. Both rigid and flexible CD patients reported significant improvements from baseline to 1 year according to the numeric rating scale for the neck (-2.4 and -2.7, respectively), Neck Disability Index (-8.4 and -13.3, respectively), modified Japanese Orthopaedic Association score (0.1 and 0.6), and EQ-5D (0.01 and 0.05) (p < 0.05). However, HRQOL changes from baseline to 1 year did not differ between rigid and flexible CD patients.

CONCLUSIONS

Patients with rigid CD have worse baseline cervical malalignment compared with those with flexible CD but do not significantly differ in terms of baseline disability. Rigid CD was associated with more invasive surgery and more aggressive corrections, resulting in increased operative time and blood loss. Despite more extensive surgeries, rigid CD patients had equivalent improvements in HRQOL compared with flexible CD patients. This study quantifies the importance of analyzing flexion-extension images, creating a prognostic tool for surgeons planning CD correction, and counseling patients who are considering CD surgery.

Intra- and Post-Complications of Cervical Laminoplasty for the Treatment of Cervical Myelopathy: An Analysis of a Nationwide Database

STUDY DESIGN

Retrospective database study.

OBJECTIVE

To assess the intra- and postoperative complications of cervical laminoplasty and to evaluate the effect of intraoperative neuromonitoring use on postoperative limb paralysis incidence.

SUMMARY OF BACKGROUND DATA

Cervical laminoplasty is a known procedure for the management of cervical spondylotic myelopathy (CSM).

METHODS

This was a retrospective study of 532 patients with CSM who underwent cervical laminoplasty between 2007 and the first quarter of 2016 using the Humana subset of the PearlDiver Database. The database was queried using the relevant International Classification of Diseases (ICD-9 and ICD-10) codes for CSM and Current Procedural Terminology (CPT) codes for cervical laminoplasty. The intra- and postoperative incidence of surgical and medical complications and reoperations was then determined and was compared with a propensity score-matched cohort of patients who had posterior laminectomy and fusion (490 patients in each group), using multivariate logistic regression analysis.

RESULTS

Laminoplasty was associated with a lower incidence of dysphagia (odds ratio [OR] = 0.37, 95% confidence interval [CI] = 0.16-0.79; P = 0.014), 30-day readmission (OR = 0.51, 95% CI = 0.35-0.75; P < 0.001), urinary tract infection (OR = 0.58, 95% CI = 0.37-0.93; P = 0.023), and incision and drainage, exploration or evacuation (OR = 0.28, 95% CI = 0.08-0.79; P = 0.026). The use of intraoperative neuromonitoring was associated with a non-significant lower incidence of limb paralysis within 1 and 3 months postoperatively (OR = 0.52 and 0.51, 95% CI = 0.23-1.19 and 0.23-1.11; P = 0.119 and 0.091, respectively).

CONCLUSION

Compared with posterior laminectomy and fusion, laminoplasty had lower rates of dysphagia, urinary tract infection, and 30-day readmission. The use of intraoperative neuromonitoring was associated with a lower risk of postoperative limb paralysis, but it did not achieve statistical significance.

LEVEL OF EVIDENCE

4.

The Severity of Cervical Disc Degeneration Does Not Impact 2-year Postoperative Outcomes in Patients With Cervical Spondylotic Myelopathy Who Underwent Laminoplasty

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

The aim of this study was to evaluate the impact of cervical disc degeneration (CDD) severity on 2-year postoperative outcomes following laminoplasty.

SUMMARY OF BACKGROUND DATA

The impact of CDD on postoperative outcomes of cervical laminoplasty has not been well established.

METHODS

A total of 144 patients who underwent open-door laminoplasty for cervical spondylotic myelopathy (CSM) were enrolled. Six cervical discs were independently analyzed for degeneration severity using a previously reported grading system (grade 0: none, grade 3: severest). The relationship between the segmental range of motion (ROM) and the severity of CDD was evaluated. Subsequently, after dividing overall patients into mild and severe CDD groups by the average of CDD scores, the mixed-effect model was applied to assess 2-year postoperative outcomes, including physician-assessed myelopathy scores, patient-reported outcomes, and preoperative radiographic parameters. Finally, as additional analysis, the severe CDD group was further divided into two groups: group 1 included patients with a grade 3 CDD change in their most stenotic level and group 2 included the others. The 2-year postoperative myelopathy score was compared between groups 1 and 2.

RESULTS

The cervical segments with grade 3 CDD showed significantly smaller ROM compared with those with grade 0, 1, or 2 CDD (P < 0.01). There were no significant differences in postoperative improvements in myelopathy, pain, patient-reported physical and mental status, and radiographic parameters, except for quality of life (QOL) scores between CDD groups. A significant (P = 0.02) postoperative improvement in QOL scores was noted in the severe CDD group. In an additional analysis, myelopathy score at 2 years postoperatively was significantly higher in group 1 than group 2 (P = 0.041).

CONCLUSION

The severity of CDD did not negatively impact 2-year postoperative laminoplasty outcomes. The postulated reason is that the decreased segmental instability in the level with severe CDD may affect surgical outcomes positively.

LEVEL OF EVIDENCE

3.

[Spondylotic cervical myelopathy : Indication of surgical treatment]

BACKGROUND

The pathogenesis of cervical spondylotic myelopathy (CSM) is often multifactorial. Hence, the treatment of this disease requires a differentiated surgical approach in order to adequately address the underlying pathology.

PURPOSE

The aim of this review is to identify factors that influence the choice of treatment strategy and to summarize them in an algorithm that serves as a decision aid in choosing the optimal indication for surgical treatment. An attempt is made to define the threshold values for the indication of surgical treatment and to discuss the ideal timing for performing surgery.

MATERIALS AND METHODS

On the basis of the published data, the influencing factors on the prognosis of CSM, as well as surgical approaches are discussed.

RESULTS

Circumferential spinal cord compression, a sharply defined myelopathy signal in the T2-weighted MRI sequence, and segmental instability at the level of the myelopathy signal mean an unfavorable prognosis for the worsening of CSM. The most important factors that influence the choice of the surgical access point are the sagittal profile of the cervical spine, the extent of myelopathy, the extent of stenosis, and the location of the myelopathy-inducing pathology. Previously existing neck pain and prior cervical surgery must also be considered.

DISCUSSION

On the basis of the research carried out, we developed an algorithm that could serve as an aid in choosing the right treatment in the setting of cervical spondylotic myelopathy.

Prognosis of cervical myelopathy based on diffusion tensor imaging with artificial intelligence methods

Diffusion tensor imaging (DTI) has been proposed for the prognosis of cervical myelopathy (CM), but the manual analysis of DTI features is complicated and time consuming. This study evaluated the potential of artificial intelligence (AI) methods in the analysis of DTI for the prognosis of CM. Seventy-five patients who underwent surgical treatment for CM were recruited for DTI imaging and were divided into two groups based on their one-year follow-up recovery. The DTI features of fractional anisotropy, axial diffusivity, radial diffusivity, and mean diffusivity were extracted from DTI maps of all cervical levels. Conventional AI models using logistic regression (LR), k-nearest neighbors (KNN), and a radial basis function kernel support vector machine (RBF-SVM) were built using these DTI features. In addition, a deep learning model was applied to the DTI maps. Their performances were compared using 50 repeated 10-fold cross-validations. The accuracy of the classifications reached 74.2% ± 1.6% for LR, 85.6% ± 1.4% for KNN, 89.7% ± 1.6% for RBF-SVM, and 59.2% ± 3.8% for the deep leaning model. The RBF-SVM algorithm achieved the best accuracy, with sensitivity and specificity of 85.0% ± 3.4% and 92.4% ± 1.9% respectively. This finding indicates that AI methods are feasible and effective for DTI analysis for the prognosis of CM.

30-Day unplanned surgery in cervical spondylotic myelopathy surgically treated: a single-center experience

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

Analyze the rate and risk factors associated with Unplanned Surgeries (US) during the first 30 days in patients treated for cervical spondylotic myelopathy.

BACKGROUND

US are often regarded as a potentially useful quality of care indicator.

METHODS

We defined US as any, non-planned, surgical procedure as a complication after "index" surgery. Demographic data, comorbidities, ASA, smoking status, surgical details and postoperative complications were collected. We conducted a subjective outcome test using the Global Outcome Score (GOS). To assess risk factors, a bivariate analysis was performed using T Student or Chi-square. Risk is shown as odds ratio (OR) with 95% confidence interval (CI). Multivariable logistic regression models with bootstrap resampling procedure were performed.
 RESULTS: The study included 303 patients (200 men) with mean age of 57.7 years (27-86) and mean follow-up of 75.35 months (16-126 m). 63.3% patients were ASA 1 or 2 and 41.9% were smokers. 77.9% of patients had some comorbidity. Anterior approach surgeries were 65.7%. Perioperative complications: 29% medical, 8.9% intraoperative and 3% implant related. US rate was 2.6%. Causes for revision were postoperative infection or deep hematomas. After bivariate analysis, the risk factors associated were diabetes mellitus (OR 2.6; 95% CI 1-5.5) and intraoperative complications (OR 6.5, 95% CI 1-40). The presence of US does not have influence in satisfaction using GOS score.

CONCLUSIONS

Our US rate was 2.6%, similar to the literature. Diabetics and patients suffering an intraoperative complication are more likely to need an early reinterventions (OR 2.2 and 6.5, respectively). US did not alter the patient's outcomes. These slides can be retrieved under Electronic Supplementary Material.

Neurological Recovery Pattern in Cervical Spondylotic Myelopathy after Anterior Surgery: A Prospective Study with Literature Review

Study Design

Prospective clinical study.

Purpose

The present study aimed to examine the neurological recovery pattern in cervical spondylotic myelopathy (CSM) after anterior cervical decompression and compare it with the existing reports in the literature.

Overview of Literature

Neurological recovery and regression of myelopathy symptoms is an important factor that determines the outcomes of surgical decompression. The present findings contribute to the literature on the pattern of neurological recovery and patient prognosis with respect to the resolution of myelopathy symptoms after surgery.

Methods

This prospective study was conducted in Government Medical College in Jammu, North India between November 2012 and October 2014, a total of 30 consecutive patients with CSM were included and treated with anterior decompression and stabilization. They were prospectively followed up for 1 year and were evaluated for their neurological recovery pattern. The postoperative outcome was evaluated using the modified Japanese Orthopaedic Association (mJOA) score. The recovery rate was calculated using Hirabayashi’s method. The JOA score was assessed before the operation and postoperatively at 1 week, 2 weeks, 1 month, 3 months, 4 months, 6 months, and 1 year.

Results

The postoperative mJOA score was 0 in the 1st month, 12.90±3.57 in the 3rd month, 13.50±3.55 in the 4th month, 14.63±3.62 in the 6th month, and 14.9±3.24 at the final follow-up of 1 year. The average recovery rate during the 1st month follow-up was 0%, and that during the 3rd month follow-up was 12.91% with a range of 0%–50%. The average recovery rate during the 4th month was 32.5%, with a range of 0%–60%, while that during the 6th month was 72.83%, with a range of 0%–100%. The average recovery rate during the final follow-up of 1 year was 54.3%.

Conclusions

Neurological recovery after surgical decompression starts from the 3rd postoperative month and progresses until the 6th postoperative month; thereafter, it gradually plateaus over the subsequent 6 months until it steadies. Symptom duration is an important factor that requires consideration while determining postoperative neurological recovery.

Placement of Titanium Mesh in Hybrid Decompression Surgery to Avoid Graft Subsidence in Treatment of Three-Level Cervical Spondylotic Myelopathy: Cephalad or Caudal?

Background

Hybrid decompression has been used to treat patients with cervical spondylotic myelopathy (CSM). However, no published study has investigated the effect of titanium mesh (TM) located cephalad or caudal in hybrid decompression surgery on the graft subsidence in treatment of three-level CSM.

Material/Methods

Forty-eight cases with three-level CSM who underwent the procedure of hybrid decompression from Jan 2014 to Jan 2017 were retrospectively reviewed. Radiological outcomes immediately postoperatively and at the final follow-up were compared between cases from group A (TM located cephalad, n=21) and group B (TM located caudal, n=27).

Results

No differences were observed in the 2 groups in terms of number, sex, or duration of follow-up. The average follow-up was 4.38±0.439 months in group A and 4.81±0.509 months in group B (p>0.05). The index loss of anterior (AIBH), middle (MIBH), and posterior interbody height (PIBH) in group A were 0.857±0.448/1.00±0.525/1.33±0.608, respectively, which were all lower than that in group B (P<0.05), as was the occurrence of TM subsidence. However, there was no significance difference in height loss of adjacent intervertebral space between groups. All angles were decreased at the final follow-up in both groups (p<0.05). More decrease of C2–C7 angle occurred in group B (p>0.05), and segmental angle in group A decreased more than in group B (p>0.05).

Conclusions

TM inferior to intervertebral cage (IC) in hybrid decompression has a higher risk for developing subsidence, and when the choice of the position of TM is available in hybrid decompression surgery, TM located cephalad was recommend to alleviate TM subsidence.

Association of VDR-FokI and VDBP-Thr420Lys polymorphisms with cervical spondylotic myelopathy: A case-control study in the population of China

BACKGROUND

Cervical spondylotic myelopathy (CSM), a common degenerative disorder, is characterized by chronic progressive compression of the cervical spinal cord. The present case-control study aimed to explore the potential role of VDR-FokI and VDBP-Thr420Lys polymorphisms in the susceptibility to CSM in the Chinese population.

METHODS

The study enrolled 318 CSM patients and 282 healthy individuals whose clinical data were retrospectively analyzed. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis was used to genotype VDR-FokI and VDBP-Thr420Lys polymorphisms. The severity of CSM was assessed using the Japanese Orthopaedic Association (JOA) score with magnetic resonance imaging (MRI) of cervical vertebra. A nonconditional binary logistic regression model was conducted for assessing the risk factors of CSM.

RESULTS

Patients in the CSM group had longer time duration to bend over desk working than the control group. The ff genotype and f allele frequency of VDR-FokI were elevated in CSM patients. Elevated Ff + ff genotype and f allele frequency of VDR-FokI might increase the risk of CSM. The VDR-FokI polymorphism was associated with nucleus pulposus capillary invasion, necrosis, hyaline degeneration and fibrosis, genesis and hyperplasia of cartilage-like cells, and fibrocyst in the fibrous ring. The VDR-FokI and VDBP-Thr420Lys genotypes conformed to Hardy-Weinberg equilibrium which showed that VDR-FokI and VDBP-Thr420Lys had group representation characteristics.

CONCLUSION

Binary logistic regression analysis confirmed that VDR-FokI polymorphism and the time to bend over desk working were risk factors of CSM. Our results indicate that VDR-FokI polymorphism may be closely associated with the risk of CSM.

Cervical spondylotic myelopathy patients with prior cerebral infarction: Clinical characteristics, surgical outcomes and prognostic value of "prior cerebral infarction"

OBJECTIVE

To investigate the clinical characteristics and surgical outcomes of patients with cervical spondylotic myelopathy (CSM) and prior cerebral infarction (CI); to identify whether "prior CI" correlates with poor surgical outcomes.

PATIENTS AND METHODS

Twenty-two patients with CSM and prior CI were retrospectively reviewed and included as the CI group while 100 CSM patients without CI were included as the control group (matched for gender, age, symptom duration and surgical approach). Extensive demographic and surgery-related data for patients in both groups were collected and compared. Multivariate logistic regression analysis was performed to assess all potential factors affecting surgical outcomes.

RESULTS

Compared to the control group, the CI group had the following: significantly higher percentages of hypertension, "progressive myelopathy", "rapid progressive myelopathy" and "intramedullary T2-weighted hyperintensity on MRI"; lower mean "preoperative mJOA score" and "postoperative mJOA score"; higher percentages of "preoperative mJOA score ≤11″ and "recovery rate of mJOA score <50%". In the CI group, 14 patients had CI within 6 months before CSM, and their percentage of "rapid progressive myelopathy" was higher than that of patients who had CI over 6 months before CSM. Logistic regression analysis showed that smoking, "symptom duration ≥12 months", "T2-weighted hyperintensity" and "prior CI" correlated with poor surgical outcome.

CONCLUSION

Rapid progressive myelopathy with advanced neurological impairment and "intramedullary T2-weighted hyperintensity" are common in patients with CSM and prior CI. Surgical outcomes in these patients are poorer than those of ordinary CSM patients. "Prior CI" is a risk factor for predicting poor surgical outcomes.

Ossification of the posterior longitudinal ligament in the cervical spine: a review

Ossification of the posterior longitudinal ligament (OPLL) is a rare pathologic process of lamellar bone deposition that can result in spinal cord compression. While multiple genetic and environmental factors have been related to the development of OPLL, the pathophysiology remains poorly understood. Asymptomatic patients may be managed conservatively and patients with radiculopathy or myelopathy should be considered for surgical decompression. Multiple studies have demonstrated the morphology and size of the OPLL as well as the cervical alignment have significant implications for the appropriate surgical approach and technique. In this review, we aim to address all the available literature on the etiology, history, presentation, and management of OPLL in an effort to better understand OPLL and give our recommendations for the treatment of patients presenting with OPLL.

Global Spinal Alignment in Patients With Cervical Spondylotic Myelopathy

STUDY DESIGN

A prospective radiographic analysis of cervical spondylotic myelopathy (CSM).

OBJECTIVE

The aim of this study was to clarify the pathophysiology of CSM, and use the characteristic of global spinal alignment for determining the surgical strategy.

SUMMARY OF BACKGROUND DATA

Radiographic evaluation of CSM, in general, comprises cervical magnetic resonance imaging (MRI) and regional cervical radiography, which cannot distinguish between cervical hyperlodorsis with spinopelvic compensation and cervical lordorsis with normal global alignment.

METHODS

Our inclusion criteria were preoperative whole spine radiography and cervical MRI and health-related quality of life scores. Global spinal alignment was characterized by cervical lordosis (CL), C7 sagittal vertical axis (SVA), T1 slope (T1S), thoracic kyphosis (TK), lumbar lordosis (LL), pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), and knee flexion angle (KFA). Cervical alignment was characterized by O-C2, C2-4, C5-7, and C2-7 angles; cranial center of gravity (CCG) C7SVA; and C2-7 SVA. Responsible lesion determined using MRI was divided from C2/3 to C7/T1.

RESULTS

Eighty-eight surgically treated CSM patients with EOS full spine imaging were prospectively analyzed. There were 72 normal (Type 1; SVA <50 mm) and 16 positive (Type 2; SVA ≥50 mm) global balance patients. There were significant differences in age, T1S, KFA, T1S-CL, SVA, CCG-SVA, and C2-7 SVA between Type 1 and Type 2. C3/4 lesion was more common in Type 2 than in Type 1. There was a positive correlation between global sagittal, but not regional, balance, and responsible lesion. C3/4 lesion was more frequent in older, male, high SVA, large T1S-CL, large KFA, and large cranial lordosis (C2-4/C5-7 angle) patients.

CONCLUSION

This study indicates the necessity for global alignment evaluation, particularly in older CSM patients because of their compensation mechanism for global malalignment. Surgical strategy for cranial type CSM should be carefully selected considering global balance.

LEVEL OF EVIDENCE

4.

The Role of Dynamic Magnetic Resonance Imaging in Cervical Spondylotic Myelopathy

Dynamic spinal cord compression has been investigated for several years, but until the advent of open MRI, the use of dynamic MRI (dMRI) did not gain popularity. Several publications have shown that cervical cord compression is both static and dynamic. On many occasions the evaluation of cervical spondylotic myelopathy (CSM) is straightforward, but patients are frequently encountered with a significantly worse clinical examination than would be suggested by radiological images. In this paper, we present an extensive review of the literature in order to describe the importance of dMRI in various settings and applications. A detailed literature review was performed in the Medline and Pubmed databases using the terms “cervical spondylotic myelopathy”, “dynamic MRI”, “kinetic MRI”, and “myelomalalcia” for the period of 1980-2016. The study was limited to English language, human subjects, case series, retrospective studies, prospective reports, and clinical trials. Reviews, case reports, cadaveric studies, editorials, and commentaries were excluded. The literature search yielded 180 papers, 19 of which met inclusion criteria. However, each paper had evaluated results and outcomes in different ways. It was not possible to compile them for meta-analysis or pooled data evaluation. Instead, we evaluated individual studies and present them for discussion. We describe a number of parameters evaluated in 2661 total patients, including dynamic changes to spinal cord and canal dimensions, transient compression of the cord with changes in position, and the effects of position on the intervertebral disc. dMRI is a useful tool for understanding the development of CSM. It has found several applications in the diagnosis and preoperative evaluation of many patients, as well as certain congenital dysplasias and Hirayama disease. It is useful in correlating symptoms with the dynamic changes only noted on dMRI, and has reduced the incidence of misdiagnosis of myelopathy.

Two-Year Results of the Prospective Spine Treatment Outcomes Study: Analysis of Postoperative Clinical Outcomes Between Patients with and without a History of Previous Cervical Spine Surgery

OBJECTIVE

History of previous cervical spine surgery is a frequently cited cause of worse outcomes after cervical spine surgery. The purpose of this study was to determine any differences in clinical outcomes after cervical spine surgery between patients with and without a history of previous cervical spine surgery.

METHODS

A multicenter prospective database was reviewed retrospectively to identify patients with cervical spondylosis undergoing surgery with a minimum 2-year follow-up. Patients were divided into 2 groups: patients with (W) or without (WO) previous history of cervical spine surgery. Statistical analyses of Health-Related Quality of Life scores were analyzed with statistical software to fit linear mixed models for continuous longitudinal outcome.

RESULTS

A total of 1286 patients (377 W, 909 WO) met criteria for inclusion. Overall, patients in both groups experienced an improvement in their Health-Related Quality of Life scores. However, patients in the W group had significantly decreased improvement compared with WO patients in the Neck Disability Index score and the following SF-36 domain scores: Role Physical, Bodily Pain, General Health, Vitality, Social Functioning, Health Transition, and Physical Component Summary at all time points (P < 0.05). There was no statistically significant difference between the W and WO groups in operative time, estimated blood loss, length of stay, or complications (P > 0.05).

CONCLUSIONS

Patients with a history of previous cervical spine surgery had inferior improvement in quality of life outcome scores. Patients with a history of previous surgical intervention who elect to undergo subsequent surgeries should be appropriately counseled about expected results.

Comparative Study of Surgical Treatment and Nonsurgical Follow Up for Thoracic Ossification of the Posterior Longitudinal Ligament: Radiological and Clinical Evaluation

STUDY DESIGN

A prospective clinical study of factors related to myelopathy deterioration caused by thoracic myelopathy because of ossification of the posterior longitudinal ligament (T-OPLL).

OBJECTIVE

The objective of the study was to investigate factors related to myelopathy deterioration caused by T-OPLL.

SUMMARY OF BACKGROUND DATA

Detailed analyses of factors related to myelopathy deterioration caused by T-OPLL have not been reported.

METHODS

Twenty-two patients (group O) received observation therapy because of the absence of or mild myelopathy, which was defined as walking unaided or with support, and a Japanese Orthopedic Association (JOA) score above 7 points; and 24 patients (group S) were treated with posterior decompression and fusion with instrumentation. Age, sex, body mass index (BMI), presence of diabetes mellitus (DM), and JOA score were obtained for all patients. Radiologically, the T-OPLL level, number of T-OPLLs, canal diameter ratio (CDR), morphology, ossification of the ligamentum flavum (OLF), and cervical OPLL were examined on reconstructed CT, and the presence of hyperintense areas (HIAs) on T2-weighted sagittal MR images.

RESULTS

In total, the patients included 22 males and 24 females and had an age range from 18 to 80 years. Sex, DM, JOA score in each domain, OPLL location, OPLL number, CDR of OPLL, morphology, OLF, and cervical OPLL did not differ significantly between groups N and S. However, cases in group N had a significantly higher age, lower weight, lower BMI, lower discontinuous rate on sagittal CT, and a lower HIA rate on MRI. Postoperatively, discontinuous segments connected and became continuous across the disc space in all patients in group S without progression of OPLL thickness.

CONCLUSION

Age, weight, BMI, discontinuity between rostral and caudal OPLL lesions, and occurrence of a high intensity area on MRI are likely to be associated with development of myelopathy.

LEVEL OF EVIDENCE

3.

Role of Atlantoaxial and Subaxial Spinal Instability in Pathogenesis of Spinal "Degeneration"-Related Cervical Kyphosis

BACKGROUNDS

The role of subaxial and atlantoaxial instability in the pathogenesis of "degeneration"-related cervical kyphosis is evaluated.

MATERIAL AND METHODS

During the period 2013-2016, the authors treated 21 patients having cervical kyphosis that was related to degenerative spinal disease. The patients presented with symptoms related to cervical myelopathy. Kyphosis was diagnosed on the basis of described radiologic parameters. The patients were divided into 3 groups. Group A (10 patients) had manifest radiologic evidence of atlantoaxial dislocation, type 1 facetal instability, abnormal increase in atlantodental interval, and evidence of cord compression by the odontoid process. Group B (5 patients) had axial or central atlantoaxial facetal instability (type 2 or 3 atlantoaxial facetal instability) and subaxial spinal instability. Group C (6 patients) had subaxial spinal instability. The patients were treated by only stabilization. Group A patients underwent atlantoaxial fixation, group B patients underwent atlantoaxial and subaxial fixation, and group C patients underwent only subaxial spinal fixation. The operation was aimed at arthrodesis of the spinal segments. No bone or soft tissue decompression was done.

RESULTS

During the minimum follow-up period of 6 months, all patients improved in their neurologic symptoms and demonstrated evidence of spinal arthrodesis. There were no major surgical complications.

CONCLUSIONS

Spinal instability plays a major role in the generation of cervical spinal kyphosis. Atlantoaxial instability may form the primary and nodal site of development of the process of spinal degeneration in general and kyphosis in particular.

Atypical symptoms in patients with cervical spondylosis might be the result of stimulation on the dura mater and spinal cord

Patients with cervical spondylosis often present with some atypical symptoms such as vertigo, headache, palpitation, nausea, abdominal discomfort, tinnitus and blurred vision and hypomnesia. Although there are a few hypotheses about the etiology of those symptoms, none of them have provided evidence convincing enough to explain the clinical, pathological and anatomic manifestation of those symptoms. One of the more acceptable explanations is that those symptoms are the results of stimulation of the sympathetic nerves in the posterior longitudinal ligament. The clinical fact that dissection of the posterior longitudinal ligament significantly alleviates the severity of those symptoms seems like an evidence for the validity of this hypothesis. However, recent clinical studies showed that laminoplasty, which has no effect on the posterior longitudinal ligament, can achieve the similar effect. In this paper, we hypothesize that stimulation of the dura mater and spinal cord might be the cause of atypical symptoms in patients with cervical spondylosis.

Impact of dynamic alignment, motion, and center of rotation on myelopathy grade and regional disability in cervical spondylotic myelopathy

OBJECT

Cervical stenosis is a defining feature of cervical spondylotic myelopathy (CSM). Matsunaga et al. proposed that elements of stenosis are both static and dynamic, where the dynamic elements magnify the canal deformation of the static state. For the current study, the authors hypothesized that dynamic changes may be associated with myelopathy severity and neck disability. This goal of this study was to present novel methods of dynamic motion analysis in CSM.

METHODS

A post hoc analysis was performed of a prospective, multicenter database of patients with CSM from the AOSpine North American study. One hundred ten patients (34%) met inclusion criteria, which were symptomatic CSM, age over 18 years, baseline flexion/extension radiographs, and health-related quality of life (HRQOL) questionnaires (modified Japanese Orthopaedic Association [mJOA] score, Neck Disability Index [NDI], the 36-Item Short Form Health Survey Physical Component Score [SF-36 PCS], and Nurick grade). The mean age was 56.9 ± 12 years, and 42% of patients were women (n = 46). Correlations with HRQOL measures were analyzed for regional (cervical lordosis and cervical sagittal vertical axis) and focal parameters (kyphosis and spondylolisthesis between adjacent vertebrae) in flexion and extension. Baseline dynamic parameters (flexion/extension cone relative to a fixed C-7, center of rotation [COR], and range of motion arc relative to the COR) were also analyzed for correlations with HRQOL measures.

RESULTS

At baseline, the mean HRQOL measures demonstrated disability and the mean radiographic parameters demonstrated sagittal malalignment. Among regional parameters, there was a significant correlation between decreased neck flexion (increased C2–7 angle in flexion) and worse Nurick grade (R = 0.189, p = 0.048), with no significant correlations in extension. Focal parameters, including increased C-7 sagittal translation overT-1 (slip), were significantly correlated with greater myelopathy severity (mJOA score, Flexion R = −0.377, p = 0.003; mJOA score, Extension R = −0.261, p = 0.027). Sagittal slip at C-2 and C-4 also correlated with worse HRQOL measures. Reduced flexion/extension motion cones, a more posterior COR, and smaller range of motion correlated with worse general health SF-36 PCS and Nurick grade.

CONCLUSIONS

Dynamic motion analysis may play an important role in understanding CSM. Focal parameters demonstrated a significant correlation with worse HRQOL measures, especially increased C-7 sagittal slip in flexion and extension. Novel methods of motion analysis demonstrating reduced motion cones correlated with worse myelopathy grades. More posterior COR and smaller range of motion were both correlated with worse general health scores (SF-36 PCS and Nurick grade). To our knowledge, this is the first study to demonstrate correlation of dynamic motion and listhesis with disability and myelopathy in CSM.

Spinal cord cross-sectional area during flexion and extension in the patients with cervical ossification of posterior longitudinal ligament

PURPOSE

The pathomechanism of cervical myelopathy due to cervical ossification of posterior longitudinal ligament (C-OPLL) remains unclear. No previous literature has quantified the influence of dynamic factors on cervical myelopathy due to C-OPLL. The purpose was to investigate the influence of dynamic factors on the spinal column in the patients with C-OPLL using CT scan after myelography (MCT).

METHODS

The study included 41 patients with cervical myelopathy due to C-OPLL. An MCT was done during neck flexion and extension, and spinal cord cross-sectional areas (SCCSA) were measured at each disc level between C2/3 and C7/T1. Ossification morphology at each segment was divided into three groups, connection department, coating part, and non-connection department of OPLL group. Dynamic changes of SCCSA in each group of ossification morphology were calculated. The relationship between clinical results and SCCSA at the narrowest level was investigated.

RESULTS

MCT showed SCCSA changes during neck extension; 7.4 ± 5.1 mm(2) in the connection department, 5.8 ± 6.0 mm(2) in the coating part, and 6.7 ± 6.4 mm(2) in the non-connection department of OPLL group. There difference was not statistically significant. There was a weak correlation between the JOA score and SCCSA at the narrowest level (R = 0.49). There was no significant correlation between the recovery rate of JOA score and SCCSA at the narrowest level (R = 0.37).

CONCLUSION

Dynamic factors are seen both in cervical myelopathy patients with the continuous type of OPLL and others. Deterioration of myelopathy could be induced by motion effects even in the connection department of OPLL.