Mid-term clinical effect of resecting posterior longitudinal ligament in anterior approach for cervical spondylosis with sympathetic symptoms: retrospective cohort analysis.

STUDY DESIGN: Retrospective cohort analysis. OBJECTIVE: The purpose of this study is to investigate whether the removal of the posterior longitudinal ligament (PLL) affects the mid-term outcome of anterior cervical fusion for cervical spondylosis with sympathetic symptoms(CSSS). METHODS: From January 2012 to July 2013, 66 patients who were diagnosed with CSSS with ≥ 10-year follow-up at our institution were assessed. All patients were divided into two groups: Group A (36 cases) in which patients underwent anterior cervical fusion with PLL resection and Group B (30 cases) in which patients underwent anterior cervical fusion without PLL resection. The sympathetic symptom 20-point system was used to evaluate the sympathetic symptoms, such as tinnitus, headache and vertigo, etc. And the neurological status was assessed by the Japanese Orthopedic Association (JOA) scores. Clinical and radiologic data were evaluated preoperatively, 9 days, 3 months, 6 months, 12 months, 24 months, 60 months, and 120 months postoperatively. Data collected included all perioperative complications as morbidities that occurred during the period of follow-up. RESULTS: The postoperative JOA scores and 20-point score can be significantly improved compared with preoperative whether the PLL is removed in both groups. However, the postoperative 20-point score of patients in group A was significantly different from that in group B. No loosening and displacement of prosthesis occurred. CONCLUSION: A better clinical effect could be attained when resecting the PLL in the operation. The PLL may play an important role in CSSS. The mid-term outcomes of anterior cervical fusion with PLL resection were satisfied in treating CSSS.

Patients with a large ossification of the posterior longitudinal ligament have a higher incidence of arteriosclerosis in the carotid artery.

PURPOSE: This study aimed to investigate the impact of the severity of cervical ossification of the posterior longitudinal ligament (OPLL) on the incidence of arteriosclerosis in the carotid artery. METHODS: Patients with OPLL-induced cervical myelopathy were prospectively enrolled. The study involved analyzing patient characteristics, blood samples, computed tomography scans of the spine, and intima-media thickness (IMT) measurements of the common carotid artery. Patients were divided into two groups based on the size of the cervical OPLL to compare demographic data, comorbidities, and the presence of thickening of the carotid intima-media (max IMT ≥ 1.1 mm). RESULTS: The study included 96 patients (mean age: 63.5 years; mean body mass index: 26.9 kg/m2; 71.8% male; 35.4% with diabetes mellitus). The mean maximum anteroposterior (AP) diameter of the OPLL was 4.9 mm, with a mean occupancy ratio of 43%. The mean maximum IMT was 1.23 mm. Arteriosclerosis of the carotid artery was diagnosed in 62.5% of the patients. On comparing the two groups based on OPLL size, the group with larger OPLL (≥ 5 mm) had a higher BMI and a greater prevalence of carotid intima-media thickening. This significant difference in the prevalence of carotid intima-media thickening persisted even after adjusting for patient backgrounds using propensity score matching. CONCLUSIONS: Patients with a larger cervical OPLL showed a higher frequency of intima-media thickening in the carotid artery.

Validating the preoperative Japanese Core Outcome Measures Index for the Neck and comparing quality of life in patients with cervical spondylotic myelopathy and ossification of the posterior longitudinal ligament by the patient-reported outcome measures.

PURPOSE: This cross-sectional study serves two main purposes. Firstly, it aims to validate the preoperative Japanese Core Outcome Measures Index for the Neck (COMI-Neck) in patients with cervical spondylotic myelopathy (CSM) and ossification of the posterior longitudinal ligament (OPLL). Secondly, it seeks to elucidate differences in preoperative quality of life (QOL) between these two cervical pathologies using patient-reported outcome measures (PROMs). METHODS: A total of 103 preoperative patients (86 with CSM and 17 with OPLL) scheduled for cervical spine surgery were included in the study. Validated PROMs, including the Japanese COMI-Neck, Neck Disability Index (NDI), EuroQol-5 Dimension-3 level (EQ-5D-3L), and SF-12v2, were used to assess QOL. Baseline demographic and clinical data were collected, and statistical analyses were performed to compare the PROMs between CSM and OPLL groups. RESULTS: The Japanese COMI-Neck demonstrated good construct validity, with positive correlations with NDI and negative correlations with EQ-5D-3L and SF-12v2. Comparison of preoperative PROMs between CSM and OPLL groups revealed differences in age, body mass index, and EQ-5D-3L scores. The CSM group had higher NDI scores for concentration and lower EQ-5D-3L scores for self-care compared to the OPLL group. CONCLUSIONS: This study validated the preoperative Japanese COMI-Neck in CSM and OPLL patients and identified specific QOL issues associated with each condition. The findings highlight the importance of considering disease-specific QOL and tailoring treatment plans accordingly. Further research should include postoperative assessments and a more diverse population to enhance generalizability.

A rare case of intervertebral disc calcification combined with ossification of the posterior longitudinal ligament in a child: a case report and literature review.

BACKGROUND: Intervertebral disc calcification (IDC) combined with calcification in children has been sporadically reported, while ossification of the posterior longitudinal ligament (OPLL) in the cervical spine in pediatric patients is exceedingly rare. The aim of this study is to investigate the potential prognosis and outcomes associated with this condition. CASE PRESENTATION: We present an unusual case involving a 10-year-old Chinese child diagnosed with calcified cervical disc herniation and ossification of the posterior longitudinal ligament. Conservative treatment measures were implemented, and at the 1-month and 6-month follow-up, the patient's pain exhibited significant improvement. Subsequent cervical MRI and CT scans revealed the complete disappearance of OPLL and substantial absorption of the calcified disc. During the three-month follow-up, CT demonstrated slight residual disc calcification, however, the patient remained asymptomatic with no discernible limitation in cervical motion. CONCLUSIONS: We conducted a comprehensive review of several cases presenting with the same diagnosis. It is noteworthy that IDC combined with OPLL in children constitutes a rare clinical entity. Despite imaging indications of potential spinal canal occupation, the majority of such cases demonstrate complete absorption following conservative treatment, with OPLL exhibiting a faster absorption rate than calcified discs.

[Clinical observation on the treatment of ossification of the posterior longitudinal ligament of the cervical spine using 3D printed self-stable zero-profile artificial vertebral body].

Objective: To observe the clinical efficacy of a 3D printed self-stable zero-profile artificial vertebral body for anterior cervical corpectomy decompression and fusion in the treatment of ossification of the posterior longitudinal ligament (OPLL) of the cervical spine. Methods: In this prospective randomized controlled trial, patients diagnosed with OPLL in Luohe Central Hospital from January to July 2022 were divided into a zero-profile group (3D printed self-stable zero-profile artificial vertebral body was used for internal fixation and fusion after anterior cervical subtotal decompression,) and titanium-mesh group (titanium-mesh and titanium plate were used for internal fixation and fusion after anterior cervical subtotal decompression) according to envelope random method. Operation time, intraoperative blood loss, Japanese Orthopaedic Association (JOA) score and improvement rate, incidence of postoperative prosthesis subsidence, and bone graft fusion were recorded and compared between the two groups. Results: Finally, 21 patients in the zero notch group and 20 patients in the titanium mesh group were included in the study and were followed-up. In the zero-profile group, there were 16 males and 5 females, aged (48.0±12.7) years. In the titanium-mesh group, there were 14 males and 6 females, aged (49.8±10.2) years. All the 41 patients successfully completed the operation. In the zero-profile group, the surgical time was (50.04±8.45) minutes, the blood loss was (95.38±26.07) ml and the hospitalization cost was (42.32±6.12) thousand yuan. In the titanium-mesh group, the surgical time was (59.20±11.95) minutes, the blood loss was (93.10±27.86) ml and the hospitalization cost was (42.10±6.71) thousand yuan. The surgical time in the zero-profile group was shorter than that in the titanium-mesh group (P=0.007), and there was no statistically significant difference in blood loss and hospitalization costs between the two groups (both P>0.05). The 41 patients were followed-up for (14.29±1.45) months. Four cases (20.0%) in the titanium mesh group experienced swallowing difficulties and 0 cases in the zero incision group, the difference between the two groups was statistically significant (P=0.048). No intraoperative hematoma, spinal cord nerve recompression, airway crisis, incision infection complications, and no steel plate or screw breakage or displacement occurred after surgery. At the last follow-up, all cases had bone fusion. At the follow-up of 12 months after surgery, the JOA score of the zero incision group increased from preoperative (10.33±1.71) points to (15.47±0.81) points, with an improvement rate of 76.1%±15.7%; the JOA score of the titanium mesh group increased from (10.30±1.75) points to (15.30±0.92) points, with an improvement rate of 73.2%±16.7%; there was no statistically significant difference in improvement rate between the two groups (P=0.580). At the follow-up of 12 months after surgery, 1 case (4.8%) in the zero incision group and 8 cases (40.0%) in the titanium mesh group experienced implant sinking, and the difference between the two groups was statistically significant (P=0.009). Conclusion: Compared with titanium-mesh, 3D printed self-stable zero-profile artificial vertebral body for the treatment of OPLL of the cervical spine can achieve good surgical efficacy, shorter surgical time, lower incidence of postoperative chronic swallowing discomfort, and can provide a better bone material bonding interface and be less prone to prosthesis settlement.

IL-6/Stat3 suppresses osteogenic differentiation in ossification of the posterior longitudinal ligament via miR-135b-mediated BMPER reduction.

Interleukin-6 (IL-6) has been reported to induce osteogenic differentiation of mesenchymal stem cells for increasing bone regeneration, while the role of IL-6 in osteogenic differentiation during ossification of the posterior longitudinal ligament (OPLL) remains to be determined. The current study aims to explore the downstream mechanism of IL-6 in cyclic tensile strain (CTS)-stimulated OPLL, which involves bioinformatically identified microRNA-135b (miR-135b). Initially, we clinically collected posterior longitudinal ligament (PLL) and ossified PLL tissues, from which ossified PLL cells were isolated, respectively. The obtained data revealed a greater osteogenic property of ossified PLL than non-ossified PLL cells. The effect of regulatory axis comprising IL-6, Stat3, miR-135b, and BMPER on osteogenic differentiation of CTS-stimulated ossified PLL cells was examined with gain- and loss-of-function experiments. BMPER was confirmed as a target gene to miR-135b. Knockdown of BMPER or overexpression of miR-135b inhibited the osteogenic differentiation of CTS-induced ossification in PLL cells. Besides, IL-6 promoted the post-transcriptional process to mature miR-135b via Stat3 phosphorylation. In conclusion, IL-6 inhibited CTS-induced osteogenic differentiation by inducing miR-135b-mediated inhibition of BMPER through Stat3 activation.

Prevalence and Risk Factors for Modic Changes in Symptomatic Cervical Ossification of the Posterior Longitudinal Ligament: A Retrospective Study of 203 Patients.

BACKGROUND Modic changes (MC) are abnormal bone signals under the vertebral endplates on magnetic resonance imaging (MRI) of the spine. Three types of MC may be seen on MRI as abnormal bone signals of the vertebral endplate and adjacent bone marrow. This retrospective study of 203 patients with symptomatic cervical ossification of the posterior longitudinal ligament (OPLL) aimed to evaluate factors associated with MC on cervical spine MRI. MATERIAL AND METHODS We included 203 patients with symptomatic cervical ossification of the OPLL. All patients underwent MRI with T1 and T2 sequences to assess the presence and type of MC. Univariate and multivariate logistic regression analyses were used to identify the risk factors for MC. RESULTS The prevalence of MC in patients with symptomatic cervical OPLL was 21.18%. Type 2 MC accounted for 88.64% of the cases. Local type and MC share the same segment (100.00%), followed by segmental type (77.27%), mixed type (75.00%), and continuous type (75.00%). Age (OR=1.05, 95% CI: 1.01-1.09, P=0.013) and neck pain (OR=2.67, 95% CI: 1.04-6.83, P=0.041) were significantly correlated with MC. Further receiver operating characteristic (ROC) analysis displayed an area under the curve (AUC) of 0.657 (P=0.002) for age, and the optimal cutoff was 60.50 years (sensitivity 0.67, specificity 0.68). CONCLUSIONS The results of this study found that older age and neck pain were significantly associated with development of cervical spine MC. Patients ≥60.5 years with symptomatic cervical OPLL had a higher probability of developing MC.

Reoperation rate and risk factors of reoperation for ossification of the posterior longitudinal ligament (OPLL): a systematic review and meta-analysis.

Revision surgery for OPLL is undesirable for both patients and physicians. However, the risk factors for reoperation are not clear. Thus, we sought to review the existing literature and determine the factors associated with higher reoperation rates in patients with OPLL. A search was performed using Pubmed, Embase, Web of Sciences, and Ovid to include studies regarding the risk factors of reoperation for OPLL. RoBANS (Risk of Bias Assessment tool for Nonrandomized Studies) was used for risk of bias analysis. Heterogeneity of studies and publication bias was assessed, and sensitivity analysis was performed. Statistical analysis was performed with a p-value < 0.05 using SPSS software (version 23). Twenty studies with 129 reoperated and 2,793 non-reoperated patients were included. The pooled reoperation rate was 5% (95% CI: 4% to 7). The most common cause of reoperation was residual OPLL or OPLL progression (n = 51, 39.53%). An increased risk of additional surgery was found with pre-operative cervical or thoracic angle (Standardized mean difference = -0.44; 95% CI: -0.69 to -0.19; p = 0.0061), post-operative CSF leak (Odds ratio, OR = 4.97; 95% CI: 2.48 to 9.96; p = 0.0005), and graft and/or hardware failure (OR = 192.09; 95% CI: 6.68 to 5521.69; p = 0.0101). Apart from the factors identified in our study, the association of other variables with the risk of second surgery could not be ruled out, owing to the complexity of the relationship and significant bias in the current literature.

Effect of Different Types of Ossification of the Posterior Longitudinal Ligament on the Dynamic Biomechanical Response of the Spinal Cord: A Finite Element Analysis.

Ossification of the posterior longitudinal ligament (OPLL) has been identified as an important cause of cervical myelopathy. However, the biomechanical mechanism between the OPLL type and the clinical characteristics of myelopathy remains unclear. The aim of this study was to evaluate the effect of different types of OPLL on the dynamic biomechanical response of the spinal cord. A three-dimensional finite element model of the fluid-structure interaction of the cervical spine with spinal cord was established and validated. The spinal cord stress and strain, cervical range of motion (ROM) in different types of OPLL models were predicted during dynamic flexion and extension activity. Different types of OPLL models showed varying degrees of increase in stress and strain under the process of flexion and extension, and there was a surge toward the end of extension. Larger spinal cord stress was observed in segmental OPLL. For continuous and mixed types of OPLL, the adjacent segments of OPLL showed a dramatic increase in ROM, while the ROM of affected segments was limited. As a dynamic factor, flexion and extension of the cervical spine play an amplifying role in OPLL-related myelopathy, while appropriate spine motion is safe and permitted. Segmental OPLL patients are more concerned about the spinal cord injury induced by large stress, and patients with continuous OPLL should be noted to progressive injuries of adjacent level.

Predictive biomarkers of ossification progression and bone metabolism dynamics in patients with cervical ossification of the posterior longitudinal ligament.

PURPOSE: This study aimed to establish biomarkers to predict the progression of ossification by examining ossification volume and bone metabolism dynamics in patients with ossification of the posterior longitudinal ligament (OPLL). METHODS: We assessed OPLL progression using computed tomography-based three-dimensional (3D) image analysis and examined bone metabolism dynamics in 107 patients with OPLL (men, 72; women, 35; mean age, 63.6 years). The volume of OPLL was calculated twice during the follow-up period, and OPLL progression was evaluated by the annual rate of ossification increase. Bone metabolism dynamics were assessed by routine blood tests and analysis of various serum biomarkers (including 25-hydroxyvitamin D, intact parathyroid hormone, fibroblast growth factor 23, intact N-terminal propeptide of type 1, tartrate-resistant acid phosphatase isoform 5b, sclerostin, and Dickkopf-1) and bone mineral density (BMD). Patients were classified into the progression (P) or non-progression (NP) group according to the annual rate of increase in previous 3D image analyses, and associated factors between these groups were compared. RESULTS: The P and NP groups consisted of 29 patients (23 men and 6 women) and 78 patients (49 men and 29 women), respectively. Univariate analysis revealed significant differences in terms of age, body mass index, serum phosphorus, serum sclerostin, and BMD. In multivariate analysis, age, serum phosphorus, and serum sclerostin were identified as independent factors associated with OPLL progression. CONCLUSION: Younger age, hypophosphatemia, and high serum sclerostin are risk factors for OPLL progression. Serum phosphorus and sclerostin could serve as important biomarkers for predicting ossification progression.

Effect of K­line on posterior cervical surgery versus anterior cervical surgery in patients with multi-level ossification of posterior longitudinal ligament.

PURPOSE: To evaluate the influence of K-line on the outcome of open-door laminoplasty versus anterior cervical corpectomy decompression and fusion (ACCF) for patients with more than two levels of ossification of the posterior longitudinal ligament (OPLL). METHODS: 60 patients undergoing open-door laminoplasty and 62 patients undergoing ACCF from January 2013 to January 2020 with more than 2 years of follow-up were included. Eighty-four cases with the ossification mass not beyond the K-line were grouped as K-line (+), while thirty-eight cases were grouped as K-line (-). The operation time, intraoperative blood loss, hospital stay, preoperative, postoperative, and last follow-up JOA scores, and postoperative complications were investigated. RESULTS: The improvement rate of JOA scores after posterior approaches in cases of group K-line (+) and K-line (-) was 72.4% and 53.1%, respectively, which showed a significant difference (P < 0.01). In group K-line (+), the improvement of JOA scores for open-door laminoplasty was 73.4% and 71.8% for ACCF, which showed no significant difference (P > 0.05). In group K-line (-), the improvement of JOA scores for ACCF was 52.1% and 42.9% for open-door laminoplasty, which showed a significant difference (P < 0.05). The incidence of C5 palsy was significantly lower in cases with ACCF than in cases with open-door laminoplasty (P < 0.05). CONCLUSION: For patients with more than two levels of OPLL, preoperative K-line (+) predicates a better outcome than K-line (-). For cases with K-line (-), ACCF provides better neurologic function recovery. For patients with K-line (+), open-door laminoplasty provides the same neurologic function recovery of ACCF.

Deep learning-based prediction model for postoperative complications of cervical posterior longitudinal ligament ossification.

PURPOSE: Postoperative complication prediction helps surgeons to inform and manage patient expectations. Deep learning, a model that finds patterns in large samples of data, outperform traditional statistical methods in making predictions. This study aimed to create a deep learning-based model (DLM) to predict postoperative complications in patients with cervical ossification of the posterior longitudinal ligament (OPLL). METHODS: This prospective multicenter study was conducted by the 28 institutions, and 478 patients were included in the analysis. Deep learning was used to create two predictive models of the overall postoperative complications and neurological complications, one of the major complications. These models were constructed by learning the patient's preoperative background, clinical symptoms, surgical procedures, and imaging findings. These logistic regression models were also created, and these accuracies were compared with those of the DLM. RESULTS: Overall complications were observed in 127 cases (26.6%). The accuracy of the DLM was 74.6 ± 3.7% for predicting the overall occurrence of complications, which was comparable to that of the logistic regression (74.1%). Neurological complications were observed in 48 cases (10.0%), and the accuracy of the DLM was 91.7 ± 3.5%, which was higher than that of the logistic regression (90.1%). CONCLUSION: A new algorithm using deep learning was able to predict complications after cervical OPLL surgery. This model was well calibrated, with prediction accuracy comparable to that of regression models. The accuracy remained high even for predicting only neurological complications, for which the case number is limited compared to conventional statistical methods.

Effect of posterior decompression with and without fixation on a kyphotic cervical spine with ossification of the posterior longitudinal ligament.

STUDY DESIGN: Biomechanical study. OBJECTIVE: Cervical ossification of the posterior longitudinal ligament (C-OPLL) causes myelopathy. Though posterior decompression for C-OPLL showed positive results, poor outcomes were seen in patients with a kyphotic alignment. Posterior decompression with fusion (PDF) tends to show better results compared to posterior decompression. The aim of this study is to evaluate the effects of the posterior procedures for C-OPLL. SETTING: Yamaguchi University. METHODS: Based on 3D finite element C2-C7 spine created from medical images and a spinal cord, the following compression models were created: the intact model, K-line 0 mm model, and K-line 2 mm model. These models were used to analyze the effects of posterior decompression with varied lengths of fixation. The stress of the spinal cord was calculated for intact, K-line 0 mm, and K-line 2 mm as preoperative models, and laminectomy (LN)-K-line 0 mm, PDF (C4-C5)-K-line 0 mm, PDF (C3-C6)-K-line 0 mm, LN-K-line 2 mm, PDF (C4-C5)-K-line 2 mm, and PDF (C3-C6)-K-line 2 mm model as operative models in a neutral, flexion, and extension. RESULTS: As the compression increased, stress on the spinal cord increased compared to the intact model. In the neutral, posterior decompression decreased the stress of the spinal cord. However, in flexion and extension, the stress on the spinal cord for LN-K-line 0 or 2 mm, PDF (C4-C5)-K-line 0 or 2 mm, and PDF (C3-C6)-K-line 0 or 2 mm models decreased by more than 40%, 43%, and 70% respectively compared to the K-line 0 or 2 mm model. CONCLUSIONS: In kyphotic C-OPLL, it is essential to control intervertebral mobility in the posterior approach.

Risk factors for perioperative hidden blood loss after one-segment posterior circumferential decompression surgery on thoracic ossification of the posterior longitudinal ligament: a finding of the double-layer sign on CT.

BACKGROUND: Hidden blood loss (HBL) is of increasing interest to spine surgeons. This retrospective study aimed to evaluate perioperative HBL and its risk factors in patients undergoing one-segment posterior circumferential decompression surgery on thoracic ossification of the posterior longitudinal ligament (T-OPLL). METHOD: We retrospectively studied 112 patients diagnosed with T-OPLL following posterior circumferential decompression surgery from August 2015 to June 2020. Patient demographics, blood loss-related parameters, surgery-related data and imaging parameters were extracted. Postoperative complications were also recorded. Pearson or Spearman correlation analysis was used to investigate the correlation between patient demographics and HBL. Multivariate linear regression analysis was performed to determine the independent risk factors associated with HBL. RESULTS: Forty-five men and 67 women were involved in this research, with an average age of 56.4 ± 10.2 years. The mean HBL was 459.6 ± 275.4 ml, accounting for 56.5% of the total blood loss. Multiple linear regression analysis showed that double-layer sign (P = 0.000), ossification occupancy ratio (OOR) > 60% (P = 0.030), age (P = 0.010), hematocrit (Hct) loss (P = 0.034), and postoperative Hct (P = 0.016) were independent risk factors for HBL. However, OPLL morphology (P = 0.319), operation time (P = 0.587), hemoglobin (Hb) loss (P = 0.644), and postoperative Hb (P = 0.952) were not significantly different from HBL. CONCLUSION: A high proportion of HBL was found after posterior circumferential decompression surgery on T-OPLL during the perioperative period, which should not be overlooked. Double-layer sign, OOR > 60%, age, Hct loss and postoperative Hct are independent risk factors for HBL.

MRI-based detection of cervical ossification of the posterior longitudinal ligament using a novel automated machine learning diagnostic tool.

OBJECTIVE: Currently, CT is considered the gold standard for the diagnosis of ossification of the posterior longitudinal ligament (OPLL). The objective of this study was to develop artificial intelligence (AI) software and a validated model for the identification and representation of cervical OPLL (C-OPLL) on MRI, obviating the need for spine CT. METHODS: A retrospective evaluation was performed of consecutive imaging studies of all adult patients who underwent both cervical CT and MRI for any clinical indication within a span of 36 months (between January 2017 and July 2020) in a single tertiary-care referral hospital. C-OPLL was identified by a panel of neurosurgeons and a neuroradiologist. MATLAB software was then used to create an AI tool for the diagnosis of C-OPLL by using a convolutional neural network method to identify features on MR images. A reader study was performed to compare the performance of the AI model to that of the diagnostic panel using standard test performance metrics. Interobserver variability was assessed using Cohen's kappa score. RESULTS: Nine hundred consecutive patients were found to be eligible for radiological evaluation, yielding 65 identified C-OPLL carriers. The AI model, utilizing MR images, was able to accurately segment the vertebral bodies, PLL, and discoligamentous complex, and detect C-OPLL carriers. The AI model identified 5 additional C-OPLL patients who were not initially detected. The performance of the MRI-based AI model resulted in a sensitivity of 85%, specificity of 98%, negative predictive value of 98%, and positive predictive value of 85%. The overall accuracy of the model was 98%, with a kappa score of 0.917. CONCLUSIONS: The novel AI software developed in this study was highly specific for identifying C-OPLL on MRI, without the use of CT. This model may obviate the need for CT scans while maintaining adequate diagnostic accuracy. With further development, this MRI-based AI model has the potential to aid in the diagnosis of various spinal disorders and its automated layers may lay the foundation for MRI-specific diagnostic criteria for C-OPLL.

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

BACKGROUND: To compared the clinical efficacy of two surgical methods, posterior laminectomy fusion fixation, and posterior single open-door laminoplasty, in treating multilevel cervical ossification of the posterior longitudinal ligament (OPLL). METHODS: The study retrospectively included 102 patients treated between December 2016 and December 2020. The patients were included into an observation group (56 cases) treated with total laminectomy and lateral screw fixation, and a control group (46 cases) treated with single open-door laminoplasty. RESULTS: After 24 months, both groups showed significant improvement in Japanese Orthopaedic Association (JOA) scores and Visual Analogue Scale (VAS) scores, indicating better clinical symptoms and functional recovery. There was no significant difference in preoperative JOA and VAS scores between the two groups (P > 0.05). At 24 months after surgery, there was no significant difference in JOA and VAS scores between the two groups (P > 0.05). However, the observation group had a significantly higher cervical curvature index (CCI) and lower range of motion (ROM) of the cervical spine compared to the control group (P < 0.05). The CCI in control group was lower than before surgery, while the CCI in observation group was higher than before surgery, and CCI in the control group was considerably lower than that in the observation group (P < 0.05). The complication rate was lower in the control group, with fewer cases of axial symptoms, fifth cervical nerve root palsy, and overall complications. The overall complication rate was 25.0% (14/56) in the observation group and 10.8% (5/46) in the control group (P < 0.05). CONCLUSIONS: Both posterior laminectomy fusion fixation and posterior single open-door laminoplasty yield positive outcomes in improving clinical neurological function, cervical curvature, range of motion of the cervical spine, and cervical sagittal balance. Although open-door laminoplasty is less effective than total laminectomy in maintaining CCI and sagittal balance, it excels in preserving cervical range of motion, less surgical trauma and complications. Thus, open-door laminoplasty may be a suitable first-choice treatment for multi-segmental cervical OPLL, especially for patients with lordotic cervical spine physiological curvature.

Transdural circumferential decompression for thoracic spinal stenosis caused by beak-type ossification of the posterior longitudinal ligament: a technical note.

PURPOSE: Thoracic myelopathy caused by ossification of the posterior longitudinal ligament (OPLL) in the thoracic spine is usually progressive and responds poorly to conservative therapy, making surgery the only effective treatment option. A variety of surgical procedures have been developed to treat thoracic OPLL. However, the optimal surgical approach for removal of thoracic OPLL remains unclear. In the present study, we described a newly modified posterior approach for the removal of OPLL: circular decompression via dural approach, and complete removal of OPLL can be achieved under direct vision and without neurological deficit. MATERIALS AND METHODS: Three patients with beak-type thoracic OPLL presented with progressive thoracic myelopathy and leg weakness. Magnetic resonance imaging showed the spinal cord severely compressed. The surgical management of the three patients involved the 'cave-in' circular decompression and transdural resection of OPLL. RESULTS: Transdural circumferential decompression was successfully performed in all three patients. Clinical outcome measures, including pre- and postoperative radiographic parameters, were assessed. All of the patients were followed up for an average of 12 months (ranging from 10 to 15 months), and no surgery-related complications occurred. Weakness relief and neural function recovery were satisfactorily achieved in all patients by the final follow-up. CONCLUSIONS: Transdural circumferential decompression was an effective method for thoracic spinal stenosis caused by concurrent beak-type OPLL, by which OPLL could be safely removed. It is especially useful when there is a severe adhesion between the dura OPLL.

Predictors of good outcome after anterior decompression and fusion in patients with ossification of the posterior longitudinal ligament of the thoracic spine.

BACKGROUND: There are few reports concerning determinants of the surgical outcome of anterior decompression and fusion (ADF) when performed for ossification of the posterior longitudinal ligament of the thoracic spine (T-OPLL). We investigated prognostic factors associated with neurological recovery in the patients with T-OPLL. METHODS: This retrospective study included consecutive cases of T-OPLL patients from January 2002 to January 2020 and minimum one-year follow-up. Data were collected for sex, age, body mass index, preoperative manual muscle test score for the weakest muscle, surgical data, and preoperative and postoperative findings on radiographs, magnetic resonance images, and computed tomography scans. Imaging data were also collected, including preoperative kyphotic angles, canal occupancy ratio, type of OPLL, and high-intensity areas on T2-weighted images. The Japanese Orthopaedic Association score for thoracic myelopathy (T-JOA) was used to evaluate the recovery of the thoracic myelopathy. The patients were categorized according to whether the improvement in T-JOA score was >50% or ≤50%. RESULTS: Forty-six patients who underwent anterior procedures for T-OPLL were included in the study. Preoperative and postoperative T-JOA scores were 4.2 ± 2.3 and 7.9 ± 2.1, respectively. The improvement in the T-JOA score was 54.5 ± 25.6%. The proportion of patients with beak-type OPLL was significantly higher in the >50% JOA improvement group (23/27) than in the ≤50% group (9/19) (p = 0.009) and the canal occupancy ratio was significantly lower in the >50% group (56.3 ± 12.2% vs 64.4 ± 8.73%; p = 0.0163). There were no significant between-group differences in other factors. CONCLUSIONS: Beak-type ossification and a low canal occupancy ratio are predictors of good outcome after ADF in patients with T-OPLL. ADF should be considered in patients with either or both of these features.

Regulatory Mechanism between Ferritin and Mitochondrial Reactive Oxygen Species in Spinal Ligament-Derived Cells from Ossification of Posterior Longitudinal Ligament Patient.

Primary spinal ligament-derived cells (SLDCs) from cervical herniated nucleus pulposus tissue (control, Ctrl) and ossification of the posterior longitudinal ligament (OPLL) tissue of surgical patients were analyzed for pathogenesis elucidation. Here, we found that decreased levels of ferritin and increased levels of alkaline phosphatase (ALP), a bone formation marker, provoked osteogenesis in SLDCs in OPLL. SLDCs from the Ctrl and OPLL groups satisfied the definition of mesenchymal stem/stromal cells. RNA sequencing revealed that oxidative phosphorylation and the citric acid cycle pathway were upregulated in the OPLL group. SLDCs in the OPLL group showed increased mitochondrial mass, increased mitochondrial reactive oxygen species (ROS) production, decreased levels of ROS scavengers including ferritin. ROS and ferritin levels were upregulated and downregulated in a time-dependent manner, and both types of molecules repressed ALP. Osteogenesis was mitigated by apoferritin addition. We propose that enhancing ferritin levels might alleviate osteogenesis in OPLL.

Instrumented fusion versus instrumented non-fusion following expansive open-door laminoplasty for multilevel cervical ossification of the posterior longitudinal ligament.

PURPOSE: To compare the outcomes of expansive open-door laminoplasty with instrumented fusion (ELIF) and expansive open-door laminoplasty with instrumented non-fusion (ELINF) for multilevel cervical ossification of the posterior longitudinal ligament (OPLL). METHODS: Patients who underwent ELIF or ELINF due to multilevel cervical OPLL from June 2013 to June 2019 were identified. Clinical and radiological outcomes were compared between the two groups. RESULTS: A total of 78 patients were enrolled in this study with a minimum follow-up of 24 months, including 42 patients in the ELIF group and 36 patients in the ELINF group. At the final follow-up, sagittal vertical axis (SVA) and C2-C7 Cobb angle in the ELIF group were significantly better than those in the ELINF group, and cervical range of movement (ROM) in the ELIF group decreased significantly than that in the ELINF group. The incidence of OPLL progression at the final follow-up was 4.76% (2/42) in the ELIF group and 27.78% (10/36) in the ELINF group. Postoperative Japanese Orthopaedic Association (JOA) score, neck disability index (NDI), and visual analog scale (VAS) score improved significantly in each group, but JOA score and recovery rate (RR) in the ELIF group were significantly better than those in the ELINF group at the final follow-up. When K-line was positive, the difference in the final JOA score between the two groups was not significant, but the RR in the ELIF group was significantly better than that in the ELINF group. When K-line was negative, the final JOA score and RR in the ELIF group were significant higher than those in the ELINF group. CONCLUSIONS: ELIF and ELINF were two effective surgical procedures for treating multilevel cervical OPLL. However, ELIF was superior to ELINF due to better postoperative JOA score and RR, significant improvement of C2-C7 Cobb angle and maintenance of SVA, and suppressant effect on OPLL progression, especially for patients with K-line ( - ) OPLL.