Different cutoff value of motor evoked potentials for the postoperative outcome in the ossification of the posterior longitudinal ligament surgery in the cervical and thoracic spine

BACKGROUND CONTEXT

Transcranial muscle motor evoked potentials (Tc-mMEPs), a key component of intraoperative neurophysiologic monitoring (IONM), effectively reflect the changes in corticospinal tract integrity and are closely related to the occurrence of the postoperative motor deficit (PMD). Most institutions have applied a specified (fixed) alarm criterion for the heterogeneous groups in terms of etiologies or lesion location. However, given the high risk of PMD in ossification of the posterior longitudinal ligament (OPLL) surgery, it is essential to determine a tailored cutoff value for IONM.

PURPOSE

We aimed to establish the intraoperative cutoff value of Tc-mMEPs reduction for predicting PMD in OPLL according to lesion levels.

DESIGN

Retrospective analysis using a review of electrical medical records.

PATIENT SAMPLE

In this study, we included 126 patients diagnosed with OPLL, who underwent surgery and IONM.

OUTCOME MEASURES

The occurrence of PMD immediately and 1 year after operation, as well as the decrement of intraoperative Tc-mMEPs amplitude.

METHODS

We analyzed OPLL surgery outcomes using Tc-mMEPs monitoring. Limbs with acceptable baseline Tc-mMEPs in the tibialis anterior or abductor hallucis were included in the final set. PMD was defined as a ≥1 decrease in Medical Research Council score in the legs, and it was evaluated immediately and 1year after operation. The reduction ratios of Tc-mMEPs amplitude compared with baseline value were calculated at the two time points: the maximal decrement during surgery and at the end of surgery. Receiver operating characteristic curve analysis was used to determine the cutoff value of Tc-mMEPs amplitude decrement for predicting PMDs.

RESULTS

In total, 203 limbs from 102 patients with cervical OPLL and 42 limbs from 24 patients with thoracic OPLL were included. PMD developed more frequently in thoracic lesions than in cervical lesions (immediate, 9.52% vs 2.46%; 1 year, 4.76% vs 0.99%). The Tc-mMEPs amplitude cutoff point at the end of surgery for PMD (both immediate and 1-year) was a decrease of 93% in cervical and 50% in thoracic OPLL surgeries. Similarly, the Tc-mMEPs amplitude cutoff point at the maximal decrement during surgery for PMD (both immediate and 1 year) was a reduction of 97% in cervical and 85% in thoracic OPLL surgeries.

CONCLUSIONS

The thoracic lesion exhibited a lower cutoff value than the cervical lesion for both immediate and long-term persistent PMD in OPLL surgery (Tc-mMEPs at the end of surgery measuring 93% vs 50%; and Tc-mMEPs at the maximal decrement measuring 97% vs 85% for cervical and thoracic lesions, respectively). To enhance the reliability of monitoring, considering the application of tailored alarm criteria for Tc-mMEPs changes based on lesion location in OPLL could be beneficial.

Mechanical response of human thoracic spine ligaments under quasi-static loading: An experimental study

PURPOSE

This study aimed to investigate the geometrical and mechanical properties of human thoracic spine ligaments subjected to uniaxial quasi-static tensile test.

METHODS

Four human thoracic spines, obtained through a body donation program, were utilized for the study. The anterior longitudinal ligament (ALL), posterior longitudinal ligament (PLL), capsular ligament (CL), ligamenta flava (LF), and the interspinous ligament and supraspinous ligament complex (ISL + SSL), were investigated. The samples underwent specimen preparation, including dissection, cleaning, and reinforcement, before being immersed in epoxy resin. Uniaxial tensile tests were performed using a custom-designed mechanical testing machine equipped with an environmental chamber (T = 36.6 °C; humidity 95%). Then, the obtained tensile curves were averaged preserving the characteristic regions of typical ligaments response.

RESULTS

Geometrical and mechanical properties, such as initial length and width, failure load, and failure elongation, were measured. Analysis of variance (ANOVA) revealed significant differences among the ligaments for all investigated parameters. Pairwise comparisons using Tukey's post-hoc test indicated differences in initial length and width. ALL and PLL exhibited higher failure forces compared to CL and LF. ALL and ISL + SSL demonstrated biggest failure elongation. Comparisons with other studies showed variations in initial length, failure force, and failure elongation across different ligaments. The subsystem (Th1 - Th6 and Th7 - Th12) analysis revealed increases in initial length, width, failure force, and elongation for certain ligaments.

CONCLUSIONS

Variations of both the geometric and mechanical properties of the ligaments were noticed, highlighting their unique characteristics and response to tensile force. Presented results extend very limited experimental data base of thoracic spine ligaments existing in the literature. The obtained geometrical and mechanical properties can help in the development of more precise human body models (HBMs).

[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.

A Clinical Classification of Cervical Ossification of the Posterior Longitudinal Ligament to Guide Surgical Strategy

STUDY DESIGN

A clinical classification of cervical ossification of the posterior longitudinal ligament (COPLL) was developed based on imaging findings.

OBJECTIVE

This study aimed to establish a clinical classification for COPLL and provide corresponding surgery strategies for each subtype.

SUMMARY OF BACKGROUND DATA

A practical and reliable classification is needed to guide the treatment of COPLL.

MATERIALS AND METHODS

This study retrospectively reviewed plain radiographs, computed tomography scans, and magnetic resonance images of patients diagnosed with COPLL between 2018 and 2022 at Shanghai Changzheng Hospital. The types of COPLL were classified according to the location, morphology, and canal-occupying ratio (OR) of the ossification mass. Interobserver and intraobserver reliability were evaluated using Cohen's kappa.

RESULTS

A total of 1000 cases were included, which were classified into five types: focal type (F type), short-sequential type (S type), long-sequential type (L type), high type (H type), and mixed type (M type). In addition, each type could be classified into subtype 1 or subtype 2 according to the canal-OR. Then each type could be further classified into other subtypes according to location and morphology. The interobserver reliabilities in the first and second rounds were 0.853 and 0.887, respectively. The intraobserver reliability was 0.888.

CONCLUSION

The authors classified COPLL into a system comprised of five types and several subtypes according to canal-OR, location, and morphology. Surgical strategies for each subtype are also suggested. This provides a theoretical guide for the description and surgical management of COPLL.

Percutaneous Fully-endoscopic Anterior Transcorporeal Procedure for the Treatment of Isolated Ossification of the Posterior Longitudinal Ligament in the Cervical Spine: A Case Report

BACKGROUND

With the development of spinal endoscopic techniques, on the basis of our previous experience in treating various types of cervical disc herniation with this endoscopic technique, we took the lead in applying the percutaneous fully endoscopic anterior transcorporeal procedure to be utilized in the treatment of the isolated cervical ossification of the posterior longitudinal ligament (OPLL).

CASE PRESENTATION

A 66-year-old male patient who weighed 57 kg, with a height of 169 cm was admitted to the hospital on September 16, 2021 because of recurrent pain and numbness in the neck, shoulder, and right arm for 2 years, which as aggravated for the last 2 weeks. Two years ago, the patient developed neck and shoulder pain accompanied by right arm pain without obvious predisposing factors, and numbness in the first web space of the right hand. In the last 2 weeks, he had difficulty moving the right arm, but no pain or numbness in the contralateral arm. MRI and CT scans demonstrated that the ossified posterior longitudinal ligament of the cervical 5/6 vertebrae with spinal canal stenosis and seriously compressed the spinal cord patient was treated with a percutaneous fully endoscopic anterior transcorporeal procedure.

CONCLUSION

Our percutaneous fully endoscopic anterior transcorporeal procedure is a feasible, minimally invasive surgery for treating isolated ossification of the posterior longitudinal ligament in the cervical spine.

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.

Automated Detection of the Thoracic Ossification of the Posterior Longitudinal Ligament Using Deep Learning and Plain Radiographs

Ossification of the ligaments progresses slowly in the initial stages, and most patients are unaware of the disease until obvious myelopathy symptoms appear. Consequently, treatment and clinical outcomes are not satisfactory. This study is aimed at developing an automated system for the detection of the thoracic ossification of the posterior longitudinal ligament (OPLL) using deep learning and plain radiography. We retrospectively reviewed the data of 146 patients with thoracic OPLL and 150 control cases without thoracic OPLL. Plain lateral thoracic radiographs were used for object detection, training, and validation. Thereafter, an object detection system was developed, and its accuracy was calculated. The performance of the proposed system was compared with that of two spine surgeons. The accuracy of the proposed object detection model based on plain lateral thoracic radiographs was 83.4%, whereas the accuracies of spine surgeons 1 and 2 were 80.4% and 77.4%, respectively. Our findings indicate that our automated system, which uses a deep learning-based method based on plain radiographs, can accurately detect thoracic OPLL. This system has the potential to improve the diagnostic accuracy of thoracic OPLL.

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.

High whole-body bone mineral density in ossification of the posterior longitudinal ligament

BACKGROUND CONTEXT

Recent studies suggest that ossification of the posterior longitudinal ligament (OPLL) is exacerbated by systemic metabolic disturbances, including obesity. However, although an increase in bone mineral density (BMD) measured at the lumbar spine has been reported in patients with OPLL, no studies have investigated the systemic BMD of patients with OPLL in detail.

PURPOSE

We investigated whether patients with OPLL develop increased whole-body BMD.

STUDY DESIGN

Single institution cross-sectional study.

PATIENT SAMPLE

Data were collected from Japanese patients with symptomatic OPLL (OPLL [+]; n=99). Control data (OPLL [-]; n=226) without spinal ligament ossification were collected from patients who underwent spinal decompression, spinal fusion, or hip replacement surgery.

OUTCOME MEASURES

Demographic data, including age, body mass index (BMI), comorbidities, history of treatment for osteoporosis, and history of vertebral and nonvertebral fractures, was obtained from all participants. In addition, whole-body BMD, including the lumbar spine, thoracic spine, femoral neck, skull, ribs, entire upper extremity, entire lower extremity, and pelvis, were measured in all participants using whole-body dual-energy X-ray absorptiometry.

METHODS

Patient data were collected from 2018 to 2022. All participants were categorized based on sex, age (middle-aged [<70 years] and older adults [≥70 years]), and OPLL type (localized OPLL [OPLL only in the cervical spine], diffuse OPLL [OPLL in regions including the thoracic spine]), and OPLL [-]) and each parameter was compared. The factors associated with whole-body BMD were evaluated via multivariable linear regression analysis.

RESULTS

Compared with the OPLL (-) group, the OPLL (+) group of older women had significantly higher BMD in all body parts (p<.01), and the OPLL (+) group of older men had significantly higher BMD in all body parts except the ribs, forearm, and skull (p<.01). The factors associated with increased BMD of both the femoral neck (load-bearing bone) and skull (nonload-bearing bone) were age, BMI, and coexisting diffuse OPLL in women and BMI and coexisting localized OPLL in men.

CONCLUSIONS

Patients with OPLL have increased whole-body BMD regardless of sex, indicating that it is not simply due to load-bearing from obesity. These findings suggested that OPLL is associated with a systemic pathology.

Anterior Column Realignment: Adult Sagittal Deformity Treatment Through Minimally Invasive Surgery

This article focuses on the treatment of sagittal spinal deformity using a minimally invasive technique, anterior column realignment. Traditional methods to address sagittal spine deformity have been associated with high morbidity, long operative times, and excessive blood loss. This technique uses a minimally invasive lateral retroperitoneal approach to release the anterior longitudinal ligament and apply a hyperlordotic implant for interbody fusion to restore lumbar lordosis and sagittal alignment.

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.

Is conservative treatment a good choice for pediatric intervertebral disc calcification in children?

PURPOSE

Paediatric intervertebral disc calcification (PIDC) is a rare disease, and its aetiology remains unknown. This study aimed to analyse the characteristics and clinical outcomes of patients with PIDC.

METHODS

After applying the exclusion and inclusion criteria, 159 children diagnosed with PIDC were analysed at our hospital between January 2010 and November 2020. Patients' demographic and clinical data were collected, such as sex, pain, duration time, physical examination, white blood cell count, erythrocyte sedimentation rate, C-reactive protein, and radiography, computed tomography, and magnetic resonance imaging findings. Patients were followed up for at least 6 months, and radiography or symptoms were evaluated. Fisher's exact test or χ2-test was used for statistical analyses.

RESULTS

One hundred and fifty-nine patients were ultimately followed up with for about 12.5 ± 5.8 months. There were 103 male and 56 female, with an average age of 6.08 ± 2.62 years (2 months to 12 years). A total of 109 patients had only one PIDC, 29 patients had two PIDCs, and 21 patients had multiple PIDCs. Thirty patients were found incidentally and were asymptomatic. A total of 106 patients had neck torticollis. Sixteen patients had IDC herniations, fifteen patients had posterior longitudinal ligament calcification, two patients had anterior longitudinal ligament calcification, and 17 patients had herniation of the vertebral canal. All patients underwent conservative treatment, and none underwent surgery. All patients' symptoms resolved after either collar fixation or neck traction.

CONCLUSION

PIDC can be treated conservatively, even when accompanied by herniation, longitudinal ligament calcification, or clinical neck symptoms.

LEVEL OF EVIDENCE

IV.

Relationship between K-line distance and surgical outcome in cases of laminoplasty for cervical ossification of the posterior longitudinal ligament

Although previous studies indicate that changes in cervical alignment after laminoplasty and dynamic factors influence surgical outcomes of cervical ossification of the posterior longitudinal ligament (OPLL), the relationship between the surgical outcomes, the distance between the kyphosis-line (K-line) and OPLL, and dynamic factors have not yet been quantitatively evaluated. The purpose of the present study was to analyze the relationship between ΔK-line distance and surgical outcomes in cases of laminoplasty for OPLL of the cervical spine. We retrospectively reviewed 46 consecutive patients (33 men and 13 women) with cervical OPLL who underwent laminoplasty. "K-line distance" was measured as the minimum interval between the K-line and OPLL on lateral radiographs. The following factors were analyzed: K-line distance in neutral, flexion, and extension neck positions, ΔK-line distance, preoperative C2-7 range of motion (ROM), preoperative segmental ROM, preoperative C2-7 lordotic angle, occupying ratio of the OPLL, disease duration, preoperative and postoperative Japanese Orthopaedic Association (JOA) score, and recovery rate. Patients were divided into flexion K-line (+) and flexion K-line (-) groups. We then analyzed the influence of the K-line distance on surgical outcomes and conducted multivariate analysis to analyze the factors affecting surgical outcomes. The JOA score recovery rate in the flexion K-line (-) group was significantly lower than that in the flexion K-line (+) group (P = .024). The ΔK-line distance was significantly negatively correlated with the JOA score recovery rate (r = -0.531, P < .001). Additionally, multivariate analysis showed that ΔK-line distance (OR = -2.143, P = .015) was negatively correlated with the JOA score recovery rate. The ΔK-line distance is considered useful for the quantitative evaluation of dynamic factors and static compression factors due to OPLL through the measurement of dynamic radiographic images.

Prevalence and characteristics of thoracic ossification of the posterior longitudinal ligament in 3299 Black patients: a cross-sectional study of a prospectively registered database

OBJECTIVES

To the best of our knowledge, the prevalence of thoracic ossification of the posterior longitudinal ligament (T-OPLL) in the Black population has never been studied and is still unknown. The purpose of this study was to examine the prevalence and characteristics of T-OPLL in the Black patients.

METHODS

This is a cross-sectional study. All patients who underwent chest CT for the trauma screening and whose race was classified as 'Black' on the questionnaire were recruited in the study from March 2019 to March 2020. Demographic data, including age, sex, body mass index (BMI) and presence of diabetes mellitus (DM), were recorded. T-OPLL was defined as ectopic OPLL of more than 2 mm thickness in the axial plane image of the CT scan. The prevalence and characteristics of T-OPLL, and the association of T-OPLL with BMI and DM were evaluated.

RESULTS

A total of 3299 Black patients (1507 women and 1792 men) were included for the analysis. The prevalence of T-OPLL was 1.5% (50 patients), with 2.4% for females and 0.8% for males. The highest prevalence was observed in patients at the age of 70 years (3.8%). Thickness of T-OPLL was between 2 and 3 mm in 46% (23/50) of the patients, and the largest thickness was 6.1 mm. T-OPLL was significantly associated with female sex and the presence of DM.

CONCLUSIONS

The prevalence of T-OPLL was 1.5% in the 3299 Black patients who underwent chest CT for the trauma screening, with 2.4% for females and 0.8% for males.

Comparison of the Effects of Lumbar Spine Flexion on the Acoustic Windows Between Young and Elderly Patients

BACKGROUND

The effects of lumbar flexion on posterior longitudinal ligament (PLL) length as an acoustic window for neuraxial block in older patients have not been fully elucidated.

OBJECTIVE

This study aimed to compare changes in PLL length during lumbar spine flexion in young and old patients.

STUDY DESIGN

Observational cohort study.

SETTING

Tertiary University Hospital.

METHODS

Forty young and older adult patients were placed in the lateral decubitus position. To flex the lumbar spine, patients were asked to flex their hips and knees and then their neck and shoulder toward their knees as much as they could (fetal position). An assistant pushed the patients' abdomen to the back and held their neck and legs to help them maintain position. To obtain an optimal ultrasound view, lumbar spinal ultrasonography was performed from L5/S1 to L2/L3 using a paramedian oblique sagittal plane. PLL lengths were measured on the ultrasound image before fetal position, after unassisted fetal position, and after assisted fetal position.

RESULTS

PLL lengths increased after lumbar spine flexion in both young and older adult  patients, except at the L3-L4 level in old patients. The change in PLL length during lumbar spine flexion was significantly lower in old patients than in young patients at the L5-S1 and L3-L4 levels (P = 0.0028 and P = 0.0134, respectively). After lumbar spine flexion, the PLL length was significantly different between the spinal levels in older patients (P = 0.0392).

LIMITATIONS

First, we measured the PLL length as an acoustic window for neuraxial block using lumbar spinal ultrasonography. Second, the researcher who obtained the spinal ultrasound view was not blinded to the patient's group and position. However, the researcher who measured the PLL lengths on ultrasonography was blinded. Third, all participants had no history of surgery, trauma, or congenital abnormalities of the spine, regardless of age.

CONCLUSION

Lumbar spine flexion can increase PLL length in young and old patients. However, lumbar spine flexion is less effective in increasing the PLL length in old patients than in young patients.

Global Trends Of The Researches On Ossification Of Posterior Longitudinal Ligament In Thoracic Spine: A Bibliometric And Visualization Study

STUDY DESIGN

Bibliometric analysis OBJECTIVE: Thoracic ossification of the posterior longitudinal ligament (TOPLL) was a rare but intractable disease, and was the second leading cause of thoracic myelopathy. This study aimed to illustrate the overall knowledge structure, and development trends of TOPLL, using a bibliometric analysis and newly developed visualization tools.

METHODS

Research datasets were acquired from the Web of Science. The literature search was also limited to articles that were published until Oct 30, 2021. VOS viewer and Citespace software was provided to analyze the data and generate visualization knowledge maps. Annual trend of publications, distribution, H-Index status, co-authorship status and research hotspots were analyzed.

RESULTS

206 publications met the requirement. Japan published most papers (92), both total citations (1574) and H-index (24) ranked first of all the countries. The most productive organizations were Peking University (22). The most productive authors were Yamazaki M (18). The most productive journals were Spine (33). Diagnosis and treatment on the accuracy of surgical segments, prognosis of patients, and gene research were the research hotspots in the recent years.

CONCLUSION

The study showed an upward trend with a stable rise in recent years. Japan is country with the highest productivity, not only in quality, but also in quantity. Peking University and Spine have been the largest contributor. Indeed, this study provides great insights to the growth and development of TOPLL. Moreover, it will contribute to the growth of the international frontier.

Comparison of perioperative complications in anterior decompression with fusion and posterior decompression with fusion for thoracic ossification of the posterior longitudinal ligament -a retrospective cohort study using a nationwide inpatient database

BACKGROUND

Thoracic ossification of the posterior longitudinal ligament (T-OPLL) is a rare disease, which can cause spinal cord compression leading to various neurological symptoms. There are limited treatment options for T-OPLL, surgery is generally considered the only effective treatment. However, few studies have investigated surgical complications in patients with T-OPLL, and there are no data regarding surgical risks in anterior decompression with fusion (ADF) when compared with posterior decompression with fusion (PDF) for T-OPLL.

METHODS

Patients who were diagnosed as T-OPLL and underwent ADF via the anterior approach and PDF via the posterior approach from April 1, 2012 to March 31, 2018, were extracted from the Diagnosis Procedure Combination (DPC) database. We analyzed perioperative systemic and local complication rates after ADF and PDF and compared them using propensity score matching (PSM) method. In each of the two groups, we investigated the details of length of stay, costs, mortality, and discharge destination.

RESULTS

In total 1344 patients (ADF: 88 patients, PDF: 1256 patients), 176 patients were investigated after PSM (88 pairs). While the incidence of overall systemic complication was significantly higher in the ADF group (ADF/PDF: 25.0%/8.0%, P = 0.002), there was no significant difference in the overall local complication rate (15.9%/19.3%, P = 0.55). Specifically, respiratory complications were more frequently observed in the ADF group (9.1%/0%, P = 0.004), however, other systemic and local complications did not differ significantly between the two groups. The length of stay was 1.7 times longer (P < 0.001) and the medical costs were 1.4 times higher (P < 0.001) in patients with perioperative complications, compared to those without perioperative complications.

CONCLUSION

We demonstrated the perioperative complications of ADF and PDF in patients with T-OPLL using a large national database. ADF showed a higher incidence of respiratory complications. Development of perioperative complications was associated with longer hospital stay and higher medical costs.

Improved diagnostic performance of plain radiography for cervical ossification of the posterior longitudinal ligament using deep learning

Background

A high false-negative rate has been reported for the diagnosis of ossification of the posterior longitudinal ligament (OPLL) using plain radiography. We investigated whether deep learning (DL) can improve the diagnostic performance of radiologists for cervical OPLL using plain radiographs.

Materials and methods

The training set consisted of 915 radiographs from 207 patients diagnosed with OPLL. For the test set, we used 200 lateral cervical radiographs from 100 patients with cervical OPLL and 100 patients without OPLL. An observer performance study was conducted over two reading sessions. In the first session, we compared the diagnostic performance of the DL-model and the six observers. The diagnostic performance was evaluated using the area under the receiver operating characteristic curve (AUC) at the vertebra and patient level. The sensitivity and specificity of the DL model and average observers were calculated in per-patient analysis. Subgroup analysis was performed according to the morphologic classification of OPLL. In the second session, observers evaluated the radiographs by referring to the results of the DL-model.

Results

In the vertebra-level analysis, the DL-model showed an AUC of 0.854, which was higher than the average AUC of observers (0.826), but the difference was not significant (p = 0.292). In the patient-level analysis, the performance of the DL-model had an AUC of 0.851, and the average AUC of observers was 0.841 (p = 0.739). The patient-level sensitivity and specificity were 91% and 69% in the DL model, and 83% and 68% for the average observers, respectively. Both the DL-model and observers showed decreases in overall performance in the segmental and circumscribed types. With knowledge of the results of the DL-model, the average AUC of observers increased to 0.893 (p = 0.001) at the vertebra level and 0.911 (p < 0.001) at the patient level. In the subgroup analysis, the improvement was largest in segmental-type (AUC difference 0.087; p = 0.002).

Conclusions

The DL-based OPLL detection model can significantly improve the diagnostic performance of radiologists on cervical radiographs.

Cervical Ossification of the Posterior Longitudinal Ligament (OPLL) in Native Hawaiians and/or Polynesians: A 3-year Retrospective Demographic and Descriptive Pilot Study

Ossification of the posterior longitudinal ligament (OPLL) is a disease characterized by the replacement of the posterior longitudinal ligament with ectopic bone and cartilage. Historically, the disease was described as highly prevalent in Japanese and other Asian populations. However, recent studies suggest OPLL may have a higher prevalence in non-Asian communities than previously believed. To date, there are no demographic or epidemiologic studies examining OPLL in Native Hawaiian or Polynesian communities. The purpose of this study was to review the demographics and comorbidities of a cohort of patients with OPLL from the author's institution, designated as either Native Hawaiian and/or Polynesian (NHP) or Non-Native Hawaiian and/or Polynesian (NNHP). Demographic findings from this study were similar to previous literature demonstrating higher rates of OPLL in men and older patients with an average age of 56 years in the NHP group and 65 years in the NNHP group. There were no statistically significant differences in the rates of type II diabetes mellitus, coronary vascular disease, chronic kidney disease, or hypertension between NHP and NNHP groups. The NHP group exhibited statistically higher rates of obesity when compared to the NNHP group. Obesity's risk in the development or progression of OPLL in the NHP population has not been examined and requires additional investigation. This study serves as a beginning for further demographic and epidemiologic investigations into OPLL in Native Hawaiian and Polynesian communities to facilitate improved identification of those at risk and guide diagnosis and treatment of these patients.

Comparison of Surgical Outcomes After Open- and Double-Door Laminoplasties for Patients with Cervical Ossification of the Posterior Longitudinal Ligament: A Prospective Multicenter Study

STUDY DESIGN

A prospective multicenter study.

OBJECTIVE

To evaluate and compare the surgical outcomes after open-door (OD) and double-door (DD) laminoplasties in subjects with cervical ossification of the posterior longitudinal ligament (OPLL).

SUMMARY OF BACKGROUND DATA

Although previous studies compared clinical results after OD and DD laminoplasties, they were performed at a single institution with a relatively small sample size targeting mixed pathologies, including cervical spondylotic myelopathy.

METHODS

This study was performed by the Japanese Multicenter Research Organization for Ossification of the Spinal Ligament. A total of 478 patients with myelopathy caused by cervical OPLL from 28 institutions were prospectively registered from 2014 to 2017 and followed up for 2 years. Of these, 41 and 164 patients received OD and DD laminoplasties, respectively. Demographic information, medical history, and imaging findings were collected. Clinical outcomes were assessed using the cervical Japanese Orthopaedic Association, Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire, and visual analog scale scores.

RESULTS

Age, sex, symptom duration, and comorbidities were not significantly different between the groups. Segmental ossification was the most frequent in both the groups. No significant differences in K-line type, canal occupying ratio, C2 to C7 angles, and range of motion were found. Both the procedures reduced the cervical range of motion postoperatively. A comparable frequency of perioperative complications was observed between the groups. The cervical Japanese Orthopaedic Association scores showed a similar improvement at 2 years postopera- tively. The reduction in visual analog scale score for neck pain was favorable in the OD group (P = 0.02), while other pain assessments did not show any significant differences between the groups. The functional outcomes assessed using the Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire presented equivalent effective rates.

CONCLUSION

The results demonstrated almost comparable surgical outcomes between OD and DD laminoplasties. Lamino- plasty is a valuable technique as a therapeutic option for cervical OPLL.Level of Evidence: 2.

Restrained Eating and Vegan, Vegetarian and Omnivore Dietary Intakes

There are a significant number of studies on cognitive restraint among individuals with varying dietary patterns. Although most research has found that vegetarians report higher levels of cognitive restraint compared to non-vegetarians, many studies have contributed inconsistent results. The aim of the current study, therefore, was to assess any differences between groups with varying dietary patterns on cognitive restraint and other disordered eating pattern. The second objective was to examine determinants of cognitive restraint in individuals adhering to a vegan diet, a vegetarian diet and an omnivore diet. Two-hundred and fifty-four participants with varying dietary patterns completed the Three-Factor Eating Questionnaire, the Perseverative Thinking Questionnaire and the Eating Habits Questionnaire. Our results indicated that both vegetarian and vegan groups showed a significantly lower cognitive restraint, lower emotional eating and lower uncontrolled eating than those who followed an omnivorous diet. In addition, these both groups following a plant-based diet have shown more cognitions, behaviours and feelings related to an extreme focus on healthy eating (orthorexia nervosa) than group following an omnivorous diet. There were no significant differences between the groups in perseverative thinking. Core characteristics of repetitive negative thinking was a significant predictor of cognitive restraint in vegans. Feeling positively about healthy eating predicted cognitive restraint among vegetarians. Problems associated with healthy eating and feeling positively about healthy eating predicted cognitive restraint among individuals following an omnivorous diet. Knowledge of predictors of cognitive restraint may serve as a psychological intervention goal or psychoeducation goal among individuals with varying dietary patterns.

Long Non-coding RNA XIST May Influence Cervical Ossification of the Posterior Longitudinal Ligament Through Regulation of miR-17-5P/AHNAK/BMP2 Signaling Pathway

Long non-coding RNAs (lncRNAs) play an important role in the development of bone-related diseases. This study was conducted to investigate the role and mechanism of lncRNA X inactive specific transcript (XIST) in the occurrence of cervical ossification of the posterior longitudinal ligament (OPLL). Here, primary human ligament fibroblasts cells (LFCs) were isolated from 30 cases of OPLL and 30 normal cervical posterior longitudinal ligament (non-OPLL) tissues to perform the qPCR and Western blot assay. We found that the mRNA level of lncRNA XIST was significantly increased in OPLL LFCs compared to non-OPLL LFCs. By bioinformatics analysis, we found that lncRNA XIST has four binding sites for miR-17-5p and found that the mRNA level of miR-17-5p was also significantly decreased in OPLL LFCs compared to non-OPLL LFCs. Since AHNAK is the target gene of miR-17-5p, we further found that the expression of AHNAK was significantly reduced in non-OPLL LFCs after being transfected with miR-17-5p mimic. The qPCR results showed that the mRNA expressions of BMP2 and Runx2 were significantly decreased. After being transfected with lncRNA XIST siRNA in the non-OPLL LFCs, the mRNA levels of lncRNA XIST, AHNAK, BMP2, and Runx2 were significantly decreased and the phosphorylated protein of Smad1/5/8 was reduced. After being cultured by mechanical vibration, the mRNA levels of lncRNA XIST, AHNAK, BMP2, Runx2, COL1, OC, OPN, and Phospho1 were significantly increased, but the mRNA expression of miR-17-5p was significantly decreased. The expression of phosphorylated Smad1/5/8 protein was also significantly increased. Together, this study was the first to determine that XIST gene inhibition plays an important role in the occurrence of cervical OPLL, through the mechanism of regulation of miR-17-5P/AHNAK/BMP2 signaling pathway. Thus, XIST may be a potential target that could be modulated for the treatment of cervical OPLL.

The association between obesity, diet quality and hearing loss in older adults

BACKGROUND

With the aging population, the prevalence of age-related hearing loss will increase substantially. Prevention requires more knowledge on modifiable risk factors. Obesity and diet quality have been suggested to play a role in the etiology of age-related hearing loss. We aimed to investigate independent associations of body composition and diet quality with age-related hearing loss.

METHODS

We performed cross-sectional and longitudinal analyses (follow-up: 4.4 years) in the population-based Rotterdam Study. At baseline (2006-2014), 2,906 participants underwent assessment of body composition, diet, and hearing. Of these 2,906 participants, 636 had hearing assessment at follow-up (2014-2016). Association of body composition and of diet quality with hearing loss were examined using multivariable linear regression models.

RESULTS

Cross-sectionally, higher body mass index and fat mass index were associated with increased hearing thresholds. These associations did not remain statistically significant at follow-up. We found no associations between overall diet quality and hearing thresholds.

CONCLUSIONS

This study shows that a higher body mass index, and in particular a higher fat mass index, is related to age-related hearing loss. However, whether maintaining a healthy body composition may actually reduce the effects of age-related hearing loss in the aging population requires further longitudinal population-based research.

Computer-assisted virtual operation planning in anterior controllable anterior-displacement and fusion surgery for ossification of the posterior longitudinal ligament based on actual computed tomography data

OBJECTIVES

To investigate the effect of computer-assisted virtual operation planning (CAVOP) on anterior controllable anterior-displacement and fusion (ACAF) surgery for ossification of the posterior longitudinal ligament (OPLL).

PATIENTS AND METHODS

A total of 25 patients with OPLL were enrolled in the study from September 2017 to December 2017. Preoperative Computed tomography (CT) scanning data were input into Mimics software to reconstruct three-dimensional (3D) models of actual cervical OPLL.Preoperative simulation of each surgical procedure and measurement of main parameters for intraoperative decision were conducted. Postoperative CT were used to test the clinical value of the preoperative planning. Width of vertebrae-OPLL complex (VOC), thickness of resected vertebral body (VB), height of intervertebral spacer, and length of screws and anterior plate were analyzed.

RESULTS

There were no significant differences between the length of screws, width of VOC, and thickness of anterior resection of vertebrae in preoperative CT and postoperative CT. Statistical differences were found between preoperative and postoperative height of intervertebral space and length of anterior plate.

CONCLUSION

A virtual ACAF surgical procedure for OPLL is feasible and useful clinically in surgical planning. It may provide a valuable tool for surgeons in formulating an appropriate surgical plan.

Cross-Sectional and Longitudinal Association between Glycemic Status and Body Composition in Men: A Population-Based Study

This study sought to evaluate the associations between changes in glycemic status and changes in total body (TB), trunk, and appendicular fat (FM) and lean mass (LM) in men. A population-based study of men aged 20⁻66 years at baseline were included in cross-sectional (n = 430) and three-year longitudinal (n = 411) analyses. Prediabetes was defined as fasting glucose 100⁻125 mg/dL. Type 2 diabetes (T2D) was determined by: self-reported diabetes, current anti-diabetic drug use (insulin/oral hypoglycemic agents), fasting glucose (≥126 mg/dL), or non-fasting glucose (≥200 mg/dL). Body composition was evaluated by dual-energy X-ray absorptiometry. Longitudinal analyses showed that changes in TB FM and LM, and appendicular LM differed among glycemic groups. Normoglycemic men who converted to prediabetes lost more TB and appendicular LM than men who remained normoglycemic (all, p < 0.05). Normoglycemic or prediabetic men who developed T2D had a greater loss of TB and appendicular LM than men who remained normoglycemic (both, p < 0.05). T2D men had greater gains in TB FM and greater losses in TB and appendicular LM than men who remained normoglycemic (all, p < 0.05). Dysglycemia is associated with adverse changes in TB and appendicular LM.

The effects of recurrent physical abuse on the co-development of behavior problems and posttraumatic stress symptoms among child welfare-involved youth

The primary aim of the current study was to examine the longitudinal effects of ongoing physical abuse on the co-development of externalizing behavior problems and posttraumatic stress (PTS) symptoms among child welfare-involved adolescents. Using three waves of data from the National Survey of Child and Adolescent Well-Being, we performed unconditional and conditional parallel process latent growth curve modeling in a structural equation modeling framework. The study sample included 491 adolescents who were between 11 and 13 years of age at baseline. Higher levels of initial PTS symptoms were associated with higher levels of externalizing behavior problems, but the rate of change in PTS symptoms were not significantly associated with the rate of change in externalizing behavior problems over time. Although physical abuse was concurrently associated with both externalizing behavior problems and PTS symptoms at all assessment points, there were no lagged effects. Additionally, we found that physical abuse indirectly affects subsequent development of externalizing behavior problems and PTS symptoms through ongoing physical abuse. Findings highlight the comorbidity of externalizing behaviors and PTS symptoms among early adolescents in the child welfare system, underlining the importance of screening for and addressing these problems simultaneously. Findings also point to the need for continued assessment of and protection from ongoing physical abuse during adolescence.

Detection of genetic alterations in cfDNA as a possible strategy to monitor the neoplastic progression of Barrett's esophagus

Barrett's esophagus (BE) is associated with an increased risk of developing esophageal adenocarcinoma. Despite the low absolute risk of neoplastic progression of BE, probability increases with the diagnosis of dysplasia. For this reason, BE patients undergo an endoscopy-based surveillance that is, however, burdensome for patients, subject to inter-observer subjectivity, and expensive for national health systems. Thus, less invasive and low-cost diagnostic tools are needed. This study is aimed at finding a simple and reliable method to detect in the circulating cell-free DNA (cfDNA) of BE patients evidence of the molecular instability that accompanies BE carcinogenesis. We chose the loss of heterozygosity analysis because chromosomal region gains or losses have been described in BE and esophageal adenocarcinoma. Furthermore, this analysis does not require an a priori knowledge of tumor specific mutations and/or rearrangements. Previous data showed a good consistency between tissue and cfDNA alterations. Here, we report that, in the cfDNA of dysplastic BE patients, the frequency of genetic alterations is statistically higher than that of metaplastic BE patients (P = 0.005). Interestingly, after endoscopic treatment, the alteration frequency dropped, suggesting that cfDNA can also be used to monitor curative effects. Among the used markers, those that map nearby TP53 gene were the most discriminant between metaplastic and dysplastic BE. Furthermore, longitudinal follow-up cases showed that genetic alterations can be found in cfDNA before the appearance of a detectable lesion. Altogether, our data suggest that the use of liquid biopsy could become a minimally invasive diagnostic tool to implement BE patient monitoring.

Open-door Laminoplasty for Multilevel Cervical Spondylotic Myelopathy and Ossification of the Posterior Longitudinal Ligament (OPLL) using Titanium Reconstruction Miniplate and Screws

To review outcome of 25 patients who underwent open-door cervical laminoplasty for multilevel cervical spondylotic myelopathy (MCSM) and ossification of the posterior longitudinal ligament (OPLL) using titanium reconstruction miniplate and screws. Records of 18 men and 7 women aged 35 to 78 (mean, 62.6) years were reviewed retrospectively from October 2009 and October 2014 at Bangabandhu Sheikh Mujib Medical University (BSMMU) and in our private settings, Dhaka, Bangladesh. Four patients had 5 levels (C3-C7), 21 patients had 4 levels (C3-C6) decompression and 3 patients (12%) performed foraminotomies. A total of 104 laminae were opened, all of them were fixed with a titanium reconstruction miniplates. In 21 patients, a 20-hole titanium miniplate bent to the contour of a lamina was used and fixed into 4 laminae and 4 patients fixed in 5 laminae levels. In most patients, screw fixation was unicortical and no spacer or bone graft was used. Demographic and surgical data were collected and clinical outcomes were assessed with neck pain score, neck disability index and Nurick's grading. Outcome analysis was done using Odom's criteria. The mean follow-up duration was 1.8 (range, 1-5) years. Diagnoses were MCSM (n=20), OPLL (n=5). Mean estimated blood loss (EBL) was 120ml (range: 50-200), mean surgery time was 153 min (range: 75-240). Following Nurick's grading, 23 patients (92%) improved, 2 (08%) had the same Nurick grade. No intraoperative complications were noted and average hospital stay was 6.12 days (range: 5 to 9). Significance improvements in overall NDI scores occurred at 1 year follow up (p<0.002). Radiographic evaluation showed an increase in the mean sagittal diameter from 13.3mm at pretreatment to 19.4mm post surgery. Two patients developed transient C5 palsy. Open-door Laminoplasty technique is safe, easy and achieves a good canal expansion and neurological recovery and can be used as an alternative treatment for cases of MCSM and OPLL patients without instability.

Preserving Posterior Complex Can Prevent Adjacent Segment Disease following Posterior Lumbar Interbody Fusion Surgeries: A Finite Element Analysis

Objective

To investigate the biomechanical effects of the lumbar posterior complex on the adjacent segments after posterior lumbar interbody fusion (PLIF) surgeries.

Methods

A finite element model of the L1–S1 segment was modified to simulate PLIF with total laminectomy (PLIF-LAM) and PLIF with hemilaminectomy (PLIF-HEMI) procedures. The models were subjected to a 400N follower load with a 7.5-N.m moment of flexion, extension, torsion, and lateral bending. The range of motion (ROM), intradiscal pressure (IDP), and ligament force were compared.

Results

In Flexion, the ROM, IDP and ligament force of posterior longitudinal ligament, intertransverse ligament, and capsular ligament remarkably increased at the proximal adjacent segment in the PLIF-LAM model, and slightly increased in the PLIF-HEMI model. There was almost no difference for the ROM, IDP and ligament force at L5-S1 level between the two PLIF models although the ligament forces of ligamenta flava remarkably increased compared with the intact lumbar spine (INT) model. For the other loading conditions, these two models almost showed no difference in ROM, IDP and ligament force on the adjacent discs.

Conclusions

Preserved posterior complex acts as the posterior tension band during PLIF surgery and results in less ROM, IDP and ligament forces on the proximal adjacent segment in flexion. Preserving the posterior complex during decompression can be effective on preventing adjacent segment degeneration (ASD) following PLIF surgeries.

Ossified Posterior Longitudinal Ligament With Massive Ossification of the Anterior Longitudinal Ligament Causing Dysphagia in a Diffuse Idiopathic Skeletal Hyperostosis Patient

Descriptive case report.To report a case of a diffuse idiopathic skeletal hyperostosis (DISH) patient with both massive ossification of the anterior longitudinal ligament (OALL) leading to severe dysphagia as well as ossification of the posterior longitudinal ligament (OPLL) causing mild cervical myelopathy, warranting not only an anterior approach but also a posterior one.Although DISH can cause massive OALL in the cervical spine, severe dysphagia resulting from DISH is a rare occurrence. OALLs are frequently associated with OPLL. Treatment for a DISH patient with OPLL in setting of OALL-caused dysphagia is largely unknown.A 70-year-old man presented with severe dysphagia with mild cervical myelopathy. Neurological examination showed mild spastic paralysis and hyper reflex in his lower extremities. Plane radiographs and computed tomography of the cervical spine revealed a discontinuous massive OALL at C4-5 and continuous type OPLL at C2-6. Magnetic resonance imaging revealed pronounced spinal cord compression due to OPLL at C4-5. Esophagram demonstrated extrinsic compression secondary to OALL at C4-5.We performed posterior decompressive laminectomy with posterior lateral mass screw fixation, as well as both resection of OALL and interbody fusion at C4-5 by the anterior approach. We performed posterior decompressive laminectomy with posterior lateral mass screw fixation, as well as both resection of OALL and interbody fusion at C4-5 by the anterior approach. Severe dysphagia markedly improved without any complications.We considered that this patient not only required osteophytectomy and fusion by the anterior approach but also required decompression and spinal fusion by the posterior approach to prevent both deterioration of cervical myelopathy and recurrence of OALL after surgery.

A modified needle-inside-needle technique for the ganglion impar block

PURPOSE

The ganglion impar is the fused terminus of the paired sympathetic chain located at the level of the sacrococcygeal junction. It has been blocked using a bent and a curved spinal needle via the anococcygeal ligament. It has also been approached through the sacrococcygeal disc using a straight spinal needle. We describe a needle-inside-needle modification of the latter approach.Technical features: A 22-gauge (G), 1(1/2)-inch (38 mm) needle is introduced through the sacrococcygeal ligament under fluoroscopy via the sacrococcygeal disc. A 25-G, 2-inch (50 mm) needle is introduced through the 22-G needle. Placement is confirmed with injection of iopamidol 300, 0.2 mL in the retroperitoneal space with the comma sign.

CONCLUSIONS

The bent and curved needle techniques are associated with significant discomfort, tissue trauma and risk of rectal perforation due to difficulty in obtaining a midline needle tip position. The straight spinal needle approach minimizes these problems, however there is increased risk of discitis and a longer spinal needle may help also raise incidence of needle breakage. The needle-inside-needle technique may reduce these risks.

Should we brush twice a day? Determinants of dental health among young adults in Finland

We explore the determinants of dental ill-health as measured by the occurrence of caries. A recursive bivariate probit model that was derived from health production and demand theory is employed to model caries, while taking account of dental care use. The data are from a follow-up questionnaire used in a longitudinal study of the Northern Finland 1966 Birth Cohort, with respondents aged 31 (n = 5020). The factors controlled for relate to family background and health behavior during their youth, current socioecononomic variables and dental health stock. The total effects on the occurrence of caries of the explanatory variables are computed. Among females, factors increasing caries are body mass index and intake of alcohol, sugar and soft drinks, and those reducing caries are birth weight and adolescent school achievement. Among males, caries is positively related to the metropolitan residence and negatively related to education and healthy diet. Smoking increases caries, whereas dental care use, regular dental attendance and brushing teeth at least twice a day decrease caries. To promote oral health, attention should focus on policies to improve dental health education and to reduce the impacts of common risk factors.

Biomarker discovery by comprehensive phenotyping for autoimmune diseases

There is a well-recognized but unmet need for biological markers to characterize disease type, status, progression, and response to therapy in autoimmune diseases. We are developing and applying an integrated bioanalytical platform and clinical research program to facilitate comprehensive differential phenotyping of patient samples and enable the discovery of biomarkers. Our measurement platform includes microvolume laser scanning cytometry for the quantification of hundreds of cellular parameters in whole blood and other samples, liquid chromatography-mass spectrometry and gas chromatography-mass spectrometry for the quantification of proteins and low molecular weight biomolecules in serum and other fluids or tissues, and specific immunoassays for the quantification of trace proteins in serum. We describe the technologies and discuss initial applications to the analysis of subjects with rheumatoid arthritis (RA) and healthy controls.

Regional cerebral blood flow assessed with 99mTc-ECD SPET as a marker of progression of mild cognitive impairment to Alzheimer's disease

Patients diagnosed with mild cognitive impairment (MCI) have a higher risk of developing Alzheimer's disease (AD). However, not all such patients develop this kind of dementia. The purpose of this prospective study was to assess whether regional cerebral blood flow (rCBF) patterns measured with technetium-99m ethyl cysteinate dimer single-photon emission tomography ((99m)Tc-ECD SPET) in patients suffering from MCI are useful in predicting progression to AD. The study group comprised 42 patients who fulfilled MCI criteria according to the International Psychogeriatric Association and the Alzheimer's Disease Cooperative Study. rCBF was calculated in 16 regions of interest (ROIs). All patients were clinically assessed for 1-3 years. Twenty-one developed AD (group I) while the initial diagnosis of MCI was retained in the other 21 (group II). ROC curves were designed, and sensitivity, specificity, positive and negative predictive values, and positive and negative likelihood ratios were determined for each ROI. Compared with group II (MCI), group I (AD) showed a significant reduction of relative blood flow (RBF), ranging from 7% to 10%, in the following areas: right and left prefrontal, right and left frontal, right and left parietal, right and left temporal, right and left frontoparietotemporal and left posterior lateral temporal. Left prefrontal, left frontal and left parietal areas showed sensitivities and specificities higher than 75% and areas below the ROC curve close to 80%. This study shows that RBF patterns in the right and left prefrontal, right and left frontal and left parietal areas are sensitive early markers of progression towards AD. Reduction of rCBF in the medial temporal and anterior lateral temporal cortex has no value as a predictor since it also occurs in patients with MCI who remain stable.

Role of prostaglandin I2 in the gene expression induced by mechanical stress in spinal ligament cells derived from patients with ossification of the posterior longitudinal ligament

Ossification of the posterior longitudinal ligament of the spine (OPLL) is characterized by ectopic bone formation in the spinal ligaments, and mechanical stress has been suggested to play an important role in the progression of OPLL. To identify the genes that participate in OPLL, the differential display reverse transcription-polymerase chain reaction (RT-PCR) method was used. A 283-base pair cDNA fragment corresponding to prostaglandin I2 (PGI2) synthase was highly expressed in OPLL cells compared with non-OPLL cells. To examine the effect of mechanical stress on the expression of PGI2 synthase, cells were subjected to uniaxial cyclic stretch (0.5 Hz, 20% stretch), and PGI2 synthase mRNA expression was assessed by quantitative RT-PCR. Cyclic stretch induced an increase in PGI2 synthase in OPLL cells in a time-dependent manner, whereas no change was observed in non-OPLL cells. Cyclic stretch for 9 h also induced a 2.86x increase in PGI2 production. Beraprost (a stable PGI2 analog) and dibutyryl cAMP (a membrane-permeable cAMP analog) increased the mRNA expression of alkaline phosphatase (ALP) as a marker for osteogenic differentiation up to 240 and 200%, respectively, in OPLL cells, whereas no change was observed in non-OPLL cells. The increases in ALP mRNA induced by beraprost and cyclic stretch were both inhibited by SQ22536, a potent adenylate cyclase inhibitor. These data suggest that the increase in PGI2 synthase induced by mechanical stress plays a key role in the progression of OPLL, at least in part through the induction of osteogenic differentiation in spinal ligament cells via the PGI2/cAMP system.

[Clinical and radiological study of ossification of the anterior longitudinal ligament in the cervical spine]

Twenty-seven patients with ossification of the anterior longitudinal ligament (OALL) in diffuse idiopathic skeletal hyperostosis (DISH) in the cervical region were diagnosed among 2000 individuals during 10 months and analyzed clinically and radiologically by two neurosurgeons. Sex distribution was 20 men and 7 women with ages ranging from 57 to 82 years (average: 72.3 y.o.). Main signs and symptoms were dysesthesia of the upper extremities, stiff neck, dizziness and dysphagia (33%). Three patients had diabetes mellitus, 14 had hypertension, and 15 had hyperuremia. Ossification of the posterior longitudinal ligament (OPLL) co-existed in 18 patients (66%). Number of vertebral bodies with cervical OALL ranged from 4 to 6 (average: 4.8) and thickness of ossification of the anterior longitudinal ligament was from 2 to 6 (average: 3.1) mm. Originally we divided OALL in the cervical region into 3 types, nodular-type; 16 cases, continuous-type; 7 cases, and mixed-type; 4 cases. Small OPLL can be diagnosed by either cervical CT or myelo-CT. DISH is thought to be a benign clinical entity, but patients with OALL in DISH, accompanied by OPLL and those accompanied by dysphasia are frequently encountered and sometimes may be treated surgically.

[Imaging findings in 122 cases of Pott's disease]

Spinal tuberculosis is a frequent skeletal involvement in tuberculosis. We report 122 cases between 1983 and 1998 of Pott's disease explored by plain radiographies in all cases, CT-scan in 22 cases and MRI in 6 cases. The lesion involved one localization in 98 cases, two localizations in 9 cases and multiple localizations in 15 cases. The usual form associating the discal and vertebral involvement was noted in 70%. Unusual forms were seen in 30% of the cases The localizations were: posterior arch (20 cases), centrosomatic (10 cases), suboccipital (4 cases) and subligamentar (2 cases). In addition, the CT scan noted vertebral lesion with soft tissue abscess in all cases and epidural lesion in 9 cases. MRI performed in 6 cases showed epidural lesions in 4 cases: epiduritis (2 cases) and abscess (2 cases). The disco-vertebral puncture-biopsy, performed in 12 cases, confirmed the diagnosis in 7 cases. The diagnosis of Pott's disease was confirmed biologically in 30 cases. Radiographic exploration of Pott's disease is improved by the contributions of CT and MRI which can identify sequestra, perilesional sclerosis and epidural or soft tissue abscesses. Discovertebral aspiration biopsy provides the key to diagnosis.

[Obstructive sleep apnea syndrome induced by ossification of the anterior longitudinal ligament with ankylosing spondylitis]

A 66-year-old man who had received a diagnosis of ankylosing spondylitis at the age of 50 was referred to our hospital for further evaluation of sleep apnea experienced for the last 3 years. Polysomnography yielded a diagnosis of obstructive sleep apnea syndrome with an apnea index of 41/hr. Computed tomographic scans demonstrated complete closure of the oropharynx during sleep at a site of marked ossification and hypertrophy of the cervical anterior longitudinal ligament. Nasal continuous positive airway pressure (nasal CPAP) with the use of chinstrap, but not nasal CPAP alone, dramatically decreased the patient's apnea index to 2.4/hr. We reported this case because, to the best of our knowledge, it is the first to demonstrate a causative association between ankylosing spondylitis and obstructive sleep apnea syndrome.

Relationship between morphology of iliolumbar ligament and lower lumbar disc degeneration

Previous imaging studies have shown little difference in the degree of disc degeneration between L4-L5 and L5-S1. We hypothesized that because the morphology of the iliolumbar ligament affects the stability of the lumbosacral junction, then it could determine the lower lumbar disc degeneration. Fifty-three male and 47 female patients were classified into three groups according to their disc degeneration grade-those in whom the L5-S1 disc was less degenerated (group A), more degenerated (group B), and equally degenerated (group C) compared to the L4-L5 disc on T2-weighted magnetic resonance images. The length and direction of the anterior and posterior iliolumbar ligaments were measured on T1-weighted axial images. The iliolumbar ligament was shorter in group A than in group B or C, and was oriented significantly more posteriorly in group A than in groups B or C. The morphology of the iliolumbar ligament, especially its length and direction, can be a factor influencing the development of disc degeneration at L4-L5 and L5-S1.

Bone mineral density in patients with ossification of the posterior longitudinal ligament in the cervical spine

Bone mineral density (BMD) has not been clearly determined in patients with ossification of the posterior longitudinal ligament (OPLL) in the cervical spine. BMD in patients with OPLL was measured in the third vertebral body in the lateral projection and in the distal part of the radius in the anteroposterior projection using dual-energy X-ray absorptiometry (DXA). Patients with OPLL had significantly higher BMD than healthy controls in both the lumbar spine and radius. Observing BMD by gender and age group, high BMD was recognized especially in female patients over 60 years of age. Significantly increased BMD was observed in patients with ankylosing spinal hyperostosis (ASH) in addition to OPLL. These findings suggest that patients with OPLL may tend to develop systemic hyperostosis, leading to the pathological ectopic ossification observed in OPLL.