Ossification of the posterior longitudinal ligament is linked to heterotopic ossification of the ankle/foot tendons.

INTRODUCTION: Systemic osteogenesis has been speculated to be involved in the pathogenesis of ossification of the posterior longitudinal ligament (OPLL). Our purpose was to compare the radiologic prevalence and severity of heterotopic ossification in foot tendons of Japanese patients with OPLL and to determine their association with systemic heterotopic ossification. MATERIALS AND METHODS: Clinical and radiographic data of 114 patients with OPLL were collected from 2020 to 2022. Control data were extracted from a medical database of 362 patients with ankle radiographs. Achilles and plantar tendon ossification were classified as grades 0-4, and the presence of osteophytes at five sites in the foot/ankle joint was assessed by radiography. Factors associated with the presence and severity of each ossification were evaluated by multivariable logistic regression and linear regression analysis. RESULTS: The prevalence of Achilles and plantar tendon ossification (grade ≥ 2) was 4.0-5.5 times higher in patients with OPLL (40-56%) than in the controls (10-11%). The presence of Achilles tendon ossification was associated with OPLL, age, and coexisting plantar tendon ossification, and was most strongly associated with OPLL (standardized regression coefficient, 0.79; 95% confidence interval, 1.34-2.38). The severity of Achilles and plantar tendon ossification was associated with the severity of ossification of the entire spinal ligament. CONCLUSIONS: The strong association of foot tendon ossification with OPLL suggests that patients with OPLL have a systemic osteogenesis background. These findings will provide a basis for exploring new treatment strategies for OPLL, including control of metabolic abnormalities.

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.

Perioperative complications and cost of posterior decompression with fusion in thoracic spine for ossification of the posterior longitudinal ligament and ossification of the ligamentum flavum -a comparative study using a national inpatient database.

BACKGROUND: Although posterior decompression with fusion (PDF) are effective for treating thoracic myelopathy, surgical treatment has a high risk of various complications. There is currently no information available on the perioperative complications in thoracic ossification of the longitudinal ligament (T-OPLL) and thoracic ossification of the ligamentum flavum (T-OLF). We evaluate the perioperative complication rate and cost between T-OPLL and T-OLF for patients underwent PDF. METHODS: Patients undergoing PDF for T-OPLL and T-OLF from 2012 to 2018 were detected in Japanese nationwide inpatient database. One-to-one propensity score matching between T-OPLL and T-OLF was performed based on patient characteristics and preoperative comorbidities. We examined systemic and local complication rate, reoperation rate, length of hospital stays, costs, discharge destination, and mortality after matching. RESULTS: In a total of 2,660 patients, 828 pairs of T-OPLL and T-OLF patients were included after matching. The incidence of systemic complications did not differ significantly between the T-OPLL and OLF groups. However, local complications were more frequently occurred in T-OPLL than in T-OLF groups (11.4% vs. 7.7% P = 0.012). Transfusion rates was also significantly higher in the T-OPLL group (14.1% vs. 9.4%, P = 0.003). T-OPLL group had longer hospital stay (42.2 days vs. 36.2 days, P = 0.004) and higher medical costs (USD 32,805 vs. USD 25,134, P < 0.001). In both T-OPLL and T-OLF, the occurrence of perioperative complications led to longer hospital stay and higher medical costs. While fewer patients in T-OPLL were discharged home (51.6% vs. 65.1%, P < 0.001), patients were transferred to other hospitals more frequently (47.5% vs. 33.5%, P = 0.001). CONCLUSION: This research identified the perioperative complications of T-OPLL and T-OLF in PDF using a large national database, which revealed that the incidence of local complications was higher in the T-OPLL patients. Perioperative complications resulted in longer hospital stays and higher medical costs.

A patient and public involvement study to explore patient perspectives on the efficacy of treatments for pain and numbness derived from ossification of posterior longitudinal ligament of the spine.

BACKGROUND: Chronic pain and numbness are common complaints in patients with ossification of the posterior longitudinal ligament of the spine (OPLL). However, it is unclear whether the current treatments are effective in patients with OPLL in terms of improving pain and numbness. METHODS: A cross-sectional survey of patients with OPLL was conducted to determine patient satisfaction with surgery and drug therapy for pain and numbness, and its association with health-related quality of life. The survey was conducted by a patient association and its members, and anonymized data were analyzed by physicians. Comparisons between groups were made using T-tests or Kruskal-Wallis and Steel-Dwass tests, chi-square tests, and Fisher's exact tests. RESULTS: Data from 121 patients with OPLL (age 69 ± 11 years, 69 males; 43 females; and 7 unknown) who completed a mailed questionnaire were analyzed. Of the 93 patients with a history of surgery for OPLL, 24% and 18% reported much improvement in pain and numbness, respectively. After surgery, 42% and 48% reported some improvement, and 34% and 34% reported no improvement, respectively. Patients whose numbness did not improve with surgery had a significantly poorer health-related quality of life than those who did. Of the 78 patients who received medication, only 2% reported "much improvement," 64% reported "some improvement," and 31% reported "no improvement at all." Compared to patients with OPLL only in the cervical spine, those with diffuse-type OPLL showed poorer improvement in numbness after surgery and poorer quality of life. CONCLUSIONS: The majority of patients with OPLL belonging to the association were unsatisfied with surgery and pharmacotherapy in terms of pain and numbness improvement, indicating that there is an unmet medical need for more effective treatment for chronic pain and numbness in patients with OPLL.

Malignant character of an ossified posterior longitudinal ligament in a hyperflexion injury: A case report.

The present study reports the case of a 50-year-old obese male with ankylosing spondylitis, Scheuermann's kyphosis. The patient was asymptomatic concerning the ectopic ossification of the posterior longitudinal ligament (OPLL) at the cervical spine; he developed quadriparesis and respiratory insufficiency following minor head trauma. Even though trauma to the cervical spine in patients with OPLL is common, to the best of our knowledge, this is the first reported case of an extensive osteophyte with a lethal outcome after syncope. In rare occasions, it may be present with syncope and potentially lethal outcomes, particularly when precipitated by trauma. Therefore, the management of OPLL with significant canal stenosis should not be unnecessarily delayed.

Degenerative Thoracic Myelopathy: A Scoping Review of Epidemiology, Genetics, and Pathogenesis.

STUDY DESIGN: Literature Review. OBJECTIVE: Myelopathy affecting the thoracic spinal cord can arise secondary to several aetiologies which have similar presentation and management. Consequently, there are many uncertainties in this area, including optimal terminology and definitions. Recent collaborative cervical spinal research has led to the proposal and subsequent community adoption of the name degenerative cervical myelopathy(DCM), which has facilitated the establishment of internationally-agreed research priorities for DCM. We put forward the case for the introduction of the term degenerative thoracic myelopathy(DTM) and degenerative spinal myelopathy(DSM) as an umbrella term for both DCM and DTM. METHODS: Following PRISMA guidelines, a systematic literature search was performed to identify degenerative thoracic myelopathy literature in Embase and MEDLINE. RESULTS: Conditions encompassed within DTM include thoracic spondylotic myelopathy, ossification of the posterior longitudinal ligament, ossification of the ligamentum flavum, calcification of ligaments, hypertrophy of ligaments, degenerative disc disease, thoracic osteoarthritis, intervertebral disc herniation, and posterior osteophytosis. The classic presentation includes girdle pain, gait disturbance, leg weakness, sensory disturbance, and bladder or bowel dysfunction, often with associated back pain. Surgical management is typically favoured with post-surgical outcomes dependent on many factors, including the causative pathology, and presence of additional stenosis. CONCLUSION: The clinical entities encompassed by the term DTM are interrelated, can manifest concurrently, and present similarly. Building on the consensus adoption of DCM in the cervical spine and the recent proposal of degenerative cervical radiculopathy(DCR), extending this common nomenclature framework to the terms degenerative spinal myelopathy and degenerative thoracic myelopathy will help improve recognition and communication.

Two-level Anterior Cervical Corpectomy and Fusion versus Posterior Open-door Laminoplasty for the Treatment of Cervical Ossification of Posterior Longitudinal Ligament: A Comparison of the Clinical Impact on the Occipito-Atlantoaxial Complex.

OBJECTIVE: Both two-level anterior cervical corpectomy and fusion (t-ACCF) and posterior open-door laminoplasty (ODLP) are effective surgical procedures for the treatment of ossification of the posterior longitudinal ligament (OPLL). Previous studies have identified different effects of different surgical procedures on the upper and subaxial cervical spine (UCS, SCS), however, there are no studies on the effects of t-ACCF and ODLP on the occipito-atlantoaxial complex. Therefore, the purpose of this study is to compare the changes in sagittal parameters and range of motion (ROM) of the occipito-atlantoaxial complex in OPLL patients treated with t-ACCF and ODLP. METHODS: This was a retrospective study that included 74 patients who underwent t-ACCF or ODLP for the treatment of OPLL from January 2012 to August 2022 at our institution. Preoperative, 3-month, and 1-year postoperative cervical neutral, flexion-extension, and lateral flexion radiographs were taken. Sagittal parameters including Cobb angle of C2-7, C0-2, C0-1, C1-2, C2 slope, and the ROM were measured. The clinical outcome was assessed using the JOA, VAS, and NDI scores preoperatively and at 3 and 12 months postoperatively. Multiple linear regression was employed to identify factors influencing changes in UCS. RESULTS: In the ODLP group, the SCS (C2-7) Cobb angle was significantly reduced (12.85 ± 10.0 to 7.68 ± 11.27; p < 0.05), and the UCS (C0-2) Cobb angle was significantly compensated for at 1 year postoperatively compared with the t-ACCF group (3.05 ± 4.09 vs 0.79 ± 2.62; p < 0.01). The SCS and lateral flexion ROM of the ODLP group was better maintained than t-ACCF (14.51 ± 6.00 vs 10.72 ± 3.79; 6.87 ± 4.56 vs 3.81 ± 1.67; p < 0.01). The compensatory increase in C0-2, C0-1, and C1-2 ROM was pronounced in both groups, especially in the ODLP group. The results of multiple linear regression showed that only the surgical procedure was a significant factor influencing UCS. CONCLUSION: The loss of the SCS Cobb angle was more pronounced in ODLP relative to t-ACCF, resulting in a significant compensatory increase in UCS and atlantoaxial Cobb angle. The ROM of the UCS, atlantooccipital, and atlantoaxial joints was significantly increased in both groups, this may accelerate degenerative changes in the occipital-atlantoaxial complex, may leading to poorer outcomes in the long-term; of these, ODLP should receive more attention. In contrast, t-ACCF better maintains normal curvature of the SCS and occipito-atlantoaxial complex but loses more ROM.

Thick Skin on the Dorsal Spine in Osteoproliferative Disease: Ossification of the Posterior Longitudinal Ligament and Diffuse Idiopathic Skeletal Hyperostosis.

Background Although the correlation between reduced skin thickness and reduced bone density has been investigated, no study has evaluated skin thickness and osteoproliferative diseases, including ossification of the posterior longitudinal ligament (OPLL) and diffuse idiopathic skeletal hyperostosis (DISH). Methodology This retrospective cohort study consisted of 99 consecutive patients aged ≥60 years treated for spinal surgery at our hospital between January 2022 and March 2023. Skin thickness was measured at the dorsal side of the cervical, thoracic, and lumbar vertebrae on the sagittal cross-section image of whole-spine CT. Based on the median value, skin thickness was categorized into two groups based on a median thickness of 4 mm. Bone mineral density (BMD) was assessed. The sum of the vertebral body and intervertebral bridging osteophytes of the anterior longitudinal and posterior longitudinal ligament were defined as the OALL index and OPLL index. Serum levels of bone metabolism-related markers, such as tartrate-resistant acid phosphatase type 5b, procollagen I N-propeptide, 25-hydroxyvitamin D, and periostin, were measured. To assess the association between skin thickness and imaging findings, we calculated the adjusted odds ratios, adjusting for age, sex, and body mass index (BMI) and using univariate and multivariate logistic regression analyses. Results No significant differences were found in skin thickness in the three dorsal regions of the cervical, thoracic, and lumbar spine (median = 3.3 mm versus 3.5 mm versus 3.4 mm, p = 0.357) and bone metabolism-related markers. Adjusting for age, sex, and BMI, cervical, thoracic, and lumbar skin thicknesses were related to DISH, the OPLL index, and the OPLL and OPLL index, respectively. Conclusions Skin thickness did not correlate with BMD but with the amount of spinal ossification. A correlation was found between skin thickness and vertebral and intervertebral ossification; vertebral osteophytes, OPLL, and DISH may be more common in thicker skin.

MRI-based vertebral bone quality score in cervical ossification of the posterior longitudinal ligament: a comparison with cervical spondylotic myelopathy using propensity score matching.

BACKGROUND: Bone mineral density plays a key role in the assessment of operative instrumentation complications and clinical outcomes. The MRI-based vertebral bone quality (VBQ) score has been introduced as a novel marker of bone quality. However, few studies have investigated the relationship between VBQ score and patients associated with cervical ossification of the posterior longitudinal ligament (OPLL). PURPOSE: The aims of the study were (1) to reveal bone mineral density between cervical OPLL and cervical spondylotic myelopathy (CSM) group by VBQ score, (2) to compare the VBQ score of cervical OPLL between male and female group, (3) to explore the relationship between segmental VBQ scores associated with OPLL. STUDY DESIGN: Retrospective cohort study. PATIENT SAMPLE: Consecutive series of 425 patients at a single academic institution. OUTCOME MEASURES: MRI based measurements of C2-C7 VBQ scores. METHODS: Preoperative noncontrast T1-weighted MRIs of the cervical spine was used to measure the VBQ score. The VBQ score was defined as the mean value of the signal intensity of the vertebrae divided by that of the cerebrospinal fluid (CSF) space at the cisterna magna. Patients with cervical OPLL and CSM were matched based on age, sex, body mass index (BMI), comorbidity, medication history, diet habit, smoking, alcohol consumption via propensity score matching (PSM). Normality of each VBQ score was tested by the Shapiro-Wilk test. Wilcoxon's rank-sum test was used to compare matched cohorts. Kruskal-Wallis test was performed to compare the VBQ scores between segments. Multivariate logistic regression analysis was used to evaluate factors associated with the development of cervical OPLL. RESULTS: A total of 425 patients were assessed. For final analysis, 135 paired patients were compared between the cervical OPLL and CSM groups, and 22 paired patients were compared between male and female group associated with cervical OPLL. There were no statistically significant differences in age, sex, BMI, comorbidity, medication history, diet habit, smoking, alcohol between the matched cohorts. OPLL group was associated with lower VBQ score compared with CSM group at C3, while there were no differences in VBQ score for the other levels between the two groups. There were no differences between male and female group associated with OPLL in C2-C7 VBQ scores. VBQ scores of cervical OPLL are variable between segments, with significantly lower scores at C6, C7 compared with C1-C5. Multivariate logistic regression analysis showed that BMI was correlated with the development of OPLL (regression coefficient, 0.162; 95% confidence interval, 0.010-0.037). Additional risk factors included hypertension, calcium supple history and smoking. CONCLUSIONS: This study demonstrates that cervical OPLL is associated with lower VBQ score at C3, with no differences for the other levels when compared with CSM derived from measurements on MRI. No differences were found between male and female group associated with OPLL in C2-C7 VBQ scores. Cervical OPLL were found to have smaller VBQ score at C6, C7 compared with C1-C5. Our findings provide new insight for bone density assessment in cervical OPLL patient.

Posterior Thoracic Antidisplacement and Fusion Surgery for a Special Type of Ossification of the Posterior Longitudinal Ligament in the Thoracic Spine: Indications and Preliminary Clinical Results of 2-Year Follow-Up.

OBJECTIVE: To describe a novel technique, posterior thoracic antidisplacement and fusion (PTAF), for a special type of ossification of the posterior longitudinal ligament in the thoracic spine (T-OPLL), and to evaluate its safety and efficacy. METHODS: From July to December 2020, 5 consecutive patients with beak-type T-OPLL located at the thoracic vertebral body level underwent PTAF surgery. Their demographic data, radiological parameters, perioperative complications, and surgery-related findings were recorded and analyzed. The surgical outcomes were assessed using a modified Japanese Orthopedic Association scale, and the recovery rate was calculated using the Hirabayashi's method. RESULTS: All patients were followed up for at least two years. The mean thickness of OPLL was 9.4 ± 1.0 mm, and the OPLL spinal canal occupying ratio was 67.7% ± 8.5%. Postoperatively, the mean antidisplacement distance of OPLL was 8.1 ± 1.8 mm, and the average shortened distance of the spinal column was 6.0 ± 1.13 mm. The mean operation time and blood loss were 158.2 ± 26.3 minutes and 460 ± 89.4 mL, respectively. Perioperative complications were cerebrospinal fluid leakage and instrument failure, 2 cases each. The mean modified Japanese Orthopedic Association score was increased from 3.6 ± 2.9 before surgery to 9.4 ± 3.0 at the last follow-up, and the average recovery rate was 84.2 ± 30.5%. CONCLUSIONS: The preliminary clinical outcomes indicate that PTAF is a safe and effective method for the treatment of beak-type T-OPLL, which has its apex located at the vertebral body level and has a high spinal canal occupation ratio.

Three-dimensional morphological changes in ossification of the posterior longitudinal ligament of the thoracic spine following posterior decompression and fusion surgery.

BACKGROUND: Using three-dimensional image analysis, we previously reported suppression of ossification progression following posterior fusion surgery for cervical ossification of the posterior longitudinal ligament (OPLL). Here, we aimed to evaluate the morphological changes in thoracic OPLL using three-dimensional analysis. METHODS: Seventeen patients (eight males and nine females; mean age, 56.9 years) who underwent posterior decompression and fusion (PDF) for thoracic OPLL were included. We evaluated the OPLL volume using a novel analysis involving creating a three-dimensional model from computed tomography images to measure the volume accurately. Additionally, OPLL thickness, width, and length were measured on sagittal and axial computed tomography planes. We investigated the morphological changes in OPLL after PDF. Furthermore, patients were classified into reduced volume and increased volume groups and associated factors were compared. RESULTS: The mean OPLL volume was 1,677 mm3 preoperatively and 1,705 mm3 at the final examination and did not significantly differ. Volume reduction was observed in 7 of 17 cases (41 %). Although OPLL width and length significantly increased postoperatively, OPLL thickness significantly reduced from 7.1 mm preoperatively to 6.5 mm postoperatively (all, p < 0.05). The annual thickness changes significantly differed (p <0.05) in the reduced volume group (-0.36 mm/year) compared to that in the increased volume group (-0.06 mm/year). CONCLUSIONS: Thoracic OPLL after PDF becomes thinner in the anteroposterior direction but increases horizontally and craniocaudally. The reduction in OPLL thickness was related to a reduction in ossification volume. We believe that volume reduction in thoracic OPLL is influenced by pulsation of the dural sac.

Biomechanical Comparison of Anterior Cervical Corpectomy Decompression and Fusion, Anterior Cervical Discectomy and Fusion, and Anterior Controllable Antedisplacement and Fusion in the Surgical Treatment of Multilevel Cervical Spondylotic Myelopathy: A Finite Element Analysis.

PURPOSE: Multilevel cervical spondylotic myelopathy poses significant challenges in selecting optimal surgical approaches, warranting a comprehensive understanding of their biomechanical impacts. Given the lack of consensus regarding the most effective technique, this study aims to fill this critical knowledge gap by rigorously assessing and comparing the biomechanical properties of three distinct surgical interventions, including anterior controllable antedisplacement and fusion (ACAF), anterior cervical corpectomy decompression and fusion (ACCF), and anterior cervical discectomy and fusion (ACDF). The study offers pivotal insights to enhance treatment precision and patient outcomes. METHODS: The construction of the cervical spine model involved a detailed process using CT data, specialized software (Mimics, Geomagic Studio, and Hypermesh) and material properties obtained from prior studies. Surgical instruments were modeled (titanium mesh, anterior cervical plate, interbody cage, and self-tapping screws) to simulate three surgical approaches: ACAF, ACCF, and ACDF, each with specific procedures replicating clinical protocols. A 75-N follower load with 2 Nm was applied to simulate biomechanical effects. RESULTS: The range of motion decreased more after surgery for ACAF and ACDF than for ACCF, especially in flexion and lateral bending. ACCF have higher stress peaks in the fixation system than those of ACAF and ACDF, especially in flexion. The maximum von Mises stresses of the bone-screw interfaces at C3 of ACCF were higher than those of ACAF and ACDF. The maximum von Mises stresses of the bone-screw interfaces at C6 of ACDF were much higher than those of ACAF and ACCF. The maximum von Mises stresses of the grafts of ACCF and ACAF were much higher than those of ACDF. The maximum von Mises stresses of the endplate of ACCF were much higher than those of ACAF and ACDF. CONCLUSION: The ACAF and ACDF models demonstrated superior cervical reconstruction stability over the ACCF model. ACAF exhibited lower risks of internal fixation failure and cage subsidence compared to ACCF, making it a promising approach. However, while ACAF revealed improved stability over ACCF, higher rates of subsidence and internal fixation failure persisted compared to ACDF, suggesting the need for further exploration of ACAF's long-term efficacy and potential improvements in clinical outcomes.

Spinal Deformity Manifested by Urinary Tract Infection: A Case of Acute-on-Chronic Mobility Dysfunction.

A 53-year-old man with diabetes mellitus presented to the emergency department with a fever and impaired mobility. A preliminary diagnosis of urinary tract infection was made based on dysuria and pyuria. History-taking revealed a history of gait disturbance and difficult urination. A thorough physical examination suggested a spinal abnormality. MRI scan revealed a narrow spinal canal due to ossification of the posterior longitudinal ligament and diffuse idiopathic skeletal hyperostosis. Throughout the diagnostic process, we employed both vertical tracing to investigate the causes of urinary tract infection and horizontal tracing to explore comorbidities such as diabetes. Additionally, we introduced appropriate social security and support systems under the name of diagnostic excellence.

CTSD upregulation as a key driver of spinal ligament abnormalities in spinal stenosis.

Spinal stenosis (SS) is frequently caused by spinal ligament abnormalities, such as ossification and hypertrophy, which narrow the spinal canal and compress the spinal cord or nerve roots, leading to myelopathy or sciatic symptoms; however, the underlying pathological mechanism is poorly understood, hampering the development of effective nonsurgical treatments. Our study aims to investigate the role of co-expression hub genes in patients with spinal ligament ossification and hypertrophy. To achieve this, we conducted an integrated analysis by combining RNA-seq data of ossification of the posterior longitudinal ligament (OPLL) and microarray profiles of hypertrophy of the ligamentum flavum (HLF), consistently pinpointing CTSD as an upregulated hub gene in both OPLL and HLF. Subsequent RT-qPCR and IHC assessments confirmed the heightened expression of CTSD in human OPLL, ossification of the ligamentum flavum (OLF), and HLF samples. We observed an increase in CTSD expression in human PLL and LF primary cells during osteogenic differentiation, as indicated by western blotting (WB). To assess CTSD's impact on osteogenic differentiation, we manipulated its expression levels in human PLL and LF primary cells using siRNAs and lentivirus, as demonstrated by WB, ALP staining, and ARS. Our findings showed that suppressing CTSD hindered the osteogenic differentiation potential of PLL and LF cells, while overexpressing CTSD activated osteogenic differentiation. These findings identify CTSD as a potential therapeutic target for treating spinal stenosis associated with spinal ligament abnormalities.

A novel computed tomography scoring system for evaluating the risk of dural defects in anterior surgery for cervical ossification of the posterior longitudinal ligament.

OBJECTIVE: To develop and validate a computed tomography (CT)-based scoring system for evaluating the risk of dural defects (DDs) in anterior surgery for cervical ossification of the posterior longitudinal ligament (OPLL). METHODS: We retrospectively analyzed CT imaging features of 114 OPLL patients in our institute who received anterior decompression surgery. Intraoperative DDs were found in 16 patients. A multivariable logistic regression was used to evaluate the predictors. According to the odd ratio of the included risk factors, we developed a CT scoring system for evaluating the risk of DDs in anterior OPLL surgery. The system was further validated in an independent group of 39 OPLL patients. RESULTS: We developed a CT scoring system as follows: hook sign (2 points), K-line (-) (1 point) and broad base (1 point). Thus, the system comprised 4 total points, and patients were at high risks of dural defects when the score ≥3 points. The operating characteristics of a score ≥3 for predicting DDs in the validation group were: sensitivity of 0.83, specificity of 0.94, LR positive of 13.75, LR negative of 0.18 and AUC of 0.886. The discriminatory ability of the proposed score could be demonstrated in the validation cohort. CONCLUSIONS: The relatively simple and easy-to-use scoring system we propose integrates the 3 most reliable spinal CT findings observed in patients with OPLL and a DD. The likelihood to identify the underlying risks of spinal CSF leaks may be useful to triage patients who may benefit from indirect decompression techniques.

Respiratory dysfunction in degenerative cervical myelopathy: A systematic review.

INTRODUCTION: Degenerative cervical myelopathy is a condition of symptomatic cervical spinal cord compression secondary to a range of degenerative spinal pathology. Respiratory symptoms such as shortness of breath are not uncommonly reported by people with DCM and respiratory dysfunction has been described in several DCM studies. The objective of this review was therefore to systematically synthesise the current evidence on the relationship between DCM and respiratory function. METHODS: The review was registered on PROSPERO and adhered to PRISMA guidelines. Ovid MEDLINE and Embase were searched from inception to 14th March 2023. DCM studies reporting on any measure or outcome relating to respiratory function or disease were eligible. Reference lists of included studies and relevant reviews articles were hand searched. Title, abstract and full text screening, risk of bias and GRADE assessments were completed in duplicate. A quantitative synthesis is presented. RESULTS: Of 1991 studies identified by literature searching, 13 met inclusion criteria: 3 cohort studies, 5 case-control studies, 1 case series and 4 case studies. Forced vital capacity (FVC), peak expiratory flow rate (PEFR) and maximal voluntary ventilation (MVV) were reported to be lower in DCM patients than controls; there was inconsistency in comparisons of forced expiratory volume in 1 s (FEV1). There was conflicting evidence on whether surgical decompression was associated with improvements in respiratory parameters and on the relationship between level of spinal cord compression and respiratory dysfunction. CONCLUSION: DCM may be associated with respiratory dysfunction. However, consistency and quality of evidence is currently low. Further work should characterise respiratory dysfunction in DCM patients more rigorously and investigate putative mechanisms such as disruption to cervical nerve roots responsible for diaphragmatic innervation and damage to descending spinal projections from brainstem respiratory centres.

MRI-based lesion quality score assessing ossification of the posterior longitudinal ligament of the cervical spine.

BACKGROUND CONTEXT: No method currently exists for MRI-based determination of ossification of the posterior longitudinal ligament (OPLL) of the cervical spine using objective criteria. PURPOSE: The purpose of this study was to develop an MRI-based score to determine whether a lesion represents a cervical OPLL lesion and to establish the objective diagnostic value. STUDY DESIGN: Retrospective cohort in a single medical institution. PATIENT SAMPLE: Thirty-five patients undergoing surgery for OPLL (Group A) and 99 patients undergoing cervical disc arthroplasty for soft disc herniation (Group B) between 2011 and 2020 were retrospectively included. All OPLL lesions on unenhanced MRI scan were correlated with a corresponding CT scan. Demographics were comparable between the two groups. OUTCOME MEASURES (PHYSIOLOGIC MEASURES): Using unenhanced magnetic resonance imaging (MRI), the T1- and T2- lesion quality (LQ) scores were calculated. Receiver operating characteristic (ROC) analysis was performed to calculate the area-under-the-curve (AUC) of both LQ scores as a predictor of the presence of OPLL. Computed tomography (CT)-based Hounsfield unit (HU) values of OPLL lesions were obtained and compared with both LQ scores. The LQ scores for MRI scanners from different manufacturers were compared using Student's t test to confirm the validity of the LQ score by scanner type. METHODS: The regions of interest for signal intensity (SI) were defined as the darkest site of the lesion and the cerebrospinal fluid (CSF) at the cerebellomedullary cistern. The T1 and T2 LQ scores were measured as the ratio of the SI at the darkest site of the lesion divided by the SI of the CSF. RESULTS: The T1 and T2 LQ scores in Group A were significantly lower than those in Group B (p<.001). ROC analysis determined that T1 and T2 LQ scores of 0.46 and 0.07, respectively, could distinguish the presence of OPLL with an accuracy of 0.93 and 0.89, respectively (p<.001). When the T1 LQ score of the lesion is <0.46, a diagnosis of OPLL may be suspected with 100% sensitivity and 92.3% specificity. The HU of the lesion had a moderate negative correlation with the T1 LQ score (r=-0.665, p<.0001). Both LQ scores were unaffected by manufacturer type. CONCLUSIONS: This study found a correlation between the MRI-based T1 LQ scores and CT-based HU value for identifying OPLL lesions. Additional studies will be needed to validate that the T1 LQ score from the unenhanced MRI scan can identify cervical OPLL.

Patient-Reported Outcomes and Patient Satisfaction Following Surgery for Thoracic Myelopathy.

Introduction: The association between postoperative patient-reported outcomes (PROs) and patient satisfaction remains poorly defined in patients undergoing surgery for thoracic myelopathy. This study aimed to investigate PROs and patient satisfaction following surgical intervention for thoracic myelopathy. Methods: A prospective cohort of 133 patients who underwent surgery for thoracic myelopathy at 13 hospitals between April 2017 and August 2021 was enrolled. Patient demographics and perioperative complications were recorded. PROs were assessed using questionnaires administered preoperatively and 1 year postoperatively, including the EuroQol-5 dimension, physical and mental component summaries of the 12-item Short-Form Health Survey, Oswestry Disability Index, and numerical rating scales for low back, lower extremity, and plantar pain. Patients were categorized into two groups: satisfied (very satisfied, satisfied, and slightly satisfied) and dissatisfied (neither satisfied nor dissatisfied, slightly dissatisfied, dissatisfied, and very dissatisfied). Results: The mean age of the patients was 66.5 years, comprising 87 men and 46 women. The most common diagnoses were ossification of the ligamentum flavum (48.8%) and thoracic spondylotic myelopathy (26.3%). Seventy-four (55.6%) and 59 (44.3%) patients underwent decompression surgery and underwent decompression with fusion, respectively. Eight patients required reoperation due to postoperative surgical site infection, hematoma, and insufficient decompression in four, three, and one patient. Ninety (67.7%) patients completed both the preoperative and postoperative PRO questionnaires, all of which demonstrated significant improvement. Among them, 58 (64.4%) and 32 (35.6%) reported satisfaction and dissatisfaction with their treatment, respectively. The satisfied group showed superior improvement in PROs than the dissatisfied group, although there were no significant differences in complication rates between the two groups. Conclusions: The 64.4% satisfaction rate observed in patients undergoing surgery for thoracic myelopathy was lower than that reported in previous studies on cervical or lumbar spine surgery. The dissatisfied group exhibited significantly poorer quality of life (QOL) and higher pain scores than the satisfied group.

Comparison of Surgical Outcomes After Posterior Decompression by Junior or Senior Surgeons for Patients With Cervical Ossification of the Posterior Longitudinal Ligament: Results From Retrospective Multicenter Cohort Study.

STUDY DESIGN: Retrospective multicenter study. OBJECTIVES: To investigate surgical outcomes following posterior decompression for cervical ossification of the posterior longitudinal ligament (OPLL) when performed by board-certified spine (BCS) or non-BCS (NBCS) surgeons. METHODS: We included 203 patients with cervical OPLL who were followed for a minimum of 1 year after surgery. Demographic information, medical history, and imaging findings were collected. Clinical outcomes were assessed preoperatively and at the final follow-up using the Japanese Orthopedic Association (JOA) score and the visual analog scale (VAS) for the neck. We compared outcomes between BCS surgeons, who must meet several requirements, including experience in more than 300 spinal surgeries, and NBCS surgeons. RESULTS: BCS surgeons performed 124 out of 203 cases, while NBCS surgeons were primary in 79 cases, with 73.4% were directly supervised by a BCS surgeon. There was no statistically significant difference in surgical duration, estimated blood loss, and perioperative complication rates between the BCS and NBCS groups. Moreover, no statistically significant group differences were observed in each position of the C2-7 angle and cervical range of motion at preoperation and the final follow-up. Preoperative and final follow-up JOA scores, VAS for the neck, and JOA score recovery rate were comparable between the two groups. CONCLUSIONS: Surgical outcomes, including functional recovery, complication rates, and cervical dynamics, were comparable between the BCS and NBCS groups. Consequently, posterior decompression for cervical OPLL is considered safe and effective when conducted by junior surgeons who have undergone training and supervision by experienced spine surgeons.

Surgical Decompression of Thoracic Ossification of the Posterior Longitudinal Ligament through Posterior Approach: A Case Report.

Thoracic ossification of the posterior longitudinal ligament (OPLL) is a rare condition that is mainly accompanied by cervical OPLL or ossification of thoracic ligamentum flavum. In case of causing neurological manifestations, it is preferred to treat the condition surgically. Several surgical procedures were introduced, including anterior, posterior, or combined approaches. Laminectomy with instrumented fusion is the most popular procedure utilized via the posterior approach. A 32-year-old obese woman, who suffered from back pain and weakness in both lower extremities for one month, was referred to our spine outpatient clinic. Imaging revealed lower thoracic OPLL (T7/T8 & T8/T9 & T9/T10). The posterior longitudinal ligament had a mixed ossification pattern (beaked and continuing cylindrical). To maintain thoracic spine stability and prevent future kyphosis, we performed laminectomy and long segment fixation (T7 to T12). The post-operative neurological examination revealed a considerable increase in muscle strength and significant pain relief.