Aortic pulsation prevents the development of ossification of anterior longitudinal ligament toward the aorta in patients with diffuse idiopathic skeletal hyperostosis (DISH) in Japanese: Results of chest CT-based cross-sectional study

Background

The development and etiology of diffuse idiopathic skeletal hyperostosis (DISH) were far from complete understanding. Even the precise mechanism of the development of its typical right-sided ossification of the anterior longitudinal ligament (OALL) frequently compared to ‘flowing candle wax’, a hallmark of DISH, remains unknown.

Metabolite profiling of plasma in patients with ossification of the posterior longitudinal ligament

Background

Metabolomics is one of the “omics” technologies, and is a comprehensive analysis of small molecule metabolites which include amino acid, nucleotides, carbohydrates and fatty acid. The purpose of the present study was to compare the differences of metabolite profiling between patients with ossification of the posterior longitudinal ligament (OPLL) and control subjects.

Wnt signaling pathway correlates with ossification of the spinal ligament: A microRNA array and immunohistochemical study

Background

Ossification of the posterior longitudinal ligament or the ligamentum flavum parallels endochondral ossification. Cell differentiation at the ossification front is known to be important during this process, although the factors regulating its initiation and progression are still unclear. The purpose of this study was to identify factors important for the regulation of chondrocyte/osteoblast differentiation during spinal ossification.

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.     

Lumbar spinal canal stenosis leads to locomotive syndrome in elderly patients

Background

Locomotive syndrome is a condition in which the ability to lead a normal life is restricted owing to a dysfunction in one or more of the parts of the musculoskeletal system. Although lumbar spinal canal stenosis (LSS) is considered to cause locomotive syndrome, a detailed assessment of the association between two pathologies has not yet been reported.

Symptomatic ossification of the anterior longitudinal ligament with stenosis of the cervical spine: a report of seven cases

Seven men with a mean age of 63.9 years (59 to 67) developed dysphagia because of oesophageal compression with ossification of the anterior longitudinal ligament (OALL) and radiculomyelopathy due to associated stenosis of the cervical spine. The diagnosis of OALL was made by plain lateral radiography and classified into three types; segmental, continuous and mixed. Five patients had associated OALL in the thoracic and lumbar spine without ossification of the ligamentum flavum. All underwent removal of the OALL and six had simultaneous decompression by removal of ossification of the posterior longitudinal ligament or a bony spur. All had improvement of their dysphagia. Because symptomatic OALL may be associated with spinal stenosis, precise neurological examination is critical. A simultaneous microsurgical operation for patients with OALL and spinal stenosis gives good results without serious complications.     

Ossification of the spinal ligament. A radiographic reevaluation in Bologna, Italy

A radiographic reevaluation of cervical spine films of 1,258 adult patients and of thoraco-lumbar spine films of 488 of these was performed at the Rizzoli Orthopaedic Institute (Bologne, Italy), in order to detect ossification of the posterior longitudinal ligament (OPLL), the anterior longitudinal ligament (OALL), the yellow ligament (OYL) and the nuchal ligament at the cervical level, and OPLL, OALL and OYL at the thoraco-lumbar level. The incidence of OALL, OYL and ossification of the nuchal ligament corresponded with those previously reported in the literature. Cervical OPLL was found in 1.83%, with a definite prevalence in the 45-64 age group where the figure was 2.83%. This incidence is much higher than that hitherto reported in Caucasians, and is nearly the same as that in Japan. Possible explanations for this discrepancy are proposed.     

Cervical ossification of the posterior longitudinal ligament: Biomechanical analysis of the influence of static and dynamic factors

Objective

Cervical myelopathy due to ossification of the posterior longitudinal ligament (OPLL) is induced by static factors, dynamic factors, or a combination of both. We used a three-dimensional finite element method (3D-FEM) to analyze the stress distributions in the cervical spinal cord under static compression, dynamic compression, or a combination of both in the context of OPLL.

Methods

Experimental conditions were established for the 3D-FEM spinal cord, lamina, and hill-shaped OPLL. To simulate static compression of the spinal cord, anterior compression at 10, 20, and 30% of the anterior–posterior diameter of the spinal cord was applied by the OPLL. To simulate dynamic compression, the OPLL was rotated 5°, 10°, and 15° in the flexion direction. To simulate combined static and dynamic compression under 10 and 20% anterior static compression, the OPLL was rotated 5°, 10°, and 15° in the flexion direction.

Results

The stress distribution in the spinal cord increased following static and dynamic compression by cervical OPLL. However, the stress distribution did not increase throughout the entire spinal cord. For combined static and dynamic compression, the stress distribution increased as the static compression increased, even for a mild range of motion (ROM).

Conclusion

Symptoms may appear under static or dynamic compression only. However, under static compression, the stress distribution increases with the ROM of the responsible level and this makes it very likely that symptoms will worsen. We conclude that cervical OPLL myelopathy is induced by static factors, dynamic factors, and a combination of both.     

Comparison of three approaches for femoral tunnel during double-bundle anterior cruciate ligament reconstruction: A case controlled study

Background

It is still controversial whether which femoral tunnel creation technique is best during anterior cruciate ligament reconstruction (ACLR). We aimed to clarify the features of three different techniques based on the femoral tunnel position created with the same tunnel-creating concept and the measurement data.

An epidemiological survey on ossification of ligaments in the cervical and thoracic spine in individuals over 50 years of age

An epidemiological survey on ossification of the spinal ligaments was performed on a total of 1,058 subjects over the age of 50 years by means of roentgenography of the cervical and thoracic spine. Ossification of the posterior longitudinal ligament (OPLL) of the cervical spine was detected in 34 subjects (3.2%) with a predilection for men, whereas OPLL in the thoracic spine was found in 8 (0.8%). There were 325 cases (30.7%) of ossification of the anterior longitudinal ligament (OALL) of stage II or above by Forestier's classification in the region from the cervical to thoracic vertebrae, and these cases included a significantly greater number of men. Ossification of the ligamenta flava (OLF) was observed in 48 cases (4.5%). As for the coexistence of ossification of these ligaments, 364 individuals (34.4%) had at least one instance of OPLL and OALL (stage II or above) in the region from the cervical to thoracic spine, and OLF in the thoracic spine.     

Perioperative complications of anterior decompression with fusion versus laminoplasty for the treatment of cervical ossification of the posterior longitudinal ligament: propensity score matching analysis using a nation-wide inpatient database

BACKGROUND CONTEXT

Surgical treatment of cervical ossification of the posterior longitudinal ligament (OPLL) has a high risk of various complications. Anterior decompression with fusion (ADF) and laminoplasty (LAMP) are the most representative surgical procedures. However, few studies have compared the two procedures in terms of perioperative surgical complications.

Nucleotide pyrophosphatase gene polymorphism associated with ossification of the posterior longitudinal ligament of the spine.

Ossification of the posterior longitudinal ligament (OPLL) of the spine is a disease that causes paralysis by compressing the spinal cord. Based on the fact that the nucleotide pyrophosphatase (Npps) gene is responsible for ectopic ossification in ttw, an OPLL model mouse, the possibility was explored whether the human NPPS gene is associated with susceptibility to and severity of OPLL. First, we screened for single-nucleotide polymorphisms (SNPs) in the human NPPS locus using selected 25 OPLL patients with young onset (< 35 years old) or severe ossification (> 10 ossified vertebrae), and identified three novel SNPs in the locus. A case-control association study between 180 OPLL patients and 265 non-OPLL controls showed that one of these SNPs, IVS15-14T --> C substitution, was more frequently observed in OPLL patients (p = 0.022), especially in those with severe ossification (p < 0.0001) and young onset (p = 0.002), than in controls. A stratified study with the number of ossified vertebrae in OPLL patients revealed that IVS15-14T --> C substitution (p = 0.013) as well as young onset (p = 0.046) and female sex (p = 0.006) were associated with severe ossification. We conclude that the IVS15-14T --> C substitution in the human NPPS gene is associated not only with susceptibility to, but also with severity of OPLL.     

Predictors for progression of two different types of cervical lesions in rheumatoid arthritis treated with biologic agents

Background

Biologic agents (BAs) enabled not only a reduction of disease activity but also a slowing down of structural damage to the joints in patients with rheumatoid arthritis (RA). However, the incidence of cervical lesions in patients with RA is still high.

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

Purpose

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

Methods

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

Results

MCT showed SCCSA changes during neck extension; 7.4 ± 5.1 mm² in the connection department, 5.8 ± 6.0 mm² in the coating part, and 6.7 ± 6.4 mm² in the non-connection department of OPLL group. There difference was not statistically significant. There was a weak correlation between the JOA score and SCCSA at the narrowest level (R = 0.49). There was no significant correlation between the recovery rate of JOA score and SCCSA at the narrowest level (R = 0.37).

Conclusion

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

Effect of posterior instrumented fusion on three-dimensional volumetric growth of cervical ossification of the posterior longitudinal ligament: a multiple regression analysis

Background Context

Despite the fact that ossification of posterior longitudinal ligament (OPLL) is a three-dimensional disease, conventional studies have focused mainly on a two-dimensional measurement, and it is difficult to accurately determine the volume of OPLL growth and analyze the factors affecting OPLL growth after posterior decompression (laminoplasty or laminectomy and fusion).

Cervical curvature, spinal cord MRIT2 signal, and occupying ratio impact surgical approach selection in patients with ossification of the posterior longitudinal ligament

Objective

Factors impacting surgical options and outcomes in patients with cervical ossification of the posterior longitudinal ligament (OPLL) were explored.

Methods

A retrospective analysis was conducted of 127 eligible cervical OPLL patients (61 males, 66 females) aged 41–70 years (mean 55.2 years) selected from 152 total OPLL patients treated from 2002 to 2006, with 5–10-year (mean 6.8 years) follow-up. Patients underwent anterior subtotal corpectomy with ossification ligament resection (anterior surgery, n = 68) or posterior cervical double-door laminoplasty (posterior surgery, n = 59). Radiographic assessments of cervical curvature, T2-weighted MRI (MRIT2) signal, and OPLL occupying ratio were correlated with surgical strategy before surgery and at 1, 5 weeks, and 5 years.

Results

Lordosis increased following anterior surgery, though kyphosis improved by 10.3 %. The canal stenosis occupying ratio was >50 %, and short-term improvement following anterior surgery was significantly higher than posterior surgery (P > 0.0001). Superior neurological function was observed in patients with unchanged versus high spinal MRIT2 signals (P = 0.0434). No significant differences were observed in short-term outcomes between anterior and posterior surgeries in high spinal MRIT2 signal patients, but anterior surgery produced significantly better long-term outcomes at 1 week (P = 0.7564) and 1 year (P = 0.0071). Complications occurred in five anterior and three posterior surgeries.

Conclusion

Preoperative assessment of cervical curvature, MRIT2 signal, and occupying ratio can be used to guide clinical surgical approach selection to potentially produce better long-term outcomes in patients with OPLL.     

Biomechanical study of the spinal cord in thoracic ossification of the posterior longitudinal ligament

Background

Ossification of the posterior longitudinal ligament (OPLL) in the thoracic spine produces myelopathy. This is often progressive and is not affected by conservative treatment. Therefore, decompressive surgery is usually chosen.

Objective

To conduct a stress analysis of the thoracic OPLL.

Methods

The three-dimensional finite element spinal cord model was established. We used local ossification angle (LOA) for the degree of compression of spinal cord. LOA was the medial angle at the intersection between a line from the superior posterior margin at the cranial vertebral body of maximum OPLL to the top of OPLL with beak type, and a line from the lower posterior margin at the caudal vertebral body of the maximum OPLL to the top of OPLL with beak type. LOA 20°, LOA 25°, and LOA 30° compression was applied to the spinal cord in a preoperative model, the posterior decompressive model, and a model for the development of kyphosis.

Results

In a preoperative model, at more than LOA 20° compression, high stress distributions in the spinal cord were observed. In a posterior decompressive model, the stresses were lower than in the preoperative model. In the model for development of kyphosis, high-stress distributions were observed in the spinal cord at more than LOA 20° compression.

Conclusions

Posterior decompression was an effective operative method. However, when the preoperative LOA is more than 20°, it is very likely that symptoms will worsen. If operation is performed at greater than LOA 20°, then correction of kyphosis by fixation of instruments or by forward decompression should be considered.     

Prediction of quadriceps strength recovery after anterior cruciate ligament reconstruction with a hamstring autograft: Decision tree analysis

Background

The wide variations in patient demographics and concomitant injuries make the prediction of which patients will regain strength quickly following anterior cruciate ligament (ACL) reconstruction challenging. This study aimed to identify the dominant factor affecting quadriceps strength recovery after ACL reconstruction with a hamstring tendon autograft and to construct a predictive model for quadriceps strength recovery using decision tree analysis.

Association between serum leptin and bone metabolic markers, and the development of heterotopic ossification of the spinal ligament in female patients with ossification of the posterior longitudinal ligament

Obesity is a risk factor for ossification of the posterior longitudinal ligament (OPLL) of the spine, which is characterized by heterotopic bone formation in the posterior longitudinal spinal ligament. Hyperleptinemia is a common feature of obese people and leptin is believed to be an important factor in the pathogenesis of OPLL. However, the association between leptin and bone metabolism and the development of OPLL is not understood fully. The objective of the present study was to determine the association between serum leptin concentration and bone metabolic markers and the extent of heterotopic ossification of the spinal ligament in patients with OPLL. The serum concentrations of leptin, insulin, fructosamine, bone-specific alkaline phosphatase, and carboxyterminal propeptide of type I procollagen, urine deoxypyridinoline levels, and the number of vertebrae with OPLL involvement were measured in 125 (68 males and 57 females) patients with OPLL. The correlation between leptin and these other factors was then examined. Serum leptin and insulin concentrations were increased significantly in OPLL females compared to non-OPLL female controls. In the females with OPLL, serum leptin concentrations corrected for body mass index correlated positively with the number of vertebrae with OPLL involvement. In females, serum leptin levels were significantly higher in patients in whom OPLL extended to the thoracic and/or lumbar spine than in patients in whom OPLL was limited to the cervical spine. Our results suggest that hyperleptinemia, in combination with hyperinsulinemia, may contribute to the development of heterotopic ossification of the spinal ligament in female patients with OPLL.