Advances in surgical strategies for ossification of posterior longitudinal ligament involving the C 2 segment / 中国修复重建外科杂志

OBJECTIVE@#To evaluate the application of surgical strategies for the treatment of cervical ossification of the posterior longitudinal ligament (OPLL) involving the C 2 segment.@*METHODS@#The literature about the surgery for cervical OPLL involving C 2 segment was reviewed, and the indications, advantages, and disadvantages of surgery were summarized.@*RESULTS@#For cervical OPLL involving the C 2 segments, laminectomy is suitable for patients with OPLL involving multiple segments, often combined with screw fixation, and has the advantages of adequate decompression and restoration of cervical curvature, with the disadvantages of loss of cervical fixed segmental mobility. Canal-expansive laminoplasty is suitable for patients with positive K-line and has the advantages of simple operation and preservation of cervical segmental mobility, and the disadvantages include progression of ossification, axial symptoms, and fracture of the portal axis. Dome-like laminoplasty is suitable for patients without kyphosis/cervical instability and with negative R-line, and can reduce the occurrence of axial symptoms, with the disadvantage of limited decompression. The Shelter technique is suitable for patients with single/double segments and canal encroachment >50% and allows for direct decompression, but is technically demanding and involves risk of dural tear and nerve injury. Double-dome laminoplasty is suitable for patients without kyphosis/cervical instability. Its advantages are the reduction of damage to the cervical semispinal muscles and attachment points and maintenance of cervical curvature, but there is progress in postoperative ossification.@*CONCLUSION@#OPLL involving the C 2 segment is a complex subtype of cervical OPLL, which is mainly treated through posterior surgery. However, the degree of spinal cord floatation is limited, and with the progress of ossification, the long-term effectiveness is poor. More research is needed to address the etiology of OPLL and to establish a systematic treatment strategy for cervical OPLL involving the C 2 segment.

Anterior controllable anteriodisplacement and fusion for treatment of severe cervical ossification of posterior longitudinal ligament / 第二军医大学学报

Objective To report a novel technique named anterior controllable antedisplacement and fusion (ACAF) for the treatment of severe ossification of the posterior longitudinal ligament of the cervical spine, which allows for direct decompression of the nerve without resection of the ossification, making up for deficiencies in traditional anterior or posterior decompression. Methods The main surgical procedures of the ACAF included treatment of intervertebral space, removal of the anterior part of vertebrae, installation of titanium plate and interbody fusion cages, bilateral osteotomies of the vertebrae, and antedisplacement of the vertebrae ossification complex. The clinical data of two patients undergoing this surgery for severe ossification of the posterior longitudinal ligament of cervical spine were collected and analyzed. Results ACAF enabled direct decompression of spinal cord and nerve root through antedisplacement of the vertebrae ossification complex. The two patients who underwent ACAF gained satisfactory restoration with decompression of spinal cord and good recovery of neurological function, with no specific complications. Conclusion ACAF surgery takes into account the effectiveness of anterior direct decompression and the safety of posterior indirect decompression. Preliminary results shows that it can be used for severe cervical ossification of the posterior longitudinal ligament.

Anterior controllable anteriodisplacement and fusion for treatment of severe cervical ossification of posterior longitudinal ligament / 第二军医大学学报

Objective To report a novel technique named anterior controllable antedisplacement and fusion (ACAF) for the treatment of severe ossification of the posterior longitudinal ligament of the cervical spine,which allows for direct decompression of the nerve without resection of the ossification,making up for deficiencies in traditional anterior or posterior decompression.Methods The main surgical procedures of the ACAF included treatment of intervertebral space,removal of the anterior part of vertebrae,installation of titanium plate and interbody fusion cages,bilateral osteotomies of the vertebrae,and antedisplacement of the vertebrae ossification complex.The clinical data of two patients undergoing this surgery for severe ossification of the posterior longitudinal ligament of cervical spine were collected and analyzed.Results ACAF enabled direct decompression of spinal cord and nerve root through antedisplacement of the vertebrae ossification complex.The two patients who underwent ACAF gained satisfactory restoration with decompression of spinal cord and good recovery of neurological function,with no specific complications.Conclusion ACAF surgery takes into account the effectiveness of anterior direct decompression and the safety of posterior indirect decompression.Preliminary results shows that it can be used for severe cervical ossification of the posterior longitudinal ligament.

Minimally Invasive Anterior Decompression Technique without Instrumented Fusion for Huge Ossification of the Posterior Longitudinal Ligament in the Thoracic Spine: Technical Note And Literature Review

OBJECTIVE: Several surgical methods have been reported for treatment of ossification of the posterior longitudinal ligament (OPLL) in the thoracic spine. Despite rapid innovation of instruments and techniques for spinal surgery, the postoperative outcomes are not always favorable. This article reports a minimally invasive anterior decompression technique without instrumented fusion, which was modified from the conventional procedure. The authors present 2 cases of huge beak-type OPLL. Patients underwent minimally invasive anterior decompression without fusion. This method created a space on the ventral side of the OPLL without violating global thoracic spinal stability. Via this space, the OPLL and anterior lateral side of the dural sac can be seen and manipulated directly. Then, total removal of the OPLL was accomplished. No orthosis was needed. In this article, we share our key technique and concepts for treatment of huge thoracic OPLL. METHODS: Case 1. 51-year-old female was referred to our hospital with right lower limb radiating pain and paresis. Thoracic OPLL at T6–7 had been identified at our hospital, and conservative treatment had been tried without success. Case 2. This 54-year-old female with a 6-month history of progressive gait disturbance and bilateral lower extremity radiating pain (right>left) was admitted to our institute. She also had hypoesthesia in both lower legs. Her symptoms had been gradually progressing. Computed tomography scans showed massive OPLL at the T9–10 level. Magnetic resonance imaging of the thoracolumbar spine demonstrated ventral bony masses with severe anterior compression of the spinal cord at the same level. RESULTS: We used this surgical method in 2 patients with a huge beaked-type OPLL in the thoracic level. Complete removal of the OPLL via anterior decompression without instrumented fusion was accomplished. The 1st case had no intraoperative or postoperative complications, and the 2nd case had 1 intraoperative complication (dural tear) and no postoperative complications. There were no residual symptoms of the lower extremities. CONCLUSION: This surgical technique allows the surgeon to safely and effectively perform minimally invasive anterior decompression without instrumented fusion via a transthoracic approach for thoracic OPLL. It can be applied at the mid and lower level of the thoracic spine and could become a standard procedure for treatment of huge beak-type thoracic OPLL.

Posterior Trans-Dural Repair of Iatrogenic Spinal Cord Herniation after Resection of Ossification of Posterior Longitudinal Ligament

Iatrogenic spinal cord herniation is a rare complication following spinal surgery. We introduce a posterior trans-dural repair technique used in a case of thoracic spinal cord herniation through a ventral dural defect following resection of ossification of the posterior longitudinal ligament (OPLL) in the cervicothoracic spine. A 51-year-old female was suffering from paraplegia after laminectomy alone for cervicothoracic OPLL. Magnetic resonance imaging revealed a severely compressed spinal cord with pseudomeningocele identified postoperatively. Cerebrospinal fluid leak and iatrogenic spinal cord herniation persisted despite several operations with duroplasty and sealing agent. Finally, the problems were treated by repair of the ventral dural defect with posterior trans-dural duroplasty. Several months after surgery, the patient could walk independently. This surgical technique can be applied to treat ventral dural defect and spinal cord herniation.

Compression Angle of Ossification of the Posterior Longitudinal Ligament and Its Clinical Significance in Cervical Myelopathy

OBJECTIVES: The correction of clinical and radiologic abnormalities in patients with symptomatic ossification of the posterior longitudinal ligament (OPLL) is the current mainstay of treatment. This study aimed to identify radiographic predictors of severity of myelopathy in patients with symptomatic OPLL. METHODS: Fifty patients with symptomatic cervical OPLL were enrolled. Based on Japanese Orthopedic Association (JOA) scores, patients were divided into either the mild myelopathy (n=31) or severe myelopathy (n=19) group. All subjects underwent preoperative plain cervical roentgenogram, computed tomography (CT), and MR imaging (MRI). Radiological parameters (C2–7 sagittal vertical axis, SVA; C2–7 Cobb angle; C2–7 range of motion, ROM; OPLL occupying ratio; and compression angle) were compared. Compression angle of OPLL was defined as the angle between the cranial and caudal surfaces of OPLL at the maximum level of cord compression RESULTS: The occupying ratio of the spinal canal, C2–7 Cobb angle, C2–7 SVA, types of OPLL, and C2–7 ROM of the cervical spine were not statistically different between the two groups. However, the OPLL compression angle was significantly greater (p=0.003) in the severe myelopathy group than in the mild myelopathy group and was inversely correlated with JOA score (r=-0.533, p<0.01). Furthermore, multivariate regression analysis demonstrated that the compression angle (B=-0.069, p<0.001) was significantly associated with JOA scores (R=0.647, p<0.005). CONCLUSION: Higher compression angles of OPLL have deleterious effects on the spinal cord and decrease preoperative JOA scores.

Circumferential Spinal Cord Decompression through a Single Posterior Approach with Microendoscopy for Thoracic and Thoracolumbar Ossification of the Posterior Longitudinal Ligament

Thoracic and thoracolumbar ossification of the posterior longitudinal ligament (OPLL) can be difficult to treat due to the anatomical position. The purpose of this study was to report the significance of a novel surgical technique that represented two cases of thoracic or thoracolumbar OPLL. The first patient was a 72-year-old woman who had a beak-type OPLL at the T11/12. The second was a 45-year-old woman who had a beak-type OPLL at the T12/L1. We performed circumferential spinal cord decompression through a single posterior approach with microendoscopy in both cases. The postoperative computed tomography revealed the complete removal of the OPLL, and the magnetic resonance imaging confirmed adequate decompression of the spinal cord. Preoperative symptoms were substantially improved in both patients. To date, we have used this novel technique to treat five patients with thoracic or thoracolumbar OPLL. This new surgical technique is likely to be useful in patients with a beak-type OPLL of the thoracic or thoracolumbar spine.

Cervical Spine CT and MRI Findings in a Patient with Ossification of the Posterior Longitudinal Ligament

No abstract available.

Clinics in diagnostic imaging (161). Cervical OPLL with cord compression

A 53-year-old man presented with acute cervical myelopathy following a fall. Cervical radiography and computed tomography showed ossification of the posterior longitudinal ligament (OPLL) from C2 to C6 level, with severe cervical canal stenosis and cord compression. Magnetic resonance imaging further showed increased T2-weighted signal in the spinal cord at the level of greatest central spinal canal stenosis. OPLL is a significant cause of myelopathy in Asian populations and is found in up to 25% of patients presenting with cervical compression myelopathy. The clinical presentation, radiological evaluation and management of OPLL are discussed.

A new expansive two-open-doors laminoplasty for multilevel cervical spondylotic myelopathy: technical report and follow-up results / Nova tecnica de laminoplastia expansiva para tratamento de mielopatia espondilotica cervical: descricao tecnica e resultados de follow-up

The laminoplasty technique was devised by Hirabayashi in 1978 for patients diagnosed with multilevel cervical spondylotic myelopathy. Objective: To describe an easy modification of Hirabayashi’s method and present the clinical and radiological results from a five-year follow-up study. Method and Results: Eighty patients had 5 levels of decompression (C3-C7), 3 patients had 6 levels of decompression (C2-T1) and 3 patients had 4 levels of decompression (C3-C6). Foraminotomies were performed in 23 cases (27%). Following Nurick`s scale, 76 patients (88%) improved, 9 (11%) had the same Nurick grade, and one patient worsened and was advised to undergo another surgical procedure. No deaths were observed. The mean surgery time was 122 min. Radiographic evaluation showed an increase in the mean sagittal diameter from 11.2 mm at pretreatment to 17.3 mm post surgery. There was no significant difference between pretreatment and post-surgery C2-C7 angles. Conclusions: This two-open-doors laminoplasty technique is safe, easy and effective and can be used as an alternative treatment for cases of multilevel cervical spondylotic myelopathy without instability. .

A laminoplastia é técnica clássica descrita por Hirabayashi em 1978 para descompressão do canal cervical sem utilizar prótese. A principal indicação é o tratamento da mielopatia espondilotica cervical sem instabilidade. Objetivo: Descrever modificação simples da técnica de laminoplastia clássica de Hirabayashi com resultados clínicos e radiográficos em 5 anos de acompanhamento. Resultados e Método: Foram acompanhados 86 pacientes. Em 80, foi feita descompressão por laminoplastia em 5 níveis (C3-C7); em 3, descompressão em 6 níveis (C2-T1); em 3, descompressao em 4 níveis (C3-C6). Em 23 casos (27%), foi realizada foraminotomia associada a descompressão medular. O acompanhamento dos pacientes foi feito utilizando a escala de Nurick. Em 76 pacientes (88%) houve melhora do grau de Nurick. Não houve mortalidade associada à técnica. O tempo médio do procedimento cirúrgico foi de 122 minutos. Em relação à avaliação radiográfica, houve aumento do diâmetro sagital médio do canal cervical de 11,2mm para 17,3mm. Não houve diferença estatística do ângulo C2-C7 nas avaliações antes e após o procedimento cirúrgico. Conclusão: A nova técnica de laminoplastia descrita no presente estudo foi segura, de fácil execução, efetiva, não utiliza protese e não há instabilidade do canal cervical. .

Does Intramedullary Signal Intensity on MRI Affect the Surgical Outcomes of Patients with Ossification of Posterior Longitudinal Ligament?

OBJECTIVES: Patients with cervical ossification of posterior longitudinal ligament (OPLL) are susceptible to cord injury, which often develops into myelopathic symptoms. However, little is known regarding the prognostic factors that are involved in minor trauma. We evaluated the relationship between minor trauma and neurological outcome of OPLL and investigated the prognostic factors with a focus on compressive factors and intramedullary signal intensity (SI). METHODS: A total of 74 patients with cervical myelopathy caused by OPLL at more than three-levels were treated with posterior decompression surgeries. We surveyed the space available for spinal cord (SAC), the severity of SI change on T2-weighted image, and diabetes mellitus (DM). The neurological outcome using Japanese Orthopedic Association (JOA) scale was assessed at admission and at 12-month follow-up. RESULTS: Among the variables tested, preoperative JOA score, severity of intramedullary SI, SAC, and DM were significantly related to neurological outcome. The mean preoperative JOA were 11.3+/-1.9 for the 41 patients who did not have histories of trauma and 8.0+/-3.1 for the 33 patients who had suffered minor traumas (p<0.05). However, there were no significant differences in the recovery ratios between those two groups. CONCLUSIONS: Initial neurological status and high intramedullary SI in the preoperative phase were related to poorer postoperative outcomes. Moreover, the patients with no histories of DM and larger SACs exhibited better improvement than did the patients with DM and smaller SACs. Although the initial JOA scores were worse for the minor trauma patients than did those who had no trauma prior to surgery, minor trauma exerted no direct effects on the surgical outcomes.

The Insertion/Deletion Polymorphism of Angiotensin I Converting Enzyme Gene is Associated With Ossification of the Posterior Longitudinal Ligament in the Korean Population

OBJECTIVE: To determine whether ACE insertion/deletion (I/D) polymorphism is associated with the ossification of the posterior longitudinal ligament (OPLL) of the spine in the Korean population. METHODS: A case-control study was conducted to investigate the association between I/D polymorphism of the angiotensin I converting enzyme (peptidyl-dipeptidase A) 1 (ACE) gene and OPLL. The 95 OPLL patients and 274 control subjects were recruited. Polymerase chain reaction for the genotyping of ACE I/D polymorphism was performed. The difference between the OPLL patients and the control subjects was compared using the contingency chi2 test and the logistic regression analysis. For statistical analysis, SPSS, SNPStats, SNPAnalyzer, and Helixtree programs were used. RESULTS: The genotype and allele frequencies of ACE I/D polymorphism showed significant differences between the OPLL patients and the control subjects (genotype, p<0.001; allele, p=0.009). The frequencies of D/D genotype and D allele in the OPLL group were higher than those in the control group. In logistic regression analysis, ACE I/D polymorphism was associated with OPLL (dominant model; p=0.002; odd ratio, 2.20; 95% confidence interval, 1.33-3.65). CONCLUSION: These results suggest that the deletion polymorphism of the ACE gene may be a risk factor for the development of OPLL in the Korean population.

Acute Hydrocephalus Following Cervical Spinal Cord Injury

We present a case of acute hydrocephalus secondary to cervical spinal cord injury in a patient with diffuse ossification of the posterior longitudinal ligament (OPLL). A 75-year-old male patient visited the emergency department with tetraparesis and spinal shock. Imaging studies showed cervical spinal cord injury with hemorrhage and diffuse OPLL from C1 to C4. We performed decompressive laminectomy and occipitocervical fusion. Two days after surgery, his mental status had deteriorated to drowsiness with dilatation of the right pupil. Findings on brain computed tomography revealed acute hydrocephalus and subarachnoid hemorrhage in the cerebellomedullary cistern, therefore, extraventricular drainage was performed immediately. Acute hydrocephalus as a complication of cervical spine trauma is rare, however, it should be considered if the patient shows deterioration of neurologic symptoms.

Mielopatia torácica por calcificação do ligamento amarelo cursando com hiperproteinorraquia e resposta à corticoterapia: relato de caso / Thoracic myelopathy due to calcification of the ligamentum flavum with hyperproteinorachia and responsive to steroid therapy: case report

Calcificação e ossificação do ligamento amarelo ou do ligamento longitudinal posterior são causas de mielopatia compressiva, mais frequentes nos níveis torácicos inferiores e bastante raras em populações ocidentais. A descompressão cirúrgica é a única terapia proposta, mas a doença costuma ser progressiva e sua recorrência após a cirurgia não é incomum. Mediadores inflamatórios podem ter algum papel na progressão da mielopatia compressiva, mas não se tem notícia de qualquer proposta de abordagem terapêutica envolvendo agentes anti-inflamatórios. Neste contexto, relatamos um caso de mielopatia compressiva por calcificação do ligamento amarelo em que se observou hiperproteinorraquia e resposta à corticoterapia. Tais informações são inéditas e podem fornecer novas ideias para a compreensão da doença.

Calcification and ossification of the ligamentum flavum or of the posterior longitudinal ligament are causes of compressive myelopathy, more frequent in the lower thoracic levels, and extremely rare in Western populations. Surgical decompression is the only therapy, but the disease is usually progressive, and its recurrence after surgery is common. Inflammatory mediators might play a role in the progression of compressive myelopathy, but, to our knowledge, the therapeutic approach involving anti-inflammatory agents has never been tried before. We report a case of compressive myelopathy due to calcification of the ligamentum flavum, in which hyperproteinorachia and response to steroid therapy have been observed. Those data have not been published before and might provide new ideas for the disease understanding.

Association of Estrogen Receptor 2(ESR 2) Gene Polymorphisms with Ossification of the Posterior Longitudinal Ligament of the Spine

STUDY DESIGN: Genetic screening of the estrogen receptor 2 (ESR2) genes in patients with ossification of the posterior longitudinal ligament (OPLL). OBJECTIVE: We studied the relationships between ESR2 gene polymorphisms and OPLL to understand the pathophysiology of OPLL. SUMMARY OF LITERATURE REVIEW: The OPLL has a strong genetic component. Several familial surveys and human leukocyte antigen (HLA) haplotype studies reveal that genetic background is an important component in the occurrence of OPLL and a large number of gene analysis studies were utilized to clarify the susceptible gene for OPLL, including COL11A2, BMP-2, TNF-alpha, NPPS, leptin receptor, transforming growth factor (TGF)-beta, Retinoic X receptor, ER, IL-1, PTH, and VDR have been performed. MATERIALS AND METHOD: Genomic deoxyribonucleic acid (DNA) samples obtained from 164 patients (93 men and 71 women) with OPLL and 219 control subjects, without the disease (105 men and 114 women) were amplified by polymerase chain reaction, and polymorphism genotypes were determined by the restriction endonuclease digestion. The distribution of genotypes was compared between the patients with the disease and the control subjects. RESULTS: The polymorphism of ESR2 [rs1256049, exon6, Val328Val, p=0.018, odd ratio (OR)=2.41, 95 confidence interval (CI)=1.15-5.02 in the recessive model] only showed statistically significant association between the control and the OPLL groups. The rest SNPs of ESR2 did not show any significant differences between the control and the OPLL groups. CONCLUSIONS: Estrogen receptor 2 (ESR2) gene polymorphisms (rs 1256049) was associated with OPLL. In future studies, we will perform target SNP chip between OPLL and candidate gene.

Relationship Between Somatosensory Evoked Potential Diversification during Operation and Short Term Outcome of Ossification of Posterior Longitudinal Ligament of Cervical Spine / 中国康复理论与实践

@#Objective To explore the relationship between the somatosensory evoked potential (SEP) diversification during operation and the short term outcome of ossification of posterior longitudinal ligament (OPLL) of cervical spine. Methods 70 OPLL inpatients from February 2008 to February 2011were included in this study. All patients received anterior cervical operation. According to the diversification of the SEP during surgery, the patients were divided into 2 groups. The preoperative and postoperative JOA scores of the OPLL patients were collected. Results There were 35 patients in the SEP no change group and 30 in SEP improved group. There was no difference in the preoperative JOA scores between them (P>0.05), but was significantly different in the postoperative JOA scores (P>0.05). Conclusion There is some relationship between the SEP diversification during operation and the short term outcome of OPLL of cervical spine.

Relationship of Radiological Characteristics and Clinical Symptoms of Ossification of Posterior Longitudinal Ligament of Cervical Spine / 中国康复理论与实践

@# Objective To explore the relationship of the radiological characteristics and clinical symptoms of ossification of the posteriorlongitudinal ligament (OPLL) of cervical spine. Methods 200 OPLL patients were recruited into this study. The data of JOA scores of theOPLL patients were collected. The stenotic rate of the cervical spine canal was calculated by the sagittal plane CT. The sorts and ossificatedcervicle were also identified by the images. Results The stenotic rate of the cervical spine canal was 19.8% to 60.3% with average 42.9%,the JOA scores was 4 to 15, averaged 10. Linear regression showed the stenotic rate of the cervical spine canal was negatively correlatedwith the JOA scores (P<0.01). There were 94 cases for segmental-type, 46 for mixed-type, 23 for continuous-type and 37 for focal-type. Thethird and fourth cervical vertebrae were susceptible to ossify. Conclusion The higher the OPLL occupation ratio, the worse the clinicalOPLL symptoms. The OPLL patients following clinical symptoms with spinal cord oppression are more likely the segmental-type.

Single Stage Circumferential Cervical Surgery (Selective Anterior Cervical Corpectomy with Fusion and Laminoplasty) for Multilevel Ossification of the Posterior Longitudinal Ligament with Spinal Cord Ischemia on MRI

OBJECTIVE: Anterior cervical corpectomy with fusion (ACF) or laminoplasty may be associated with substantial number of complications for treating multilevel cervical ossification of the posterior longitudinal ligament (OPLL) with significant cord compression. For more safe decompression and stabilization in multilevel cervical OPLL with prominent cord compression, we propose circumferential cervical surgery (selective ACF and laminoplasty) based on our favorable experience. METHODS: Twelve patients with cervical myelopathy underwent circumferential cervical surgery and all patients showed multilevel OPLL with signal change of the spinal cord on magnetic resonance imaging (MRI). A retrospective review of clinical, radiological, and surgical data was conducted. RESULTS: There were 9 men and 3 women with mean age of 56.7 years and a mean follow up period of 15.6 months. The average corpectomy level was 1.16 and laminoplasty level was 4.58. The average Japanese Orthopedic Association score for recovery was 5.1 points and good clinical results were obtained in 11 patients (92%) (p < 0.05). The average space available for the cord improved from 58.2% to 87.9% and the average Cobb's angle changed from 7.63 to 12.27 at 6 months after operation without failure of fusion (p < 0.05). Average operation time was 8.36 hours, with an estimated blood loss of 760 mL and duration of bed rest of 2.0 days. There were no incidences of significant surgical complications, including wound infection. CONCLUSION: Although the current study examined a small sample with relatively short-term follow-up periods, our study results demonstrate that circumferential cervical surgery is considered favorable for safety and effectiveness in multilevel OPLL with prominent cord compression.

Inter- and Intra-observer Variability of a Cervical OPLL Classification Using Reconstructed CT Images

BACKGROUND: The lateral radiograph-based system described by Tsuyama is used widely to classify ossification of the posterior longitudinal ligament (OPLL) of the cervical spine. However, OPLL is a complex 3-dimensional (3-D) lesion, not a simple and uniplanar one, which is often difficult to identify on a lateral radiograph. Furthermore, its reliability among spine surgeons has not been investigated. Given the popularity of a reconstructed computed tomography (CT), this study examined the inter- and intra-observer reliability of lateral radiograph-based OPLL classification using that modality. METHODS: Five spine surgeons independently reviewed the lateral radiograph, axial CT, 2-D (sagittal) and 3-D reconstructed CT images of 108 OPLL patients on 2 separate occasions. Based on these images, the reviewers classified each OPLL case according to the Tsuyama's system. The kappa values were used to assess the statistical reliability. RESULTS: The inter- and intra-observer kappa values were only 0.51 and 0.67 for the lateral radiograph, even in combination with the axial CT images, 0.70 and 0.85 for 2-D CT images, and 0.76 and 0.86 for 3-D CT images, respectively. These kappa values showed a good-to-excellent range for the 2-D and 3-D reconstructed CT images while those of the lateral radiograph indicated a fair range. According to the OPLL types, the inter- and intra-observer reliability was low in the continuous type and high in the circumscribed type on the lateral radiograph. However, the low reliability of the continuous type on lateral radiograph was overcome somewhat using 2-D and 3-D reconstructed CT images. CONCLUSIONS: The inter- and intra-observer kappa values were only 0.51 and 0.67 for the lateral radiograph, even in combination with the axial CT images, 0.70 and 0.85 for 2-D CT images, and 0.76 and 0.86 for 3-D CT images, respectively. These kappa values showed a good-to-excellent range for the 2-D and 3-D reconstructed CT images while those of the lateral radiograph indicated a fair range. According to the OPLL types, the inter- and intra-observer reliability was low in the continuous type and high in the circumscribed type on the lateral radiograph. However, the low reliability of the continuous type on lateral radiograph was overcome somewhat using 2-D and 3-D reconstructed CT images.

Prevalence and Association Factors of Posterior Longitudinal Ligament in Patients with Spondyloarthropathies

OBJECTIVE: To investigate prevalence of ossification of posterior longitudinal ligament (OPLL) in Korean patients with Spondyloarthropathies (SpA), and the associations between OPLL and clinical, radiologic findings of SpA. METHOD: A cross-sectional radiological review was performed in patients diagnosed with SpA from 2000 to 2007. Each of two physiatrists and musculoskeletal radiologists screened the cervical (lateral) and pelvis (anterior-posterior) radiographs of these patients separately, then confirmed presence of OPLL. Bath ankylosing spondylitis radiology index (BASRI) of the cervical spine and grade of sacroiliitis were also measured. A review of the medical records and laboratory findings was conducted to investigate the association between the clinical, laboratory findings and the OPLL. RESULTS: Among 172 patients with SpA, OPLL was found in 16 patients (9.3%; 95% CI 5.0, 13.6). There were significant associations between OPLL and old age (p=0.043), symptoms and signs of myeloradiculopathy (p=0.030), and diabetes mellitus (DM) (p=0.022). CONCLUSION: The prevalence of OPLL in Korean patients with SpA is 9.3%. OPLL in patients with SpA is associated with old age, symptoms and signs of myeloradiculopathy, and diabetes. However, no factors specific characteristics of SpA were associated with OPLL.