Co-existence of ossification of the nuchal ligament is associated with severity of ossification in the whole spine in patients with cervical ossification of the posterior longitudinal ligament -A multi-center CT study-

Background

Previous studies have shown that patients with cervical ossification of the posterior longitudinal ligament (OPLL) often have co-existing ossification of the nuchal ligament (ONL). However, no studies have focused on ONL and its relevance to the severity of OPLL or ossification of other spinal ligaments, such as anterior longitudinal ligament (OALL), ligamentum flavum (OLF), and supraspinous/interspinous ligament (OSIL).

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.     

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.     

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.     

颈椎后纵韧带骨化症的手术治疗

目的探讨颈椎后纵韧带骨化症手术治疗方法及其疗效。方法回顾性分析2002年1月至2008年1月我院65例颈椎后纵韧带骨化症手术治疗病例。均有程度不等的脊髓压迫症状。41例合并发育性颈椎管狭窄,平均椎管狭窄率42．1％。术前均行X线、CT平扫加矢状位重建和MRI检查。其中23例行前路手术,37例行后路手术,5例行前后路联合手术。结果65例获6～72个月随访,平均随访时间19个月。根据日本矫形外科学会评分标准,颈前路手术平均改善率70％,颈后路手术平均改善率66．3％,颈前后路联合手术平均改善率75．4％。术后并发节段性神经根麻痹5例。结论根据患者病情和影像学表现,尤其是CT矢状位重建,仔细分析后纵韧带骨化部位、范围及椎管狭窄率,选择合适手术方法,方能减少并发症,提高手术疗效。     

An epidemiological study on the ossification of the anterior longitudinal ligament of the spine

An epidemiological study was carried out in connection with the multiphasic screening examination of 1,057 people (442 men and 615 women) in the village of Yachiho. The purpose of this study was to define the etiology of OALL (ossification of the anterior longitudinal ligament) and disc narrowing. The prevalence of disc narrowing increased with age, but OALL was not correlated with aging. OALL was found more frequently in men, but disc narrowing showed no difference between each sexes. The body height and weight-height index were higher in the OALL cases. The body height shrinkage by aging was greater in the patients with disc narrowing cases. The index of thoracic kyphosis was higher in the OALL cases than in the patients with disc narrowing ones. OALL was associated with ossification of the other ligaments of the spine, but disc narrowing was not. This study suggests that despite some similarities, OALL is etiologically different from disc narrowing.     

Management of anesthesia in patients with the potential for difficult intubation due to ossification of anterior longitudinal ligament (OALL)

Ossification of anterior longitudinal ligament (OALL) is a disease inducing ossification of the ligamentum longitudinale anterius of the backbone. The esophagus can be compressed by the disease, which also can induce hoarse voice and dysphagia. Furthermore, the trachea can also be compressed. Difficult intubation had been anticipated based on the preoperative evaluation in this case, but the intubation fortunately was not difficult. However, OALL can accompany difficult intubation, and we anesthesiologists must pay attention to the disease.     

Ossification of posterior longitudinal ligament of the cervical spine in non-Japanese Asians

"The Japanese disease," ossification of the posterior longitudinal ligament, is not confined to the Japanese only. A similar incidence of 0.8% was found in this study among non-Japanese Asians. Of 5167 patients who attended the Mount Elizabeth Hospital in Singapore for cervical spine complaints, 43 patients were found to have ossification of the posterior longitudinal ligament, forming the largest non-Japanese series. All but one patient were of Mongolian origin, and males were affected four times more commonly than females. Diabetes mellitus was present in 16%. There was a significant association between ossification of the posterior longitudinal ligament and calcification of other cervical paraspinal ligaments. It is suggested that a generalized tendency to calcification may be an important etiological factor in ossification of the posterior longitudinal ligament. Four of the patients required surgery, and in our experience, anterior spinal fusion with removal of the ossified ligament or multilevel laminoplasty gives satisfactory results.     

Ossification of the posterior longitudinal ligament in vitamin D-resistant rickets: case report and review of the literature

STUDY DESIGN: A case report of cervical myelopathy caused by ossification of the posterior longitudinal ligament in a patient with vitamin D-resistant rickets is presented together with a review of literature. OBJECTIVE: To report the diagnosis of ossification of the posterior longitudinal ligament in a white woman with vitamin D-resistant rickets. SUMMARY OF BACKGROUND DATA: The association between ossification of the posterior longitudinal ligament and untreated vitamin D-resistant rickets has been reported in Japan, but infrequently in white populations. In whites, ossification of the posterior longitudinal ligament is closely associated with diffuse idiopathic skeletal hyperostosis. A clear association between ossification of the posterior longitudinal ligament and vitamin D-resistant rickets in white populations has not yet been established. METHODS: The medical record and imaging studies of a patient treated at the authors' institution for cervical myelopathy caused by ossification of the posterior longitudinal ligament in the setting of treated vitamin D-resistant rickets were reviewed. A Medline search of the medical literature between 1966-1999 was performed to identify pertinent studies and similar case reports. RESULTS: The occurrence of spinal stenosis in untreated adults with vitamin D-resistant rickets has been reported in all regions of the spine in Japanese patients. The association between ossification of the posterior longitudinal ligament and untreated vitamin D-resistant rickets was first reported in Japan, where ossification of the posterior longitudinal ligament is endemic. This association may be incidental, because reports on ossification of the posterior longitudinal ligament in whites are not as frequent as in Japanese, reflecting the higher prevalence of this condition in Japan. CONCLUSION: Ossification of the posterior longitudinal ligament and ossification of the posterior longitudinal ligament associated with deranged calcium or phosphate metabolism may be different pathologic entities sharing a common outcome. Adequate treatment of vitamin D-resistant rickets may not always prevent or reverse ossification of the posterior longitudinal ligament.     

Cervical spine stenosis due to ossification of the posterior longitudinal ligament in Italian patients: surgical treatment and outcome

Ossification of the posterior longitudinal ligament (OPLL) of the cervical spine is a frequent pathological entity in people of Japanese and Asian extraction and is reported with increasing frequency also in the USA; on the contrary, reports in the European and particularly in the Italian literature remain rare. This paper describes 8 Italian patients with cervical spine stenosis due to OPLL extending three to five vertebral segments (and above C3 in four cases). Magnetic resonance imaging shows the extent of the ossification well in terms of height and cord compression, while computed tomography is useful to measure the thickness of the bone mass and the residual spinal canal. Anterior cervical decompression by discectomy, corpectomy, and removal of the ossified ligament is the treatment of choice and results in clinical improvement in most cases. Decompressive laminectomy may be reserved for patients with ossification extending to four or five levels and above C3. The surgical technique and intraoperative findings are discussed. Received: 30 March 1998     

Ossification of the posterior longitudinal and yellow ligaments on the lumbar spine

Ossification of the posterior longitudinal ligament and ossification of the yellow ligament are the main causes of spinal canal stenosis. This article describes a case of ossification of the posterior longitudinal and yellow ligaments on the lumbar spine. The patient presented with gradually worsening left lower-extremity ache and pain. The deep tendon reflex was hyperreflexia in the lower extremities. Disturbances existed in the blade and bowel. The ossified lesion of ossification of the posterior longitudinal ligament was observed at L5-S1, and plain lateral radiographs and computed tomography revealed ossification of the yellow ligament on L3, which occupied a large part of the spinal canal. Because of the findings on the preoperative radiographs, we performed posterior approach decompression and bone grafting and excisied the ossified lesion. Pedicle screws were inserted from L3 to S1. The patient's symptoms disappeared postoperatively, and his Japanese Orthopaedic Association score was 25 two weeks postoperatively. No standard surgical procedure exists for the treatment of lumbar ossification of the posterior longitudinal ligament, but it is important to select a surgical procedure according to individual patient conditions. Many factors, such as local mechanic stress, tissue metabolism, high glucose, and genetics, contribute to the progression of ossification of the posterior longitudinal and yellow ligaments on the lumbar spine. However, the mechanism is unclear. Further study and long-term follow-up on lumbar ossification of the posterior longitudinal ligament is needed.     

颈胸腰多发性椎间盘突出伴椎管狭窄症

目的 探讨同时发生在颈、胸、腰段的联合性多节段椎管狭窄的临床特点及治疗方法。方法 采用回顾性研究方法对手术治疗颈、胸、腰段的联合性多节段椎管狭窄的病例进行总结分析。结果 7例病人均同时患颈胸腰三处椎管狭窄。椎间盘突出、后纵韧带骨化、椎板及小关节增生肥大为造成颈胸腰椎管狭窄的主要病因。病人接受一处椎管减压3例，二处椎管减压3例，三处椎管减压1例。结论 同时发生在颈胸腰的椎管狭窄因各节段椎管狭窄致病原因复杂，脊髓受压迫时间较长，临床症状上多样化，易于相互影响。治疗上应先对各部位病情及影像学结果综合后作出轻重缓急的判断，以安排治疗上的先后次序。     

Total (anterior and posterior) decompression of the spinal cord: surgical treatment for combined ossification of the posterior longitudinal ligament and yellow ligament of the thoracic spine

The ossification of the posterior longitudinal ligament (OPLL) combined with ossification of the yellow ligament (OYL) in the thoracic spine can compress the spinal cord from the anterior and posterior direction, resulting in serious myelopathy. For these cases we devised a treatment consisting of two steps, total decompression of the spinal cord. The first step is removal of ossified yellow ligament posteriorly following wide laminectomy and the second step is removal of ossified posterior longitudinal ligament anteriorly, followed by interbody fusion. As the final procedure of the first step, two parallel deep gutters, covering the complete length of the ossified ligament to be removed anteriorly, are drilled from the posterior direction into the vertebral body along both sides of the dura. This pretreatment makes removal of the ossified ligament from the anterior, during the second stage, much easier and safer. This operation appears to be a promising operative procedure from our seven case experiences so far.     

Expansive laminoplasty for myelopathy in ossification of the longitudinal ligament

Laminectomy, which had long been used for treatment of cervical spondylotic myelopathy, including ossification of the longitudinal ligament in the cervical spine, had numerous complications such as postoperative malalignment of the cervical spine and vulnerability of the spinal cord caused by total removal of the posterior structures. In 1977 Hirabayashi devised an open door expansive laminoplasty, which is a relatively easier and safer procedure than laminectomy, that eliminated such problems by preserving the posterior elements. The decompression effect of the expansive laminoplasty against a compressed spinal cord is comparable with that of laminectomy and anterior decompression followed by fusion, whereas the expansive laminoplasty has no structural problems and adverse effects on adjacent disc levels that often are associated with anterior decompression followed by fusion. Average recovery rate of expansive laminoplasty for cervical spondylotic myelopathy has been reported to be approximately 60% (Japanese Orthopaedic Association score) and with long term stability. At present, authors consider all patients with cervical spondylotic myelopathy candidates for expansive laminoplasty except for those having preoperative kyphosis and single level lesion without canal stenosis. Two remaining problems of expansive laminoplasty to be solved are prevention of C5,C6 radicular pain and/or paresis, the most frequent complication that occurs in approximately 5% to 10% of the patients, although most complications resolve spontaneously within 2 years, and correction of nonlordotic alignment to lordosis which are essential for posterior decompression effect of expansive laminoplasty by allowing the spinal cord to shift dorsally.     

Cervical spinal cord injury caused by vertebral body fracture in a patient with concomitant OALL and OPLL

We encountered a case of cervical spinal cord injury associated with cervical vertebral dislocation fracture that occurred in a patient with concomitant ossification of the anterior and posterior longitudinal ligaments. The cervical vertebrae were injured by hyperextension in a car accident. On admission, shearing fracture was noted in the OALL region and vertebral body OPLL region over the posterior column at the fourth cervical level, but no dislocation or neurological findings were noted. Restlessness occurred and caused dislocation several hours after admission, leading to complete injury of the cervical spinal cord. The patient died of complications after 3 weeks. Vertebral body fracture complicated by both OALL and OPLL is very rare, and only four cases have been reported. Since vertebral injury causes delayed fracture/dislocation after a symptom-free interval in cases with ligament ossification, accurate clinical evaluation early after injury and early fixation are necessary.     

胸椎后纵韧带骨化的临床特点及治疗策略

目的回顾研究手术治疗胸椎后纵韧带骨化症(OPLL)的临床特点及治疗方法。方法1991至2005年手术治疗胸椎OPLL55例,男19例,女36例;年龄35～73岁,平均51.9岁。均伴有脊髓损害。手术方式包括单纯椎管后壁切除术34例、前方OPLL切除减压术15例以及前后路联合手术6例。结果55例中36例(65.5%)合并胸椎黄韧带骨化(OLF),18例(32.7%)合并颈椎OPLL。单纯发生于上胸椎的OPLL13例(23.6%),中胸椎12例(21.8%),下胸椎及胸腰段17例(30.9%),广泛分布者13例(23.6%)。43例获得随访,平均随访时间47.1个月(6～168个月)。37例神经功能有改善,改善率为76.6%,无改善2例,加重4例。前方入路获随访者13例,其中3例症状加重,余改善率平均为82.9%(42.9%～100%)。后路椎管后壁切除术获随访者25例,1例无改善,1例加重,余改善率平均为72.6%(22.2%～100%)。前后路联合手术获随访5例,1例无改善,余改善率平均为83.9%。结论胸椎OPLL常合并胸椎OLF及颈椎OPLL。上胸椎OPLL合并颈椎管狭窄可一期行颈后路单开门及上胸椎椎管后壁切除术。两个节段以内的OPLL且不合并有造成脊髓压迫的胸椎OLF可行前路OPLL切除减压术,否则行后路椎管后壁切除术。单节段的OPLL合并胸椎OLF可行前后路联合手术。     

Spinal canal size in ossification of the posterior longitudinal ligament of the cervical spine

BACKGROUND: The size of the spinal canal is a factor that contributes to the neurologic deficits associated with cervical ossification of the posterior longitudinal ligament (OPLL). METHODS: Bone-window computed tomography (CT) examinations of the cervical spine in 64 patients with cervical OPLL were reviewed. Forty-two patients underwent surgical treatment (anterior decompression: 16 patients, posterior decompression: 26 patients). The remaining 22 patients were managed conservatively. Selection of the surgical approach, anterior or posterior, was based on the longitudinal extent of cord compression. RESULTS: The mean developmental size of the spinal canal in the posterior decompression group (10.7 mm at C4) was significantly smaller than the other 2 groups. The spinal canal was narrowed by OPLL to 2.9 to 10.0 mm. The proportion of the patients showing motor deficits of the lower extremities significantly increased when the sagittal canal diameter was narrowed to less than 8 mm. CONCLUSIONS: This study demonstrates critical values of CT-determined spinal canal stenosis. Developmental size of the spinal canal and the residual anterior-posterior canal diameters resulting from OPLL spinal cord compression are important factors influencing clinical management and the neurologic state.     

Hyperostotic lumbar spinal stenosis. A review of 12 surgically treated cases with roentgenographic survey of ossification of the yellow ligament at the lumbar spine

Although there is considerable literature concerning ossification of the posterior longitudinal ligament or the ligamentous flava (OPLL or OYL) in the cervical and thoracic spine, there are only a few references about OPLL or OYL in the lumbar spine. The authors have described lumbar spinal stenosis due to OPLL or OYL as hyperostotic lumbar spinal stenosis, and analyzed 12 surgically documented cases with this condition. The symptoms and signs of hyperostotic lumbar spinal stenosis are the same as those seen in degenerative lumbar spinal stenosis, but the degree of paraparesis is much more severe in hyperostotic lumbar spinal stenosis. Computed tomography scan imaging clearly demonstrates OPLL or OYL in the lumbar spine, although some lesions can be seen on the lateral view of a plain roentgenogram. The results of 12 surgical cases suggest that decompression laminectomy produces relief of symptoms. An analysis of 2,403 plain lumbar roentgenograms showed an incidence of 8.4% OYL in the lumbar spine, with frequent involvement of the upper and middle lumbar spine. A classification system of OYL in the lumbar spine has been developed. The entire spine should be examined before surgery on a patient with hyperostotic lumbar spinal stenosis because of a tendency to ossify spinal ligaments at other levels.     

颈椎后纵韧带骨化合并硬膜囊骨化的CT影像特点及临床意义

目的探讨颈椎后纵韧带骨化合并硬膜囊骨化的CT影像特点及临床意义。方法前路手术治疗21倒颈椎后纵韧带骨化患者,术前均行CT三维重建检查,明确后纵韧带骨化诊断及骨化物类型。术中5例患者被证实合并硬膜囊骨化．其中3例手术切除骨化物时造成硬膜囊缺损而出现脑脊液漏,另2例采用骨化物漂浮法减压。结果4例患者的CT横断面影像具有典型的双影征,矢状面成像表现为分层结构。3例脑脊液漏患者经非手术治疗均得以痊愈。随访1～3年,合并硬膜囊骨化患者的神经功能平均恢复率低于其他患者。结论CT三维影像有助于患者术前硬膜囊骨化的诊断,这对前路手术治疗后纵韧带骨化具有重要意义。     

Cervical myelopathy treated by canal-expansive laminaplasty. Computed tomographic and myelographic findings

The operation known as canal-expansive laminaplasty has the following advantages over wide laminectomy: (1) osseous protection of the spinal cord is retained, (2) the invasion of the cord by scar tissue is minimized, and (3) the stability of the spine is retained. We are reporting the clinical, computed tomographic, and computed myelographic findings before and after this operation in twenty-four patients with cervical myelopathy due to cervical spondylosis, spinal stenosis, or ossification of the posterior longitudinal ligament. The clinical results were excellent in four patients, good in eighteen, and fair in two. Symmetrical expansion of the spinal canal was clearly demonstrated by computed tomograms, and the metrizamide ring on the myelograms had a normal rounded curvature.