The pattern of spinal and extraspinal hyperostosis in patients with ossification of the posterior longitudinal ligament and the ligamentum flavum causing myelopathy

Thirty one patients suffering from myelopathy associated with ossification of the posterior longitudinal ligament and ligamentum flavum of the spine have been investigated. The pattern of spinal and peripheral hyperostosis was recorded in each case. Flowing anterior vertebral hyperostosis and ligamentous ossification at the enthesis around the pelvis and hips were the most frequent associations, occurring in approximately 86% of patients. The distribution and incidence of the spinal and extraspinal hyperostosis in this series corresponds closely to the findings in diffuse idiopathic skeletal hyperostosis (DISH). The present findings indicate that patients suffering from cervical myelopathy and ossification of the posterior longitudinal ligament should be regarded as manifesting focal features of a more generalised disorder producing skeletal hyperostosis.     

Anatomical and radiological observations concerning ossification of the sacrotuberous ligament: is there a relation to spinal diffuse idiopathic skeletal hyperostosis (DISH)?

In a collection of 101 anatomical preparations of the human pelvis, ossification of the sacrotuberous ligament was found in 8 cases. In 7 of these, the ossification showed a characteristic intraligamentous morphology, with a broad-based origin at the ischial tuberosity and tapering off craniomedially. The length varied between 1.1 and 7.2 cm. The surface of the bone formations appeared fasciculated, except in one case which had a wax-like flowing bone formation lying upon the sacrotuberous ligament. Careful anatomical and radiological examination of the spine, the ulnae, the calcanei and the iliac crests in these 8 cases, revealed in only one case any findings (spurs at the olecranon) that could be attributed to extraspinal manifestations of diffuse idiopathic skeletal hyperostosis (DISH). Indeed, in no case were the most widely accepted diagnostic criteria of DISH, the spinal alterations, seen. We therefore suggest that ossification of the sacrotuberous ligament is an autonomous finding and not a good indicator of the presence of spinal DISH.     

Ossification of the posterior longitudinal ligament

Two asymptomatic, unusually young male patients aged 18 and 21 with ossification of the longitudinal posterior ligament of the cervical spine are presented. Geographical distribution, pathological and radiologic aspects of the disease are discussed together with those signs differentiating it from ankylosing spinal hyperostosis.     

Diffuse idiopathic skeletal hyperostosis. Review of diagnostic criteria and analysis of 915 cases]

DISH is a common systemic skeletal disease, probably of dysmetabolic and/or degenerative origin, yet of unknown etiology. It is observed in middle-aged or elderly patients of both sexes, and is characterized by ossification of the anterior longitudinal ligament on the antero-lateral aspect of the spine, and by ossifying enthesopathy, in both the central and the peripheral skeleton. Diagnosis is solely based on radiographic abnormalities, according to the so-called Resnick criteria. In the present study, the spines of 915 patients (414 males, 501 females, mean age: 65 years) were considered, and the peripheral entheses (heel, patella and elbow) of 494 of them (234 males and 260 females). The incidence of DISH was 14.09% (129 cases): 17.6% in males (73 cases) and 11.7% in females (56 cases). DISH strikes in the VI and VII decades of life most. The most affected sites of the spine were: the dorsal portion (100%), especially in the D7-D11 segment (93%); the lumbar spine in L1-L3 (81%), and the cervical spine, in the C5-C7 segment (69%). Peripheral areas of involvement were: pelvis (90%), heel (76%), elbow (46%) and knee (29%). The symptoms of DISH must be promptly detected: the disease is not asymptomatic, but presents with pain and stiffness in the spine, recurrent tendinitis and bursitis, and myelopathy.     

Paravertebral ligamentous ossification: DISH,OPLL and OLF

This is an overview of paravertebral ligamentous ossification based on our 5-year experience in ossification of posterior longitudinal ligament (109 cases) and ossification of ligamentum flavum (18 cases). Paravertebral ligamentous ossification is designated as the disorder caused by frequently coexisting ossification of paravertebral ligaments, DISH, OPLL, and OLF. The frequency of the occurrence of isolated ossification of PLL and OLF in Japan is still uncertain. DISH, which is not rare in Europe or North America, is frequently associated with ossification of the posterior aspect of the vertebral bodies, but it may be less symptomatic. The major cause of the probably higher incidence of symptomatic patients in Japan may be due to associated narrowing of the spinal canal.     

Diffuse skeletal hyperostosis in idiopathic hypoparathyroidism

A case of idiopathic hypoparathyroidism (IHP) is reported with extensive ligamentous and tendinous ossification and soft tissue calcification. The pertinent radiological features of IHP and the unusual findings in this case are reviewed together with similar previously reported cases. Whether IHP is a causative or aggravating factor in the aetiology of the skeletal changes is discussed with particular reference to their similarity to diffuse idiopathic skeletal hyperostosis (DISH). We conclude that, in patients with an ossifying diathesis, IHP acts as a stimulant resulting in exuberant skeletal hyperostosis that is indistinguishable from DISH.     

Degenerative diseases of the vertebral column

Several distinct degenerative processes affect the articulations of the vertebral column; each is associated with characteristic radiographic and pathologic abnormalities, and many are accompanied by significant clinical manifestations. A discussion of these processes is best accomplished according to the type of joint that is involved. With regard to cartilaginous articulations, of which the intervertebral disk is most important, intervertebral (osteo)chondrosis, spondylosis deformans, and, in the cervical spine, uncovertebral arthrosis are the major degenerative disorders. Osteoarthritis (osteoarthrosis) affects any of the synovium-lined joints of the vertebral column, including the apophyseal, costovertebral, transitional lumbosacral, median atlantoaxial, and sacroiliac articulations. Fibrous articulations, ligaments, or entheses (sites of tendon or ligament attachment to bone) are involved in diffuse idiopathic skeletal hyperostosis, ossification of the posterior spinal ligaments, and Baastrup disease. Of the many complications of these degenerative processes, alignment abnormalities (including segmental instability, degenerative spondylolisthesis, senile kyphosis, and degenerative scoliosis), intervertebral disk displacement, calcification or ossification, and spinal stenosis are the most important.     

Ossification of the posterior longitudinal ligament of the spine.

"The Japanese disease" or ossification of the posterior longitudinal ligament of the cervical spine was initially thought to affect only the Japanese people. Non-Japanese Asian and Caucasian cases have been reported but appear to be exceedingly rare. The reason is unknown. Although the disease appears to be generally benign, it can cause a myelopathy. We present here 16 non-Japanese patients in Singapore who were found to have ossification of the posterior longitudinal ligament in the cervical, thoracic and lumbar spine.     

Association between monoclonal gammopathy of undetermined significance (MGUS) and diffuse idiopathic skeletal hyperostosis (DISH)

PURPOSE: To determine whether an association exists between monoclonal gammopathy of undetermined significance (MGUS) and diffuse idiopathic skeletal hyperostosis (DISH). MATERIALS AND METHODS: Radiological studies of skeleton were performed in a series of 76 patients (51 males and 25 females) affected by MGUS, observed in a consecutive period of 36 months. They revealed hyperostotic lesions similar to those described in DISH. RESULTS: Patients affected by MGUS complicated by DISH were 35 (24 males and 11 females). The prevalence of skeletal hyperostosis (46%) appears higher than that reported by the literature in the general population (mean 15 %). Typically, the vertebral column is the predominant site of abnormalities in MGUS as well as in DISH: involvement of dorsal spine was observed in 16 males and 10 females; cervical spine in 12 males and 4 females, and lumbar in 9 males and 2 females. Peripheral ossifying enthesopathy ("whiskering" in the pelvis) was found in 7 cases, 5 males and 2 females. CONCLUSIONS: DISH is probably an ossifying diathesis of unknown aetiology; its occurrence in multiple myeloma and especially in MGUS is much higher because it is a fortuitous association. Many causes (accidental, dysmetabolic or degenerative) of DISH-like syndrome complicating dysgammaglobulinemias have been supposed, but at the present time this association remains a mere guess. A pathogenetic "event" responsible for hyperostosis may be supposed: in fact, in MGUS bone stimuli induced by osteoclast activating factor (OAF) and plasma cell proliferation -- even if lower than those observed in multiple myeloma -- are much more prolonged in time (see the slow progression of this condition, before it becomes symptomatic), so that the rate of calcium mobilized from skeleton and localized into soft tissues (i.e., tendons and ligaments) is higher. In this manner, the incidence of DISH-like ossification is higher than that observed in multiple myeloma and in the general population.     

Heterotopic bone formation in patients with DISH following total hip replacement

Radiographs of 236 patients who underwent total hip replacement (THR) were evaluated for heterotopic bone formation. There was no significant difference in the presence and degree of ossification in patients with and without diffuse idiopathic skeletal hyperostosis (DISH). The authors conclude that DISH is not a significant risk factor in the development of heterotopic bone formation following THR.     

Diffuse idiopathic skeletal hyperostosis as a cause of dysphagia

Radiographic, clinical and pathologic abnormalities of diffuse idiopathic skeletal hyperostosis (DISH) are presented. Definite criteria must be fulfilled to differentiate DISH from other diseases of the spine, especially intervertebral osteochondrosis and ankylosing spondylitis. A case of massive DISH in the cervical spine causing dysphagia is described.     

Calcification of the alar ligament of the cervical spine: imaging findings and clinical course

Ligamentous calcification of the cervical spine has been reported in the yellow ligament, anterior and posterior longitudinal ligaments and interspinous ligament. Calcification in the upper cervical spine is rare, although some cases with calcification of the transverse ligament of the atlas have been reported. Two patients with calcification of the alar ligament with an unusual clinical presentation and course are described. Examination by tomography and computed tomography (CT) showed calcification of the alar ligament and the transverse ligament of the atlas. CT documented decreased calcification as symptoms resolved. There may be a role for CT in the search for calcifications in the upper cervical spine in patients presenting with neck pain and pharyngodynia if radiographs are normal. Received: 13 October 2000 Revision requested: 17 November 2000 Revision received: 18 December 2000 Accepted: 19 December 2000     

Plasma cell dyscrasias and diffuse idiopathic skeletal hyperostosis. Is it a merely accidental association?

The radiologic staging of a series of 144 patients (88 males and 56 females) affected with plasma-cell dyscrasias and observed over a 26-month period, revealed both the well-known bone myeloma-related abnormalities and hyperostotic lesions similar to those described in diffuse idiopathic skeletal hyperostosis. The incidence of skeletal hyperostosis was 31.94%, much higher than that reported in literature for the general population (5%). Typically, the axial skeleton is the most common location for abnormalities in multiple myeloma (MM) as well as in DISH: involvement of the dorsal spine was observed in 65% of cases, the cervical spine was involved in 34.8% of patients, and the lumbar spine in 28.3%. Peripheral ossifying enthesopathy, considered as "whiskering" in the pelvis, was found in 12 cases (8.2%), 7 males and 5 females. DISH was indifferently present in both MM (23 cases), with severe osteolysis (stage III) or simple osteoporosis (stage I), and monoclonal gammopathy of undetermined significance (MGUS) (17 cases), usually without any myeloma-related bone lesions, and in Waldenstr?m disease (4 cases). Many hypotheses are discussed as to the possible pathogenesis (e.g.: accidental, dysmetabolic, or degenerative) of hyperostosis in dysgammaglobulinemias, but, to date, they are no more than mere guesses. DISH is a disorder the etiology of which is still unknown: it is likely to be an ossifying diathesis, but its incidence in both illnesses--which are both plasma-cell dyscarsias--is too high for the association to be accidental. Thus, a pathogenetic factor produced by multiple myeloma can be hypothesized, capable of increasing the so-called idiopathic hyperostosis.     

颈椎前路手术中相关神经损伤并发症的常见原因及治疗

目的 回顾颈椎前路手术中相关神经损伤的常见原因及治疗方法.方法 2008年1月-2009年12月手术治疗859例颈椎病、颈椎后纵韧带骨化症及颈椎外伤行颈椎前路手术患者,对术后出现脊髓损伤症状加重及相关神经损伤的7例患者的临床资料进行回顾性分析.结果 859例患者中共5例发生脊髓损伤,发生率为0.58%;1例发生喉返神经损伤,发生率为0.12%;1例发生喉上神经损伤,发生率为0.12%.术后血肿发生脊髓损伤4例,经过清除血肿、甲基强的松龙等药物、高压氧及时治疗,均逐渐恢复至正常;术后发生脊髓损伤症状加重1例,经气管切开、呼吸机支持治疗及激素、高压氧治疗后脊髓损伤症状逐渐恢复至原有水平.术后发生喉返神经、喉上神经损伤患者2例经过激素、脱水等药物保守治疗,术后3个月内均恢复至正常.结论 颈椎病、颈椎后纵韧带骨化症及颈椎外伤患者行颈椎前路手术中均可能发生脊髓损伤及相关神经损伤,如能注意预防和及时治疗,预后较好.

Abstract：

Objective To review the relevant causes for and treatment of nerve injuries in the anterior cervical surgery. Methods From January 2008 to December 2009,859 cages of cervical spondylosis,ossification of cervical posterior longitudinal ligament and cervical spine trauma were treated by anterior cervical surgery.This study retrospectively analyzed the clinical data of seven cases who were with worsened symptoms of spinal cord injury and related nerve injury. Results Of 859 cases,five cases(0.58%)were with spinal cord injury,one(0.12%)with recurrent laryngeal nerve injury and one (0.12%)with laryngeal nerve injury.Hematoma occurred in four cases after surgery caused spinal cord injury and all the four patients recovered to normal after removal of the hematoma and timely treatment with mythylprednisolone and hyperbaric oxygen.Cervical spine trauma was worsened in one patient after the anterior cervical surgery.The patient restored to its original level of spinal cord gradually through some measures such as tracheotomy,ventilator support,hormone therapy and hyperbaric oxygen treatment.Laryngeal nerve injuries in two cases recovered to normal after conservative treatment with hormone,dehydration and other drugs within three months after surgery. Conclusions Anterior cervical surgery of cervical spondylosis,ossification of cervical posterior longitudinal ligament and cervical spine trauma are likely to induce the related nerve damage.The good prognosis can be obtained under timely prevention and treatment.     

Diffuse idiopathic skeletal hyperostosis: diagnostic significance of radiographic abnormalities of the pelvis

Retrospective evaluation of the osseous pelvis in 93 patients with severe diffuse idiopathic skeletal hyperostosis (DISH) revealed 14 locations of radiographic abnormalities. Two osteoradiologists independently studied these sites for abnormalities in a prospective, blinded fashion in 103 patients over the age of 45 years. Lateral radiographs of the thoracolumbar spine were quantitatively and qualitatively evaluated to determine whether DISH, spondylosis deformans, or a normal spine was present. Statistical analysis was performed for evaluation of interobserver reliability, the relationship between pelvic and spinal abnormalities, and the significance and predictive values of pelvic abnormalities for DISH versus non-DISH and DISH versus spondylosis deformans. Although significantly higher frequencies and greater extents of radiographic abnormalities at 10 of 14 pelvic locations were noted for DISH compared with non-DISH, this number decreased to four of 14 locations when compared with spondylosis deformans. The alterations in three of these four pelvic sites consisted of ossification of ligaments. These changes appear to be good indicators of the presence of spinal DISH and support the concept that DISH is an entity separate from spondylosis deformans.     

颈椎病患者后纵韧带的磁共振影像及临床意义

目的：探讨颈椎病后纵韧带的磁共振影像特点及其临床意义。方法：对2000年4月。2002年4月的42例颈椎病的磁共振影像和临床资料进行回顾性分析。结果：磁共振检查提示后纵韧带骨化9例，后纵韧带肥厚17例，颈椎问盘脱出16例。16例行颈椎后路手术，26例行颈椎前路手术切除后纵韧带。平均改善率为61．8％，优11例，占31．4％；良14例，占40％；一般8例，占22．9％；差2例，占5．7％。结论：MRI对后纵韧带骨化、后纵韧带肥厚和颈椎问盘脱出的诊断有重要价值，对手术方案的选择有重要意义。     

Ossification of the posterior longitudinal ligament of the lumbar spine

The ossification of the cervical posterior longitudinal ligament (OPLL) is widely known and studied in Japan where a roentgenological incidence of 2.06% adults affected has been found. Data concerning the ossification of the lumbar posterior longitudinal ligament are few and occasional. An epidemiological survey on lumbar OPLL was performed by the authors in Matsumoto, Japan, on a total of 792 subjects, 554 of whom over the age of 35, by means of X-ray of the lumbar spine. Ossification of the lumbar posterior longitudinal ligament was detected in 23 subjects (2.9%), with no significant difference between males (3.0%) and females (2.8). Lumbar OPLL was absent in the 238 subjects aged less than 34; it was the most prevalent after the age of 45 (5.1% in males and 4.5% in females). The ossification developed in two ways: continuous ossified layer extending over several vertebrae; circumscribed ossification of the ligament corresponding to the level of the intervertebral disk (retrodiscal type). The result of this epidemiological survey showed a roentgenological incidence of lumbar OPLL of the same magnitude than that of cervical OPLL.     

Posterior longitudinal ligament ossification myelopathy and hypothyroidism

Two elderly white women with a long history of hypothyroidism and myelopathy showed ossification in posterior longitudinal ligament at their cervical spine. Case histories are presented and the reported association of PLLO with other conditions discussed.     

Ossification of the cervical posterior longitudinal ligament with severe myelopathy and fatal outcome

Ossification of the posterior longitudinal ligament is rare among Caucasians. We describe a new case with lethal outcome and we discuss the radiographic and pathologic findings. Posterior longitudinal ligament ossification is a benign disease in most cases, but it may cause severe myelopathy due to spinal stenosis. Diagnosis may be suspected or made on lateral views of the cervical spine and ascertained by CT.     

螺旋CT扫描多平面重建（MPR）诊断颈椎退行性病变

目的 :探讨螺旋CT扫描并多平面重建 (MPR)对颈椎退行性病变的诊断价值。材料和方法 :对 45例颈椎病患者利用常规颈椎CT扫描和螺旋CT扫描并行MPR重建 ,对比分析扫描结果。结果 :螺旋CT扫描并MPR重建除显示 42例表现为一个以上椎间盘突出并压迫神经根及硬脊膜囊外 ,还显示椎体后缘骨质增生 3 0例 ,钩椎关节骨质增生 2 1例 ,2 3例共 2 7个椎间孔狭窄 ,12例共 15个横突孔狭窄 ,9个狭窄横突孔边缘骨质硬化增白 ,并可整体直观的观察韧带骨化、肥厚及椎管狭窄情况。结论 :螺旋CT扫描并MPR重建在显示颈椎退行性变各种病理改变方面比常规CT扫描具有重要的价值。