黄韧带骨化的影像学诊断

作者对２１例胸椎黄韧带骨化的影像学表现进行了分析。在侧位Ｘ线片上，可见骨化的黄韧带突入椎管，体层摄影则可勾划出黄韧带骨化特征。依阻塞程度不同，脊髓造影片上可呈完全性或不完全性梗阻。在不完全梗阻的侧位片上常提示压迫来自椎管后方。ＣＴ扫描显示黄韧带骨化增生，造成椎管狭窄及脊髓压迫。ＭＲＩ检查除可显示位于椎管后缘的黄韧带呈低信号变化之外，还能显示出骨化灶的范围，从而排作其他原因引起的脊髓外压迫。     

Neuroradiological examination of thoracic radiculo-myelopathy due to ossification of the ligamentum flavum

Summary Sixteen cases of thoracic radiculomyelopathy due to ossification of the ligamentum flavum (OLF) were analyzed. The patients ranged in age from 39 to 78 years (average 57 years). There were 13 men and 3 women. A significant predilection of OLF for the lower thoracic spine (T9/10, T10/11, T11/12) was noticed. Plain X-ray of the thoracic spine and multidirectional tomography could give important information about the site of ossification. Computed tomography with the intrathecal injection of the water-soluble contrast material clearly demonstrated the ossification and the degree of compression of the spinal cord. The disadvantages of using computed tomography for diagnosing OLF included the necessity for the scan level to be previously decided by other methods because computed tomography of the entire spine was impractical. Magnetic resonance imaging was performed in 14 patients and gave important information about OLF and the compression of the spinal cord. The combination of MRI and computed tomography seems the most useful for the precise diagnosis of OLF.     

MRI of ossification of ligamentum flavum.

Magnetic resonance imaging of 28 patients with radiological and/or histopathologically proved ossification of the ligamentum flavum (OLF) was reviewed. The locations of OLF were cervical (n = 4), thoracic (n = 22), and lumbar (n = 2). On T1- and T2-weighted images, OLF demonstrated low signal intensity. Areas of high or intermediate signal intensity within the OLF on T1-weighted images were observed in three cases and were interpreted to be due to fat infiltration. In six cases, high intensity areas in the spinal cord caused by compressing OLF were demonstrated on T2-weighted images. Gadolinium-diethylenetriamine pentaacetic acid, which was used in four cases, showed cord enhancement at the level of compression by OLF in three cases.     

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.     

Effect of low back posture on the morphology of the spinal canal

Objective. To define the possible mechanism of posture-dependent symptoms of spinal stenosis by measuring the effect of low back posture on morphologic changes of the intervertebral discs and spinal canal in healthy young people. Design.Twenty healthy young volunteers underwent magnetic resonance imaging while supine with their spine in neutral, flexed, extended, and right and left rotational positions. The axial MR images at the middle of the intervertebral discs of L3–4 and L4–5 were analyzed to measure the difference in the size and shape of the intervertebral discs and spinal canal in each posture. Results.  Extension or rotation decreased the sagittal diameters and cross-sectional areas of the dural sac and spinal canal and increased the thickness of the ligamentum flavum, whereas flexion had the opposite effects. The gap between the convex posterior disc margin and the anterior margin of the facet joint on each side, represented as the subarticular sagittal diameter, increased with flexion and decreased with extension or rotation. The direction of rotation did not result in asymmetry of the subarticular sagittal diameter, but right rotation caused thickening of the right ligamentum flavum, and vice versa. The shape and dimensions of the disc did not change significantly according to the positions of the low back. Conclusions.With extension or rotation, the thickness of the ligamentum flavum increased and the posterior margin of the intervertebral disc was approximated to the facet joint without any change in shape and size of the disc. These phenomena result in a decrease in the size of the spinal canal and dural sac in extension or rotation postures in young healthy people without disc degeneration, and may explain the posture-dependent symptom of spinal stenosis. Received: 18 October 1999 Revision requested: 9 November 1999 Revision received: 13 December 1999 Accepted: 17 January 2000     

Unusual CT/MR features of putative ligamentum flavum ossification in a North African woman

To display the unusual spinal CT and MR findings in a 48-year-old North African woman presenting with two adjacent intracanalar mineralized epidural outgrowths exhibiting mature bone organization with "cortical" and "trabecular" areas and pseudoarthritic changes at their interface. An unusual form of ligamentum flavum ossification (LFO) was speculated, of which features are discussed under the light of the available literature.     

Myelopathy due to ossification or calcification of the ligamentum flavum: radiologic and histologic evaluations

The clinical, radiologic, and histologic features of ossification and calcification of the ligamentum flavum were studied in 18 patients. Ossification (15 patients) usually occurred in the lower thoracic spine in men of various ages, while calcification (three patients) was found exclusively in the cervical region of older women. Histologic examinations of ossification showed mature lamellar bone associated with proliferated cartilage replacing the ligamentum flavum (endochondral ossification). This corresponded well with radiographic and computed tomographic (CT) appearances. In the cases with calcification of the ligamentum flavum, calcification within the degenerated ligamentous fibers was observed on histologic examination, and correlated well with an oval nodular density on radiographs and CT. The two conditions differ in clinical, radiologic, and histologic considerations. Pathomechanisms in the development of these lesions and clinical significance are also discussed.     

黄韧带肥厚的磁共振诊断

笔者对37例经手术与病理证实的黄韧带肥厚(HLF)之临床与磁共振表现及离体标本之光镜与电镜所见进行了分析。认为磁共振对HLF的诊断价值是:(1)可多方位显示HLF的位置、形态与厚度,对HLF在椎管内折曲情况及脊神经根管内神经根受卡压程度的判定优于其它影象检查。(2)可大范围、富有连续性地观察黄韧带周围的其它组织,有利于发现HLF之并存症,对多部位的HLF及多种病因引起之椎管狭窄症的诊断有重要价值。(3)对脂肪组织的显示甚为灵敏,有助于观察硬膜外脂肪的形态改变,可较精确测量硬膜囊矢状径、借助于硬膜囊受压百分比的测定可提示脊髓受压的程度。(4)可观察脊髓充血、水肿及变性引起之MR信号改变。 本组病例诊断中之假阴性与假阳性率为7％,文中探讨了降低假阴性与假阳性率的方法。 HLF的病理改变主要是弹力纤维的萎缩、断裂、纤维化及脂肪浸润与钙化,本组病例显示弹力纤维的钙化具有由外向内发展的方向性与规律性,此点在文献中尚未见报道。     

Cyst of the ligamentum flavum

We report the case of a patient with sciatica resulting from a cyst of the ligamentum flavum. Received: 1 December 1999/Accepted: 2 May 2000     

Ossification of the posterior longitudinal ligament and ligamentum flavum: imaging features

Ossifications of the posterior longitudinal ligament and ligamentum flavum are both special subcategories of degenerative diseases responsible for compression of the spinal cord. Ossification of the ligaments is well demonstrated by plain radiography and computed tomography. Magnetic resonance imaging noninvasively provides useful information about the degree and extent of spinal cord compression as well as the character of the ossification. T2-weighted sequences are most effective to evaluate both spinal cord compression due to the ossification and abnormal signal intensity of the spinal cord.     

Ossification of the ligamentum flavum

Summary A case of thoracic myelopathy due to ossification of the ligamentum flavum is presented. A fifty-five year old female complained of sensory and motor disturbance of lower limbs. Neuroradiologically, in addition to ossification of the posterior longitudinal ligament throughout the spines, ossified ligamenta flava were found at the Th10–11 level and magnetic resonance imaging (MRI) clearly showed the spinal cord compressed at the same level by a low-intensity-signal lesion. Laminectomy and removal of the ossfied ligamenta flava improved her neurological dysfunction. The usefulness of the MRI in the neuroradiological diagnosis was confirmed.     

Intraosseous microcystic meningioma

Extradural ectopic meningioma is a rare tumor. We report on an example of microcystic meningioma arising in the skull of an elderly woman. Radiological examination revealed a localized osteolytic lesion in the left parietal bone. At surgery, it was discovered that the tumor was located within the skull without any evidence of extraosseous extension. The light microscopic, immunohistochemical and ultrastructural features were consistent with a microcystic variant of meningioma. To our knowledge, this is the first case of an intraosseous microcystic meningioma, and we believe that this type of meningioma should be considered in the differential diagnoses of myxoid bone tumors of the calvarium. Received: 10 January 2000 Revision requested: 21 February 2000 Revision received: 8 March 2000 Accepted: 13 March 2000     

Immunoglobulin D myeloma presenting as an extraosseous soft tissue tumor

We report a 69-year-old man who suffered an extraosseous tumor of immunoglobulin D myeloma (lambda type) in the shoulder girdle, mimicking a primary soft tissue sarcoma. The tumor was isointense with adjacent muscle on T1-weighted MR images, and hyperintense on T2-weighted images. No continuity with the neighboring bone was noted. After administration of gadolinium, the central part of the tumor showed marked contrast enhancement. Although the tumor showed a complete response to the initial chemotherapy, the patient died of the disease 31 months after its initial manifestation. Several bone marrow aspirations and biopsies of the ilium and sternum had shown no increase in plasma cells (range 0.6–1.2%) until the disease became advanced 19 months after its initial manifestation. Received: 1 September 2000 Revision requested: 9 October 2000 Revision received: 11 November 2000 Accepted: 15 November 2000     

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.     

术中唤醒试验在严重脊柱黄韧带骨化症手术中的应用

目的 对全身麻醉下术中唤醒试验(wake-up test,WUT)在严重脊柱黄韧带骨化症手术中应用的安全性进行评估.方法 2004年6月-2010年6月对35例黄韧带骨化症患者在全身麻醉下行术中唤醒后采用后路椎板切除减压治疗,其中男23例,女12例;平均年龄50.5岁(32～71岁).颈椎4例,胸椎24例,腰椎7例;单节段14例,多节段21例.结果 平均手术时间190 min(120～260 min),平均失血量350 ml(220～520 ml),平均每例减压2.6个椎板(1～5个).全部患者随访6～72个月,平均29.5个月.术前日本骨科学会(JOA)评分为(4.286±1.0167)分,术后JOA评分为(8.171±1.0428)分(P<0.01).术中有3例出现神经症状加重,采取措施后2例神经功能逐渐恢复,1例未能恢复,其余患者均未出现术后瘫痪等严重并发症.结论 全身麻醉下术中唤醒试验在严重黄韧带骨化症手术中的临床应用疗效满意,可有效避免神经症状加重甚至瘫痪等严重并发症发生.

Abstract：

Objective To assess the efficacy and safety of intraoperative wake-up test during surgery for ossification of the ligamentum flavum(OLF). Methods Between June 2004 and June 2010,35 patients(23 males and 12 females,at age range of 32-71 years,mean 50.5 years) with OLF underwent posterior decompressive laminectomy and excision of OLF.The operation wag performed on the cervical vertebrae in four patients,on the thoracic vertebrae in 24 and on the lumbar spine in seven,with monosegmental OLF in 14 patients and multisegmental OLF in 21.The outcomes were evaluated using Japanese Orthopaedic Association (JOA) scale. Results The operation lasted for mean 190 minutes (120-260 minutes),with the blood loss for mean 350 ml (220-520 ml)and the mean 2.4(1-5) lamin receiving decompression.The follow-up period ranged from 6 to 72 months (mean 29.5 months).The JOA score was improved from 4.302±1.023 preoperatively to 8.327±1.032 at the final follow-up (P<0.01).The neurological symptoms was aggravated during operation in three patients,for whom the muscles force recovered gradually in two patients but one showed no change after special measures.No serious complication was found in the other patients postoperatively. Conclusions The wake-up test can serve as an effective monitoring during the procedure ofthe decompressive laninectomy in the patients with severe OLF and decrease the occurrence of neurologic deficit complications.     

Normal and degenerative posterior spinal structures: MR imaging

A retrospective study of the magnetic resonance (MR) images of the lumbar spines of 13 healthy subjects and 30 patients with degenerative changes was done. In the healthy subjects, the vertebral facets, thickness of the cartilage and ligamentum flavum, signal characteristics of the bone marrow, and size of the spinal canal were studied. In the patients with degenerative changes in one of these structures, MR images in the sagittal plane were useful in demonstrating hypertrophy of the ligamentum flavum or the vertebral facets, in grading the degree of foraminal stenosis, and in measuring the sagittal diameter of the spinal cord. MR images in the axial plane facilitated detailed analysis of the facet joint and more accurate measurements of the thickness of the ligamentum flavum and spinal canal diameter. MR images were compared with computed tomography scans in 12 patients.     

Pelvic instability after bone graft harvesting from posterior iliac crest: report of nine patients

Objective. To report the imaging findings in nine patients who developed pelvic instability after bone graft harvest from the posterior aspect of the iliac crest. Design and patients. A retrospective study was performed of the imaging studies of nine patients who developed pelvic pain after autologous bone graft was harvested from the posterior aspect of the ilium for spinal arthrodesis. Plain films, bone scans, and CT and MR examinations of the pelvis were reviewed. Pertinent aspects of the clinical history of these patients were noted, including age, gender and clinical symptoms. Results. The age of the patients ranged from 52 to 77 years (average 69 years) and all were women. The bone graft had been derived from the posterior aspect of the iliac crest about the sacroiliac joint. All patients subsequently developed subluxation of the pubic symphysis. Eight patients had additional insufficiency fractures of the iliac crest adjacent to the bone graft donor site, and five patients also revealed subluxation of the sacroiliac joint. Two had insufficiency fractures of the sacrum and one had an additional fracture of the pubic ramus. Conclusions. Pelvic instability is a potential complication of bone graft harvesting from the posterior aspect of the iliac crest. The pelvic instability is manifested by insufficiency fractures of the ilium and subluxation of the sacroiliac joints and pubic symphysis. Received: 25 January 2000 Revision requested: 22 May 2000 Revision received: 15 September 2000 Accepted: 4 January 2001     

Compressive myelopathy in fluorosis: MRI

We examined four patients with fluorosis, presenting with compressive myelopathy, by MRI, using spin-echo and fast low-angle shot sequences. Cord compression due to ossification of the posterior longitudinal ligament (PLL) and ligamentum flavum (LF) was demonstrated in one and ossification of only the LF in one. Marrow signal was observed in the PLL and LF in all the patients on all pulse sequences. In patients with compressive myelopathy secondary to ossification of PLL and/or LF, fluorosis should be considered as a possible cuase, especially in endemic regions.     

Hematoma in the cervical ligamentum flavum. Report of a case and review of the literature

Hematoma of the cervical ligamentum flavum is very rare, and its pathogenesis is unknown. We describe a case of ligamentum flavum hematoma in the cervical spine causing severe myelopathy. Postoperative histological examination suggested it was the result of the rupture of a hemangioma or of an arteriovenous malformation in the ligamentum flavum. After removal of the lesion, the patient’s condition immediately improved. Review of all three reported cases, including this one, showed that complete resection of the mass resulted in immediate relief of symptoms of incomplete paraplegia. The findings of magnetic resonance imaging (MRI) of the hematoma may vary with time, and they may show no characteristic intensity. However, MRI of this case revealed that the tissues surrounding the mass were enhanced with gadolinium diethylene triamine penta-acetic acid, and an area of homogeneous iso-intensity was clearly surrounded by a low-intensity area (flavum) on T2-weighed short-tau inversion recovery images. These findings could be characteristic of the ligamentum flavum hematoma and might help in the differentiation from a cervical epidural hematoma.     

Juxtacortical chondromyxoid fibroma arising in an apophysis

We present a rare case of juxtacortical chondromyxoid fibroma arising in the lesser trochanter of the right femur which corresponds to an apophysis. Radiography showed a well-defined expansive lesion with a sclerotic margin measuring 5×3.5 cm in diameter in the lesser trochanter. On spin echo T1-weighted images, the lesion revealed low signal intensity similar to muscle. On spin echo T2-weighted images, the lesion revealed high heterogeneous signal intensity, which after gadolinium injection showed heterogeneous enhancement. The inner margin of the cortex was intact and adjacent bone marrow was of normal signal intensity. The outer margin of the lesion was also clearly defined and extension into adjacent soft tissue beyond the exophytic cortical outgrowth was not evident. Received: 1 March 2000 Revision requested: 28 March 2000 Revision received: 1 May 2000 Accepted: 8 May 2000