11/63. Impact of longitudinal distance of the cervical spine on the results of expansive open-door laminoplasty. STUDY DESIGN: A retrospective study in patients who underwent expansive open-door laminoplasty (ELAP) for cervical myelopathy and in whom the cervical alignment was nonlordotic at the final follow-up to analyze the correlation between the longitudinal distance of the cervical spine and surgical results. OBJECTIVES: To determine the impact of longitudinal distance of the cervical spine on surgical results of ELAP and to propose a new concept, the redundant spinal cord, that may influence patient selection for ELAP. SUMMARY OF BACKGROUND DATA: Results in many studies have demonstrated that postoperative cervical alignment has significant effect on surgical results, and spines that are malaligned are thought to deteriorate. The current surgical data showed that not all patients with postoperative malalignment had poor surgical results. patients with cervical spondylotic myelopathy (CSM) tended to have better clinical results than those with ossification of the posterior longitudinal ligament (OPLL). methods: Results in 70 patients who underwent ELAP for cervical myelopathy with postoperative cervical malalignment were investigated. The longitudinal distance index (LDI) was defined as the length of a vertical line between the posteroinferior edges of C2 and C7 divided by the anteroposterior diameter of C4 and was measured on lateral neutral radiographs at final follow-up. Correlation between LDI and surgical results represented by Japanese Orthopedic association scores and percentage of recovery were analyzed statistically in each patient. RESULTS: patients with CSM had smaller LDI and better surgical results than those with OPLL. Weak but significant negative correlation was detected between LDI and percentage of recovery, indicating that longitudinal distance of the cervical spine may have some degree of impact on the surgical results of ELAP. CONCLUSION: A decrease in LDI represents shortening of the cervical spine caused by multiple disc degeneration and may influence surgical results of ELAP by inducing redundancy of the spinal cord in patients with postoperative malalignment. ( info) |
12/63. hypertrophy of the posterior longitudinal ligament is a prodromal condition to ossification: a cervical myelopathy case report. STUDY DESIGN: A histopathologic examination of a specimen that showed hypertrophy of the posterior longitudinal ligament of the cervical spine. OBJECTIVES: To illustrate the possibility of hypertrophy of the posterior longitudinal ligament as a prodromal condition to ossification of the posterior longitudinal ligament. SUMMARY OF BACKGROUND DATA: Despite much study, the pathology of ossification of the posterior longitudinal ligament still remains unclear. Hypertrophic change often is seen in the part of the ossified ligament; however, there have been few histopathologic reports on hypertrophy of the posterior longitudinal ligament. Some reports have suggested that hypertrophy of the posterior longitudinal ligament is a prodrome of ossification of the posterior longitudinal ligament. methods: A 64-year-old man was admitted to the hospital because of gait disturbance and developed oliguria. In a plain radiograph, segmental ossification of the posterior longitudinal ligament was found at C4, C5, and C6. Computed tomograph myelogram revealed a soft tissue shadow, maximum 3.8 mm in diameter, on the dorsal side of the ossification of the posterior longitudinal ligament at C5 and C6. Magnetic resonance T1-weighted image (T1WI) showed an equivalent signal with the intervertebral disc on the dorsal side of ossification of the posterior longitudinal ligament. This lesion was enhanced with Gd-DTPA and confirmed as hypertrophy of the posterior longitudinal ligament. Cervical anterior decompression and fusion were performed using Yamaura's technique. The ossified and thickened lesion was elevated and removed en bloc. Then, hematoxylin-eosin and toluidine blue staining was performed to detect metachromasia. RESULTS: Macroscopic examination of the specimen revealed that soft tissue formation was connected with the C4-C5 intervertebral space and extended downward to C6-C7. Histopatholgically, collagen fibers were proliferating in the long-axis direction on both ventral and dorsal sides. This was surrounded by extended nucleus pulposus-like chondrocyte tissue, where endplate cartilage was detected around the C4 pedicle. Roux staining was low, and partial vascular and cellular infiltration was observed, although it was not marked. CONCLUSION: The herniated nucleus pulposus involving endplate cartilage from C4-C5 was limited to the superficial layer, and proliferation of nucleus pulposus-like chondrocytes occurred in the herniated tissue, where they might undergo a change in cell phenotype. The results of the present study support the hypothesis that hypertrophy of the posterior longitudinal ligament is a prodromal condition to ossification of the posterior longitudinal ligament. ( info) |
13/63. Identification of ossification of the posterior longitudinal ligament extending through the dura on preoperative computed tomographic examinations of the cervical spine. STUDY DESIGN: To establish the diagnosis of dural penetration on preoperative computed tomographic studies of the cervical spine in patients with ossification of the posterior longitudinal ligament (OPLL). OBJECTIVES: To define before surgery the pathognomonic computed tomographic findings of OPLL extending to and through the dura. SUMMARY OF BACKGROUND DATA: On preoperative computed tomographic studies, Hida et al have described the single-layer sign characterized by a solid mass of hyperdense OPLL and the double-layer sign defined by two (anterior and posterior) ossified rims surrounding a central nonossified but hypertrophied posterior longitudinal ligament. Only 1 of the 9 patients exhibiting the single-layer sign but 10 of 12 patients showing the double-layer sign had no separate dural plane identified at surgery. methods: Only 2 of 54 patients undergoing multilevel cervical circumferential OPLL procedures had absent dura at surgery. Computed tomographic examinations for all patients were retrospectively reviewed to determine unique signs of dural penetration. RESULTS: Dura was absent in 1 of 12 patients who had the single-layer CT sign that was additionally characterized by an irregular C angular configuration. Only 1 of 4 patients exhibiting the double-layer computed tomographic sign had absent dura at surgery. The remaining 38 patients had the smooth-layer sign, characterized by more regular margins of classic (22 patients) or early OPLL (16 patients). CONCLUSIONS: The double-layer computed tomographic sign is more pathognomonic for dural penetration than the single-layer sign. The smooth-layer sign, indicating a clean dural plane, is more typical in North American patients. ( info) |
14/63. 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. ( info) |
15/63. Clinics in diagnostic imaging (55). Ossification of the posterior longitudinal ligament. Ossification of the posterior longitudinal ligament (OPLL) of the cervical spine associated with diffuse idiopathic skeletal hyperostosis is described in a 70-year-old Caucasian man presenting with a rapidly progressive myelopathy. The acute nature of his myelopathic symptoms and cervical canal stenosis necessitated posterior decompressive surgery. Four other patients with OPLL are presented to illustrate the spectrum of imaging findings. The computed tomographic features of OPLL are distinctive.A 2-5 mm thick linear ossified strip along the posterior vertebral margin usually at mid cervical (C3 to C5) level characterises the condition. Magnetic resonance (MR) imaging is valuable in excluding possible cord damage and associated disc lesions prior to surgery. A calcified central sequestrated disc is the only condition that may be mistaken for the segmental and retrodiscal forms of OPLL In a clinical setting of compressive myelopathy, it is pertinent to distinguish between these two conditions since a sequestrated disc has a more favourable surgical prognosis. The merits and relevance of anterior and posterior surgery together with their possible complications are outlined. ( info) |
16/63. Unusual appearance of an en plaque meningioma of the cervical spinal canal. A case report and literature review. STUDY DESIGN: A case report of a patient with cervical spinal cord and nerve root compression caused by a meningioma en plaque together with calcification of the posterior longitudinal ligament is presented,with a review of the literature. OBJECTIVE: To present the diagnosis of a calcified dural meningioma en plaque, with extradural extension into the ligamentum flavum, in a woman with cervical myelopathy and neuropathy. SUMMARY OF BACKGROUND DATA: This case demonstrates that the cervical spine can be involved in dural meningioma en plaque with calcifications, in a manner mimicking ossification of the ligamentum flavum, which has never been previously reported. methods: A patient presenting with cervical cord and nerve root compression caused by ossification of the posterior longitudinal ligament and a concurrent calcified dural meningioma en plaque was treated surgically and has made a gradual recovery. Imaging studies,surgical findings, and histopathologic evaluation were analyzed to support the diagnosis. RESULTS: At surgery, ossification of the posterior longitudinal ligament was noted, along with a calcified lesion involving the posterior cervical dura and the adjacent ligamentum flavum. A calcified meningioma was diagnosed by histopathologic examination of the dural-based lesion. CONCLUSION: Although previously not described, the diagnosis of calcified dural meningioma en plaque should be considered in all patients presenting with spinal cord and/or nerve root compression,even at cervical levels. Although ossification of the posterior longitudinal ligament and ossification of the ligamentum flavum are more common etiologies of partially circumferential spinal calcification, dural-based meningiomas with extension into the surrounding ligaments demand early recognition because they can be associated with a poorer prognosis. ( info) |
17/63. Bilateral phrenic nerve palsy as a complication of anterior decompression and fusion for cervical ossification of the posterior longitudinal ligament. STUDY DESIGN: A case report of bilateral phrenic nerve palsy as a complication of anterior decompression and fusion for cervical ossification of the posterior longitudinal ligament (OPLL). OBJECTIVES: To present a case of a rare and serious complication of cervical spinal surgery and to investigate its cause. SUMMARY OF BACKGROUND DATA: There have been a number of reports of phrenic nerve palsy after cardiac surgery, but the authors have found no previous description of this complication related to spinal surgery. methods: The authors describe the clinical presentation and management of a case of bilateral phrenic nerve palsy subsequent to the surgery for cervical OPLL. Also, the literature is reviewed concerning surgical approaches for the treatment of OPLL and the occurrence of phrenic nerve palsy subsequent to any form of therapy. RESULTS: Bilateral phrenic nerve palsy occurred after anterior decompression and fusion for cervical OPLL. Bilateral phrenic nerve palsy was diagnosed radiographically: postoperative chest radiograph showed bilateral laxity of the diaphragm. movement of the bilateral diaphragm appeared 3 weeks after surgery. The patient successfully returned to normal daily life after ventilatory support for 3 months, although nocturnal oxygen support was still necessary at the latest follow-up, 3 years after surgery. The possible causes of this complication include bilateral C4 nerve root stretching, iatrogenic injury of the gray matter in the ventral horn, alteration of blood circulation related to spinal edema, or re-impingement on the spinal cord at the cranial part of the decompression site. CONCLUSIONS: Bilateral phrenic nerve palsy occurred after anterior decompression and fusion for cervical OPLL. Bilateral phrenic nerve palsy should be kept in mind as a serious complication of spinal surgery. It should be considered when patients unexpectedly fail to wean from the ventilator after surgery. ( info) |
| Ossification of the posterior longitudinal ligament (OPLL) is an uncommon cause of compressive myelopathy outside japan. A case of cervical cord compression in a female whose MRI showed OPLL is reported. T2 weighted MRI images are the most effective to evaluate both spinal cord compression due to ossification and abnormal signal intensity of the cord. OPLL should be included in the differential diagnosis of cervical radiculomyelopathy. ( info) |
19/63. Cervical cord injury in an elderly man with a fused spine--a case report. We report a case of an elderly man presenting with co-existing diffuse idiopathic skeletal hyperostosis (DISH) and ossified posterior longitudinal ligament (OPLL) resulting in central cord syndrome. Only three such cases have been reported co-existing with DISH. The patient recovered most of his neurological deficit through conservative management. A discussion on the radiological features of DISH co-existing with OPLL and how these differ from ankylosing spondylitis (AS) follows. ( info) |
20/63. quadriplegia complicating ossification of the posterior longitudinal ligament. We report a case of quadriplegia complicating ossification of posterior longitudinal ligament (OPLL) in a patient who was also found to have diffuse idiopathic skeletal hyperostosis (DISH). She also had osteomalacia (Vit. D deficiency) with secondary hyperparathyroidism. There could be a cause and effect relationship between the abnormal biochemistry and OPLL. ( info) |