Cervical spinal cord injury associated with ossification of the posterior longitudinal ligament

Among 231 patients with cervical injuries treated over 12 years, 15 had cervical spinal cord injury associated with ossification of the posterior longitudinal ligament. All of them were male and most had injuries due to a relatively weak external force. Four of them underwent surgery. There was little difference in improvement of paralysis between the conservatively and the surgically treated group.     

Pathology of the spinal cord damaged by ossification of the posterior longitudinal ligament associated with spinal cord injury

A 63-year-old male became quadriplegic after spinal injury associated with ossification of the posterior longitudinal ligament of the cervical spine and died 4 years later. A postmortem examination of the cervical spinal cord showed various unfavorable pathological changes accounting for severe myelopathy.     

Biomechanical study of the spinal cord in thoracic ossification of the posterior longitudinal ligament

Background

Ossification of the posterior longitudinal ligament (OPLL) in the thoracic spine produces myelopathy. This is often progressive and is not affected by conservative treatment. Therefore, decompressive surgery is usually chosen.

Objective

To conduct a stress analysis of the thoracic OPLL.

Methods

The three-dimensional finite element spinal cord model was established. We used local ossification angle (LOA) for the degree of compression of spinal cord. LOA was the medial angle at the intersection between a line from the superior posterior margin at the cranial vertebral body of maximum OPLL to the top of OPLL with beak type, and a line from the lower posterior margin at the caudal vertebral body of the maximum OPLL to the top of OPLL with beak type. LOA 20°, LOA 25°, and LOA 30° compression was applied to the spinal cord in a preoperative model, the posterior decompressive model, and a model for the development of kyphosis.

Results

In a preoperative model, at more than LOA 20° compression, high stress distributions in the spinal cord were observed. In a posterior decompressive model, the stresses were lower than in the preoperative model. In the model for development of kyphosis, high-stress distributions were observed in the spinal cord at more than LOA 20° compression.

Conclusions

Posterior decompression was an effective operative method. However, when the preoperative LOA is more than 20°, it is very likely that symptoms will worsen. If operation is performed at greater than LOA 20°, then correction of kyphosis by fixation of instruments or by forward decompression should be considered.     

Acute cervical cord injury associated with ossification of the posterior longitudinal ligament

OBJECTIVE: Patients with ossification of the posterior longitudinal ligament (OPLL) sometimes present with acute spinal cord injury caused by only minor trauma. In the present study, we reviewed our experience of acute cervical cord injury associated with OPLL to understand the pathomechanisms and to provide clinical information for management of this disorder. METHODS: Twenty-eight patients were retrospectively analyzed. There were 26 men and 2 women, aged 45 to 78 years (mean, 63.0 yr). Most patients experienced incomplete spinal cord injury (Frankel Grade A, 3; B, 1; C, 15; and D, 9). RESULTS: Radiological studies revealed continuous- or mixed-type OPLL in 14 patients and segmental-type OPLL in 14 patients. The sagittal diameter of the spinal canal was reduced to 4.1 to 10 mm at the narrowest level as a result of OPLL. Developmental size of the spinal canal was significantly smaller in the group with segmental OPLL. Magnetic resonance imaging scans revealed that spinal cord injury occurred predominantly at the caudal edge of continuous-type OPLL or at the disc levels. Surgery was performed in 24 patients either by posterior (18 patients) or anterior (6 patients) decompression at various time intervals after the trauma. Twenty patients (71%) displayed improvement in Frankel grade. CONCLUSION: The present study demonstrates the preexisting factors and pathomechanisms of acute spinal cord injury associated with cervical OPLL. Magnetic resonance imaging is useful to understand the level and mechanism of injury. Further investigation will be needed to elucidate the role of surgical decompression.     

Surgical management of cervical cord injury with ossification of the cervical posterior longitudinal ligament

Objective: To identify an appropriate surgical approach for the management of cervical cord injury with ossification of the posterior longitudinal ligament. Methods: A retrospective study of 25 cases of cervical cord injury with ossification of the posterior longitudinal ligament was performed. Two cases were classified as Frankel grade A, three as grade B, fourteen as grade C, and six as grade D. Treatment procedures consisted of anterior decompression with instrumentation (twelve patients), posterior decompression (eight patients), and combined anterior and posterior decompression (five patients). Results: There were no iatrogenic injuries of great vessels, trachea, esophagus or spinal cord. All patients were followed up for 15–86 months (average, 38.3 months). All segment with anterior fixation attained solid fusion, without implants loosening or breakage. No reclosed open‐door was found after posterior laminoplasty. Twenty‐one patients improved by one to two Frankel grades. The patients with complete spinal cord injury achieved no neurologic recovery, but did experience relief of upper limb pain or numbness. Conclusion: The surgical outcomes of cervical cord injury with ossification of the posterior longitudinal ligament were satisfactory. It is important to select a suitable surgical approach according to the findings on radiological imaging and the clinical characteristics and general condition of the patients.     

伴颈椎后纵韧带骨化的颈脊髓损伤临床特点与疗效

目的探讨颈椎后纵韧带骨化（OPLL）患者外伤时脊髓损伤的临床特点及疗效。方法回顾性分析19例脊髓损伤患者OPLL骨化类型与颈髓NRIT2高信号变化范围、手术方式与手术前后脊髓功能变化的关系。结果伴OPLL的颈椎在较轻的外力作用下常可出现较严重脊髓损伤。伤后8h内行甲泼尼龙冲击治疗12例患者,2例死于并发症,10例患者脊髓功能明显改善。手术治疗17例,1例手术后27d死亡,16例患者术后半年颈髓功能Frankel评分改善。结论OPLL患者外伤后脊髓损伤的程度往往较重,骨化类型与NRI颈髓信号改变平面直接相关。甲泼尼龙冲击治疗、手术减压均有助于颈髓功能的恢复。     

双开门揭盖式椎板分块切除治疗严重颈椎后纵韧带骨化伴颈脊髓损伤

目的:评价双开门揭盖式椎板分块切除治疗严重颈椎后纵韧带骨化症(ossification of posterior longitudinal ligament,OPLL)伴颈脊髓损伤的临床疗效。方法:回顾性分析2012年6月至2014年6月治疗严重颈椎OPLL合并颈脊髓损伤38例患者资料,所有患者接受后路双开门揭盖式椎板分块切除减压内固定术,男25例,女13例;年龄42~78岁,平均58.2岁;35例有明确颈部外伤史,3例仅受轻微暴力(与颈部突然过伸有关)。术前颈部功能障碍指数(Neck Disability Index,NDI)19.8±4.4,术前日本矫形外科协会评分(Japanese Orthopaedics Score,JOA)为8.1±1.7;术前CT重建显示骨化韧带均分布在3个节段以上,椎管占位50%~85%,平均70.7%。结果:所有患者获得随访,时间10~24个月,平均15.6个月。手术时间90~150 min,平均120 min;出血量300~800 ml,平均(480±80)ml。末次随访时颈椎NDI和JOA评分分别为7.5±2.5和13.5±2.0,均较术前明显改善(P0.05)。术前颈椎前凸Cobb角为(8.10±2.70)°,末次随访时为(15.60±1.80)°,差异有统计学意义(P0.05)。术后发生深部感染1例,硬膜外血肿1例,C5神经根麻痹症状3例,轴性症状(axial symptom,AS)8例。无椎动脉损伤、神经症状加重、脑脊液漏、内固定失败等并发症。结论:颈椎后路双开门揭盖式椎板分块切除减压技术治疗重度颈椎OPLL合并颈脊髓损伤患者疗效良好,安全、可行,临床值得推广应用。     

Cervical cord compression secondary to ossification of the posterior longitudinal ligament

STUDY DESIGN: Resident's case problem. BACKGROUND: A 52-year-old Chinese male with a 10-year history of gradually worsening right hip stiffness, weakness, and pain was referred to physical therapy by his orthopedist, who made a diagnosis of developmental dysplasia of the right hip, with possible Legg-Calve-Perthes disease. The patient reported multiple falls over the last several years and a gradual onset of low back pain with an onset of "electricity" down both legs. The patient also reported mild numbness in both forearms and the right hand over the previous several months. This resident's case problem illustrates how a physical therapist recognized the presence of an atypical musculoskeletal pathology through the use of hypothesis-driven clinical reasoning and detailed physical examination. DIAGNOSIS: Examination of the patient's lumbar and cervical spine and hips revealed joint dysfunctions. Neurological testing revealed hyperreflexia. Special testing revealed lower extremity clonus with a positive Babinski sign with gait disturbances. The patient was referred back to his primary physician and then to a neurologist and neurosurgeon. An MRI revealed cervical myelopathy due to ossification of the posterior longitudinal ligament from C3/C4 to C5/C6. The patient then underwent a C3 through C7 laminectomy. DISCUSSION: It is always imperative that sound clinical reasoning be used when performing physical therapy evaluations, regardless of the referral status of the patient. Patients with nonmusculoskeletal pathology may seek physical therapy services and it is the physical therapist's responsibility to complete a thorough examination and refer to specialists when appropriate.     

High incidence of venous thromboembolism after acute cervical spinal cord injury in patients with ossification of the posterior longitudinal ligament

Objective: To determine the incidence of venous thromboembolism (VTE) in patients with acute cervical spinal cord injury (SCI) and ossification of the posterior longitudinal ligament (OPLL).Design: Prospective cohort study.Setting: A department of a university hospital in Japan.Participants: This study included 57 patients (OPLL, n = 10; non-OPLL, n = 47) treated for acute cervical SCI between January 2011 and April 2017. Patients were classified according to motor complete paralysis (MC), motor incomplete paralysis (MIC), or normal motor function, based on American Spinal Injury Association (ASIA) Impairment Scale results.Interventions: N/A.Outcome Measures: All patients were screened for VTE by D-dimer monitoring, and some underwent ultrasonography. If ultrasonography indicated deep venous thrombosis (DVT) or if the D-dimers increased to ≥10 µg/mL, patients underwent contrast venography to detect VTE, including DVT or pulmonary embolism. We compared blood coagulability and VTE incidence in the OPLL and non-OPLL groups.Results: VTE occurred in 11 (19.3%) of 57 patients. The incidence of VTE was higher in the OPLL group than in the non-OPLL group (50% vs. 12.8%; P = 0.017) and higher in the MC group (57.1%) than in the MIC (8.3%; P = 0.002) or normal group (5.3%; P = 0.002). In the MC group, VTE occurred in 50% of OPLL patients and in 62.5% of non-OPLL patients (P = 0.529). In the MIC group, VTE occurred in 50% of OPLL patients and in none of the non-OPLL patients (P = 0.022).Conclusions: Patients with OPLL tended to develop VTE after SCI with motor complete and incomplete paralysis.     

Staged spinal cord decompression through posterior approach for thoracic myelopathy caused by ossification of posterior longitudinal ligament.

STUDY DESIGN: Prospective clinical study of the effect of staged elimination of anatomic factors inhibiting posterior shift of the thoracic spinal cord on the degree of posterior shift of the thoracic spinal cord and its significance in augmenting the safety of ossification of posterior longitudinal ligament (OPLL) manipulation in thoracic OPLL myelopathy. OBJECTIVES: To develop a comprehensive method that enables safe and sufficient decompression of the spinal cord for thoracic OPLL myelopathy. SUMMARY OF BACKGROUND DATA: Decompression of the spinal cord by direct manipulations of thoracic OPLLs, via either anterior or posterior approach, caused some iatrogenic catastrophic spinal cord injuries, and methods to prevent such injuries during surgery have not yet been developed. METHODS: Procedures of elimination of anatomic factors inhibiting posterior shift of the thoracic spinal cord were performed in stages at intervals of between 1 month and 11 years depending on patients' neurologic status. The first stage operation consisted of extensive cervicothoracic laminoplastic decompression with or without posterior longitudinal durotomy, and if the decompression were insufficient, measures for OPLL-spinal cord separation with or without OPLL manipulation were added. RESULTS: All 17 patients with thoracic OPLL myelopathy showed improvements of neurology comparable with those with successful anterior approaches after decompression. The mean follow-up period was 42 months (range 6-101 months). Neurologic improvements persisted for the entire follow-up period in all patients except one patient who developed arachnoid cyst compressing the dorsum of the once-decompressed spinal cord 30 months after surgery. CONCLUSIONS: Staged posterior decompression to eliminate anatomic factors inhibiting posterior shift of the thoracic spinal cord is the safest and the most reliable method of spinal cord decompression to treat thoracic OPLL myelopathy, so far. However, long-term results are required before the methods can be established.     

Total decompression of the spinal cord for combined ossification of posterior longitudinal ligament and yellow ligament in the thoracic spine

Summary One of the causes of hyperostosis in the spinal canal, ossification of the posterior longitudinal ligament (OPLL) combined with ossification of the yellow ligament (OYL) in the thoracic spine, can result in serious myelopathy, leading to sandwich-type compression of the spinal cord from anterior and posterior. For such cases we devised a treatment of total decompression of the spinal cord and intervertebral body fusion. This operation consists of two steps. The first step is designed for posterior and lateral decompression of the spinal cord by removal of the OYL following wide laminectomy. The second step is removal of the OPLL anteriorly for anterior decompression, followed by interbody fusion. As the final procedure of the first step, two deep parallel gutters, covering the extent of the OPLL to be removed anteriorly, are drilled down from the rear into the vertebral body along both sides of the dura. This pretreatment makes removal of the OPLL anteriorly during the second stage much easier, faster, and safer. This operation is lengthy and demanding. However, based on our experience so far, it appears to be a promising surgical procedure.

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Zusammenfassung Die Verknöcherung des Ligamentum longitudinale posterius (OPLL) in Kombination mit der Verknöcherung des Ligamentum flavum (OYL) am Brustwirbel, die als eine Erkrankung der Wirbelkanal-hyperostose genannt wird, kann schwere Myelopathie verursachen, die zur Sandwich-Abdrückung des Rückenmarks von der Vorder- und Rückseite aus kommt. Für diesen Fall haben wir uns eine totale Druckentlastungstechnik des Rückenmarks und eine Spondylosynthese (spinal fusion) des Wirbelkörpers ausgedacht. Diese Operationstechnik besteht aus zwei Stufen. Die erste Stufe zielt auf die vordere und laterale Druckentlastung des Rückenmarks, die mit Entfernung des OYL nach der umfangreichen Laminektomie erreicht werden kann. Die zweite Stufe ist die vordere Entfernung des OPLL für vordere Druckentlastung, die durch die Spondylosynthese des Wirbelkörpers erreicht werden kann. Als letztes Verfahren der ersten Stufe werden zwei parallele tiefe Furchen, die bis an den Bereich des OPLL reichen, mit dem Drillbohrer von der Rückseite in den Wirbelkörper entlang den beiden Seiten des dura mater spinalis gebohrt. Diese Vorbehandlung macht die Entfernung des OPLL von stirnseitiger Richtung aus bei der zweiten Stufe noch leichter, schneller und sicherer. Diese Operation nimmt viel Zeit in Anspruch. Jedoch scheint es uns nach unseren vorliegenden Erfahrungen, daß these Operation ein vielversprechendes Verfahren sei.

     

Cervical cord compression from ossification of the posterior longitudinal ligament in non-orientals

We report 14 cases of symptomatic ossification of the posterior longitudinal ligament (OPLL) diagnosed in non-oriental men between 1978 and 1985. All 14 patients had incomplete spinal cord syndromes due to OPLL in the cervical spine and had been referred undiagnosed from other institutions. Twelve had severe myelopathy and seven were wheelchair-bound before OPLL was diagnosed, while six patients had had operations elsewhere for their neurological dysfunction. There was a close association between OPLL and diffuse idiopathic skeletal hyperostosis (Forestier's disease) on plain radiographs, seven patients having both disorders. Enhanced CT scans proved to be the best diagnostic method for the localisation of cord compression, and magnetic resonance imaging, used on four recent cases, provided the best visualisation of the extent of involvement in the sagittal plane. We aim to heighten awareness of OPLL in non-orientals, in whom the clinical features, histological characteristics, and radiographic patterns are very similar to those of oriental patients.     

Radiological study of cervical ossification of the posterior longitudinal ligament.

The rate of progression of cervical ossification of the posterior longitudinal ligament (OPLL) was radiologically studied during a 3-year period in three patient populations: (a) after laminoplasty (25 patients), (b) after laminectomy (16 patients), and (c) in patients who were managed without surgery (56 patients). There appeared to be no significant difference between these two surgical procedures in postoperative progression of OPLL. When progression of OPLL was compared between patients treated surgically and nonsurgically, posterior surgery accelerated progression of OPLL.     

Postmortem study of the spinal cord showing snake-eyes appearance due to damage by ossification of the posterior longitudinal ligament and kyphotic deformity

CLINICAL DESIGN: A case report. OBJECTIVES: To elucidate the clinical role of snake-eyes appearance in this case, correlation between radiological, clinical and postmortem study was performed. SETTING: Aichi, Japan. CASE REPORT: A 73-year-old man developed weakness and pain in the upper limbs due to kyphotic deformity secondary to laminectomy for cervical ossification of the posterior longitudinal ligament. Axial magnetic resonance imaging revealed snake-eyes appearance from C4 to C6. He died of acute myocardial infarction 3 months after anterior decompressive surgery. RESULTS: A postmortem examination of the cervical spinal cord showed small cystic six necrotic areas at the junction of the central gray matter and the ventrolateral posterior column, one in the right and one in the left, in association with neuronal loss in the anterior horn. CONCLUSIONS: Bilateral small intramedullary high-signal areas known as 'snake-eyes appearance' located around the central gray matter and the ventrolateral posterior column, are associated with neuronal loss in the compressed anterior horn that played an important role in worsening weakness of the upper limbs.     

无脊髓压迫症状颈椎后纵韧带骨化患者的影像学特点及临床意义

目的:探讨无脊髓压迫症状颈椎后纵韧带骨化(OPLL)患者的影像学特点及临床意义。方法:分析42例无脊髓压迫症状颈椎OPLL患者初次就诊的影像学资料,男25例,女17例,年龄40～78岁,平均57岁。根据影像学表现对OPLL进行分型,观察椎管最大受压处骨化物占位率(OPLL占位率)与椎管最大受压节段活动范围(ROM)的相关性,同时观察MRI T2像上脊髓内信号的变化并随访患者症状进展情况。结果:根据Tsuyama分型标准,本组连续型24例,混合型10例,节段型8例。OPLL占位率20%～64%,平均38.4%;最大受压节段ROM平均4.5°。线性回归显示OPLL椎管占位率与ROM呈负相关(P<0.01)。所有患者未出现MRI T2相脊髓内信号改变。随访2年～5年6个月,平均3年8个月,所有患者末次随访查体均未发现脊髓压迫症临床表现。结论:无脊髓压迫症状的颈椎OPLL,以连续型骨化多见,椎管最大受压节段活动范围较小可能是其无脊髓压迫症状的原因之一。     

Cervical ossification of the posterior longitudinal ligament: Anterior versus posterior approach

Background:

The optimal approach to provide satisfactory decompression and minimize complications for ossification of the posterior longitudinal ligament (OPLL) involving multiple levels (3 levels or more) remains controversial. The purpose of this study was to compare the results of two surgical approaches for cervical OPLL involving multiple levels; anterior direct decompression and fixation, and posterior indirect decompression and fixation. We present a retrospective review of 56 cases followed at a single Institution.

Materials and Methods:

We compared patients of multiple levels cervical OPLL that were treated at a single institution either with anterior direct decompression and fixation or with posterior indirect decompression and fixation. The clinical records of the patients with a minimum duration of follow-up of 2 years were reviewed. The associated complications were recorded.

Results:

Fifty-six patients constitute the clinical material. 26 cases were treated by anterior corpectomy and fixation and 30 cases received posterior laminectomy and fixation. The two populations were similar. It was found that both anterior and posterior decompression and fixation can achieve satisfactory outcomes, and posterior surgery was accomplished in a shorter period of time with lesser blood loss. Although patients had comparable preoperative Japanese Orthopaedics Association (JOA) scores, those with a canal occupancy by OPLL more than 50% and managed anteriorly had better outcomes. However, for those with more severe stenosis, anterior approach was more difficult and associated with higher risks and complications. Despite its limitations in patients with high occupancy OPLLs, through the multiple level laminectomy, posterior fixation can achieve effective decompression, maintaining or restoring stability of the cervical spine, and thereby improving neural outcome and preventing the progression of OPLL.

Conclusions:

The posterior indirect decompression and fixation has now been adopted as the primary treatment for cervical OPLL involving multiple levels with the canal occupancy by OPLL <50% at our institution because this approach leads to significantly less implant failures. Those patients with the occupancy ≥50% managed with anterior approach surgeries had better outcomes, but approach was more difficult and associated with higher risk and complications.     

Secondary medulla oblongata involvement following middle cervical spinal cord injury associated with latent traumatic instability in a patient with ossification of the posterior longitudinal ligament

STUDY DESIGN: A case report. OBJECTIVES: To report a rare case of extension of edema and hemorrhage from initial C4-5 spinal injury to the medulla oblongata. SETTING: Center for Spinal Disorders and Injuries, Bibai Rosai Hospital, Japan. METHODS: A 68-year-old man with ossification of the posterior longitudinal ligament (OPLL) had sustained tetraplegia after tumbling over a stone. Initially, the patient was diagnosed with an acute C4-5 spinal cord injury without radiological abnormalities and was treated conservatively. At 7 h after the injury, the patient had an ascending neurological deficit, which required respiratory assistance. Magnetic resonance imaging revealed a marked swelling of the spinal cord above C4-5 extending to the medulla oblongata. RESULTS: Retrospective radiological assessment revealed that the spine was unstable at the injury level because of discontinuities in both anterior and posterior longitudinal ligaments. There was also signal intensity change within the retropharyngeal space at the C4-5 intervertebral disc. This injured segment was highly vulnerable to post-injury dynamic stenosis and easily sustained secondary neural damage. CONCLUSIONS: This case report emphasizes a careful radiological assessment of latent structural instability in patients with OPLL in order to detect and prevent deteriorative change in the spinal cord.