Epidural angioleiomyoma: an extraordinary cause of compressive myelopathy-MRI findings with histopathological correlation.

BACKGROUND: Angioleiomyomas are benign mesenchymal tumors usually located in the limbs, with anecdotal reports in the spine. We present an atypical case of an epidural spine angioleiomyoma presenting with compressive myelopathy symptoms. The diagnosis was suggested based on MRI findings, and subsequently confirmed histopathologically. RESULTS: This is the first known occurrence of pure spinal epidural angioleiomyoma as a source of compressive myelopathy. The imaging presentation, especially the 'dark reticular sign' on MRI, was crucial in suggesting the diagnosis despite the atypical location CONCLUSION: This report serves to raise awareness among clinicians and radiologists about including angioleiomyoma in differential diagnoses for spinal epidural lesions with indicative MRI features. The favorable outcome after surgical intervention underscores the necessity of swift and accurate diagnosis followed by appropriate treatment for such uncommon spinal tumors.

Aggressive vertebral hemangiomas in children.

BACKGROUND: Aggressive vertebral hemangiomas are rare tumors in children, usually occurring in the thoracic spine that can cause significant neurological morbidity. They are technically difficult to treat with significant risk of blood loss during surgery. METHODS: We describe a case of aggressive vertebral hemangioma managed in our institution. We performed a literature review of reported cases of aggressive vertebral hemangiomas in pediatric age group. We discuss the clinical presentation, diagnosis, and management of these lesions. RESULTS: We identified 23 cases of aggressive vertebral reported in children. Neurodeficit was the most common presentation, and the most common location was the thoracic spine. Surgery was the most common modality of treatment. All the patients reported in literature had improvement in their symptoms after treatment. CONCLUSION: Although technically challenging, aggressive vertebral hemangiomas have a good outcome after treatment. Treatment should be tailored to the individual patient. Further studies are needed to determine the optimum treatment strategy.

Multifocal spinal inflammatory myofibroblastic tumors in a juvenile paraparetic dog.

A 1-year-old, female English Bulldog presented with a 10-day history of progressive paraparesis. Neuroanatomical localization was consistent with T3-L3 segment myelopathy. Magnetic resonance imaging (MRI) revealed a severely compressive, mildly contrast enhancing, extradural, dorsal, broad-based mass at the level of L3-4. Similar, non-compressive, smaller nodules were present along the extradural space and dura mater of the caudal lumbar spine. Owners elected euthanasia based on these imaging findings and progressive clinical signs. Necropsy, histopathology and immunohistochemistry revealed a mesenchymal mass and nodules, admixed with numerous inflammatory cells. The diagnosis of an extradural inflammatory myofibroblastic tumor (IMT) with a multifocal presentation was made.

How i do it: biportal endoscopic thoracic decompression for ossification of the ligamentum flavum.

BACKGROUND: Currently, decompressive laminectomy with or without concomitant fusion is a standard treatment for ossification of the ligamentum flavum (OLF). However, conventional thoracic decompressive laminectomy is not free of the inevitable destruction of the posterior ligamentous complex, and facet injury may lead to various sequelae. METHOD: We used the biportal endoscopic technique for posterior thoracic decompression (BE-PTD) and describe the steps with discussion regarding the indications, advantages, possible complications, and ways to overcome complications. CONCLUSION: BE-PTD can obtain endoscopic visualizations of all the boundaries of the OLF lesion and achieve direct neural decompression of thoracic OLF.

Compressive vertebral hemangiomas with neurological deficits: diagnosis, surgical strategies and long term outcome.

PURPOSE: Compressive vertebral hemangiomas with neurological deficits (CVHND) form a rare, unique subset of lesions comprising of differing clinico-imaging findings, pathologic behavior and treatment, when compared to the commoner and usually incidental intra-osseus vertebral hemangiomas (VH). Though various surgical strategies and a broad array of adjuncts have evolved and changed over the years, there is paucity of comprehensive data from sizeable series of such patients treated surgically with long term follow up. The purpose of this study is to device an optimum management strategy in CVHND based on our surgical experience. MATERIALS AND METHODS: The data from electronic medical records of 26 consecutive patients operated in our department from 2009 to 2019 were retrospectively analyzed. RESULTS: There were 11 males and 15 females with a mean age of 34.7 years. Neurological examination revealed paraparesis or paraplegia with myelopathy in all patients with Frankel score of B, C and D in 1 (3.9%), 11 (42.3%) and 14 (53.8%) patients respectively. Sixteen patients (61%) underwent laminectomy and gross total excision of extradural soft tissue component, 7 (27%) laminectomy with posterolateral fusion, three (12%) underwent additional anterior interbody support. The mean follow up was 72.4 months and at last follow-up 24 patients (92%) were Frankel E. Symptomatic recurrence was seen in two patients operated early in the series, they underwent re-surgery, gross total excision with posterolateral fusion, remaining neurologically intact at last follow up. CONCLUSIONS: Pre-operative embolization, surgical excision of extradural component and intra-operative vertebroplasty form the mainstay of treatment for CVHND. Instrumented posterolateral fusion with optional anterior interbody support accomplished through the same approach is required only in a minority of cases. The long-term outcome following timely and appropriate treatment is excellent. Anterior or anterolateral approaches for intervertebral support and radical procedures like total en-bloc spondylectomy (TES) are not usually required.

Verminous myelopathy secondary to aberrant Dirofilaria immitis migrans was detected in the cervical subarachnoid space of four dogs using MRI and CT.

Aberrant Dirofilaria immitis migrans is a rare cause of neurologic signs in dogs, however, published studies describing the computed tomographic (CT) and magnetic resonance imaging (MRI) characteristics of this problem are currently lacking. The objective of this retrospective case series study was to describe the clinical and imaging findings for four adult dogs with verminous myelopathy due to aberrant Dirofilaria immitis migrans within the cervical subarachnoid space. All dogs were toy breeds, were heartworm antigen positive, had neurologic signs (ranging from cervical hyperesthesia to tetraparesis), and similar MRI findings. In two patients additionally imaged with CT, findings were variable. On MRI, each dog had a single large, dorsal- to laterally located, intradural-extramedullary, fusiform mass with characteristic stippled, mixed T2-weighted and T1-weighted signal intensity, hypo-to-iso T1-weighted signal intensity, and spinal cord compression. Nematodes were identified as serpentine or circular subarachnoid structures with low T2-weighted and T1-weighted signal in the sagittal and transverse image planes, respectively. CT (n = 2 dogs) demonstrated focal regions of mildly enhancing intradural-extramedullary spinal cord compression in 1 dog. Dorsal laminectomy and durotomy were performed in two dogs at C3-C4. A C4-5 hemilaminectomy with durotomy and dural biopsy was performed in one dog. Extraction of live, immature adult, female D. immitis worms was performed in three dogs. Operated dogs had complete post-surgical resolution of clinical signs. One dog was euthanized without surgery; necropsy revealed an adult heartworm in the spinal subarachnoid space at C2. Findings indicated that cervical spinal subarachnoid D. immitis aberrant migration should be considered as a differential diagnosis for dogs with this combination of clinical and CT/MRI imaging findings, and that the prognosis may be good with early detection and surgical removal.

The prediction of intraoperative cervical cord function changes by different motor evoked potentials phenotypes in cervical myelopathy patients.

BACKGROUND: Surgery is usually the treatment of choice for patients with cervical compressive myelopathy (CCM). Motor evoked potential (MEP) has proved to be helpful tool in evaluating intraoperative cervical spinal cord function change of those patients. This study aims to describe and evaluate different MEP baseline phenotypes for predicting MEP changes during CCM surgery. METHODS: A total of 105 consecutive CCM patients underwent posterior cervical spine decompression were prospectively collected between December 2012 and November 2016. All intraoperative MEP baselines recorded before spinal cord decompression were classified into 5 types (I to V) that were carefully designed according to the different MEP parameters. The postoperative neurologic status of each patient was assessed immediately after surgery. RESULTS: The mean intraoperative MEP changes range were 10.2% ± 5.8, 14.7% ± 9.2, 54.8% ± 31.9, 74.1% ± 24.3, and 110% ± 40 in Type I, II, III, IV, and V, respectively. There was a significant correlation of the intraoperative MEP change rate with different MEP baseline phenotypes (r = 0.84, P < 0.01). Postoperative transient new spinal deficits were found 0/31 case in Type I, 0/21 in Type II, 1/14 in Type III, 2/24 in Type IV, and 4/15 in Type V. No permanent neurological injury was found in our cases series. CONCLUSIONS: The MEP baselines categories for predicting intraoperative cervical cord function change is proposed through this work. The more serious the MEP baseline abnormality, the higher the probability of intraoperative MEP changes, which is beneficial to early warning for the cervical cord injury.

Autopsy of malignant paraganglioma causing compressive myelopathy due to vertebral metastases.

Paraganglioma is a neuroendocrine tumor arising from extra-adrenal sites in the peripheral nervous system. Although malignant paraganglioma is known to metastasize to bones, including vertebral bodies, there is little literature on the compressive myelopathy accompanied by sphincter dysfunction; to our knowledge, only 12 cases have been reported. Moreover, neuropathological investigations of the spinal cord in this state have not been well-documented. This autopsy report describes a 55-year-old man with malignant paraganglioma and compression myelopathy caused by vertebral metastasis. The present case showed a gradual numbness and a sudden onset of irreversible paraplegia with sphincter dysfunction, which were not palliated these neurologic dysfunctions despite radiotherapy. Computed tomography (CT) revealed multiple metastases to the bones, lymph nodes, and lungs when he was diagnosed with malignant paraganglioma. At the same time, he had numbness, and magnetic resonance imaging (MRI) showed multiple diffuse metastatic lesions in the vertebral bodies. Following abrupt onset of paralysis, MRI showed fractured third and sixth thoracic vertebral bodies. An autopsy revealed residual vertebral metastases with fractures of the third and sixth thoracic vertebral bodies, resulting in compressive myelopathy at the fourth thoracic segment, which was characterized by complete spinal cord destruction. Destructive spinal cord lesion-induced secondary degeneration was observed in the gracile fasciculus at the rostral side and in the pyramidal tract at the caudal side, which showed Wallerian degeneration. Such pathology was consistent with the presenting neurological symptoms, including paraplegia and somatic sensory loss below the fourth thoracic spinal cord segment. Although it is difficult to identify the pathognomonic morphological changes responsible for the sphincter dysfunction, the present case suggests a supranuclear dysregulation of the somatosensory and central autonomic nervous systems involved in urination and defecation. Based on a review of the literature and the features of the present case, paraganglioma can metastasize aggressively even with a low pathological grading. This case of vertebral metastasis as a result of malignant paraganglioma may not be extraordinary but the autopsy report is rare. This autopsy revealed transverse myelopathy as a result of malignant vertebral metastasis of malignant paraganglioma.

Does three-grade classification of T2-weighted increased signal intensity reflect the severity of myelopathy and surgical outcomes in patients with cervical compressive myelopathy? A systematic review and meta-analysis.

The three-grade classification of increased signal intensity (ISI) on T2-weighted magnetic resonance imaging (MRI) is used extensively in patients with cervical compressive myelopathy (CCM). However, the efficacy and value in the prediction of this classification are still unclear and no systematic review and meta-analysis have been conducted on this topic. The objective of this study is to investigate the efficacy and value in prediction of the three-grade classification of ISI on the severity of myelopathy and surgical outcomes. Randomized or non-randomized controlled studies using three-grade classification of ISI (grade 0, none; grade 1, light or obscure; and grade 2, intense or bright) in patients with CCM were sought in the following databases: PubMed, Embase, and Cochrane Library. The pooled Japanese Orthopedic Association (JOA)/modified JOA (mJOA) score, neuro-functional recovery rate, C2-C7 lordotic angle, and range of motion (ROM) were calculated. A total of 8 studies containing 1101 patients were included in this review. Patients in grade 0 had the highest preoperative and postoperative JOA/mJOA score and recovery rate, while those parameters for patients in grade 2 were the lowest. Nevertheless, no statistically significant difference was found regarding the preoperative C2-C7 lordotic angle and ROM among three grades. Our meta-analysis suggests that the three-grade classification of ISI on T2-weighted MRI can reflect the severity of myelopathy and surgical outcomes in patients with CCM. The higher ISI grade indicates more severe myelopathy and surgical outcomes. Overall, the three-grade classification of ISI is instructive and should be used universally.

Update on Surgical Treatment of Wobblers.

Cervical vertebral compressive myelopathy (CVCM) represents the most significant disease of the spinal cord in horses for which surgical treatment is described. Current surgical methods used include ventral interbody fusion with kerf cut cylinders and dorsal laminectomy. Polyaxial pedicle screw and rod constructs and ventral locking compression plating have been introduced in the treatment of equine CVCM and present promising alternative approaches to achieve ventral interbody fusion. Advancements in diagnostic imaging and endoscopy of the cervical vertebral canal may improve reliable preoperative identification of the exact locations of spinal cord compression in horses with CVCM to improve postoperative outcomes.

Extremely high preoperative C7 slope limits compensatory cervical lordosis after muscle-preserving selective laminectomy.

PURPOSE: A high C7 slope induces C2-C7 lordosis to compensate for cervical sagittal balance adjustments. A muscle-preserving selective laminectomy (SL) can maintain this compensation postoperatively. This study evaluated the effect of an extremely high C7 slope on C2-C7 lordotic compensation following SL. METHODS: This study enrolled 151 cervical compressive myelopathy patients who underwent SL. Lateral cervical spine radiographs were taken before surgery and during final follow-up. Patients were divided into extremely high C7 slope (≥ 30°) (EH) and non-high C7 slope (< 30°) (NH) groups and the influence of a high C7 slope on radiological and surgical outcomes was examined. RESULTS: Mean age was higher in group EH (p < 0.001). Preoperatively, patients in group EH had a larger C2-C7 sagittal vertical axis (SVA) (p = 0.001) and greater cervical lordosis (p < 0.001). Although C2-C7 SVA increased after surgery, mean C2-C7 angle of group EH decreased. Mismatches between C7 slope and C2-C7 angle increased for group EH postoperatively (p = 0.015). Postoperative Japanese Orthopedic Association (JOA) score and recovery rate (RR) were slightly lower in group EH (p = 0.001 and p = 0.006, respectively). Multiple linear regression analyses revealed that extremely high C7 slope, not age, affected the RR of JOA score (p = 0.006). CONCLUSIONS: Patients in group EH were older and had highly compensated cervical sagittal alignment preoperatively. They demonstrated postoperative cervical sagittal balance mismatch increases and slightly worse functional recovery. An extremely high C7 slope limited compensatory cervical lordosis following SL. These slides can be retrieved under Electronic Supplementary Material.

Hirayama disease/cervical flexion-induced myelopathy progressing to spastic paraparesis: A report on three cases with literature review.

Hirayama disease (HD)/cervical flexion-induced myelopathy (CFIM) is a lower motor neuron disease conventionally affecting a single upper extremity. We describe three men progressing after a long stable period to develop severe spastic paraparesis and bladder disturbances as a protracted implication of HD. The age at onset was 20, 24, and 15 years, while the age at presentation was 27, 41, and 57 years, respectively. The second phase of disease progression occurred after 4, 13, and 28 years of stationary period. All had CFIM with characteristic magnetic resonance imaging features as observed during progressive stages. The anterior dural shift extended variably from C4 to D4 levels with a median value of 5 mm and was maximum at C6 to C7 levels, pushing the cord anteriorly causing compression. This study emphasizes the need to recognize this unusual subgroup of HD and mandates long-term follow-up with timely intervention in arresting the progression/improving the deficits.

Endoscopic partial corpectomy using anterior decompression for cervical myelopathy.

Symptomatic ventral cervical cord compressions have been treated by anterior discectomy with fusion, anterior corpectomy and fusion, discectomy with an artificial disc, and minimally invasive techniques. There are complications associated with the fusion procedure, especially when a long segment fusion is undertaken. Partial removal of the vertebral body without fusion could help in avoiding fusion and its associated complications. We are describing the detailed surgical technique, indications, limitations, and early results of endoscopic partially corpectomy. The detailed endoscopic technique of how to remove minimal portion of the anterior and middle part of the vertebra with the removal of compressing posterior portion is described. To the best of the author's knowledge, this procedure has not been described in the literature till date. This technique has the advantages of preservation of most of the vertebral body and disc. The stability of the spine is maintained without the patient having to undergo the additional procedure of spinal fusion. There is a shorter length of hospital stay. The technique can also be used in special conditions, such as when a migrated disc behind the vertebral body or any bony compression opposite the vertebral body is encountered. It avoids injury to the longus colli muscles and damage to most of the annulus fibrosis. It preserves motion segments at the operated and adjacent segments without any significant decrease in the disc and vertebral height. A relatively short follow-up and the experience in a relatively small number of patients till now, are the limitations to the widespread use of this technique. Although long-term follow-up of this procedure in a large number of patients is not currently available, endoscopic partial corpectomy seems to be an effective and an alternative method for dealing with anteriorly located cervical compression. Long-term follow-up in a large number of patients is required to assess for the safety and effectiveness of the procedure.

Degenerative Cervical Myelopathy: A Clinical Review.

Degenerative Cervical Myelopathy (DCM) is the most common form of spinal cord impairment in adults and results in disability and reduced quality of life. DCM can present with a wide set of clinical and imaging findings, including: 1) pain and reduced range of motion of the neck, and motor and sensory deficits on clinical exam, and 2) cord compression due to static and dynamic injury mechanisms resulting from degenerative changes of the bone, ligaments, and intervertebral discs on MRI. The incidence and prevalence of DCM has been estimated at a minimum of 4.1 and 60.5 per 100,000, respectively, but surgical trends and an aging population suggest these numbers will rise in the future. The diagnosis of DCM is based on clinical examination, with a positive Hoffmann's sign and hand numbness typically appearing in the upper limbs, and gait abnormalities such as difficulty with tandem gait serving as sensitive diagnostic findings. Loss of bladder function may also occur in patients with severe DCM. The degree of neurological impairment can be measured using the modified Japanese Association Scale (mJOA) or Nurick grade. Non-operative management has a limited role in the treatment, while surgical management has been shown to both be safe and effective for halting disease progression and improving neurological function. Predictors of surgical outcome include age and baseline severity, indicating that early recognition of DCM is important for ensuring an optimal surgical outcome.

Compressive myelopathy in severe angular kyphosis: a series of ten patients.

OBJECTIVE: Compressive myelopathy in severe angular kyphosis is rare and challenging for surgical treatment. The goal of this retrospective study was to report a series of ten patients with compressive myelopathy in severe angular kyphosis and the results of surgical decompression and correction of kyphosis. METHODS: Between 2010 and 2014, 10 patients were surgically treated for severe angular kyphosis with a progressive onset or a sudden onset of paraplegia in investigator group. In these ten patients (seven males and three females), the etiologic diagnosis included eight cases of congenital kyphosis and two of neurofibromatosis; the distribution of spine level was from C5 to T11; the duration from onset until surgery ranged from 1 to 120 months; follow-up ranged from 12 to 26 months (mean 18.5 months); the kyphosis angle of the patients ranged from 50° to 180°. Magnetic resonance imaging demonstrated the spinal cord thinning and compression at apex in most of patients. All patients underwent decompressive surgery by single-stage posterior vertebral column resection or both anterior corpectomy fusion and posterior fixation. Neurological status was evaluated using the ASIA impairment classification and the motor score. RESULTS: Postoperatively, all patients had different kyphosis correction rate from 24 to 100 %. Nine patients showed neurological improvement; one patient showed no improvement. Among them, one sudden onset ASIA A adolescent paraplegic patient improved to ASIA E within 1 year of follow-up. One ASIA C adolescent paraplegic patients deteriorated neurologically to ASIA A after surgery and improved to ASIA D with 12-month follow-up. CONCLUSIONS: Compressive myelopathy in severe angular congenital kyphosis is usually occurred high incidence rate at apex of upper thoracic spine (T1-T4). The duration from onset of paraplegia until surgery and the severity of paraplegia before surgery are two key factors for neurological prognosis after surgery.

Prognostic value of intraoperative MEP signal improvement during surgical treatment of cervical compressive myelopathy.

PURPOSE: The purpose of the current study was to evaluate the prognostic value of intraoperative improved transcranial motor evoked potential (MEP) after cervical cord decompressive surgery for cervical compressive myelopathy (CCM). METHOD: A consecutive series of 59 CCM patients who underwent cervical cord decompressive surgery were studied between December 2013 and April 2015 in this study. And all patients were divided into three subgroups: the patients with intraoperative improved MEP, without obvious MEP change and MEP degeneration. MEP and modified Japanese Orthopedic Association (mJOA) score were mainly utilized to assess intra-, pre- and post-operative neurologic function; all patients had reliable and stable MEP baseline. The early neurologic outcomes and the long-term mJOA improvement rate were evaluated after surgery. RESULTS: There were 21 patients with intraoperative monitoring improvement (MEP improved rate, 140 ± 76 %), 32 patients without obvious MEP change and six patients with MEP degeneration. The early motor or sensory outcome showed varying degrees of recovery in the MEP improvement group. The long-term mJOA improvement rate among the three groups was 59.5 ± 4.2, 48.9 ± 3.9 and 40.6 ± 7.4 %, respectively, after 6-month follow-up, and the improvement group was better than the other two groups with statistical significance (59.5 ± 4.2 vs. 48.9 ± 3.9 %, p < 0.05; 59.5 ± 4.2 vs. 40.6 ± 7.4, p < 0.05). CONCLUSION: Patients with intraoperative MEP improvement after cervical cord decompression have better prognosis in early and long-term neurologic recovery in CCM surgery.

Subclinical respiratory dysfunction in chronic cervical cord compression: a pulmonary function test correlation.

OBJECTIVE Respiratory abnormalities are well documented in acute spinal cord injury; however, the literature available for respiratory dysfunction in chronic compressive myelopathy (CCM) is limited. Respiratory dysfunction in CCM is often subtle and subclinical. The authors studied the pattern of respiratory dysfunction in patients with chronic cord compression by using spirometry, and the clinical and surgical implications of this dysfunction. In this study they also attempted to address the postoperative respiratory function in these patients. METHODS A prospective study was done in 30 patients in whom cervical CCM due to either cervical spondylosis or ossification of the posterior longitudinal ligament (OPLL) was diagnosed. Thirty age-matched healthy volunteers were recruited as controls. None of the patients included in the study had any symptoms or signs of respiratory dysfunction. After clinical and radiological diagnosis, all patients underwent pulmonary function tests (PFTs) performed using a standardized Spirometry Kit Micro before and after surgery. The data were analyzed using Statistical Software SPSS version 13.0. Comparison between the 2 groups was done using the Student t-test. The Pearson correlation coefficient was used for PFT results and Nurick classification scores. A p value < 0.05 was considered significant. RESULTS Cervical spondylotic myelopathy (prolapsed intervertebral disc) was the predominant cause of compression (n = 21, 70%) followed by OPLL (n = 9, 30%). The average patient age was 45.06 years. Degenerative cervical spine disease has a relatively younger onset in the Indian population. The majority of the patients (n = 28, 93.3%) had compression at or above the C-5 level. Ten patients (33.3%) underwent an anterior approach and discectomy, 11 patients (36.7%) underwent decompressive laminectomy, and the remaining 9 underwent either corpectomy with fusion or laminoplasty. The mean preoperative forced vital capacity (FVC) (65%) of the patients was significantly lower than that of the controls (88%) (p < 0.001). The mean postoperative FVC (73.7%) in the patients showed significant improvement compared with the preoperative values (p = 0.003). The mean postoperative FVC was still significantly lower than the control value (p = 0.002). The mean preoperative forced expiratory volume in 1 second (FEV1) (72%) of the patients was significantly lower than that of the controls (96%) (p < 0.001). The mean postoperative FEV1 (75.3%) in the cases showed no significant improvement compared with the preoperative values (p = 0.212). The mean postoperative FEV1 was still significantly lower than the control value (p < 0.001). The mean postoperative FEV1/FVC was not significantly different from the control value (p = 0.204). The mean postoperative peak expiratory flow rate was significantly lower than the control value (p = 0.01). The mean postoperative maximal voluntary ventilation was still significantly lower than the control value (p < 0.001). On correlating the FVC and Nurick scores using the Pearson correlation coefficient, a negative correlation was found. CONCLUSIONS There is subclinical respiratory dysfunction and significant impairment of various lung capacities in patients with CCM. The FVC showed significant improvement postoperatively. Respiratory function needs to be evaluated and monitored to avoid potential respiratory complications.

Magnetic resonance imaging assessment of degenerative cervical myelopathy: a review of structural changes and measurement techniques.

Degenerative cervical myelopathy encompasses a spectrum of age-related structural changes of the cervical spine that result in static and dynamic injury to the spinal cord and collectively represent the most common cause of myelopathy in adults. Although cervical myelopathy is determined clinically, the diagnosis requires confirmation via imaging, and MRI is the preferred modality. Because of the heterogeneity of the condition and evolution of MRI technology, multiple techniques have been developed over the years in an attempt to quantify the degree of baseline severity and potential for neurological recovery. In this review, these techniques are categorized anatomically into those that focus on bone, ligaments, discs, and the spinal cord. In addition, measurements for the cervical spine canal size and sagittal alignment are also described briefly. These tools have resulted collectively in the identification of numerous useful parameters. However, the development of multiple techniques for assessing the same feature, such as cord compression, has also resulted in a number of challenges, including introducing ambiguity in terms of which methods to use and hindering effective comparisons of analysis in the literature. In addition, newer techniques that use advanced MRI are emerging and providing exciting new tools for assessing the spinal cord in patients with degenerative cervical myelopathy.

Clinical and radiographic outcome of unilateral open-door laminoplasty with alternative levels centerpiece mini-plate fixation for cervical compressive myelopathy: a five-year follow-up study.

INTRODUCTION: To evaluate the five year clinical and radiographic outcome of unilateral open-door laminoplasty with alternative levels centerpiece mini-plate fixation for cervical compressive myelopathy. METHODS: From August 2009 to June 2010, 56 patients with cervical compressive myelopathy underwent unilateral open-door laminoplasty with alternative levels centerpiece mini-plate fixation with a mean age of 64.8 years. Clinical results were investigated including Japanese Orthopedic Association (JOA) scores, Neck Dysfunction Index (NDI), occurrences of complications and neurological deterioration. Radiographic results including cervical alignments, cervical range of motion (ROM), spinal canal enlargement and spinal cord decompression were assessed on X-ray, three-dimensional CT and MRI. RESULTS: The mean follow-up period was 59.2 months (range 53∼64 months), and all patients achieved osseous fusion at hinge side at an average of 6.8 months after operation. The average cost from admission to discharge is $9817.9. Compared to previous all-level fixation, the cost decreased nearly 40 %. During the follow-up, all patients showed a significant improvement in the JOA score and NDI score. A 23.2 % incidence of axial neck pain were also observed; Significant enlargement of the spinal canal and spinal cord drift was achieved and well maintained, overall cervical ROM decreased by 27.1 % (mean 12.9° loss) at the final follow-up and cervical lordosis decreased slightly in all patients without statistic difference. No instrumentation failure or lamina reclosure was observed in our study. Comparing mini-plate segments and suture segments, the mean AP diameter and Pavlov's ratio at the final follow-up showed no statistic difference, only open angle at the final follow-up showed significant decrease. CONCLUSIONS: Unilateral open-door laminoplasty with alternative levels centerpiece mini-plate fixation is a safe, effective and economical surgical method for cervical compressive myelopathy and the five year result is satisfactory.