Modified Japanese Orthopaedic Association Research Articles

MRI evidence of brain atrophy, white matter damage, and functional adaptive changes in patients with cervical spondylosis and prolonged spinal cord compression.

To investigate the effect of cervical spondylosis (CS) in the brain with a combination of advanced neuroimaging techniques. Twenty-seven patients with CS and 24 age- and gender-matched healthy controls were studied. Disease severity was quantified using the Modified Japanese Orthopaedic Association Scoring System (mJOHA). Magnetic resonance (MR) imaging of the brain and spinal cord, functional MR imaging (fMRI) with a bilateral rest/finger-tapping paradigm, brain diffusion tensor imaging (DTI), voxel-based morphometry (VBM), and MR spectroscopy of the sensorimotor cortex were performed. A total of 92.3% of patients had more than one herniated disc. In the MRI, 33.33% presented signs of myelopathy. The mJOHA score was 13.03 ± 2.83. Compared with controls, DTI results showed significant lower FA values in Corpus callosum, both corticospinal tracts and middle cerebellar peduncles (p < 0.05 corrected). Only in CS patients fMRI results showed activation in both globus pallidi, caudate nucleus, and left thalamus (p < 0.001). Subject-specific activation of the BOLD signal showed in CS patients lower activation in the sensorimotor cortex and increased activation in both cerebellum hemispheres (p < 0.05 corrected). VBM showed bilateral clusters of gray matter loss in the sensorimotor cortex and pulvinar nucleus (p < 0.05 corrected) of CS patients. NAA/Cr was reduced in the sensorimotor cortex of CS patients (p < 0.05). Linear discriminant and support vector machine analyses were able to classify > 97% of CS patients with parameters obtained from the fMRI, DTI, and MRS results. CS may lead to distal brain damage affecting the white and gray matter of the sensorimotor cortex causing brain atrophy and functional adaptive changes. • This study suggests that patients with cervical spondylosis may present anatomical and functional adaptive changes in the brain. • Cervical spondylosis may lead to white matter damage, gray matter volume loss, and functional adaptive changes in the sensorimotor cortex. • The results reported in this work may be of value to better understand the effect of prolonged cervical spine compression in the brain.

Transforaminal Posterior Approach Is Effective for Treatment of Lower Thoracic Spine Spondylodiscitis.

Patients with lower-thoracic spine pathologies that affect anterior column stability and compress the neural tissues need anterior decompression and reconstruction. Anterior approaches result in long-term morbidities. Posterior laminectomy and fixation alone may not be sufficient to maintain spine stability. To evaluate the results of a posterior-only transforaminal thoracic interbody fusion approach for patients with thoracic disc space infection in terms of the improvement in neurologic status, resolution of infection, correction of kyphotic deformity, and assessment of post-operative complications. A prospective study was done on 40 patients with lower thoracic spine spondylodiscitis. All patients were assessed with pre-operative imaging. Neurologic assessment was performed using the American Spinal Injury Association (ASIA) Impairment Scale and functionally by the modified Japanese Orthopedic Association (JOA) scale. Pre-operative and post-operative white blood cell count, erythrocyte sedimentation rate, and C-reactive protein levels were compared. All patients were operated on through a posterior approach using the transforaminal thoracic interbody fusion for decompression, reconstruction, and anterior fusion. Mean age of patients was 49years; mean operative period was 188min; mean blood loss was 611mL. Twelve patients' ASIA scores improved and only two patients' scores declined. One patient died 11months post-operatively due to septicemia. The mean follow-up period was 27.8months. The modified JOA score improved from 6.3 ± 1.6 to 9.5 ± 0.6. The local kyphosis angle was improved from 13.8 to 6.9° post-operatively, with insignificant loss of correction at the end of follow-up. Thirty-eight out of 40 patients had solid anterior fusion at the end of follow-up. The clinical outcomes of this study showed that the transforaminal thoracic interbody approach is effective for both decompression and anterior reconstruction of the lower thoracic spine in patients with spondylodiscitis.

Evaluating the differences between 1D, 2D, and 3D occupying ratios in reflecting the JOA score in cervical ossification of the posterior longitudinal ligament

To compare the differences between the one-dimensional (1D) length, two-dimensional (2D) area, and three-dimensional (3D) volume occupying ratios, and to assess the difference between the central and peripheral types of ossification of the posterior longitudinal ligament (OPLL). In total, 60 patients were included in this study, and 1D and 2D occupying ratios were obtained using Centricity PACS (GE Healthcare), while a 3D model was created using MIMICS® (Materialise, Leuven, Belgium). Clinical symptoms were measured preoperatively by the modified Japanese Orthopedic Association (JOA) score, short-form health survey (SF-36), and neck disability index. The increased signal intensity (ISI) in T2-weighted MRI was divided into three groups: grade 0, none; grade1, limited to one disc level; or grade2, beyond one disc level. The axial view of spinal canal in CT was vertically divided into three equal parts. Then, the OPLL was categorized by central and peripheral type according to the location of most protruded tip. The 1D, 2D, and 3D occupying ratios had a significantly negative relationship with JOA score (r=-0.503; -0.506; -0.516, respectively). There was little difference in the JOA score between the central and peripheral types (17.15 vs. 17.12, P=0.785). The relationship with MR ISI, according to the central and peripheral type, showed no significant difference. In each multiple regression analysis, the 1D, 2D, and 3D occupying ratios were determined to have more influence on the JOA score (Beta: -0.364, -0.411, -0.462, respectively) than age, sex, most severe level, OPLL type, location type, and MR ISI. There was no difference between 1D, 2D, and 3D occupying ratios in reflecting the JOA score in cervical OPLL. Also, it is sufficient to reflect the occupying ratio in the clinical outcome without distinguishing between central and peripheral type.

Surgical Outcomes According to Dekyphosis in Patients with Ossification of the Posterior Longitudinal Ligament in the Thoracic Spine.

ObjectiveOssification of posterior longitudinal ligament (OPLL) in the thoracic spine may cause chronic compressive myelopathy that is usually progressive, and unfavorable by conservative treatment. Although surgical intervention is often needed, the standard surgical method has not been established. Recently, it has been reported that posterior decompression with dekyphosis is effective surgical technique for favorable clinical outcome. The purpose of this study was to evaluate the surgical outcomes in patients with thoracic OPLL according to dekyphosis procedure and to identify predictive factors for the surgical results. MethodsA total of 25 patients with thoracic OPLL who underwent surgery for myelopathy from May 2004 to March 2017, were retrospectively reviewed. Patients with cervical myelopathy were excluded. We assessed the clinical outcomes according to various surgical approaches. The modified Japanese orthopedic association (JOA) scores for the thoracic spine (total, 11 points) and JOA recovery rates were used for investigating surgical outcomes. ResultsOf the 25 patients, 10 patients were male and the others were female. The mean JOA score was 6.7±2.3 points preoperatively and 8.8±1.8 points postoperatively, yielding a mean recovery rate of 53.8±31.0%. The mean patients’ age at surgery was 52.4 years and mean follow-up period was 40.2 months. According to surgical approaches, seven patients underwent anterior approaches, 13 patients underwent posterior approaches, five patients underwent combined approaches. There was no significant difference of the surgical outcomes related with different surgical approaches. Age (≥55 years) and high signal intensity on preoperative magnetic resonance (MR) image in the thoracic spine were significant predictors of the lower recovery rate after surgery (p<0.05). Posterior decompression with dekyphosis procedure was related to the excellent surgical outcomes (p=0.047). Dekyphosis did not affect the complication rates. ConclusionIn this study, our result elucidated that old age (≥55 years) and presence of intramedullary high signal intensity on preoperative MR images were risk factors related to poor surgical outcomes. In the meanwhile, posterior decompression with dekyphosis affected favorable clinical outcome. Posterior approach with dekyphosis procedure can be a recommendable surgical option for favorable results.

Using a machine learning approach to predict outcome after surgery for degenerative cervical myelopathy.

Degenerative cervical myelopathy (DCM) is a spinal cord condition that results in progressive non-traumatic compression of the cervical spinal cord. Spine surgeons must consider a large quantity of information relating to disease presentation, imaging features, and patient characteristics to determine if a patient will benefit from surgery for DCM. We applied a supervised machine learning approach to develop a classification model to predict individual patient outcome after surgery for DCM. Patients undergoing surgery for DCM as a part of the AOSpine CSM-NA or CSM-I prospective, multi-centre studies were included in the analysis. Out of 757 patients 605, 583, and 539 patients had complete follow-up information at 6, 12, and 24 months respectively and were included in the analysis. The primary outcome was improvement in the SF-6D quality of life indicator score by the minimum clinically important difference (MCID). The secondary outcome was improvement in the modified Japanese Orthopedic Association (mJOA) score by the MCID. Predictor variables reflected information about pre-operative disease severity, disease presentation, patient demographics, and comorbidities. A machine learning approach of feature engineering, data pre-processing, and model optimization was used to create the most accurate predictive model of outcome after surgery for DCM. Following data pre-processing 48, 108, and 101 features were chosen for model training at 6, 12, and 24 months respectively. The best performing predictive model used a random forest structure and had an average area under the curve (AUC) of 0.70, classification accuracy of 77%, and sensitivity of 78% when evaluated on a testing cohort that was not used for model training. Worse pre-operative disease severity, longer duration of DCM symptoms, older age, higher body weight, and current smoking status were associated with worse surgical outcomes. We developed a model that predicted positive surgical outcome for DCM with good accuracy at the individual patient level on an independent testing cohort. Our analysis demonstrates the applicability of machine-learning to predictive modeling in spine surgery.

Prospective Analysis of Functional Outcome of Single-Stage Surgical Treatment for Symptomatic Tandem Spinal Stenosis.

Background:Tandem spinal stenosis (TSS) is a rare presentation leading to combined clinical features of upper motor neuron and lower motor neuron lesion which includes intermittent neurogenic claudication with or without neurological deficit, progressive gait imbalance and gait disturbances. In literature, there is controversy whether stage surgery or single-stage surgery should be done.Materials and Methods:From June 2009 to November 2016 in a series of 1381 patients who underwent surgery for various degenerative spinal conditions, 82 patients were diagnosed with having symptomatic TSS with an incidence of 5.93%. All patients diagnosed with TSS underwent single-stage surgical intervention by one surgical team. The perioperative factors were recorded for each patient. All patients were evaluated preoperatively and postoperatively at each followup with the modified Japanese Orthopaedic Association (mJOA) score, Nurick's grading, Oswestry disability index (ODI) and Cooper scale.Results:In this study, 82 patients including 70 males and 12 females underwent simultaneous surgical intervention for symptomatic TSS. The mean age of patients was 61.78 ± 10.48 years. There was a significant improvement in mJOA score, Nuricks grading, ODI and Coopers scale postoperatively as compared to preoperative values (P < 0.05).Conclusion:Symptomatic TSS can be safely managed by single-stage surgical intervention with good postoperative results or without a significant increase in complication rates. Single-stage surgical intervention helps to relieve the symptoms of both cervical and lumbar spinal cord compression, avoids the risk of repeated anesthesia, reduce the duration of surgery, repeated hospitalization hence, reducing the cost for hospitalization and also reducing the rehabilitation, recuperation time and early functional recovery justifies single-stage surgical intervention.

Machine Learning for the Prediction of Cervical Spondylotic Myelopathy: A Post Hoc Pilot Study of 28 Participants

Cervical spondylotic myelopathy (CSM) severity and presence of symptoms are often difficult to predict based simply on clinical imaging alone. Similarly, improved machine learning techniques provide new tools with immense clinical potential. A total of 14 patients with CSM and 14 controls underwent imaging of the cervical spine. Two different artificial neural network models were trained; 1)to predict CSM diagnosis; and 2) to predict CSM severity. Model 1 consisted of 6 inputs including 3 common imaging scales for the evaluation of cord compression, alongside 3 objective magnetic resonance imaging measurements. The outcome for model 1 was binary to predict CSM diagnosis. Model 2 consisted of 23 input variables derived from probabilistic volume mapping measurements of white matter tracts in the region of compression. The outcome of model 2 was linear, to predict the modified Japanese Orthopedic Association (mJOA) score. Model 1 was used in predicting CSM. The mean cross-validated accuracy of the trained model was 86.50% (95% confidence interval, 85.16%-87.83%) with a median accuracy of 90.00%. Area under the curve (AUC) was calculated for each repetition. Average AUC for each repetition was 0.947 with a median AUC of 1.0. Average sensitivity, specificity, positive predictive value, and negative predictive value were 90.25%, 85.05%, 81.58%, and 91.94%, respectively. Model 2 was used in modeling mJOA. The mJOA model predicted scores, with a mean and median error of -0.29 mJOA points and -0.08 mJOA points, respectively, mean error per batch was 0.714 mJOA points. Machine learning provides a promising method for prediction, diagnosis, and even prognosis in patients with CSM.

The Relation between Cord Signal and Clinical Outcome after Anterior Cervical Discectomy in Patients with Degenerative Cervical Disc Herniation.

Introduction:Cervical spondylotic myelopathy is a cervical cord compressive lesion that occurs as a result of the normal degenerative process which may cause magnetic resonance imaging (MRI) cord intensity changes that may worsen the clinical outcome even after successful anterior cervical decompression.Objective:To assess the relation between MRI T2 Weighted images (T2 WI) hyperintense cord signal and clinical outcome after anterior cervical discectomy in patients with degenerative cervical disc herniation.Materials and Methods:This is a retrospective observational study that was conducted on twenty-five patients with degenerative cervical disc prolapse associated with MRI T2WI hyperintense cord signal, at the Department of Neurosurgery, Qena University Hospital, South Valley University from August 2014 to December 2016. A complete clinical and radiological evaluation of the patients was done. Anterior cervical discectomy and fusion was done for all patients. Patients were clinically assessed preoperatively and postoperatively at 3, 6, and 12 months using Modified Japanese Orthopedic Association (MJOA) score. Radiographic assessment was done by preoperative and postoperative T2WI MRI. The statistical analysis was done using Statistical Package for the Social Sciences (SPSS) software (version 22.0).Results:There were 25 patients included in the study; 16 (64%) females and 9 (36%) males. The mean age was 46.89 ± 7.52 standard deviation (SD) years with range from 26 to 64 years, 3 (12%) patients had worsened in the form of postoperative motor power deterioration, and 14 (56%) patients has no improvement and remain as preoperative condition. The remaining 8 (32%) patients had a reported postoperative improvement of symptoms and signs according to MJOA score. The mean follow-up period (in months) was 11 ± 2.34 (SD).Conclusion:The presence of T2W hyperintense signal on preoperative MRI predicts a poor surgical outcome in patients with cervical disc prolapse. The regression of T2W ISI postoperatively correlates with better functional outcomes.

Alterations in Cortical Thickness and Subcortical Volume are Associated With Neurological Symptoms and Neck Pain in Patients With Cervical Spondylosis.

Advanced cervical spondylosis (CS) can cause structural damage to the spinal cord resulting in long-term neurological impairment including neck pain and motor weakness. We hypothesized long-term structural reorganization within the brain in patients with CS. To explore the associations between cortical thickness, subcortical volumes, neurological symptoms, and pain severity in CS patients with or without myelopathy and healthy controls (HCs). High-resolution T1-weighted structural magnetic resonance imaging (MRI) scans from 26 CS patients and 45 HCs were acquired. Cortical thickness and subcortical volumes were computed and compared to the modified Japanese Orthopedic Association (mJOA) and the Neck Disability Index (NDI) scores. Cortical thinning within the superior frontal gyrus, anterior cingulate, precuneus, and reduction in putamen volume were associated with worsening neurological and pain symptoms. Among the strongest associations were cortical thickness within the left precuneus (R2 = 0.34) and left and right putamen (R2 = 0.43, 0.47, respectively) vs mJOA, and the left precuneus (R2 = 0.55), insula (R2 = 0.57), and right putamen (R2 = 0.54) vs NDI (P≤.0001 for all). Cortical thickness along Brodmann areas 3a, 4a, and 4p were also moderately associated with mJOA. Preliminary evidence also suggests that patients with CS may undergo cortical atrophy at a faster rate than HCs. Patients with CS appear to exhibit cortical thinning and atrophy with worsening neurological and pain symptoms in specific brain regions associated with sensorimotor and pain processing.

Neurological Recovery Pattern in Cervical Spondylotic Myelopathy after Anterior Surgery: A Prospective Study with Literature Review

Study DesignProspective clinical study.PurposeThe present study aimed to examine the neurological recovery pattern in cervical spondylotic myelopathy (CSM) after anterior cervical decompression and compare it with the existing reports in the literature.Overview of LiteratureNeurological recovery and regression of myelopathy symptoms is an important factor that determines the outcomes of surgical decompression. The present findings contribute to the literature on the pattern of neurological recovery and patient prognosis with respect to the resolution of myelopathy symptoms after surgery.MethodsThis prospective study was conducted in Government Medical College in Jammu, North India between November 2012 and October 2014, a total of 30 consecutive patients with CSM were included and treated with anterior decompression and stabilization. They were prospectively followed up for 1 year and were evaluated for their neurological recovery pattern. The postoperative outcome was evaluated using the modified Japanese Orthopaedic Association (mJOA) score. The recovery rate was calculated using Hirabayashi’s method. The JOA score was assessed before the operation and postoperatively at 1 week, 2 weeks, 1 month, 3 months, 4 months, 6 months, and 1 year.ResultsThe postoperative mJOA score was 0 in the 1st month, 12.90±3.57 in the 3rd month, 13.50±3.55 in the 4th month, 14.63±3.62 in the 6th month, and 14.9±3.24 at the final follow-up of 1 year. The average recovery rate during the 1st month follow-up was 0%, and that during the 3rd month follow-up was 12.91% with a range of 0%–50%. The average recovery rate during the 4th month was 32.5%, with a range of 0%–60%, while that during the 6th month was 72.83%, with a range of 0%–100%. The average recovery rate during the final follow-up of 1 year was 54.3%.ConclusionsNeurological recovery after surgical decompression starts from the 3rd postoperative month and progresses until the 6th postoperative month; thereafter, it gradually plateaus over the subsequent 6 months until it steadies. Symptom duration is an important factor that requires consideration while determining postoperative neurological recovery.

Full-endoscopic transforaminal procedure to treat the single-level adjacent segment disease after posterior lumbar spine fusion: 1-2 years follow-up.

Adjacent segment disease (ASD) is one of the potential risks after lumbar spine surgery with instrumentation. Revision surgery needs to be performed on patients suffered from ASD. The traditional open surgery takes severe injury to the body. We investigated the clinical outcome of using full-endoscopic transforaminal procedure to treat the single-level adjacent segment diseases after posterior lumbar fusion. 33 patients (average 71 years, ranged 65-84 years old) underwent full-endoscopic transforaminal procedure were involved. The Oswestry Disability Index (ODI), Modified Japanese Orthopedic Association (mJOA) score and visual analogue scale (VAS) score were used to evaluate the clinical effect. The complication, hospital stay, hospitalization costs and blood loss were investigated according to the patient's records. The mean VAS score was 1.8 and mJOA score was 5.4 postoperatively. Improvement rate was 78%. The mean ODI was 14.6 postoperatively. The mean length of hospital stay, hospitalization costs and blood loss was 2.5 days, $3500 and 15 mL, respectively. No complication or recurrence was observed in any of the patients at the final follow-up. Full-endoscopic transforaminal procedure is a safe and effective technique. It is economical, acceptable and mini-invasive. Of course, it also can shorten the length of hospital stay and decrease bleeding. For revision surgery to treat ASD, this technique can achieve good clinical effects.

Posterior Sublaminar Wiring and/or Transarticular Screw Fixation for Reducible Atlantoaxial Instability Secondary to Symptomatic Os Odontoideum: A Neglected Technique?

Study DesignRetrospective case analysis.PurposeWe retrospectively evaluated the clinical and radiological outcomes of posterior sublaminar wiring (PSLW) and/or transarticular screw fixation (TASF) for reducible atlantoaxial instability (AAI) secondary to os odontoideum.Overview of LiteratureLimited information is available about the surgical outcomes of symptomatic os odontoideum with AAI.MethodsWe examined 23 patients (12 women and 11 men) with os odontoideum and reducible AAI. The average age of the patients at the time of the operation was 44.2 years. The average follow-up duration was 4.5 years. Thirteen patients with anterior AAI underwent PSLW alone, while 10 patients with combined (anterior+posterior) AAI underwent PSLW and TASF. An autogenous iliac bone graft was used for all patients. Nine patients complained of neck or suboccipital pain, and 14 complained of myelopathy.ResultsAngulational instability (preoperative 18.7°±8.9° vs. postoperative 2.1°±4.6°, p<0.001), translational instability (16.3±4.9 mm vs. 1.8±2.2 mm, p<0.001), and segmental angle of the C1–C2 joint (23.7°±7.2° vs. 28.4°±3.8°, p<0.05) showed significant improvement postoperatively. Neck Visual Analog Scale score (6.2±2.4 vs. 2.5±1.8, p<0.05) and the modified Japanese Orthopedic Association (9.1±3.1 vs. 13.2±2.6, p<0.05) score also improved, with a recovery rate of 51.8%. Among the three patients who developed nonunion and/or wire breakage, one underwent revision surgery with repeat PSLW and was finally able to achieve fusion. The final fusion rate was 91.3%.ConclusionsPSLW and/or TASF provided satisfactory clinical and radiological outcomes in reducible AAI secondary to os odontoideum without significant neurological complications. Our results suggest that PSLW and/or TASF can be considered a viable surgical option over segmental fixation in highly selected cases of os odontoideum with reducible AAI.

Are the sagittal cervical radiographic modifiers of the Ames-ISSG classification specific to adult cervical deformity?

OBJECTIVEThe Ames-International Spine Study Group (ISSG) classification has recently been proposed as a tool for adult cervical deformity evaluation. This classification includes three radiographic cervical sagittal modifiers that have not been evaluated in asymptomatic adults. The aim of this study was to determine whether the sagittal radiographic modifiers described in the Ames-ISSG cervical classification are encountered in asymptomatic adults without alteration of health-related quality of life (HRQOL).METHODSThe authors conducted a cross-sectional study of subjects with an age ≥ 18 years and no cervical or back-related complaints or history of orthopedic surgery. All subjects underwent full-body biplanar radiographs with the measurement of cervical, segmental, and global alignment and completed the SF-36 HRQOL questionnaire. Subjects were classified according to the sagittal radiographic modifiers (chin-brow vertical angle [CBVA], mismatch between T1 slope and cervical lordosis [TS-CL], and C2-7 sagittal vertical axis [cSVA]) of the Ames-ISSG classification for cervical deformity, which also includes a qualitative descriptor of cervical deformity, the modified Japanese Orthopaedic Association (mJOA) myelopathy score, and the Scoliosis Research Society (SRS)-Schwab classification for spinal deformity assessment. Characteristics of the subjects classified by the different modifier grades were compared.RESULTSOne hundred forty-one asymptomatic subjects (ages 18-59 years, 71 females) were enrolled in the study. Twenty-seven (19.1%) and 61 (43.3%) subjects were classified as grade 1 in terms of the TS-CL and CBVA modifiers, respectively. Ninety-eight (69.5%) and 4 (2.8%) were grade 2 for these same respective modifiers. One hundred thirty-six (96.5%) subjects had at least one modifier at grade 1 or 2. There was a significant relationship between patient age and grades of TS-CL (p < 0.001, Cramer's V [CV] = 0.32) and CBVA (p = 0.04, CV = 0.22) modifiers. The HRQOL, global alignment, and segmental alignment parameters were similar among the subjects with different modifier grades (p > 0.05).CONCLUSIONSThe CBVA and TS-CL radiographic modifiers of the Ames-ISSG classification do not seem to be specific to subjects with cervical deformities and can occur in asymptomatic subjects without alteration in HRQOL.

Spinal extradural angiolipomas: 7 new cases and review of the literature

IntroductionWe present our experience with the diagnosis and treatment of spinal angiolipomas (SAL). MethodsWe used our database of surgical patients to gather epidemiological, clinical, diagnostic, treatment, and follow-up data from confirmed cases of SAL. Patients’ functional status was evaluated using the modified Japanese Orthopaedic Association (mJOA) score for thoracic myelopathy. ResultsWe included 7 patients with ages ranging between 42 and 63 years; 4 were women. Lesions in all patients were located in the thoracic epidural space; in 2 cases, lesions extended outside the spinal canal. The most frequent form of presentation was pain combined with progressive myelopathy; patients scored 5 to 9 points on the mJOA scale. Radiological findings varied; this variability clearly depended on the proportion of tumour components (cellular variant in one case, predominantly angiomatous in another, and myxoid in yet another case). Four cases displayed radiological signs of bone involvement. Surgery resulted in excellent mJOA scores except in one case (mJOA score of 10); no recurrences were detected during follow-up (periods ranging from 1 to 5 years). ConclusionsExtradural SAL can present with highly variable radiological and clinical features. Surgery must be tailored to each individual situation according to tumour extension; in some cases, it may include spinal reconstruction. Surgery results in excellent outcomes regardless of preoperative functional status and it is associated with low recurrence rates, even in case of incomplete resection.

Letter to the Editor Regarding “Development of the Portuguese Version of the Modified Japanese Orthopaedic Association Score: Cross-Cultural Adaptation, Reliability, Validity, and Responsiveness”

Letter to the Editor Regarding “Development of the Portuguese Version of the Modified Japanese Orthopaedic Association Score: Cross-Cultural Adaptation, Reliability, Validity, and Responsiveness”

In Reply to the Letter to the Editor Regarding “Development of the Portuguese Version of the Modified Japanese Orthopaedic Association Score: Cross-Cultural Adaptation, Reliability, Validity, and Responsiveness”

In Reply to the Letter to the Editor Regarding “Development of the Portuguese Version of the Modified Japanese Orthopaedic Association Score: Cross-Cultural Adaptation, Reliability, Validity, and Responsiveness”

Diffusion Tensor Imaging in a Large Longitudinal Series of Patients With Cervical Spondylotic Myelopathy Correlated With Long-Term Functional Outcome.

Fractional anisotropy (FA) of the high cervical cord correlates with upper limb function in acute cervical cord injury. We investigated the correlation between preoperative FA at the level of maximal compression and functional recovery in a group of patients after decompressive surgery for cervical spondylotic myelopathy (CSM). To determine the usefulness of FA as a biomarker for severity of CSM and as a prognostic biomarker for improvement after surgery. Patients received diffusion tensor imaging (DTI) scans preoperatively. FA values of the whole cord cross-section at the level of maximal compression and upper cervical cord (C1-2) were calculated. Functional status was measured using the modified Japanese Orthopedic Association (mJOA) scale preoperatively and at follow-up up to 2 yr. Regression analysis between FA and mJOA was performed. DTI at C4-7 was obtained in controls. Forty-four CSM patients enrolled prior to decompression were compared with 24 controls. FA at the level of maximal compression correlated positively with preoperative mJOA score. Preoperative FA correlated inversely with recovery throughout the postoperative period. This was statistically significant at 12 mo postoperation and nearly so at 6 and 24 mo. Patients with preoperative FA <0.55 had a statistically significant difference in outcome compared to FA >0.55. In the largest longitudinal study of this kind, FA promises a valid biomarker for severity of CSM and postoperative improvement. FA is an objective measure of function and could provide a basis for prognosis. FA is particularly useful if preoperative values are less than 0.55.

Usefulness of conventional magnetic resonance imaging, diffusion tensor imaging and neurite orientation dispersion and density imaging in evaluating postoperative function in patients with cervical spondylotic myelopathy

ObjectiveThe objective of this study was to evaluate the usefulness of T2 high signal intensity (T2-HSI) and decreased anteroposterior diameter (APD), diffusion tensor imaging (DTI) and neurite orientation dispersion and density imaging (NODDI) in evaluating postoperative cervical cord function. MethodsThe study included 57 postoperative cervical spondylotic myelopathy patients. Clinical evaluation and functional recovery assessments were performed using the modified Japanese Orthopaedic Association (mJOA) score and recovery rate. The presence of T2-HSI and decreased APD was recorded for exploring the relevance. Spearman correlation was applied to investigate the relationships between DTI and NODDI metrics and mJOA score. Multiple comparisons of T2 signal intensity, APD and diffusion metrics were evaluated by using multiple linear regression. ResultsOnly the recovery rate was significantly different between T2-HSI and non-T2-HSI (nT2-HSI) patients (χ2 = 4.466, p = 0.045). Significant differences were not observed between cervical cords with and without decreased APD. Diffusion metrics, including fractional anisotropy (p = 0.0005), mean diffusivity (p = 0.0008), radial diffusivity (p = 0.0003) and intracellular volume fraction (p = 0.001), were significantly correlated with mJOA score. The ability of T2 signal intensity (p = 0.421) and APD (p = 0.420) to evaluate the postoperative function was inferior to that of fractional anisotropy (p = 0.002), mean diffusivity (p = 0.001), radial diffusivity (p = 0.001) and intracellular volume fraction (p = 0.004). ConclusionConventional magnetic resonance imaging signs could be considered as a reference to make an approximate assessment, whereas DTI and NODDI could be better quantitative tools for evaluating the postoperative function and may help in interpreting residual symptoms. The translational potential of this articleDTI and NODDI could provide reliable postoperative evaluation and analysis for cervical spondylotic myelopathy patients.

Clinical Outcomes and Prognostic Factors in Patients With Myelopathy Caused by Thoracic Ossification of the Ligamentum Flavum

ObjectiveThe objective of this study was to investigate the surgical outcomes and prognostic factors for thoracic ossification of the ligamentum flavum (OLF) after decompressive laminectomy, focusing on the quantitative signal intensity ratio (SIR) of preoperative magnetic resonance imaging (MRI) and its prognostic significance. MethodsWe retrospectively reviewed 24 patients who previously underwent total laminectomy to remove OLF from 2010 to 2015. MRI and computed tomography were performed to detect OLF. The SIR between the regions of interest of high signal intensity lesions and the normal cord at the T1–2 disc levels was calculated. We divided patients into 2 groups based on the extent of the modified Japanese Orthopaedic Association (JOA) recovery rate (RR): good (RR ≥ 50%) and poor (RR < 50%). ResultsThe mean preoperative and postoperative modified JOA scores for thoracic myelopathy were 6.67 ± 1.73 and 8.63 ± 1.81, respectively (p < 0.001). The preoperative JOA score (7.5 vs. 5.83, p = 0.028), postoperative JOA score (9.83 vs. 7.42, p = 0.000), and SIR (1.16 vs. 1.41, p = 0.009) were significantly different between the good and poor RR groups. A higher preoperative JOA score and lower SIR were associated with a good RR according to the JOA criteria. ConclusionThe clinical outcomes for thoracic OLF after decompressive laminectomy were favorable. A higher RR was correlated with a lower SIR and higher preoperative modified JOA score. Therefore, a relatively low SIR on MRI and a relatively high preoperative JOA score could be positive prognostic indicators for the JOA RR in patients with thoracic OLF.

A less invasive surgery using a full-endoscopic system for L5 nerve root compression caused by lumbar foraminal stenosis.

Percutaneous endoscopic lumbar discectomy (PELD) is a relatively less invasive treatment for lumbar disc herniation (LDH). This study investigated the usefulness of a full-endoscopic system for PELD to treat L5 nerve root compression caused by lumbar foraminal stenosis (L5-LFS). Between November 2016 and December 2017, a total of 10 patients with unilateral leg pain due to L5-LFS underwent surgery using a full-endoscopic system for PELD. Patients with bilateral L5-LFS or L5-LFS with coexisting LDH and/or spondylolysis were excluded from this study. A percutaneous endoscopic translaminar approach (PETA) was performed via the ipsilateral vertebral isthmus using a 3.5-mm diameter high-speed drill. Preoperative and postoperative statuses were evaluated using the modified Japanese Orthopedic Association (mJOA) and Numerical Rating Scale (NRS) scores. The patients' mean age was 62.2 years; there were 7 male and 3 female patients. The mean recovery rate was 58.2% with the mJOA score; mean pre- and postoperative NRS scores were 7.4 and 2.3, respectively. The mean operative time was 77.6 min. Although there were no major complications, pain did not improve in an 80-year-old woman with coexisting spondylolisthesis (Meyerding grade 2). PETA using a full-endoscopic system is a safe and effective minimally invasive treatment for L5-LFS, with potential to be an alternative surgical strategy for L5-S1 interbody fusion.