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Oswestry Disability Index (ODI) was established by Fairbank in 1989 to assess functional disabilities in low back pain (LBP). It was last updated in 2019 as ODI version 2.1b (ODI AU_2.1b). ODI was first translated into Simplified Chinese Oswestry Disability Index (CODI) in 2008 by Lue. The construct validity, internal consistency, level of agreement and the floor and ceiling effects of CODI were found unclear by Yao in 2016. This study will verify how well the adapted Cantonese–Hong Kong Oswestry Disability Index version 2.1b (HKCODI) aligns with ODI AU_2.1b in the Southern Chinese population. The translation of ODI AU_2.1b was performed according to guidelines from MAPI Research Trust and American Association of Orthopaedic Surgeons. Psychometric properties of HKCODI were tested statistically by Pearson’s correlation, Cronbach’s Alpha and Intraclass Correlation Coefficient (ICC). A total of 200 subjects (109 males, 91 females) aged from 15 to 85 (mean age = 58.91) with LBP scored from 3/10 to 10/10 in the Visual Analogue Scale (VAS) were recruited in the Occupational Therapy Department of a tertiary referral center. HKCODI demonstrated strong construct validity in comparing with Hong Kong Roland–Morris Disability Questionnaire (HKRMDQ) (r = 0.666, p = 0.000), Short Form Health Survey (SF-36) Physical Composite Summary (− 0.700, p = 0.000) and VAS (0.487, p = 0.000). Excellent internal consistency and test–retest reliability were confirmed with Cronbach’s Alpha of 0.997 and ICC of 0.993 at 95% confidence level. Cross-cultural adaptation of ODI AU_2.1b has been translated and validated as HKCODI and Item-8 (Sex Life) was suggested to skip for patient older than 60. HKCODI is a fully self-administered and highly reliable tool in assessing the functional disability of patients with LBP in the Southern Chinese population.

Advances in patient selection, surgical techniques, and postoperative care have facilitated spine surgeons to manage complex spine cases with shorter operative times, reduced hospital stay and improved outcomes. We focus this article on a few areas which have shown maximum developments in management of degenerative cervical myelopathy and also throw a glimpse into the future ahead. Imaging modalities, surgical decision making, robotics and neuro-navigation, minimally invasive spinal surgery, motion preservation, use of biologics are few of them. Through this review article, we hope to provide the readers with an insight into the present state of art in cervical myelopathy and what the future has in store for us.

The study aimed for unraveling the long-term health impact of cumulative radiation exposure from full-spine radiographs on children/adolescents with scoliosis. All cohort, case–control or cross-sectional studies about radiation exposure to scoliosis patients with follow-up period as 20 years or more were included. Meta-analyses were performed for outcomes reported in two or more studies. A total of 9 eligible studies involving 35,641 participants between 1912 and 1990 fulfilled the inclusion criteria, including 18,873 patients with scoliosis and 16,768 controls as regional matched general population. The average number of full-spine radiographs was 23.13 (range: 0–618) according to 14,512 patients between 1912 and 1990 in five studies. The estimated mean cumulated radiation dose of breast was 11.35 cGy. In comparison with controls, pooled incidence rates of cancer, breast cancer and cancer mortality of patients with scoliosis were statistically significant higher [rate of cancer, odds risk (OR) = 1.46, p

Modern medical imaging facilitates the diagnosis and treatment of human diseases. However, few people are aware of the cons of radiation exposure from medical imaging. Emerging evidence reveals that cumulative doses of radiation exposure will increase the morbidity and mortality of pertaining cancer. As a special young population, patients with adolescent idiopathic scoliosis (AIS) suffer more radiation harms from repeated diagnostic imaging, most of which can be avoided in clinical practice. Accumulating evidence highlights reduced cancer risks of radiation exposure for AIS patients with low/zero radiation imaging modalities proposed, amongst which easy conversion from anterior-posterior (AP) to posterior-anterior (PA) projection for whole-spine radiographs should be stressed. It can greatly reduce radiation doses without compromising the quality of diagnostic imaging. Tight collimation combined with PA projection can further reduce radiation harms, and need to be spread to benefit people globally.

Purpose Patients with pre-existing cervical spinal canal stenosis (CSCS) may have minimal or no symptoms. However, performing preventive decompression is controversial as the incidence of CSCS leading to severe cord injury is unknown. Hence, this study aims to revisit the threshold for surgery in “silent” CSCS by reviewing the neurologic outcomes of patients with undiagnosed CSCS who sustained a cervical spinal cord injury (CSCI). Methods Two groups of subjects were recruited for analysis. Firstly, patients with trauma-induced CSCI without fracture or dislocation were included. Pre-existing CSCS was diagnosed by MRI measurements. The second group consisted of asymptomatic subjects recruited from the general population who also had MRIs performed. Canal sizes were compared between this control group and the patient group. Within the patient group, neurological assessments and outcomes by Frankel classification were performed in patients treated surgically or conservatively. Results 32 patients with CSCS were recruited. The mean spinal canal sagittal diameter (disc-level) of all CSCS cases was 5.3 ± 1.4 mm (1.3–8.2). In comparison, the diameter was 10.5 ± 1.7 mm (6.6–14.6) in the 47 asymptomatic individuals recruited from the general population. Decompression was performed in 17 patients and conservative treatment in 15. Mean follow-up was 19.3 ± 17.0 months (6–84). At the final follow-up, 3 patients (9.3%) returned to their pre-injury Frankel grade, whereas 26 patients (83.3%) lost one or more neurological grade. Three patients (9.3%) died. Conclusions Majority of patients with “silent” CSCS who sustained cervical cord injuries did not return to their pre-injury neurological status. All of these subjects have pre-existing canal stenosis hence the risk of cord injury. Given the poor neurological outcome of CSCS, a lower threshold for surgery could be indicated to avoid these disastrous injuries. However, before making any conclusive recommendation we must first identify the prevalence of “silent” CSCS in the general population and the risk of developing spinal cord injury with more prospective population-based studies.

Pott’s disease is infamous for its propensity in causing kyphosis, most commonly in the thoracic spine. Even more alarming is when there is progressive kyphosis and therefore the need to recognize when and how to intervene in acute tuberculous spondylitis. Though the deformity may be unsightly, the greatest worry has always been the attendant Pott’s paraplegia that develops once there is significant kyphosis, whether acute or that after the infection has subsided. Broadly speaking, spinal tuberculosis (TB), its attendant deformity, and its neurological deficit can be conceptually separated into acute and late, because the management principles are quite different for these distinct entities. The latter not only poses numerous surgical challenges but also greater prognostic uncertainty. In the acute form, studies have demonstrated clearly the short- and long-term benefits of a thorough debridement and anterior column reconstruction. The arguments for this approach centered on three aspects: quicker resolution of infection, preservation of neurological status, and prevention of deformity. Instrumentation using titanium implants does not impair clearance of TB infection, and its use lends immediate stability, obviating the need for bracing. Of course, anti-TB chemotherapy is still the cornerstone for completely eradicating the infection. In Pott’s disease of late onset, the best surgical approach may not be as straightforward. For the “soft” kyphus and less neurologically impaired scenario, a careful decompression and stabilization procedure represents the best chance for good outcome. The choice of surgery, and for that matter whether to proceed with surgery at all, in the “hard” kyphus of a bed-bound patient, can be a dilemma. In this case, kyphectomy and reconstruction should not be undertaken lightly given the potentially high rate of complications coupled with a lack of prospect for recovery.

Retrospective radiographic study.To assess whether flexibility as revealed by the supine radiograph, predicts in-brace curve correction.Currently there is no consensus regarding a standard method to assess curve flexibility and immediate brace effectiveness in treating adolescent idiopathic scoliosis (AIS). Brace fabrication methods may be variable but ideally it should achieve maximal curve correction. Curve flexibility governs the degree of curve correction in-brace and hence dynamic radiographs are commonly performed prior to brace fitting.This was a radiographic analysis of AIS patients treated with underarm bracing. Correlation of pre-brace, supine, and immediate in-brace Cobb angles was performed. Relationship with possible contributing factors including age, sex, body height, weight, age at menarche and Risser staging was studied. Major and minor curves were compared independently for correlation but the regression model was constructed based on the major curve only.From 105 patients with mean age of 12.2 ± 1.2 years at brace fitting, supine Cobb angle measurement has significant correlation with immediate in-brace Cobb angle (r = 0.740). Univariate analyses showed no significant relationship with age, weight, height, date of menarche, Risser stage or pre-brace Cobb angle. Our regression model (in-brace Cobb angle = 0.809 × supine Cobb angle) had good fit of the data.Supine radiograph predictably determines the flexibility of the scoliotic curve to brace treatment. It can be used as a guideline to determine the amount of correction achievable with brace-wear. The effectiveness of the brace is dependent on the inherent flexibility of the curve rather than its size or type.3.

Lack of normal reference value of diffusion tensor imaging parameters hinders its application in clinical practice. In this study, we aim to establish a comprehensive normal DTI database of Chinese subjects. Sixty-five healthy subjects aged 21–61 years were recruited and underwent 3T DTI scan of cervical spine. DTI parameters were measured in whole cord, ventral, lateral and dorsal column from C2 to C7 segments. Regions, segments, gender and age-related changes of DTI parameters were analyzed. No significant difference was found between genders (p > 0.05). DTI parameters significantly differed among different cord levels (p

Surgery for adolescent idiopathic scoliosis (AIS) is only complete after achieving fusion to maintain the correction obtained intraoperatively. The instrumented or fused segments can be referred to as the "fusion mass". In patients with AIS, the ideal fusion mass strategy has been established based on fulcrum-bending radiographs for main thoracic curves. Ideally, the fusion mass should achieve parallel endplates of the upper and lower instrumented vertebra and correct any "shift" for truncal balance. Distal adding-on is an important element to consider in AIS surgery. This phenomenon represents a progressive increase in the number of vertebrae included distally in the primary curvature and it should be avoided as it is associated with unsatisfactory cosmesis and an increased risk of revision surgery. However, it remains unknown whether any fusion mass shift, or shift in the fusion mass or instrumented segments, affects global spinal balance and distal adding-on after curve correction surgery in patients with AIS.(1) To investigate the relationship among postoperative fusion mass shift, global balance, and distal adding-on phenomenon in patients with AIS; and (2) to identify a cutoff value of fusion mass shift that will lead to distal adding-on.This was a retrospective study of patients with AIS from a single institution. Between 2006 and 2011 we performed 69 selective thoracic fusions for patients with main thoracic AIS. All patients were evaluated preoperatively and at 2 years postoperatively. The Cobb angle between the cranial and caudal endplates of the fusion mass and the coronal shift between them, which was defined as "fusion mass shift", were measured. Patients with a fusion mass Cobb angle greater than 20° were excluded to specifically determine the effect of fusion mass shift on distal adding-on phenomenon. Fusion mass shift was empirically set as 20 mm for analysis. Therefore, of the 69 patients who underwent selective thoracic fusion, only 52 with a fusion mass Cobb angle of 20° or less were recruited for study. We defined patients with a fusion mass shift of 20 mm or less as the balanced group and those with a fusion mass shift greater than 20 mm as the unbalanced group. A receiver operating characteristic (ROC) curve was used to determine the cutoff point of fusion mass shift for adding-on.Of the 52 patients studied, fusion mass shift (20 mm) was noted in 11 (21%), and six of those patients had distal adding-on at final followup. Although global spinal balance did not differ significantly between patients with or without fusion mass shift, the occurrence of adding-on phenomenon was significantly higher in the unbalanced group (55% (six of 11 patients), odds ratio [OR], 8.6; 95% CI, 2-39; p0.002) than the balanced group (12% [five of 41 patients]). Based on the ROC curve analysis, a fusion mass shift more than 18 mm was observed as the cutoff point for distal adding-on phenomenon (area under the curve, 0.70; 95% CI, 0.5-0.9; likelihood ratio, 5.0; sensitivity, 0.64; specificity, 0.73; positive predictive value, 39% [seven of 18 patients]; negative predictive value, 88% [30 of 34 patients]; OR, 4.8; 95% CI, 1-20; p = 0.02).Our study illustrates the substantial utility of the fulcrum-bending radiograph in determining fusion levels that can avoid fusion mass shift; thereby, underlining its importance in designing personalized surgical strategies for patients with scoliosis. Preoperatively, determining fusion levels by fulcrum-bending radiographs to avoid residual fusion mass shift is imperative. Intraoperatively, any fusion mass shift should be corrected to avoid distal adding-on, reoperation, and elevated healthcare costs.Level II, prognostic study.

Diffusion tensor fiber tractography is an emerging tool for the visualization of spinal cord microstructure. However, there are few quantitative analyses of the damage in the nerve fiber tracts of the myelopathic spinal cord.The aim of this study was to develop a quantitative approach for fiber tractography analysis in cervical spondylotic myelopathy (CSM).Prospective study on a series of patients.A total of 22 volunteers were recruited with informed consent, including 15 healthy subjects and 7 CSM patients. The clinical severity of CSM was evaluated using modified Japanese Orthopedic Association (JOA) score. The microstructure of myelopathic cervical cord was analyzed using diffusion tensor imaging. Diffusion tensor imaging was performed with a 3.0-T magnetic resonance imaging scanner using pulsed gradient, spin-echo, echo-planar imaging sequence. Fiber tractography was generated via TrackVis with fractional anisotropy threshold set at 0.2 and angle threshold at 40°. Region of interest (ROI) was defined to cover C4 level only or the whole-length cervical spinal cord from C1 to C7 for analysis. The length and density of tracked nerve bundles were measured for comparison between healthy subjects and CSM patients.The length of tracked nerve bundles significantly shortened in CSM patients compared with healthy subjects (healthy: 6.85-77.90 mm, CSM: 0.68-62.53 mm). The density of the tracked nerve bundles was also lower in CSM patients (healthy: 086±0.03, CSM: 0.80±0.06, p.05). Although the definition of ROI covering C4 only or whole cervical cord appeared not to affect the trend of the disparity between healthy and myelopathic cervical cords, the density of the tracked nerve bundle through whole myelopathic cords was in an association with the modified JOA score in CSM cases (r=0.949, p=.015), yet not found with ROI at C4 only (r=0.316, p=.684).The quantitative analysis of fiber tractography is a reliable approach to detect cervical spondylotic myelopathic lesions compared with healthy spinal cords. It could be employed to delineate the severity of CSM.

Jiao-Long Cui,1 Guangsheng Li,2 Kin-Cheung Mak,1,3 Keith Dip-Kei Luk,1 Yong Hu1-3 1Department of Orthopaedics and Traumatology, The University of Hong Kong, Hong Kong, People’s Republic of China; 2Department of Orthopaedics, Spinal Division, Affiliated Hospital of Guangdong Medical University, Guangdong, 3Shenzhen Key Laboratory for Innovative Technology in Orthopaedic Trauma, The University of Hong Kong-Shenzhen Hospital, Shenzhen, People’s Republic of China Background: Cervical spondylotic myelopathy (CSM) is a degenerative disorder that can chronically damage the spinal cord. The aim of this study was to investigate the column-specific degeneration in the cervical cord with CSM and explore the structure–function relationship by diffusion tensor imaging (DTI) and functional magnetic resonance imaging (fMRI).Patients and methods: DTI and blood-oxygen-level-dependent (BOLD) fMRI were obtained from 14 healthy controls and six patients with CSM at 3T. The fractional anisotropy (FA) value of anterior, lateral, and posterior column and the BOLD signal in response to somatosensory stimulation were compared among three groups: the average value of levels from C3 to C8 in the control and CSM groups and the value at maximal compression site in the CSM (CSM-mc) group. The correlation between FA value and BOLD signal was used to assess the structure–function relationship.Results: The FA value in CSM-mc was lower than control-ave in all the columns (P

Introduction Spinal tuberculosis represents a challenging disease to treat, not because of the technical expertise or the time required to cure it, but more so because of the decisions involved to treat it. The Medical Research Council (MRC) Working Party on Tuberculosis of the Spine designed trials to help address several questions. Methods A comprehensive literature search was performed using PubMed Medline, including English articles from 1934 to 1012, which pertain to spinal tuberculosis, with special effort in tracing the 13 MRC reports. The primary focus was on disease eradication, fusion rate, and a secondary focus on both short and long-term results in terms of disease recurrence and alignment. Additional searches were made on the use of spinal implants for infection cases. Results After reviewing MRC and non-MRC reports, it was evident that the “Hong Kong operation”, which involved radical debridement and strut grafting the lesion, produced better short-, medium- and long-term results in such aspects as fusion rate, spinal deformity and relapse of abscess/sinus. Subsequent work by others demonstrated the importance of prevention of progressive kyphosis, therefore the need to identify risk factors for these and pre-emptive measures such as kyphosis correction, careful graft selection, and instrumentation. Conclusion Improvement in quality of life is also accompanied by higher patient expectations. Though developing nations may lack the resources now, eventually patients will demand better functional and cosmetic results after being afflicted by this disfiguring and potentially disabling disease, and the “Hong Kong operation” represented the best outcome, provided resources were available.

Summary Background Scoliosis in skeletally immature children is often treated by implantation of a rod to straighten the spine. Rods can be distracted (lengthened) as the spine grows, but patients need many invasive operations under general anaesthesia. Such operations are costly and associated with negative psychosocial outcomes. We assessed the effectiveness and safety of a new magnetically controlled growing rod (MCGR) for non-invasive outpatient distractions. Methods We implanted the MCGR in five patients, two of whom have now reached 24 months' follow-up. Each patient underwent monthly outpatient distractions. We used radiography to measure the magnitude of the spinal curvature, rod distraction length, and spinal length. We assessed clinical outcome by measuring the degree of pain, function, mental health, satisfaction with treatment, and procedure-related complications. Findings In the two patients with 24 months' follow-up, the mean degree of scoliosis, measured by Cobb angle, was 67° (SD 10°) before implantation and 29° (4°) at 24 months. Length of the instrumented segment of the spine increased by a mean of 1·9 mm (0·4 mm) with each distraction. Mean predicted versus actual rod distraction lengths were 2·3 mm (1·2 mm) versus 1·4 mm (0·7 mm) for patient 1, and 2·0 mm (0·2 mm) and 2·1 mm (0·7 mm) versus 1·9 mm (0·6 mm) and 1·7 mm (0·8 mm) for patient 2's right and left rods, respectively. Throughout follow-up, both patients had no pain, had good functional outcome, and were satisfied with the procedure. No MCGR-related complications were noted. Interpretation The MCGR procedure can be safely and effectively used in outpatient settings, and minimises surgical scarring and psychological distress, improves quality of life, and is more cost-effective than is the traditional growing rod procedure. The technique could be used for non-invasive correction of abnormalities in other disorders. Funding Ellipse Technologies.

Diffusion tensor image (DTI) of the cervical spinal cord has been proposed to be used to identify the myelopathic level in the cervical spinal cord. Fractional anisotropy (FA) from DTI is usually used to diagnose the level of cervical spondylotic myelopathy (CSM). However, the solely use of FA value does not consider a full information of 3D multiple indices of diffusion from DTI. This study proposed to use a classification based on machine learning to extract and determine the myelopathic cord in CSM. A classification based on support tensor machine (STM) was applied on eigenvalues extracted from DTI at compressive levels of the cervical spinal cord. This is a validation study to apply STM classification in 30 patients with CSM. The benchmark of classification was the clinical level diagnosis with consensus of senior spine surgeons. The accuracy, sensitivity and specificity of the classification were evaluated in the study. Results showed the use of STM classification provided diagnostic accuracy of 89.2%, sensitivity of 71.8% and specificity of 90.1%. Using the classification based on STM, eigenvalues of DTI can be detected by computational intelligence to provide level diagnosis of CSM, which could help the surgeons to select the most appropriate surgical plan to treat CSM.

There is much variation in the choice, timing and duration of antimicrobial prophylaxis for preventing surgical site infections (SSI) but no guideline exists for scoliosis surgery. The aim of study was to compare the efficacy of two antimicrobial prophylaxis (AMP) protocols with cephazolin in preventing SSI in adolescent idiopathic scoliosis (AIS).A retrospective comparative analysis of two post-operative AMP protocols (two postoperative doses versus continued antibiotics till drain removal) was performed. Patient characteristics, pre-operative, intra- and post-operative risk factors for infection, drain use, generic drug name and number of doses administered were recorded from 226 patients with AIS who had undergone posterior spinal fusion. Details of superficial or deep SSI and wound healing aberrations, and serious adverse events were recorded. Analysis was performed to evaluate differences in the pre-, intra- and post-operative variables between the two groups.155 patients received 2 postoperative doses of AMP and 71 patients had antibiotics till drain removal. The average follow-up was 43 months. The overall rate of SSI was 1.7 % for the spine wound and 1.3 % for the iliac crest wound. 1.9 % of patients with 2 doses of AMP and 1.4 % of patients with antibiotics till drain removal had SSI. No adverse reactions attributable to cephazolin were observed.This is the first study on the AMP protocol in scoliosis surgery for SSI prevention. Results suggest that two doses of AMP are as effective as continued antimicrobial use until drain removal. Cephazolin appears to be effective and safe for prophylaxis.

Patients who have undergone neck dissection and radiotherapy are at risk of cervical spine infections. Furthermore, previous radiotherapy and cervical spine infections can lead to fistula formation to the subarachnoid space and intracranial infection. This report discusses the serious consequences of a missed cervical spine infection including cerebrospinal fluid fistula formation and persistent central nervous system infection, and serves as a reminder to clinicians of the possible association between cervical spine infections and prior head and neck surgery and radiotherapy. In all such cases, the posterior pharyngeal wall should be inspected during follow-up. Despite the appearance of an intracranial infection, the cervical spine should be investigated, especially if the response to appropriate antibiotics is suboptimal.

STUDY DESIGN A prospective study on a series of consecutive patients. OBJECTIVE To investigate the use of diffusion tensor imaging (DTI) and orientation entropy in level localization in patients diagnosed with multilevel cervical spondylotic myelopathy (CSM). SUMMARY OF BACKGROUND DATA Multilevel CSM presents complex neurological signs that make level localization difficult. DTI is recently found to be able to assess the microstructural changes of the white matter caused by cord compression. METHODS Sixteen patients with CSM with multilevel compression were recruited. The level(s) responsible for the clinical symptoms were determined by detailed neurological examination, T2-weighted (T2W) magnetic resonance imaging (MRI), and DTI. On T2W MRI, anterior-posterior compression ratio and increased signal intensities were used to determine the affected level(s). The level diagnosis results from T2W MRI, increased signal intensities, DTI, and combination method were correlated to that of neurological examination on a level-to-level basis, respectively. The accuracy, sensitivity, and specificity were calculated. RESULTS When correlated with the clinical level determination, the weighted orientation entropy-based DTI analysis was found to have higher accuracy (82.76% vs. 75.86%) and sensitivity (84.62% vs. 76.92%) than those of the anterior-posterior compression ratio. The increased signal intensities have the highest specificity (100.00%) but the lowest accuracy (58.62%) and sensitivity (53.85%). When combined with the level diagnosis result of wOE with that of anterior-posterior compression ratio, it demonstrated the highest accuracy and sensitivity that were 93.10% and 96.15%, respectively, and equal specificity (66.67%) with using them individually. CONCLUSION DTI can be a useful tool to determine the pathological spinal cord levels in multilevel CSM. This information from orientation entropy-based DTI analysis, in addition to conventional MRI and clinical neurological assessment, should help spine surgeons in deciding the optimal surgical strategy.

Cervical spondylotic myelopathy (CSM) is a common spinal cord disorder in the elderly. Diffusion tensor imaging (DTI) has been shown to be of great value for evaluating the microstructure of nerve tracts in the spinal cord. Currently, the quantitative assessment of the degeneration on the specific tracts in CSM is still rare. The aim of the present study was to use tractography-based quantification to investigate the column-specific degeneration in CSM. A total of 43 volunteers were recruited with written informed consent, including 20 healthy subjects and 23 CSM patients. Diffusion MRI was taken by 3T MRI scanner. Fiber tractography was performed using TrackVis to reconstruct the white matter tracts of the anterior, lateral and posterior column on the bilateral sides. The DTI metrics acquired from tractography, including fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD) and radial diffusivity (RD), were compared between healthy subjects and CSM patients. Compared to healthy subjects, FA was found significantly lower in the lateral (Healthy 0.64 ± 0.07 vs. CSM 0.53 ± 0.08) and posterior column (Healthy 0.67 ± 0.08 vs. CSM 0.47 ± 0.08) (p

Abnormal somatosensory evoked potential (SEP) (ie, prolonged latency) has been associated with poor surgical prognosis of cervical spondylotic myelopathy (CSM).To further characterize the extent of microstructural damage to the somatosensory tract in CSM patients using diffusion tensor imaging (DTI).Retrospective study.A total of 40 volunteers (25 healthy subjects and 15 CSM patients).Clinical, electrophysiological, and radiological evaluations were performed using the modified Japanese Orthopedic Association (mJOA) scoring system, SEP, and cord compression ratio in anatomic magnetic resonance (MR) images, respectively. Axial diffusion MR images were taken using a pulsed gradient, spin-echo-echo-planar imaging sequence with a 3-T MR system. The diffusion indices in different regions of the spinal cord were measured.Comparison of diffusion indices among healthy and myelopathic spinal cord with intact and impaired SEP responses were performed using one-way analysis of variance.In healthy subjects, fractional anisotropy (FA) values were higher in the dorsal (0.73±0.11) and lateral columns (0.72±0.13) than in the ventral column of white matter (0.58±0.10) (eg, at C4/5) (p.05). FA was dramatically dropped in the dorsal (0.54±0.16) and lateral columns (0.51±0.13) with little change in the ventral column (0.48±0.15) at the compressive lesions in CSM patients. There were no significant differences in the mJOA scores or cord compression ratios between CSM patients with or without abnormal SEP. However, patients with abnormal SEP showed an FA decrease in the dorsal column cephalic to the lesion (0.56±0.06) (ie, at C1/2, compared with healthy subjects [0.66±0.02]), but the same decrease was not observed for those without a SEP abnormality (0.67±0.02).Spinal tracts were not uniformly affected in the myelopathic cervical cord. Changes in diffusion indices could delineate focal or extensive myelopathic lesions in CSM, which could account for abnormal SEP. DTI analysis of spinal tracts might provide additional information not available from conventional diagnostic tools for prognosis of CSM.

Study design Review of surgical technique. Objective To provide accounts of the authors' preferred methods for performing anterior cervical surgery with personal tips and pearls. Summary of background data Many have described the various anterior surgical approaches to the cervical spine, and in this review, we hope to describe our preferences, highlighted with some tips and pearls. Methods Various accounts of the transoral, the anterolateral (Smith-Robinson), and the split manubrium approaches were reviewed and used as the basis of the review. Additional notes with regard to the authors' preferences were noted to provide further guidance. The descriptions were delineated from the most cephalad to the most caudal. Results The transoral, the anterolateral (Smith-Robinson), and the manubriotomy approaches were described. Each account starts with the basic preoperative considerations, then describes the incision and the main anatomical landmarks, and finally concludes with closure and main complications to monitor for. A brief description of the main pathologies that each approach may address is also provided. Conclusion The 3 anterior approaches to the cervical spine are direct and elegant solutions to pathologies arising from the anterior column. They supplement the more commonly used posterior approaches, which provide stronger multilevel fixation, and thus provide an essential tool in the armamentarium of spine surgeons.

The majority of nerve fibers in the spinal cord run longitudinally, playing an important role in connecting the brain to the peripheral nerves. There is a growing interest in applying diffusion tensor imaging (DTI) to the evaluation of spinal cord microarchitecture. The current study sought to compare the organization of longitudinal nerve fibers between healthy and myelopathic spinal cords using entropy-based analysis of principal eigenvector mapping. A total of 22 subjects were recruited, including 14 healthy subjects, seven cervical myelopathy (CM) patients with single-level compression, and one patient suffering from multi-level compression. Diffusion tensor magnetic resonance (MR) images of the cervical spinal cord were obtained using a pulsed gradient, spin-echo echo-planar imaging (SE-EPI) sequence with a 3T MR system. Regions of interest (ROIs) were drawn manually to cover the spinal cord, and Shannon entropy was calculated in principal eigenvector maps. The results revealed no significant differences in orientation entropy values along the whole length of cervical spinal cord in healthy subjects (C2-3: 0.73±0.05; C3-4: 0.71±0.07; C4-5: 0.72±0.048; C5-6: 0.71±0.07; C6-7: 0.72±0.07). In contrast, orientation entropy values in myelopathic cord were significantly higher at the compression site (0.91±0.03), and the adjacent levels (above: 0.85±0.03; below: 0.83±0.05). This study provides a novel approach to analyze the orientation information in diffusion MR images of healthy and diseased spinal cord. These results indicate that orientation entropy can be applied to determine the contribution of each compression level to the overall disorganization of principal nerve tracts of myelopathic spinal cord in cases with multi-level compression.

BACKGROUND CONTEXT: Spring-back complication after open-door laminoplasty as described by Hirabayashi is a well-known risk, but its definition, incidence, and associated neurologic outcome remain unclear. OBJECTIVE: To investigate the incidence and the neurologic consequence of spring-back closure after open-door laminoplasty. STUDY DESIGN: A retrospective radiographic and clinical review. OUTCOME MEASURES: Lateral cervical spine X-rays were evaluated. Anteroposterior diameters (APD) of the vertebral canal of C3-C7 were measured. Spring-back was defined as loss of APD on follow-up in comparison to immediate postoperative canal expansion. The loss of the end-on lamina silhouette with consequent reappearance of the lateral profile of the spinous processes was also assessed to verify the presence of spring-back. Spring-back closure was classified based on whether the collapse was total or partial, and whether all the operated levels or only a subset had collapsed (ie, complete vs. partial closure, segmental closure vs. total-construct closure). Neurologic status was documented using the Japanese Orthopaedic Association (JOA) score. METHODS: Thirty consecutive patients who underwent open-door laminoplasty from 1995 to 2005 at a single institution with a minimum follow-up of 2 years were assessed. They were all operated on using the classic Hirabayashi technique. Radiographic outcomes were assessed independently by two individuals. RESULTS: Sixteen men and 14 women with an average follow-up of 5 years (range, 2-12 years) were included. Of these patients, 24 had cervical spondylotic myelopathy and six had ossification of the posterior longitudinal ligament. Spring-back closure was found in three patients (10%) and 7 of 117 laminae (6%) within 6 months of the operation, which was further confirmed by computed tomography and magnetic resonance imaging. All spring-back closures were partial segmental closures. Gender and age were not significant factors related to spring back (p>.05). The mean JOA score on follow-up was 12.5, with a recovery rate of 40%. All patients with spring back and available JOA data exhibited postoperative neurologic deterioration. Of the three patients with spring back, two patients underwent revision surgery, whereas one declined. CONCLUSIONS: Spring-back closure occurred in 10% of our patients at or before 6 months after surgery. The incidence of spring-back by level (ie, 117 laminae) was 6%, mainly occurring at the lower cervical spine. All spring-back closures were partial segmental closures, most commonly involving C5 and C6. Postoperative neurologic deficit was associated with spring-back closure; therefore, surgeons should adopt preemptive surgical measures to prevent the occurrence of such a complication., postprint

We report a case of multiple triggering associated with Ehlers-Danlos syndrome. We postulate that the propensity for tendon degeneration in Ehlers-Danlos syndrome coupled with repetitive microtrauma might lead to fraying of the tendon fibers and, consequently, triggering. Indeed, in our case, debridement of the tendons rather than resection of A1 pulley resulted in a good long-term functional outcome 2 years after surgery.

Brown tumours may occur secondary to hyperparathyroidism in patients with chronic renal failure (CRF). Diagnosing a spinal brown tumour causing cord compression requires a high index of suspicion. We report a 65-year-old woman, who had been on haemodialysis for CRF for over 10 years, who presented with leg weakness and back pain over the thoracolumbar junction. She had a brown tumour at T8 causing subacute spinal cord compression. Ambulation was regained after surgical decompression and stabilisation. Adherence to the National Kidney Foundation guidelines in the management of patients with CRF may prevent renal osteodystrophy. Treatment of spinal brown tumour depends on the severity of the neurological deficit. Remineralisaton is expected after correction of the parathyroid level, thus negating the need for total excision of the parathyroid glands.

Introduction When assessing patients with cervical myelopathy, it is not uncommon to find patients with localizing signs that may not be entirely compatible with the 2D images seen on conventional MRI. Dynamic MRI films may add information, but with fMRI, specifically diffusion tensor imaging (DTI), more information regarding the microstructure of the tracts may be gleaned. Thus, this helps ensure that the diagnosis of cervical myelopathy is accurate and that the operation will be over the correct level(s). Materials and Methods A prospective case series in consecutive patients with cervical myelopathy was reviewed. The parameters looked at included multilevel compression, sidedness of compression, and detailed neurological assessment. T2-weighted (T2W) magnetic resonance imaging (MRI) and DTI were used to compare against a reference, the neurological findings. “Level diagnosis” and sidedness compatibility were then assessed. Results Weighted orientation entropy-based DTI analysis provided a closer match to the “level diagnosis.” Detailed DTI analysis also enabled reconciliation of neurological findings compared with conventional MRI. This was compared using simple anterior–posterior compression and high signal intensity (when available) as a means to identify level and determine clinical compatibility. Conclusion DTI has the potential of becoming a new standard for examining patients with cervical myelopathy, both in identifying diagnostic compatibility and the level most contributory to the neurological deficit. Further studies are required to further establish actual clinical usefulness of this modality.

The online version of the original article can be found under doi:10.1007/s00586-012-2455-0.