Low Radiation X-rays: Benefiting People Globally by Reducing Cancer Risks.

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.

Cancer and mortality risks of patients with scoliosis from radiation exposure: a systematic review and meta-analysis.

PURPOSE: The study aimed for unraveling the long-term health impact of cumulative radiation exposure from full-spine radiographs on children/adolescents with scoliosis. METHODS: 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. RESULTS: 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 < 0.00001; breast cancer, OR = 1.20, p = 0.02; cancer mortality, OR = 1.50, p < 0.00001]. No statistically significant differences were found in terms of reproductive events for scoliosis patients, pulmonary function and physical activity for adolescent idiopathic scoliosis patients. CONCLUSIONS: Based on 35,641 participants with over 20 years' observations from 1912 to 1990, repeated radiographs and pertaining cumulative radiation dose resulted in elevated rates of cancer, breast cancer and cancer mortality for children/adolescents with scoliosis in comparison with matched general population. It is recommended that low-radiation or radiation-free and efficient methods should be used to monitor the evolution of children/adolescents with scoliosis.

Sinew acupuncture for knee osteoarthritis: study protocol for a randomized sham-controlled trial.

BACKGROUND: Sinew acupuncture is a new modality of acupuncture in which needles are inserted into acupoints, ashi points or spasm points of sinew and muscles along the meridian sinew pathway. A previous observational study revealed that sinew acupuncture has immediate analgesic effects on various soft tissue injuries, including knee injuries. However, no rigorous trials have been conducted. This study aims to examine whether sinew acupuncture can safely relieve pain and symptoms of knee osteoarthritis (KOA) and improve patients' functional movement and quality of life. METHODS/DESIGN: A randomized, sham-controlled, patient- and assessor-blinded trial will be conducted to compare the efficacy of sinew acupuncture and sham acupuncture. Subjects will be assessed by the physician and acupuncturists. A sample of eighty-six eligible subjects will be randomized into either the sinew acupuncture group or the sham acupuncture group. The intervention will be performed in the Hong Kong Tuberculosis Association Chinese Medicine Clinic cum Training Centre of the University of Hong Kong by acupuncturists with over 3 years of acupuncture experience. Subjects will receive 10 sessions of interventions for 4 weeks, followed by a 6-week follow-up. The visual analogue scale (VAS) score at week 4 will be the primary outcome. The Western Ontario and McMasters University Osteoarthritis Index (WOMAC), Timed Up & Go Test (TUG), 8-step Stair Climb Test (SCT) and the 36-Item Short Form Survey (SF-36) will be secondary outcomes. DISCUSSION: Sinew acupuncture is a potential alternative non-pharmacological therapy for KOA. This rigorous trial will expand our knowledge of whether sinew acupuncture reduces pain intensity and improves symptoms, functional movements, and quality of life of KOA patients. TRIAL REGISTRATION: The study was registered at ClinicalTrials.gov (Identifier: NCT03099317) in March 2017.

Preventing Fusion Mass Shift Avoids Postoperative Distal Curve Adding-on in Adolescent Idiopathic Scoliosis.

BACKGROUND: 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. QUESTIONS/PURPOSES: (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. METHODS: 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. RESULTS: 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; p < 0.002) 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). CONCLUSIONS: 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 OF EVIDENCE: Level II, prognostic study.

Cervical spinal canal stenosis first presenting after spinal cord injury due to minor trauma: An insight into the value of preventive decompression.

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.

Antimicrobial prophylaxis to prevent surgical site infection in adolescent idiopathic scoliosis patients undergoing posterior spinal fusion: 2 doses versus antibiotics till drain removal.

PURPOSE: 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). METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Quantitative assessment of column-specific degeneration in cervical spondylotic myelopathy based on diffusion tensor tractography.

PURPOSE: 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. METHODS: 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. RESULTS: 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 < 0.001), while MD, AD and RD were significantly higher in the anterior, lateral and posterior column in CSM (p < 0.05). CONCLUSION: Loss of microstructural integrity was detected in the lateral and posterior column in CSM. Tractography-based quantification was capable of evaluating the subtle pathological insult within white matter on a column-specific basis, which exhibited potential clinical value for in vivo evaluation of the severity of CSM.

Normal values of cervical spinal cord diffusion tensor in young and middle-aged healthy Chinese.

PURPOSE: 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. METHODS: 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. RESULTS: No significant difference was found between genders (p > 0.05). DTI parameters significantly differed among different cord levels (p < 0.05). FA value in whole cord, grey matter, dorsal and ventral column showed significant but weak correlation with age (p < 0.05). CONCLUSION: A comprehensive normal database of DTI parameters of cervical spinal cord was established. The effect of gender and age-related changes is negligible in DTI analysis of cervical spinal cord disorders.

Is diffusion anisotropy a biomarker for disease severity and surgical prognosis of cervical spondylotic myelopathy?

PURPOSE: To explore the value of diffusion-tensor (DT) imaging in addressing the severity of cervical spondylotic myelopathy (CSM) and predicting the outcome of surgical treatment. MATERIALS AND METHODS: From July 2009 to May 2012, 65 volunteers were recruited for this institutional review board-approved study, and all gave informed consent; 20 volunteers were healthy subjects (age range, 41-62 years), and 45 were patients with CSM (age range, 43-86 years). Anatomic and DT 3.0-T magnetic resonance images were obtained. Surgical decompression was performed in 22 patients with CSM, and patients were followed up for 6 months to 2 years. The clinical severity of myelopathy and postoperative recovery were assessed by using the modified Japanese Orthopaedic Association (mJOA) score. A recovery ratio (comparison of postoperative with preoperative mJOA score) of more than 50% indicated a good clinical outcome of surgery. DT findings, patient age, T2 high signal intensity (HSI), and somatosensory evoked potential (SEP) were analyzed by using a logistic regression model to predict the surgical outcome of patients with CSM. RESULTS: A significant difference in cervical cord mean fractional anisotropy (FA) was found between healthy subjects and patients with CSM (0.65 ± 0.05 [standard deviation] vs 0.52 ± 0.13, P < .001). FA values were significantly correlated with the severity of neurologic dysfunction indicated by mJOA score (r(2) = 0.327, P = .016). Logistic regression analysis showed that mean FA (P = .030) and FA at the C2 vertebra (P = .035) enabled prediction of good surgical outcome; however, preoperative mJOA (P = .927), T2 HSI (P = .176), SEP amplitude (P = .154), and latency (P = .260) did not. CONCLUSION: FA is a biomarker for the severity of myelopathy and for subsequent surgical outcome.

Magnetically controlled growing rods for severe spinal curvature in young children: a prospective case series.

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.

Surgical treatment of acute TB spondylitis: indications and outcomes.

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.

Orientation entropy analysis of diffusion tensor in healthy and myelopathic spinal cord.

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.

Degenerative cervical myelopathy: Recent updates and future directions.

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.

Predictability of Supine Radiographs for Determining In-Brace Correction for Adolescent Idiopathic Scoliosis.

STUDY DESIGN: Retrospective radiographic study. OBJECTIVE: To assess whether flexibility as revealed by the supine radiograph, predicts in-brace curve correction. SUMMARY OF BACKGROUND DATA: 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. METHODS: 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. RESULTS: From 105 patients with mean age of 12.2 ±â€Š1.2 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. CONCLUSION: 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. LEVEL OF EVIDENCE: 3.

Efficacy of Postoperative Pain Management Using Continuous Local Anesthetic Infusion at the Iliac Crest Bone Graft Site in Patients with Adolescent Idiopathic Scoliosis: A Parallel, Double-Blinded, Randomized Controlled Pilot Trial.

Study Design Randomized controlled trial. Objective Adolescent idiopathic scoliosis (AIS) is a common spinal deformity that affects every population. In severe deformity, surgical intervention is performed. Autogenous iliac crest bone graft (ICBG) harvesting remains a common procedure worldwide for scoliosis surgery. Postoperative pain at the ICBG donor site is a major concern in patients undergoing spine surgery that affects postoperative functional outcome and consumes health care resources. Previous studies have noted a decrease in pain and postoperative analgesic use with the application of continuous infusion of anesthetic at the ICBG site in comparison with placebo. However, there is lack of evidence addressing the efficacy of continuous anesthetic infusion at the ICBG site in young patients and in particular those with spinal deformity, such as AIS. As such, this parallel, double-blinded, randomized controlled trial addressed the pain management efficacy of continuous anesthetic infusion versus saline at the ICBG site in patients with AIS during the immediate postoperative period. Methods Participants were randomized into two groups. Group A (control subjects) received 3 mL per hour of saline locally at the ICBG site, and group B (treatment subjects) received a constant rate of infusion of 3 mL per hour of 0.25% levobupivacaine. Both groups received their postoperative intervention for 47 hours. All subjects and outcome assessors were blinded to the type of intervention. Utilizing the visual analog pain scale, pain was assessed at the primary spine surgical site, ICBG site, and contralateral ICBG site. Overall physical pain was assessed by the McGill Pain Questionnaire. The degree of analgesic use and complications were also evaluated. All outcomes were assessed up until the fourth day of the patients' hospitalization following surgery. Results Twelve subjects were recruited (five in group A; seven in group B). No difference was noted at baseline regarding age, weight, height, arm span, sex, curve type, instrumented and fused levels, length of hospitalization, and pain scores between groups. Postoperatively, no difference was noted in surgical site pain between groups (p > 0.05). However, decreased ICBG and contralateral ICBG pain decreased twofold in group B patients in comparison with group A. Similarly, group B subjects had notably decreased postoperative overall pain scores (group A, mean 15.3; group B, mean 3.8). No significant differences were noted for the pain scores due to the small sample size. Conclusions This study is the first with a robust level I study design to assess the efficacy of continuous infusion of analgesia into the ICBG site in young patients with AIS. This pilot study noted a trend that continuous anesthetic infusion reduces pain at the ICBG site and may further decrease overall physical bodily pain. This study further established a sample size calculation to facilitate large-scale studies addressing these parameters. This study provides further support of postoperative pain management options for children with spinal deformities.

A Lethal Sequelae of Spinal Infection Complicating Surgery and Radiotherapy for Head and Neck Cancer.

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.

Selection of Fusion Levels Using the Fulcrum Bending Radiograph for the Management of Adolescent Idiopathic Scoliosis Patients with Alternate Level Pedicle Screw Strategy: Clinical Decision-making and Outcomes.

OBJECTIVE: Selecting fusion levels based on the Luk et al criteria for operative management of thoracic adolescent idiopathic scoliosis (AIS) with hook and hybrid systems yields acceptable curve correction and balance parameters; however, it is unknown whether utilizing a purely pedicle screw strategy is effective. Utilizing the fulcrum bending radiographic (FBR) to assess curve flexibility to select fusion levels, the following study assessed the efficacy of pedicle screw fixation with alternate level screw strategy (ALSS) for thoracic AIS. METHODS: A retrospective study with prospective radiographic data collection/analyses (preoperative, postoperative 1-week and minimum 2-year follow-up) of 28 operative thoracic AIS patients undergoing ALSS was performed. Standing coronal/sagittal and FBR Cobb angles, FBR flexibility, fulcrum bending correction index (FBCI), trunkal shift, radiographic shoulder height (RSH), and list were assessed on x-rays. Fusion level selection was based on the Luk et al criteria and compared to conventional techniques. RESULTS: In the primary curve, the mean preoperative and postoperative 1 week and last follow-up standing coronal Cobb angles were 59.9, 17.2 and 20.0 degrees, respectively. Eighteen patients (64.3%) had distal levels saved (mean: 1.6 levels) in comparison to conventional techniques. Mean immediate and last follow-up FBCIs were 122.6% and 115.0%, respectively. Sagittal alignment did not statistically differ between any assessment intervals (p>0.05). A decrease in trunkal shift was noted from preoperative to last follow-up (p = 0.003). No statistically significant difference from preoperative to last follow-up was noted in RSH and list (p>0.05). No "add-on" of other vertebra or decompensation was noted and all patients achieved fusion. CONCLUSIONS: This is the first report to note that using the FBR for decision-making in selecting fusion levels in thoracic AIS patients undergoing management with pedicle screw constructs (e.g. ALSS) is a cost-effective strategy that can achieve clinically-relevant deformity correction that is maintained and without compromising fusion levels.

Potential use of diffusion tensor imaging in level diagnosis of multilevel cervical spondylotic myelopathy.

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.

Diffusion tensor imaging of somatosensory tract in cervical spondylotic myelopathy and its link with electrophysiological evaluation.

BACKGROUND AND CONTEXT: Abnormal somatosensory evoked potential (SEP) (ie, prolonged latency) has been associated with poor surgical prognosis of cervical spondylotic myelopathy (CSM). PURPOSE: To further characterize the extent of microstructural damage to the somatosensory tract in CSM patients using diffusion tensor imaging (DTI). STUDY DESIGN/SETTING: Retrospective study. PATIENT SAMPLE: A total of 40 volunteers (25 healthy subjects and 15 CSM patients). OUTCOME MEASURES: 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. METHODS: Comparison of diffusion indices among healthy and myelopathic spinal cord with intact and impaired SEP responses were performed using one-way analysis of variance. RESULTS: 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). CONCLUSION: 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.

Quantitative analysis of fiber tractography in cervical spondylotic myelopathy.

BACKGROUND CONTEXT: 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. PURPOSE: The aim of this study was to develop a quantitative approach for fiber tractography analysis in cervical spondylotic myelopathy (CSM). STUDY DESIGN/SETTING: Prospective study on a series of patients. MATERIALS AND METHODS: 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. RESULTS: 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). CONCLUSIONS: 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.