Photographic atlas of practical anatomy, volumes 1 and 2

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Pseudoarthrosis in ankylosing spondylitis

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Complications of Anterior and Posterior Cervical Spine Surgery

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Clinical and radiological outcomes after conservative treatment of TB spondylitis: is the 15 years' follow-up in the MRC study long enough?

Introduction: Tuberculosis of the spine is a still a common disease entity, not only in developing countries but is also returning in developed countries especially in the immune-compromised patients. Conservative treatment with chemotherapy is still the main stay of treatment. This article focuses on the clinical and radiological outcomes, and problems with conservative treatment. Method: The available literature of anti-tuberculosis chemotherapy in managing spinal tuberculosis was reviewed. Data sources included relevant literature of the English language identified through Medline search from 1946 to 2011. Personal experience and unpublished reviews from the authors' institution were also included. Results: Although majority of patients respond well to anti-tuberculosis chemotherapy, about 15 % of them develop paradoxical response. The Medical Research Council (MRC) studies have shown that for patients without significant neurological deficits, operative and conservative treatment could produce the same clinical outcome at 15 years follow-up. Patients treated operatively with debridement and spinal fusion with strut graft had faster bony fusion and less kyphotic deformity. In contrast, those treated with drugs alone or with simple debridement without fusion may result in disease reactivation, severe kyphosis or late instability, which in turn may lead to late-onset Pott's paraplegia, back pain, sagittal imbalance and compromised pulmonary function that are difficult or risky to treat. Conclusion: Recognition of the clinical and radiologic features of these late sequels is important for the management. Prevention of deformity in the early disease has been added to the modern standard of treatment of TB spine. © 2012 The Author(s).published_or_final_versionSpringer Open Choice, 25 May 201

Signal-to-noise ratio of intraoperative tibial nerve somatosensory-evoked potentials

To reveal the intrinsic signal-to-noise ratio (SNR) of single-trial somatosensory-evoked potentials (SEP). SEP was recorded from 13 scoliosis patients during surgery. The power of SEP was estimated with least-square fitting to obtain the most accurate value and then to estimate the SNR of every trial of SEP. The SNR of cortical SEP from 13 cases presented individual difference among each other. According to the mean and standard deviation, the coefficients of variation of cortical and subcortical SEP were 4.2% and 23%, respectively. The SNR of SEP was estimated to be -24 ± 1 dB in cortical SEP and -22 ± 5 dB in subcortical SEP. The lowest SNR of individual case was found to be -30 dB in cortical SEP and -53 dB in subcortical SEP. The results showed that SNR of intraoperative SEP recordings varies from person to person and presents a higher variability in subcortical than that in cortical, with a broad range from -53 to -5 dB. The results from this study can be used to understand the nature of SEP signals, which could guide researchers and designers on SEP denoising method selection, extraction, and measurement, as well as equipment development. © 2010 by the American Clinical Neurophysiology Society.postprin

A Correlation Study Between In-brace Correction, Compliance To Spinal Orthosis And Health-related Quality Of Life Of Patients With Adolescent Idiopathic Scoliosis

Background It has been proposed that in-brace correction is the best guideline for prediction of the results of brace treatment for patients with Adolescent Idiopathic Scoliosis (AIS). However, bracing may be a stressful experience for patients and bracing non-compliance could be psychologically related. The purpose of this study was to assess the correlation between brace compliance, in-brace correction and QoL of patients with AIS. Methods Fifty-five patients with a diagnosis of AIS were recruited. All were female and aged 10 years or above when a brace was prescribed, none had undergone prior treatment, and all had a Risser sign of 0–2 and a Cobb angle of 25-40°. The patients were examined in three consecutive visits with 4 to 6 months between each visit. The Chinese translated Trunk Appearance Perception Scale (TAPS), the Chinese translated Brace Questionnaires (BrQ) and the Chinese translated SRS-22 Questionnaires were used in the study. The in-brace Cobb angle, vertebral rotation and trunk listing were also measured. Patients’ compliance, in-brace correction and patients’ QoL were assessed. To identify the relationship among these three areas, logistic regression model and generalized linear model were used. Result For the compliance measure, a significant difference (p = 0.008) was detected on TAPS mean score difference between Visit 1 and Visit 2 in the least compliant group (0–8 hours) and the most compliant group (17–23 hours). In addition, a significant difference (p = 0.000) was detected on BrQ mean score difference between Visit 2 and Visit 3 in the least compliant group (0–8 hours) and the most compliant group (17–23 hours). For the orthosis effectiveness measure, no significant difference was detected between the three groups of bracing hours (0–8 hours, 9–16 hours, 17–23 hours) on in-brace correction (below 40% and 40% or above). For the QoL measure, no significant difference was detected between the two different in-brace correction groups (below 40% and 40% or above) on QoL as reflected by the TAPS, BrQ and SRS-22r mean scores. Conclusion The results showed a positive relationship between patients’ brace wear compliance and patients’ QoL. Poor compliance would cause a lower QoL.published_or_final_versio

Identification of detailed time-frequency components in somatosensory evoked potentials

Somatosensory evoked potential (SEP) usually contains a set of detailed temporal components measured and identified in time domain, providing meaningful information on physiological mechanisms of the nervous system. The purpose of this study is to reveal complex and fine time-frequency features of SEP in time-frequency domain using advanced time-frequency analysis (TFA) and pattern classification methods. A high-resolution TFA algorithm, matching pursuit (MP), was proposed to decompose a SEP signal into a string of elementary waves and to provide a time-frequency feature description of the waves. After a dimension reduction by principle component analysis (PCA), a density-guided K-means clustering was followed to identify typical waves existed in SEP. Experimental results on posterior tibial nerve SEP signals of 50 normal adults showed that a series of typical waves were discovered in SEP using the proposed MP decomposition and clustering methods. The statistical properties of these SEP waves were examined and their representative waveforms were synthesized. The identified SEP waves provided a comprehensive and detailed description of time-frequency features of SEP. © 2006 IEEE.published_or_final_versio

Prediction of scoliosis correction with thoracic segmental pedicle screw constructs using fulcrum bending radiographs

Award Papers Session: A2Study Design: A retrospective series of 35 idiopathic scoliosis patients underwent spinal fusion with a segmental thoracic pedicle screw system. Objective: To evaluate the amount of scoliosis correction with segmental pedicle screw constructs, and assess whether the fulcrum bending radiograph can predict surgical correction. Summary of Background Data: The fulcrum bending radiograph is highly predictive of actual curve correction based on hook or hybrid systems. However, its predictive value in segmental pedicle screw fixation systems has not been reported. Methods: Patients diagnosed with Lenke type 1A and 1B thoracic idiopathic scoliosis who underwent posterior spinal fusion with segmental pedicle screw constructs by single surgeon from January 2000 to December 2005 were reviewed. The fulcrum flexibility rate (FFR) and correction rate were compared. Stepwise linear regression analysis was done and a prediction equation for the postoperative Cobb angle was developed. Results: Thirty-five consecutive patients were included. Age at surgery was 14.8 years. Twenty scoliosis deformities were flexible, 15 were rigid. All patients had at least 2-year follow-up. The average preoperative Cobb angle was 58°, fulcrum bending Cobb angle was 28°, and postoperative Cobb angle 15° and 16° at 1 month and 2 years, respectively, after surgery. There was significant difference between FFR (51%) and correction rate at 1 month (72%) and 2 year (70%) after surgery. The difference between fulcrum bending corrective index of flexible (122%) and rigid (203%) curves was statistically significant. Stepwise linear regression analysis showed: Predicted postoperative Cobb angle = 0.012 + 1.75 × age - 0.212 × FFR (R = 0.69, P < 0.01). Conclusion: Thoracic pedicle screw constructs achieved better scoliosis correction compared with fulcrum bending radiographs. The fulcrum bending corrective index achieved was significantly greater in rigid than flexible curves. The postoperative Cobb angles could be calculated with a predictive equation. © 2010, Lippincott Williams & Wilkins.postprintThe 29th Annual Congress of the Hong Kong Orthopaedic Association, Hong Kong, 28-29 November 2009. In Spine, 2010, v. 35 n. 5, p. 557-56

Expert’s comment concerning Grand Rounds case entitled “Closing–Opening Wedge Osteotomy for Severe, Rigid Thoraco-Lumbar Post-tubercular Kyphosis” (by S. Rajasekaran, P. Rishimugesh Kanna and Ajoy Prasad Shetty)

Prevention or correction of severe kyphotic deformity in addition to eradication of the infective focus has become the modern standard of management of tuberculosis of the spine. Circumferential excision of the kyphus is now technically feasible with the development of rigid pedicle screw fixation system and intraoperative spinal cord monitoring in the past two decades

Cervical spine disease in Asian populations

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