How has genetics altered our understanding of low back pain: implications for its treatment

Concurrent Session 15 - The gene pearl: genetics and your practiceLow back pain is one of the most common disorders seen in general, orthopaedic and rheumatological practice. While there are many causes, one of the most common is degenerative disc disease. This has traditionally been thought of as a degenerative condition with ageing and spinal loading being major aetiological factors. However, recent epidemiological and twins studies would suggest a major genetic component. Over the past 10 years, we have collected the HKU degenerative disc disease cohort, which consists of 3500 population based subjects between 18 and 55, and of Southern Chinese origin. All individuals are characterized clinically and by MRI, and blood samples obtained for DNA isolation. Using this unique database, we have demonstrated a number of novel genetic risk factors that predispose our population to disc degeneration. We were also able to demonstrate a significant relationship between degenerative disc disease and low back pain, as well as some unusual patterns of disc degeneration with relevance on the aetiology of degeneration. The talk will discuss these in detail, and how they have altered our understanding of low back pain, and therefore the ways that we should be treating them, with particular emphasis on novel diagnostic methods and biological therapies.postprintThe 2011 Combined Scientific Meeting of ANZCA / HKCA, Hong Kong, China, 14-17 May 2011

How has genetics altered our understanding of low back pain: implications for its treatment

Concurrent Session 15 - The gene pearl: genetics and your practiceLow back pain is one of the most common disorders seen in general, orthopaedic and rheumatological practice. While there are many causes, one of the most common is degenerative disc disease. This has traditionally been thought of as a degenerative condition with ageing and spinal loading being major aetiological factors. However, recent epidemiological and twins studies would suggest a major genetic component. Over the past 10 years, we have collected the HKU degenerative disc disease cohort, which consists of 3500 population based subjects between 18 and 55, and of Southern Chinese origin. All individuals are characterized clinically and by MRI, and blood samples obtained for DNA isolation. Using this unique database, we have demonstrated a number of novel genetic risk factors that predispose our population to disc degeneration. We were also able to demonstrate a significant relationship between degenerative disc disease and low back pain, as well as some unusual patterns of disc degeneration with relevance on the aetiology of degeneration. The talk will discuss these in detail, and how they have altered our understanding of low back pain, and therefore the ways that we should be treating them, with particular emphasis on novel diagnostic methods and biological therapies.postprintThe 2011 Combined Scientific Meeting of ANZCA / HKCA, Hong Kong, China, 14-17 May 2011

Progressive shoulder arthropathy

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Verification Of Measurements Of Lumbar Spinal Dimensions In T1- And T2-weighted Magnetic Resonance Imaging Sequences

BACKGROUND CONTEXT: Magnetic resonance imaging (MRI) is commonly used to assess patients with lumbar spinal stenosis. No single MRI sequence has been shown to be superior in spinal canal measurements. There are also cost concerns for the increased clinical and research use of MRI. Using only a single sequence may lower the financial burden; however, this requires spinal canal measurements in both T1 and T2 MRI to be reliable. Evidence for this is currently lacking. PURPOSE: The aim of this study was to determine the intra- and inter-reader reliability of MRI measurements of the lumbar spine and the reliability of measurements using T1- and T2-weighted MRI films. STUDY DESIGN/SETTING: Retrospective study. PATIENT SAMPLE: Forty-two randomly selected patients who underwent spinal stenosis surgery. OUTCOME MEASURES: Lumbar spinal canal measurements and reliability analysis between T1- and T2-weighted MRI. METHODS: Qualitative ratings of MRI features were performed according to previously published criteria by 2 independent readers (JP-YC, HS). Measurements in axial scan included midline anteroposterior (AP) vertebral body diameter, midvertebral body width, midline AP spinal canal diameter, midline AP dural sac diameter, spinal canal width/interpedicular distance, pedicle width (right and left), and lamina angle. Measurements in the sagittal scan included midline AP body diameter, midvertebral body height, and AP spinal canal diameter. Cronbach alpha was used to characterize intra- and inter-reader reliability for qualitative rating data. Similarly, T1 and T2 comparison also was performed in the same manner. RESULTS: Good to excellent intra- and interobserver reliability was obtained for all measurements. Reliability analysis of all T1 and T2 measurements was excellent. CONCLUSIONS: Either T1 or T2 images can be used for measurements of spinal canal dimensions. These findings are of importance, as not every patient undergoing preoperative MRI assessment will necessarily have both sequences performed and only a single sequence is required for research studies. Our findings are also of relevance in measurement of lumbar canal diameters.postprin

The value of radiographs obtained during forced traction under general anaesthesia in predicting flexibility in idiopathic scoliosis with Cobb angles exceeding 60 degree

Our aim in this prospective radiological study was to determine whether the flexibility rate calculated from radiographs obtained during forced traction under general anaesthesia, was better than that of fulcrum-bending radiographs before corrective surgery in predicting the extent of the available correction in patients with idiopathic scoliosis. We evaluated 33 patients with a Cobb angle > 60 degrees on a standing posteroanterior radiograph, who had been treated by posterior correction. Pre-operative standing fulcrum-bending radiographs and those with forced-traction under general anaesthesia were obtained. Post-operative standing radiographs were taken after surgical correction. The mean forced-traction flexibility rate was 55% (SD 11.3) which was significantly higher than the mean fulcrum-bending flexibility rate of 32% (SD 16.1) (p 60 degrees in the standing position and may identify those patients for whom supplementary anterior surgery can be avoided.published_or_final_versio

Defining clinically relevant values for developmental spinal stenosis: a large-scale magnetic resonance imaging study

STUDY DESIGN: Case-control study. OBJECTIVE: The aim of this study was to define clinically relevant relative and critical (absolute) magnetic resonance imaging values of lumbar spinal stenosis in a cohort of 100 surgical cases and 100 asymptomatic controls. SUMMARY OF BACKGROUND DATA: Developmental spinal stenosis is a precipitating factor in patients presenting with lumbar canal stenosis. Yet, due to a lack of agreement on definitions and methods of assessment, as well as ethnic-specific normative values, its prevalence and significance is not known. METHODS: This was a case-control study comparing 100 age and sex-matched asymptomatic, volunteers with that of 100 patients who underwent surgery for spinal stenosis. All patients were of Chinese ethnicity and their details were blinded to 2 observers. Spinal stenosis parameters were measured on the basis of axial (pedicle level) and sagittal (midsagittal) magnetic resonance images. RESULTS: Anteroposterior spinal canal diameters change with levels. At each level, patients were found to have significantly narrower anteroposterior canal diameters than controls. By use of receiver operating characteristic curve, we defined developmental spinal stenosis if the anteroposterior canal diameter was at L1 <20 mm, L2 <19 mm, L3 <19 mm, L4 <17 mm, L5 <16 mm, and at S1 <16 mm on the basis of a value including 50% of controls and demonstrated best sensitivity and specificity. Furthermore, for L4, L5, and S1, critical stenosis values could be defined, below which almost all subjects needed surgery, these were L4 <14 mm, L5 <14 mm, and S1 <12 mm. CONCLUSION: This is the largest magnetic resonance imaging-based study with standardized measurements and comparable groups to determine clinically relevant magnetic resonance imaging criteria for lumbar spinal stenosis. The findings strongly suggest that developmental stenosis plays an important role in the pathogenesis of symptomatic spinal stenosis. Critical values of stenosis below which symptoms were highly likely were defined. These will need to be validated by longitudinal studies in future. However, they may possess clinical utility in determining the appropriate levels requiring canal-widening surgery.Level of Evidence: 3.postprin

Decompression without Fusion for Low-Grade Degenerative Spondylolisthesis

STUDY DESIGN: Retrospective series. PURPOSE: Assess results of decompression-only surgery for low-grade degenerative spondylolisthesis with consideration of instability. OVERVIEW OF LITERATURE: There is no consensus on whether fusion or decompression-only surgery leads to better outcomes for patients with low-grade degenerative spondylolisthesis. Current trends support fusion but many studies are flawed due to over-generalization without consideration of radiological instability and their variable presentations and natural history. METHODS: Patients with surgically treated degenerative spondylolisthesis from 1990-2013 were included. Clinical and radiological instability measures were included. Any residual or recurrence of symptoms, revision surgery performed and functional outcome scores including the numerical global rate of change scale, visual analogue scale, and modified Barthel index were measured. Follow-up periods for patients were divided into short-term (10 years). RESULTS: A total of 64 patients were recruited. Mechanical low back pain was noted in 48 patients and most (85.4%) had relief of back pain postoperatively. Radiological instability was noted in 4 subjects by flexion-extension radiographs and 12 subjects with prone traction radiographs by increased disc height and reduction of olisthesis and slip angle. From the results of the short-term, mid-term and long-term follow-up, reoperation only occurred within the first 5-year follow-up period. All functional scores improved from preoperative to postoperative 1-year follow-up. CONCLUSIONS: Decompression-only for low-grade degenerative spondylolisthesis has good long-term results despite instability. Further higher-level studies should be performed on this patient group with radiological instability to suggest the superior surgical option.published_or_final_versio

Traditional growing rod versus magnetically controlled growing rod for treatment of early onset scoliosis: Cost analysis from implantation till skeletal maturity

Purpose: To compare the yearly cost involved per patient in the use of magnetically controlled growing rod (MCGR) and traditional growing rods (TGRs) in the treatment of early onset scoliosis (EOS) and to assess the overall cost burden of MCGR with reference to patient and health-care infrastructure. Methods: For a hypothetical case of a 5-year-old girl with a diagnosis of EOS, a decision-tree model using TreeAge Software was developed to simulate annual health state transitions and compare the 8-year accumulative direct, indirect, and total cost among the four groups: (1) dual MCGRs with exchange every 2 years, (2) dual MCGRs with exchange every 3 years, (3) TGR with surgical distraction every year, and (4) TGR with surgical distraction every 6 months. Base-case values and ranges of clinical parameters reflecting complication rate after each type of surgical distraction were determined from a review of literature and expert opinion. Government gazette and expert opinion provided cost estimation of growing rods, surgeries, surgical complications, and routine follow-up. Microsimulation of 1000 individuals was conducted to test the variation in total direct costs (in 2016 Hong Kong dollars (HKD)) between individuals, and estimated the standard deviations of total direct costs for each group. Results: Over the projected treatment period, indirect costs incurred by patients and family were higher for the MCGR as compared to the TGR. However, the total costs incurred by MCGR groups (group 1: HKD164k; group 2: HKD138k) were lower than those incurred by TGR groups (group 3: HKD191k; group 4: HKD290k). Although the accumulative costs of three groups (TGR with distraction every year and MCGR replacing every 2 and 3 years) were approaching each other in the first 2 years after initial implantation, at year 3 the accumulative cost of MCGR exchange every 2 years was HKD36k more than the yearly TGR surgery due to the cost of implant exchange. The cost incurred by both the MCGR groups was less than that incurred by the TGR groups from year 4 to skeletal maturity. Conclusions: The use of dual MCGRs, regardless of its 2- or 3-year exchange, was only cost saving and less expensive than the dual TGRs for EOS treatment from the fourth year of continuous treatment. Despite higher patient-related costs during MCGR treatment, it is important to consider the reduced risks and mental burden suffered by these children during repeat surgeries. With improved knowledge of the costs associated with long-term MCGR use, better constructed cost-effectiveness studies can be performed in the future.published_or_final_versio

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

Extraction of RNA from tough tissues with high proteoglycan content by cryosection, second phase separation and high salt precipitation

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