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Jason Cheung | The University of Hong Kong - Academia.edu

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Jason Cheung

The University of Hong Kong, Orthopaedics and Traumatology, Faculty Member

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Dr Jason Pui Yin Cheung joined the Department of Orthopaedics and Traumatology as a Clinical Assistant Professor in November 2012 and promoted to Clinical Associate Professor with early tenure in 2018. After obtaining his MBBS degree from The University of Hong Kong in 2007, Dr Cheung received his training in Orthopaedics at Queen Mary Hospital. He completed his membership examination in 2009 and obtained his Masters of Medical Sciences degree from The University of Hong Kong in 2012. He completed his specialist training in 2014. He obtained his Master of Surgery in 2017, Postgraduate Diploma in Molecular and Diagnostic Pathology in 2018, and Doctor of Medicine in 2019. His main research interests are paediatric growth and spinal deformity, developmental lumbar spinal stenosis, management of cervical myelopathy and orthopaedic infections.

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marek kluszczynski

Western University Canada

OTHMAN O KHALIFA

International Islamic University Malaysia

João Manuel R. S. Tavares

Universidade do Porto

Geoff Dougherty

California State University, Channel Islands

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Papers by Jason Cheung

SpineHRformer: A Transformer-Based Deep Learning Model for Automatic Spine Deformity Assessment with Prospective Validation

Bioengineering

The Cobb angle (CA) serves as the principal method for assessing spinal deformity, but manual mea... more The Cobb angle (CA) serves as the principal method for assessing spinal deformity, but manual measurements of the CA are time-consuming and susceptible to inter- and intra-observer variability. While learning-based methods, such as SpineHRNet+, have demonstrated potential in automating CA measurement, their accuracy can be influenced by the severity of spinal deformity, image quality, relative position of rib and vertebrae, etc. Our aim is to create a reliable learning-based approach that provides consistent and highly accurate measurements of the CA from posteroanterior (PA) X-rays, surpassing the state-of-the-art method. To accomplish this, we introduce SpineHRformer, which identifies anatomical landmarks, including the vertices of endplates from the 7th cervical vertebra (C7) to the 5th lumbar vertebra (L5) and the end vertebrae with different output heads, enabling the calculation of CAs. Within our SpineHRformer, a backbone HRNet first extracts multi-scale features from the inp...

Preoperative left shoulder elevation > 1 cm is predictive of severe postoperative shoulder imbalance in early onset idiopathic scoliosis patients treated with growth-friendly instrumentation

Spine deformity, May 8, 2023

A Novel Method to Measure the Sagittal Curvature in Spinal Deformities: The Reliability and Feasibility of 3-D Ultrasound Imaging

Ultrasound in Medicine and Biology, Oct 1, 2019

The objective of this study is to test the reliability of sagittal spinal curvature measurements ... more The objective of this study is to test the reliability of sagittal spinal curvature measurements using three-dimensional (3D) ultrasound in adolescent idiopathic scoliosis (AIS) patients. Ultrasound spinous process angle (USSPA) and ultrasound laminae angle (USLA) were measured on sagittal ultrasound images, while Cobb angle (XCA) was measured on sagittal Xray images. Intraclass correlation coefficients (ICC) for the intra-and inter-observer variability, linear regression analysis and Bland-Altman method including mean absolute difference (MAD) were investigated to evaluate the reliability and validity of the two ultrasound angles as compared to XCA. Excellent measurement reliabilities were demonstrated for both ultrasound angles (ICC≥0.91). Moderate to good and significant linear correlations and good agreement were demonstrated between the ultrasound methods and XCA (Thoracic: (R 2 ≥0.574) / Lumbar (R 2 ≥0.635)). No significant differences were found from the MADs between both corrected ultrasound angles and XCA. Sagittal ultrasound angles demonstrated to be reliable for assessing sagittal curvature using spinous processes and laminae, and have good and significant correlations with Cobb angles. Since it is non-ionizing and relatively low cost, this opens the possibility to provide frequent curve monitoring and evaluation, and screening for AIS patients, particularly based on sagittal profiles.

Underarm bracing for adolescent idiopathic scoliosis leads to flatback deformity

The bone & joint journal, Nov 1, 2019

The aim of this study was to determine the influence of pelvic parameters on the tendency of pati... more The aim of this study was to determine the influence of pelvic parameters on the tendency of patients with adolescent idiopathic scoliosis (AIS) to develop flatback deformity (thoracic hypokyphosis and lumbar hypolordosis) and its effect on quality-of-life outcomes. Patients and Methods This was a radiological study of 265 patients recruited for Boston bracing between December 2008 and December 2013. Posteroanterior and lateral radiographs were obtained before, immediately after, and two-years after completion of bracing. Measurements of coronal and sagittal Cobb angles, coronal balance, sagittal vertical axis, and pelvic parameters were made. The refined 22-item Scoliosis Research Society (SRS-22r) questionnaire was recorded. Association between independent factors and outcomes of postbracing ≥ 6° kyphotic changes in the thoracic spine and ≥ 6° lordotic changes in the lumbar spine were tested using likelihood ratio chi-squared test and univariable logistic regression. Multivariable logistic regression models were then generated for both outcomes with odds ratios (ORs), and with SRS-22r scores. Results Reduced T5-12 kyphosis (mean-4.3° (sd 8.2); p < 0.001), maximum thoracic kyphosis (mean-4.3° (sd 9.3); p < 0.001), and lumbar lordosis (mean-5.6° (sd 12.0); p < 0.001) were observed after bracing treatment. Increasing prebrace maximum kyphosis (OR 1.133) and lumbar lordosis (OR 0.92) was associated with postbracing hypokyphotic change. Prebrace sagittal vertical axis (OR 0.975), prebrace sacral slope (OR 1.127), prebrace pelvic tilt (OR 0.940), and change in maximum thoracic kyphosis (OR 0.878) were predictors for lumbar hypolordotic changes. There were no relationships between coronal deformity, thoracic kyphosis, or lumbar lordosis with SRS-22r scores. Conclusion Brace treatment leads to flatback deformity with thoracic hypokyphosis and lumbar hypolordosis. Changes in the thoracic spine are associated with similar changes in the lumbar spine. Increased sacral slope, reduced pelvic tilt, and pelvic incidence are associated with reduced lordosis in the lumbar spine after bracing. Nevertheless, these sagittal parameter changes do not appear to be associated with worse quality of life.

Additional file 1: of Psychometric validation of the EuroQoL 5-Dimension 5-Level (EQ-5D-5L) in Chinese patients with adolescent idiopathic scoliosis

Hong Kong (Traditional Chinese) ÂS 2012 EuroQol Group EQ-5Dâ ˘ is a trade mark of the EuroQol Gro... more

Paper #32: Complications of Magnetically Controlled Growing Rod Surgery: Multicenter Study of 26 Patients With Medium-term Follow-up

Spine deformity, Nov 1, 2014

Complications of Magnetically-Controlled Growing Rod Surgery: A Prospective Multicentre Study with Minimum 2 Year Follow-Up

Orthopaedic Proceedings, Feb 21, 2018

Propensity-matched Comparison between Chronic non-specific Low Back Pain and Axial Spondyloarthritis: Impact on patient-perceived Quality of Life

Spine, Oct 17, 2022

Study Design. Prospective study. Objective. To compare the burden between chronic nonspecific low... more Study Design. Prospective study. Objective. To compare the burden between chronic nonspecific low back pain (LBP) and axial spondyloarthropathy (SpA). Summary of Background Data. Chronic nonspecific LBP and SpA are two debilitating yet different chronic musculoskeletal disorders. To compare their burden, propensity score matching is used to control for potential confounders and match the study subjects. Materials and Methods. Two prospectively collected cohorts of LBP (n=269) and SpA (n=218) patients were studied. Outcomes included current LBP, 36-item Short Form Questionnaire, Oswestry Disability Index, EuroQol 5-dimension 5-level Questionnaire, and EuroQol Visual Analog Scale. With the inherent differences between the two types of patients, propensity score matching was performed for comparing the two groups. Baseline covariates of age, sex, education level, occupation, smoking, and drinking history were selected for the estimation of propensity scores for each subject with the logistic regression model. Significant independent variables for the outcome of current back pain were included in the multivariate logistic regressions. Results. A total of 127 matched pairs were identified, with 254 patients. In the matched cohort, more patients with chronic LBP had current back pain (95.3%) as compared with SpA (71.7%). Patients with SpA were younger (P&lt;0.001), with more males (P&lt;0.001), and better educated (P=0.001). There was less current back pain and higher nonsteroidal anti-inflammatory drug use (P&lt;0.001). Most SpA patients had lower Oswestry Disability Index than LBP patients and with low disease activity. Patients with LBP had worse outcome scores as compared with SpA patients given the same Visual Analog Scale. LBP patients had 8.6 times the odds (95% CI: 3.341–20.671; P&lt;0.001) of experiencing current back pain compared with SpA patients. Conclusions. The disease activity of SpA patients is well controlled. However, patients with chronic LBP have worse pain severity, disability, and health-related quality of life. This has implications on resource utilization and the necessity of advancing LBP understanding and management. Level of Evidence. Type I prognostic study.

Predictive factors for successful non-operative treatment and achieving MCID improvement in health-related quality of life in adult spinal deformity

BMC Musculoskeletal Disorders, Aug 22, 2022

Background: Adult spinal deformity is a spectrum of degenerative spinal diseases with increasing ... more Background: Adult spinal deformity is a spectrum of degenerative spinal diseases with increasing prevalence and healthcare burden worldwide. Identification of patients who are more likely to improve through conservative management may reduce cost and potentially prevent surgery and its associated costs and complications. This study aims to identify predictive factors for MCID in improvement of ODI and SRS-22r questionnaires in patients with adult spinal deformity treated with conservative treatment. Methods: A prospective, observational cohort study of 46 patients was conducted at a spine specialist clinic. Inclusion criteria were 30-80 years of age, diagnosis of neglected adolescent idiopathic scoliosis, de-novo scoliosis, degenerative spondylolisthesis, and sagittal plane deformities (thoracic hypokyphosis, lumbar hypolordosis), presenting with mechanical back pain with or without radicular leg pain. All patients received conservative management including medication and physiotherapy. Radiological and clinical parameters were measured at baseline and at 1-year followup. Primary outcomes were ODI and SRS-22r scores. Secondary outcomes were EQ-5D-5L scores and requiring spine surgery during conservative treatment. Predictors for MCID improvement in ODI and SRS-22r were identified using multivariate regressions and receiver operating characteristic (ROC) analyses. Results: At baseline, patients who reached MCID in ODI and/or SRS-22r showed less comorbidities (diabetes mellitus, hypertension, ischemic heart disease, osteoarthritis, cancer), smaller range of lateral spinal flexion, larger trunk shift, larger pelvic incidence, a higher EQ-5D-5L anxiety/depression dimension score, a lower SRS-22r total score, and presence of spondylolisthesis. Lateral flexion range < 25 degrees, trunk shift > 14 mm, pelvic incidence > 50 degrees, EQ-5D-5L anxiety/depression dimension score > 1, and SRS-22r total score < 3.5 were the cutoff values generated by ROC analysis. Conclusions: Both radiological and clinical predictive factors for MCID improvement in health-related quality of life were identified. Future research should identify subgroups of patients who are responsive to specific conservative treatment modalities, so as to provide information for personalized medicine.

An insight of how multiple skeletal maturity indices can be used for growth assessment: relationship between the simplified olecranon, simplified digital, and distal radius and ulna classifications

Journal of Pediatric Orthopaedics B, Jul 10, 2020

This cross-sectional study aims to investigate the relationship between the simplified olecranon,... more This cross-sectional study aims to investigate the relationship between the simplified olecranon, simplified digital, and distal radius and ulna (DRU) classifications, and whether they can aid in more comprehensive maturity assessment together. Left hand and wrist and lateral elbow radiographs from pediatric patients were assessed using the three skeletal maturity indices. The association between maturity indices was investigated using Goodman and Kruskal’s gamma, and by mapping of individual grades based on chronological age. Specific maturity grades, at which peak height velocity (PHV) occurs as previously identified, were based upon to explore how the three systems interact. A total of 114 patients (63.2% girls) were studied. Correlations and associations between the three maturity parameters were significant (all at P &lt; 0.001). Mapping revealed uneven spans and coverage of different periods by each index. Olecranon stage 1 coincided with R3 (for girls), R4 (for boys), U3, and SS1. Olecranon stage 5 occurred as early as R7, U6, and SS4. Upon elbow fusion, the simplified digital (SS5–SS8) and DRU (R8–R11 and U7–U9) classifications can be used for assessment until maturity. The inter-relationship of the simplified hand, wrist, and olecranon methods indicates their combined use. DRU grades can be used in growth periods which are less well covered. Prepubertal and growth acceleration phase of pubertal growth spurt can best be assessed by both the simplified olecranon (stages 1–3) and DRU classifications (R1–R5 and U1–U4). All three indices are required during PHV. For post-PHV, DRU (R8–R11 and U7–U9) and simplified digital method (SS5–SS8) complement each other for assessment until skeletal maturity.

Analysis of sagittal profile of spine using 3D ultrasound imaging: a phantom study and preliminary subject test

Computer methods in biomechanics and biomedical engineering. Imaging & visualization, Apr 30, 2019

Radiographic Cobb's angle is the gold standard for evaluation of spinal curvature, however X-ray ... more Radiographic Cobb's angle is the gold standard for evaluation of spinal curvature, however X-ray is ionizing. In contrast, ultrasound is non-ionizing and inexpensive, thus more accessible. However, no study has reported the reliability and accuracy of ultrasound on sagittal curvature analysis. Ultrasound and X-ray scanning were conducted on 16 sets of spine phantoms with different deformities. Intrarater and inter-rater reliability, correlations, mean absolute differences (MAD) and linear regression of Ultrasound spinous process angles (USSPA), X-ray spinous process angles (XSPA) and X-ray Cobb's angles (XCA) together with the intra-operator reliability of USSPA were investigated. In addition, USSPA and XCA of five AIS subjects were scanned using the ultrasound system. In the phantom study, excellent intra-rater and inter-rater reproducibility for the three angles and excellent intraoperator reproducibility for USSPA were demonstrated. Good to moderate correlations were obtained between lumbar XCA and XSPA and between lumbar XCA and USSPA, whereas excellent correlations were observed between the other angles. All three angles indicated positive linear relationships, with MAD of 5.8°, 3.0° and 6.0° for XSPA against XCA, USSPA against XSPA and USSPA against XCA, respectively. The results of the preliminary study demonstrated a high intrareliability for the ultrasound measurements. The measured difference between the USSPA and XCA methods was 6.3° ± 5.4°. It should be noted that ultrasound and X-ray measurements were based on different structures of the vertebrae. The results showed that ultrasound is feasible for measuring sagittal curvature and has the potential for monitoring the curve progression and evaluating sagittal spinal profiles.

Psychometric validation of the adapted Traditional Chinese version of the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ)

Journal of Orthopaedic Science, Sep 1, 2018

The manuscript submitted does not contain information about medical device(s)/drug(s). No funds w... more

Provider confidence in the telemedicine spine evaluation: results from a global study

European Spine Journal, Nov 22, 2020

Purpose To utilize data from a global spine surgeon survey to elucidate (1) overall confidence in... more Purpose To utilize data from a global spine surgeon survey to elucidate (1) overall confidence in the telemedicine evaluation and (2) determinants of provider confidence. Methods Members of AO Spine International were sent a survey encompassing participant's experience with, perception of, and comparison of telemedicine to in-person visits. The survey was designed through a Delphi approach, with four rounds of question review by the multidisciplinary authors. Data were stratified by provider age, experience, telemedicine platform, trust in telemedicine, and specialty. Results Four hundred and eighty-five surgeons participated in the survey. The global effort included respondents from Africa (19.9%), Asia Pacific (19.7%), Europe (24.3%), North America (9.4%), and South America (26.6%). Providers felt that physical exam-based tasks (e.g., provocative testing, assessing neurologic deficits/myelopathy, etc.) were inferior to inperson exams, while communication-based aspects (e.g., history taking, imaging review, etc.) were equivalent. Participants who performed greater than 50 visits were more likely to believe telemedicine was at least equivalent to in-person visits in the ability to make an accurate diagnosis (OR 2.37, 95% C.I. 1.03-5.43). Compared to in-person encounters, video (versus phone only) visits were associated with increased confidence in the ability of telemedicine to formulate and communicate a treatment plan (OR 3.88, 95% C.I. 1.71-8.84). Conclusion Spine surgeons are confident in the ability of telemedicine to communicate with patients, but are concerned about its capacity to accurately make physical exam-based diagnoses. Future research should concentrate on standardizing the remote examination and the development of appropriate use criteria in order to increase provider confidence in telemedicine technology.

Curve overcorrection predicts coronal imbalance in selective thoracic fusion in adolescent idiopathic scoliosis

Brain and spine, 2022

Role of Ultrasound in Low Back Pain: A Review

Ultrasound in Medicine and Biology, Jun 1, 2020

Low back pain is one of most common musculoskeletal disorders around the world. One major problem... more Low back pain is one of most common musculoskeletal disorders around the world. One major problem clinicians face is the lack of objective assessment modalities. Computed tomography and magnetic resonance imaging are commonly utilized but are unable to clearly distinguish patients with low back pain from healthy patients with respect to abnormalities. The reason may be the anisotropic nature of muscles, which is altered in function, and the scans provide only structural assessment. In view of this, ultrasound may be helpful in understanding the disease as it is performed in real-time and comprises different modes that measure thickness, blood flow and stiffness. By the use of ultrasound, patients with low back pain have been found to differ from healthy patients with respect to the thickness and stiffness of the transversus abdominis, thoracolumbar fascia and multifidus. The study results are currently still not conclusive, and further study is necessary to validate. Future work should focus on quantitative assessment of these tissues to provide textural, structural, hemodynamic and mechanical studies of low back pain. This review highlights the current understanding of how medical ultrasound has been used for diagnosis and study of low back pain and discusses potential new applications.

Radiograph-comparable image synthesis for spine alignment analysis using deep learning with prospective clinical validation

EClinicalMedicine, Jul 1, 2023

Association of an estrogen-sensitive<i>Pax1-Col11a1-Mmp3</i>signaling axis with adolescent idiopathic scoliosis

bioRxiv (Cold Spring Harbor Laboratory), May 27, 2023

Adolescent idiopathic scoliosis (AIS) is a common and progressive spinal deformity in children th... more Adolescent idiopathic scoliosis (AIS) is a common and progressive spinal deformity in children that exhibits striking sexual dimorphism, with girls at more than five-fold greater risk of severe disease compared to boys. Despite its medical impact, the molecular mechanisms that drive AIS are largely unknown. We previously defined a female-specific AIS genetic risk locus in an enhancer near the PAX1 gene. Here we sought to define the roles of PAX1 and newly-identified AIS-associated genes in the developmental mechanism of AIS. In a genetic study of 9,161 individuals with AIS and 80,731 unaffected controls, significant association was identified with a variant in COL11A1 encoding collagen (a1) XI (rs3753841; NM_080629_c.4004C>T; p.(Pro1335Leu); P=7.07e-11 , OR=1.118). Using CRISPR mutagenesis we generated Pax1 knockout mice (Pax1-/-). In postnatal spines we found that Pax1 and collagen (a1) XI protein both localize within the intervertebral disc (IVD)-vertebral junction region encompassing the growth plate, with less collagen (a1) XI detected in Pax1-/spines compared to wildtype. By genetic targeting we found that wildtype Col11a1 expression in growth plate cells (GPCs) suppresses expression of Pax1 and of Mmp3, encoding the matrix metalloproteinase 3 enzyme implicated in matrix remodeling. However, this suppression was abrogated in the presence of the AIS-associated COL11A1 P1335L mutant. Further, we found that either knockdown of the estrogen receptor gene Esr2, or tamoxifen treatment, significantly altered Col11a1 and Mmp3 expression in GPCs. These studies support a new molecular model of AIS pathogenesis wherein genetic variation and estrogen signaling increase disease susceptibility by altering a Pax1-Col11a1-Mmp3 signaling axis in the growth plate.

Why are Some Intervertebral Discs more Prone to Degeneration? Insights into Isolated thoracic ‘Dysgeneration’

Spine, Mar 22, 2023

Study Design. Prospective observational study. Objective. To determine the prevalence of isolated... more Study Design. Prospective observational study. Objective. To determine the prevalence of isolated thoracic degeneration on magnetic resonance imaging (MRI), demographic factors and imaging features, as well as the patient-reported quality of life outcomes associated with this condition. Summary of Background Data. Thoracic intervertebral discs are least susceptible to disc degeneration (DD) and may represent a manifestation of “dysgeneration.” These discs may never be hydrated from the beginning and seem hypointense on MRI. Patients and Methods. A population-based MRI study of 2007 volunteers was conducted. Each disc from C2/3 to L5/S1 was measured by Pfirrmann and Schneiderman grading. Disc herniation, Schmorl node (SN), high-intensity zones (HIZ), and Modic changes were studied. DD was defined by Pfirrmann 4 or 5. patient-reported quality of life scores, including a 36-item short-form questionnaire and visual analog scale for low back pain, were recorded. Subjects were divided into “isolated thoracic degeneration” (only thoracic segment) and “tandem thoracic degeneration” (thoracic with other segments). The association between imaging findings and isolated thoracic degeneration was determined using multivariate logistic regression. Results. The mean age of the subjects was 50.0 ± 0.5 and 61.4% were females (n = 1232). Isolated thoracic degeneration was identified in 2.3% of the cohort. Factors associated with isolated thoracic degeneration included lower age, C6/7 HIZ, T8/9 HIZ, and T8/9 SN. Factors associated with tandem thoracic degeneration included L4/5 posterior bulging. The thoracic and lumbar tandem degeneration group demonstrated higher bodily pain, despite a lower visual analog scale, and a higher physical component score of the 36-item short form. Conclusions. Isolated thoracic degeneration demonstrated an earlier age of onset, mostly involving the mid-thoracic region (T5/6–T8/9), and in association with findings such as SN. Subjects with tandem thoracolumbar degeneration had less severe lumbar DD and low back pain as compared with those with isolated lumbar degeneration. This paints the picture of “dysgeneration” occurring in the thoracic and lumbar spine. Level of Evidence. 1.

Lumbar Spinal Stenosis

Springer eBooks, 2022

Slow twitch paraspinal muscle dysregulation in adolescent idiopathic scoliosis exhibiting HIF‐2α misexpression

JOR spine, Nov 2, 2022

Background: Adolescent idiopathic scoliosis (AIS) refers to a three-dimensional spinal deformity ... more Background: Adolescent idiopathic scoliosis (AIS) refers to a three-dimensional spinal deformity which has a typical onset during adolescence. In most cases, the cause of the deformity cannot be clearly identified. Unbalanced paraspinal muscle activity in AIS patients was reported and hypoxia was implicated to regulate myogenesis. This study aims to investigate the association between myogenesis/muscle toning and HIF-αs activity in the pathogenesis of AIS. Methods: HIF-αs expression was examined by enzyme-linked immunosorbent assay and western blot in paraspinal myoblasts isolated from 18 subjects who underwent deformity correction surgery. QPCR was conducted to measure the gene expression levels of perinatal muscle fiber markers MYH3, MYH8; slow twitch muscle fiber markers MHY7; fast twitch muscle fiber markers MYH4; and myogenic regulatory factors MYF5 and MYOG. Slow and fast twitch muscle fiber composition in concave/ convex paraspinal musculature of AIS subjects was evaluated by immunostaining of myosin heavy chain type I (MyHC I) and myosin heavy chain type II (MyHC II). Results: Reduced HIF-2α induction under hypoxia was found in paraspinal myoblast culture of 33% AIS subjects. We detected a suppression of perinatal and slow twitch muscle fiber associated genes, but not fast twitch muscle fiber-associated genes and myogenic regulatory factors in HIF-2α misexpressed AIS myoblasts. Distinct reduction of slow twitch muscle fiber was evidenced in convex paraspinal musculature, suggesting an asymmetric expression of slow twitch muscle fiber in HIF-2α misexpressed AIS patients. Conclusions: This study indicates an association of abnormal HIF-2α expression in paraspinal myoblasts and a disproportionate slow twitch muscle fiber content in the convexity of the curvature in a subset of AIS subjects, suggesting HIF-2α dysregulation as a possible risk factor for AIS. The role of HIF-2α in paraspinal muscle function during spinal growth and its relevance in AIS prognosis warrants further investigation.

SpineHRformer: A Transformer-Based Deep Learning Model for Automatic Spine Deformity Assessment with Prospective Validation

Bioengineering

The Cobb angle (CA) serves as the principal method for assessing spinal deformity, but manual mea... more The Cobb angle (CA) serves as the principal method for assessing spinal deformity, but manual measurements of the CA are time-consuming and susceptible to inter- and intra-observer variability. While learning-based methods, such as SpineHRNet+, have demonstrated potential in automating CA measurement, their accuracy can be influenced by the severity of spinal deformity, image quality, relative position of rib and vertebrae, etc. Our aim is to create a reliable learning-based approach that provides consistent and highly accurate measurements of the CA from posteroanterior (PA) X-rays, surpassing the state-of-the-art method. To accomplish this, we introduce SpineHRformer, which identifies anatomical landmarks, including the vertices of endplates from the 7th cervical vertebra (C7) to the 5th lumbar vertebra (L5) and the end vertebrae with different output heads, enabling the calculation of CAs. Within our SpineHRformer, a backbone HRNet first extracts multi-scale features from the inp...

Preoperative left shoulder elevation > 1 cm is predictive of severe postoperative shoulder imbalance in early onset idiopathic scoliosis patients treated with growth-friendly instrumentation

Spine deformity, May 8, 2023

A Novel Method to Measure the Sagittal Curvature in Spinal Deformities: The Reliability and Feasibility of 3-D Ultrasound Imaging

Ultrasound in Medicine and Biology, Oct 1, 2019

The objective of this study is to test the reliability of sagittal spinal curvature measurements ... more The objective of this study is to test the reliability of sagittal spinal curvature measurements using three-dimensional (3D) ultrasound in adolescent idiopathic scoliosis (AIS) patients. Ultrasound spinous process angle (USSPA) and ultrasound laminae angle (USLA) were measured on sagittal ultrasound images, while Cobb angle (XCA) was measured on sagittal Xray images. Intraclass correlation coefficients (ICC) for the intra-and inter-observer variability, linear regression analysis and Bland-Altman method including mean absolute difference (MAD) were investigated to evaluate the reliability and validity of the two ultrasound angles as compared to XCA. Excellent measurement reliabilities were demonstrated for both ultrasound angles (ICC≥0.91). Moderate to good and significant linear correlations and good agreement were demonstrated between the ultrasound methods and XCA (Thoracic: (R 2 ≥0.574) / Lumbar (R 2 ≥0.635)). No significant differences were found from the MADs between both corrected ultrasound angles and XCA. Sagittal ultrasound angles demonstrated to be reliable for assessing sagittal curvature using spinous processes and laminae, and have good and significant correlations with Cobb angles. Since it is non-ionizing and relatively low cost, this opens the possibility to provide frequent curve monitoring and evaluation, and screening for AIS patients, particularly based on sagittal profiles.

Underarm bracing for adolescent idiopathic scoliosis leads to flatback deformity

The bone & joint journal, Nov 1, 2019

The aim of this study was to determine the influence of pelvic parameters on the tendency of pati... more The aim of this study was to determine the influence of pelvic parameters on the tendency of patients with adolescent idiopathic scoliosis (AIS) to develop flatback deformity (thoracic hypokyphosis and lumbar hypolordosis) and its effect on quality-of-life outcomes. Patients and Methods This was a radiological study of 265 patients recruited for Boston bracing between December 2008 and December 2013. Posteroanterior and lateral radiographs were obtained before, immediately after, and two-years after completion of bracing. Measurements of coronal and sagittal Cobb angles, coronal balance, sagittal vertical axis, and pelvic parameters were made. The refined 22-item Scoliosis Research Society (SRS-22r) questionnaire was recorded. Association between independent factors and outcomes of postbracing ≥ 6° kyphotic changes in the thoracic spine and ≥ 6° lordotic changes in the lumbar spine were tested using likelihood ratio chi-squared test and univariable logistic regression. Multivariable logistic regression models were then generated for both outcomes with odds ratios (ORs), and with SRS-22r scores. Results Reduced T5-12 kyphosis (mean-4.3° (sd 8.2); p < 0.001), maximum thoracic kyphosis (mean-4.3° (sd 9.3); p < 0.001), and lumbar lordosis (mean-5.6° (sd 12.0); p < 0.001) were observed after bracing treatment. Increasing prebrace maximum kyphosis (OR 1.133) and lumbar lordosis (OR 0.92) was associated with postbracing hypokyphotic change. Prebrace sagittal vertical axis (OR 0.975), prebrace sacral slope (OR 1.127), prebrace pelvic tilt (OR 0.940), and change in maximum thoracic kyphosis (OR 0.878) were predictors for lumbar hypolordotic changes. There were no relationships between coronal deformity, thoracic kyphosis, or lumbar lordosis with SRS-22r scores. Conclusion Brace treatment leads to flatback deformity with thoracic hypokyphosis and lumbar hypolordosis. Changes in the thoracic spine are associated with similar changes in the lumbar spine. Increased sacral slope, reduced pelvic tilt, and pelvic incidence are associated with reduced lordosis in the lumbar spine after bracing. Nevertheless, these sagittal parameter changes do not appear to be associated with worse quality of life.

Additional file 1: of Psychometric validation of the EuroQoL 5-Dimension 5-Level (EQ-5D-5L) in Chinese patients with adolescent idiopathic scoliosis

Hong Kong (Traditional Chinese) ÂS 2012 EuroQol Group EQ-5Dâ ˘ is a trade mark of the EuroQol Gro... more

Paper #32: Complications of Magnetically Controlled Growing Rod Surgery: Multicenter Study of 26 Patients With Medium-term Follow-up

Spine deformity, Nov 1, 2014

Complications of Magnetically-Controlled Growing Rod Surgery: A Prospective Multicentre Study with Minimum 2 Year Follow-Up

Orthopaedic Proceedings, Feb 21, 2018

Propensity-matched Comparison between Chronic non-specific Low Back Pain and Axial Spondyloarthritis: Impact on patient-perceived Quality of Life

Spine, Oct 17, 2022

Study Design. Prospective study. Objective. To compare the burden between chronic nonspecific low... more Study Design. Prospective study. Objective. To compare the burden between chronic nonspecific low back pain (LBP) and axial spondyloarthropathy (SpA). Summary of Background Data. Chronic nonspecific LBP and SpA are two debilitating yet different chronic musculoskeletal disorders. To compare their burden, propensity score matching is used to control for potential confounders and match the study subjects. Materials and Methods. Two prospectively collected cohorts of LBP (n=269) and SpA (n=218) patients were studied. Outcomes included current LBP, 36-item Short Form Questionnaire, Oswestry Disability Index, EuroQol 5-dimension 5-level Questionnaire, and EuroQol Visual Analog Scale. With the inherent differences between the two types of patients, propensity score matching was performed for comparing the two groups. Baseline covariates of age, sex, education level, occupation, smoking, and drinking history were selected for the estimation of propensity scores for each subject with the logistic regression model. Significant independent variables for the outcome of current back pain were included in the multivariate logistic regressions. Results. A total of 127 matched pairs were identified, with 254 patients. In the matched cohort, more patients with chronic LBP had current back pain (95.3%) as compared with SpA (71.7%). Patients with SpA were younger (P&lt;0.001), with more males (P&lt;0.001), and better educated (P=0.001). There was less current back pain and higher nonsteroidal anti-inflammatory drug use (P&lt;0.001). Most SpA patients had lower Oswestry Disability Index than LBP patients and with low disease activity. Patients with LBP had worse outcome scores as compared with SpA patients given the same Visual Analog Scale. LBP patients had 8.6 times the odds (95% CI: 3.341–20.671; P&lt;0.001) of experiencing current back pain compared with SpA patients. Conclusions. The disease activity of SpA patients is well controlled. However, patients with chronic LBP have worse pain severity, disability, and health-related quality of life. This has implications on resource utilization and the necessity of advancing LBP understanding and management. Level of Evidence. Type I prognostic study.

Predictive factors for successful non-operative treatment and achieving MCID improvement in health-related quality of life in adult spinal deformity

BMC Musculoskeletal Disorders, Aug 22, 2022

Background: Adult spinal deformity is a spectrum of degenerative spinal diseases with increasing ... more Background: Adult spinal deformity is a spectrum of degenerative spinal diseases with increasing prevalence and healthcare burden worldwide. Identification of patients who are more likely to improve through conservative management may reduce cost and potentially prevent surgery and its associated costs and complications. This study aims to identify predictive factors for MCID in improvement of ODI and SRS-22r questionnaires in patients with adult spinal deformity treated with conservative treatment. Methods: A prospective, observational cohort study of 46 patients was conducted at a spine specialist clinic. Inclusion criteria were 30-80 years of age, diagnosis of neglected adolescent idiopathic scoliosis, de-novo scoliosis, degenerative spondylolisthesis, and sagittal plane deformities (thoracic hypokyphosis, lumbar hypolordosis), presenting with mechanical back pain with or without radicular leg pain. All patients received conservative management including medication and physiotherapy. Radiological and clinical parameters were measured at baseline and at 1-year followup. Primary outcomes were ODI and SRS-22r scores. Secondary outcomes were EQ-5D-5L scores and requiring spine surgery during conservative treatment. Predictors for MCID improvement in ODI and SRS-22r were identified using multivariate regressions and receiver operating characteristic (ROC) analyses. Results: At baseline, patients who reached MCID in ODI and/or SRS-22r showed less comorbidities (diabetes mellitus, hypertension, ischemic heart disease, osteoarthritis, cancer), smaller range of lateral spinal flexion, larger trunk shift, larger pelvic incidence, a higher EQ-5D-5L anxiety/depression dimension score, a lower SRS-22r total score, and presence of spondylolisthesis. Lateral flexion range < 25 degrees, trunk shift > 14 mm, pelvic incidence > 50 degrees, EQ-5D-5L anxiety/depression dimension score > 1, and SRS-22r total score < 3.5 were the cutoff values generated by ROC analysis. Conclusions: Both radiological and clinical predictive factors for MCID improvement in health-related quality of life were identified. Future research should identify subgroups of patients who are responsive to specific conservative treatment modalities, so as to provide information for personalized medicine.

An insight of how multiple skeletal maturity indices can be used for growth assessment: relationship between the simplified olecranon, simplified digital, and distal radius and ulna classifications

Journal of Pediatric Orthopaedics B, Jul 10, 2020

This cross-sectional study aims to investigate the relationship between the simplified olecranon,... more This cross-sectional study aims to investigate the relationship between the simplified olecranon, simplified digital, and distal radius and ulna (DRU) classifications, and whether they can aid in more comprehensive maturity assessment together. Left hand and wrist and lateral elbow radiographs from pediatric patients were assessed using the three skeletal maturity indices. The association between maturity indices was investigated using Goodman and Kruskal’s gamma, and by mapping of individual grades based on chronological age. Specific maturity grades, at which peak height velocity (PHV) occurs as previously identified, were based upon to explore how the three systems interact. A total of 114 patients (63.2% girls) were studied. Correlations and associations between the three maturity parameters were significant (all at P &lt; 0.001). Mapping revealed uneven spans and coverage of different periods by each index. Olecranon stage 1 coincided with R3 (for girls), R4 (for boys), U3, and SS1. Olecranon stage 5 occurred as early as R7, U6, and SS4. Upon elbow fusion, the simplified digital (SS5–SS8) and DRU (R8–R11 and U7–U9) classifications can be used for assessment until maturity. The inter-relationship of the simplified hand, wrist, and olecranon methods indicates their combined use. DRU grades can be used in growth periods which are less well covered. Prepubertal and growth acceleration phase of pubertal growth spurt can best be assessed by both the simplified olecranon (stages 1–3) and DRU classifications (R1–R5 and U1–U4). All three indices are required during PHV. For post-PHV, DRU (R8–R11 and U7–U9) and simplified digital method (SS5–SS8) complement each other for assessment until skeletal maturity.

Analysis of sagittal profile of spine using 3D ultrasound imaging: a phantom study and preliminary subject test

Computer methods in biomechanics and biomedical engineering. Imaging & visualization, Apr 30, 2019

Radiographic Cobb's angle is the gold standard for evaluation of spinal curvature, however X-ray ... more Radiographic Cobb's angle is the gold standard for evaluation of spinal curvature, however X-ray is ionizing. In contrast, ultrasound is non-ionizing and inexpensive, thus more accessible. However, no study has reported the reliability and accuracy of ultrasound on sagittal curvature analysis. Ultrasound and X-ray scanning were conducted on 16 sets of spine phantoms with different deformities. Intrarater and inter-rater reliability, correlations, mean absolute differences (MAD) and linear regression of Ultrasound spinous process angles (USSPA), X-ray spinous process angles (XSPA) and X-ray Cobb's angles (XCA) together with the intra-operator reliability of USSPA were investigated. In addition, USSPA and XCA of five AIS subjects were scanned using the ultrasound system. In the phantom study, excellent intra-rater and inter-rater reproducibility for the three angles and excellent intraoperator reproducibility for USSPA were demonstrated. Good to moderate correlations were obtained between lumbar XCA and XSPA and between lumbar XCA and USSPA, whereas excellent correlations were observed between the other angles. All three angles indicated positive linear relationships, with MAD of 5.8°, 3.0° and 6.0° for XSPA against XCA, USSPA against XSPA and USSPA against XCA, respectively. The results of the preliminary study demonstrated a high intrareliability for the ultrasound measurements. The measured difference between the USSPA and XCA methods was 6.3° ± 5.4°. It should be noted that ultrasound and X-ray measurements were based on different structures of the vertebrae. The results showed that ultrasound is feasible for measuring sagittal curvature and has the potential for monitoring the curve progression and evaluating sagittal spinal profiles.

Psychometric validation of the adapted Traditional Chinese version of the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ)

Journal of Orthopaedic Science, Sep 1, 2018

The manuscript submitted does not contain information about medical device(s)/drug(s). No funds w... more

Provider confidence in the telemedicine spine evaluation: results from a global study

European Spine Journal, Nov 22, 2020

Purpose To utilize data from a global spine surgeon survey to elucidate (1) overall confidence in... more Purpose To utilize data from a global spine surgeon survey to elucidate (1) overall confidence in the telemedicine evaluation and (2) determinants of provider confidence. Methods Members of AO Spine International were sent a survey encompassing participant's experience with, perception of, and comparison of telemedicine to in-person visits. The survey was designed through a Delphi approach, with four rounds of question review by the multidisciplinary authors. Data were stratified by provider age, experience, telemedicine platform, trust in telemedicine, and specialty. Results Four hundred and eighty-five surgeons participated in the survey. The global effort included respondents from Africa (19.9%), Asia Pacific (19.7%), Europe (24.3%), North America (9.4%), and South America (26.6%). Providers felt that physical exam-based tasks (e.g., provocative testing, assessing neurologic deficits/myelopathy, etc.) were inferior to inperson exams, while communication-based aspects (e.g., history taking, imaging review, etc.) were equivalent. Participants who performed greater than 50 visits were more likely to believe telemedicine was at least equivalent to in-person visits in the ability to make an accurate diagnosis (OR 2.37, 95% C.I. 1.03-5.43). Compared to in-person encounters, video (versus phone only) visits were associated with increased confidence in the ability of telemedicine to formulate and communicate a treatment plan (OR 3.88, 95% C.I. 1.71-8.84). Conclusion Spine surgeons are confident in the ability of telemedicine to communicate with patients, but are concerned about its capacity to accurately make physical exam-based diagnoses. Future research should concentrate on standardizing the remote examination and the development of appropriate use criteria in order to increase provider confidence in telemedicine technology.

Curve overcorrection predicts coronal imbalance in selective thoracic fusion in adolescent idiopathic scoliosis

Brain and spine, 2022

Role of Ultrasound in Low Back Pain: A Review

Ultrasound in Medicine and Biology, Jun 1, 2020

Low back pain is one of most common musculoskeletal disorders around the world. One major problem... more Low back pain is one of most common musculoskeletal disorders around the world. One major problem clinicians face is the lack of objective assessment modalities. Computed tomography and magnetic resonance imaging are commonly utilized but are unable to clearly distinguish patients with low back pain from healthy patients with respect to abnormalities. The reason may be the anisotropic nature of muscles, which is altered in function, and the scans provide only structural assessment. In view of this, ultrasound may be helpful in understanding the disease as it is performed in real-time and comprises different modes that measure thickness, blood flow and stiffness. By the use of ultrasound, patients with low back pain have been found to differ from healthy patients with respect to the thickness and stiffness of the transversus abdominis, thoracolumbar fascia and multifidus. The study results are currently still not conclusive, and further study is necessary to validate. Future work should focus on quantitative assessment of these tissues to provide textural, structural, hemodynamic and mechanical studies of low back pain. This review highlights the current understanding of how medical ultrasound has been used for diagnosis and study of low back pain and discusses potential new applications.

Radiograph-comparable image synthesis for spine alignment analysis using deep learning with prospective clinical validation

EClinicalMedicine, Jul 1, 2023

Association of an estrogen-sensitive<i>Pax1-Col11a1-Mmp3</i>signaling axis with adolescent idiopathic scoliosis

bioRxiv (Cold Spring Harbor Laboratory), May 27, 2023

Adolescent idiopathic scoliosis (AIS) is a common and progressive spinal deformity in children th... more Adolescent idiopathic scoliosis (AIS) is a common and progressive spinal deformity in children that exhibits striking sexual dimorphism, with girls at more than five-fold greater risk of severe disease compared to boys. Despite its medical impact, the molecular mechanisms that drive AIS are largely unknown. We previously defined a female-specific AIS genetic risk locus in an enhancer near the PAX1 gene. Here we sought to define the roles of PAX1 and newly-identified AIS-associated genes in the developmental mechanism of AIS. In a genetic study of 9,161 individuals with AIS and 80,731 unaffected controls, significant association was identified with a variant in COL11A1 encoding collagen (a1) XI (rs3753841; NM_080629_c.4004C>T; p.(Pro1335Leu); P=7.07e-11 , OR=1.118). Using CRISPR mutagenesis we generated Pax1 knockout mice (Pax1-/-). In postnatal spines we found that Pax1 and collagen (a1) XI protein both localize within the intervertebral disc (IVD)-vertebral junction region encompassing the growth plate, with less collagen (a1) XI detected in Pax1-/spines compared to wildtype. By genetic targeting we found that wildtype Col11a1 expression in growth plate cells (GPCs) suppresses expression of Pax1 and of Mmp3, encoding the matrix metalloproteinase 3 enzyme implicated in matrix remodeling. However, this suppression was abrogated in the presence of the AIS-associated COL11A1 P1335L mutant. Further, we found that either knockdown of the estrogen receptor gene Esr2, or tamoxifen treatment, significantly altered Col11a1 and Mmp3 expression in GPCs. These studies support a new molecular model of AIS pathogenesis wherein genetic variation and estrogen signaling increase disease susceptibility by altering a Pax1-Col11a1-Mmp3 signaling axis in the growth plate.

Why are Some Intervertebral Discs more Prone to Degeneration? Insights into Isolated thoracic ‘Dysgeneration’

Spine, Mar 22, 2023

Study Design. Prospective observational study. Objective. To determine the prevalence of isolated... more Study Design. Prospective observational study. Objective. To determine the prevalence of isolated thoracic degeneration on magnetic resonance imaging (MRI), demographic factors and imaging features, as well as the patient-reported quality of life outcomes associated with this condition. Summary of Background Data. Thoracic intervertebral discs are least susceptible to disc degeneration (DD) and may represent a manifestation of “dysgeneration.” These discs may never be hydrated from the beginning and seem hypointense on MRI. Patients and Methods. A population-based MRI study of 2007 volunteers was conducted. Each disc from C2/3 to L5/S1 was measured by Pfirrmann and Schneiderman grading. Disc herniation, Schmorl node (SN), high-intensity zones (HIZ), and Modic changes were studied. DD was defined by Pfirrmann 4 or 5. patient-reported quality of life scores, including a 36-item short-form questionnaire and visual analog scale for low back pain, were recorded. Subjects were divided into “isolated thoracic degeneration” (only thoracic segment) and “tandem thoracic degeneration” (thoracic with other segments). The association between imaging findings and isolated thoracic degeneration was determined using multivariate logistic regression. Results. The mean age of the subjects was 50.0 ± 0.5 and 61.4% were females (n = 1232). Isolated thoracic degeneration was identified in 2.3% of the cohort. Factors associated with isolated thoracic degeneration included lower age, C6/7 HIZ, T8/9 HIZ, and T8/9 SN. Factors associated with tandem thoracic degeneration included L4/5 posterior bulging. The thoracic and lumbar tandem degeneration group demonstrated higher bodily pain, despite a lower visual analog scale, and a higher physical component score of the 36-item short form. Conclusions. Isolated thoracic degeneration demonstrated an earlier age of onset, mostly involving the mid-thoracic region (T5/6–T8/9), and in association with findings such as SN. Subjects with tandem thoracolumbar degeneration had less severe lumbar DD and low back pain as compared with those with isolated lumbar degeneration. This paints the picture of “dysgeneration” occurring in the thoracic and lumbar spine. Level of Evidence. 1.

Lumbar Spinal Stenosis

Springer eBooks, 2022

Slow twitch paraspinal muscle dysregulation in adolescent idiopathic scoliosis exhibiting HIF‐2α misexpression

JOR spine, Nov 2, 2022

Background: Adolescent idiopathic scoliosis (AIS) refers to a three-dimensional spinal deformity ... more Background: Adolescent idiopathic scoliosis (AIS) refers to a three-dimensional spinal deformity which has a typical onset during adolescence. In most cases, the cause of the deformity cannot be clearly identified. Unbalanced paraspinal muscle activity in AIS patients was reported and hypoxia was implicated to regulate myogenesis. This study aims to investigate the association between myogenesis/muscle toning and HIF-αs activity in the pathogenesis of AIS. Methods: HIF-αs expression was examined by enzyme-linked immunosorbent assay and western blot in paraspinal myoblasts isolated from 18 subjects who underwent deformity correction surgery. QPCR was conducted to measure the gene expression levels of perinatal muscle fiber markers MYH3, MYH8; slow twitch muscle fiber markers MHY7; fast twitch muscle fiber markers MYH4; and myogenic regulatory factors MYF5 and MYOG. Slow and fast twitch muscle fiber composition in concave/ convex paraspinal musculature of AIS subjects was evaluated by immunostaining of myosin heavy chain type I (MyHC I) and myosin heavy chain type II (MyHC II). Results: Reduced HIF-2α induction under hypoxia was found in paraspinal myoblast culture of 33% AIS subjects. We detected a suppression of perinatal and slow twitch muscle fiber associated genes, but not fast twitch muscle fiber-associated genes and myogenic regulatory factors in HIF-2α misexpressed AIS myoblasts. Distinct reduction of slow twitch muscle fiber was evidenced in convex paraspinal musculature, suggesting an asymmetric expression of slow twitch muscle fiber in HIF-2α misexpressed AIS patients. Conclusions: This study indicates an association of abnormal HIF-2α expression in paraspinal myoblasts and a disproportionate slow twitch muscle fiber content in the convexity of the curvature in a subset of AIS subjects, suggesting HIF-2α dysregulation as a possible risk factor for AIS. The role of HIF-2α in paraspinal muscle function during spinal growth and its relevance in AIS prognosis warrants further investigation.