Ashish Diwan

Ashish Diwan
UNSW Sydney | UNSW · Spine Service | Department of Orthopaedic Surgery | St George & Sutherland Clinical School | UNSW Medicine

MBBS MS PhD FRACS FAOrthA

About

166
Publications
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Introduction
As a surgeon my research emphasis is on repair and regeneration of tissues. Degeneration of the intervertebral disc is a common problem leading to chronic back and neck pain. Understanding the molecular and mechanical basis of degeneration and/or aging of the disc is a prelude to developing strategies for disc reconstruction, repair or regeneration. I am involved in understanding the spinal column at all levels; from the molecule to biomechanics, from clinical to socio-economic impact. The role of Bone Morphogenic Proteins is being studied extensively at at a preclinical level with a view to intiating Clinical trials. I am involved in the development of a novel nuclear replacement device to help preserve the disc following microdiscectomy. My collaboration in this field with numerous engineers will lead to clinical trials in the near future. Broad Research Areas: Orthopaedics, Disc Regeneration, Injury, Biomedical Engineering, Back Pain, Microdiscectomy Qualifications: MBBS, MS, PhD, FRACS, FAOrthA Specific Research Keywords: Biomechanics, Spine, Back Pain, Finite element modelling (spinal column), Medical Devices, Growth Factor, Regenerative Medicine, Tissue healing, Lumbar Spine Service, Disc Degeneratio
Additional affiliations
January 2019 - August 2029
UNSW Sydney
Position
  • Principal Investigator

Publications

Publications (166)
Preprint
Routine check-ups for adolescent idiopathic scoliosis are critical to monitor progression and prescribe interventions. AIS is primarily screened via physical examination. If there are features of deformity, radiographs are necessary for diagnosis or follow-up, guiding further management, i.e., bracing for moderate deformity and surgery for severe....
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Purpose Low back pain (LBP), a widely prevalent and costly disease around the world, is mainly caused by intervertebral disc (IVD) degeneration (IDD). Although numerous factors may trigger this degenerative process, microbiome dysbiosis has recently been implicated as one of the likely causes. However, the exact relationship between the microbiome...
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Intervertebral disc degeneration (IDD) is the main cause of low back pain, and little is known about its molecular and pathological mechanisms. According to reports, excessive compression is a high-risk factor for IDD; compressive stress can induce oxidative stress in nucleus pulposus (NP) cells during IDD progression that, in turn, promotes cell a...
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The blood-spinal cord barrier (BSCB) has been long thought of as a functional equivalent to the blood-brain barrier (BBB), restricting blood flow into the spinal cord. The spinal cord is supported by various disc tissues that provide agility and has different local immune responses compared to the brain. Though physiologically, structural component...
Preprint
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Purpose: To evaluate intra- and inter-rater agreement and reliability of seven reported disc height index (DHI) measurement methods on standing lateral X-ray of lumbar spine. Methods: The adult patients who had standing lateral X-ray of lumbar spine were recruited. Seven methods were used to measure DHI of each lumbar intervertebral disc level. Bla...
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Introduction Chronic low back pain disorders (CLBDs) present a substantial societal burden; however, optimal treatment remains debated. To date, pairwise and network meta-analyses have evaluated individual treatment modes, yet a comparison of a wide range of common treatments is required to evaluate their relative effectiveness. Using network meta-...
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PurposeTo evaluate the impact of discectomy on disc height (DH) in lumbar disc herniation (LDH) patients following discectomy surgery and address the association of DH change with pain score change.Methods We searched three online databases for randomized controlled trials (RCTs) and observational studies. In LDH patients, eligible for discectomy s...
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Aim To assist surgeons to determine a potential approach to reduce incidences of recurrent lumbar disc herniation and assess the current devices regarding their outcomes and complications. Method Four electronic full-text databases were systematically searched through September 2017. All results were pooled utilising meta-analysis with weighted me...
Article
With lower back pain increasingly becoming a highly prevalent economic, clinical and social burden among the global population, the demand for a reliable clinical approach for the quantification of the mechanical properties of the human intervertebral disc (IVD) to detect premature degeneration or identify the underlying pathophysiology that is ess...
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Introduction Understanding practice-based differences in treatment of lumbar disc herniations (LDHs) is vital for reducing unwarranted variation in the delivery of spine surgical health care. Identifying factors that influence surgeons’ decision-making will offer useful insights for developing the most cost-effective and safest surgical strategy as...
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Study design: Translational review encompassing basic science and clinical evidence. Objectives: Multiple components of the lumbar spine interact during its normal and pathological function. Bony stress in the lumbar spine is recognized as a factor in the development of pars interarticularis defect and stress fractures, but its relationship with...
Article
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Cigarette smoke (CS) has been consistently demonstrated to be an environmental risk factor for amyotrophic lateral sclerosis (ALS), although the molecular pathogenic mechanisms involved are yet to be elucidated. Here, we propose different mechanisms by which CS exposure can cause sporadic ALS pathogenesis. Oxidative stress and neuroinflammation are...
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PurposeRecent animal studies have discovered dysregulation of local inflammatory activity as a novel mechanism to explain fat and connective tissue accumulation in the multifidus muscle in association with intervertebral disc (IVD) degeneration/injury. This study aimed to test whether similar mechanisms are active in humans by investigation of whet...
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Bariatric surgery produces significant and quantifiable reductions in back pain. However, there is a lack of information on the association of weight changes after bariatric surgery with changes in pain score. We aim to evaluate the impact of bariatric surgery on back pain in obese patients and to address the association between changes in body mas...
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Degenerative cervical myelopathy (DCM), earlier referred to as cervical spondylotic myelopathy (CSM), is the most common and serious neurological disorder in the elderly population caused by chronic progressive compression or irritation of the spinal cord in the neck. The clinical features of DCM include localised neck pain and functional impairmen...
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Growth differentiation factor (GDF) family members have been implicated in the development and maintenance of healthy nucleus pulposus (NP) tissue, making them promising therapeutic candidates for treatment of intervertebral disc (IVD) degeneration and associated back pain. GDF6 has been shown to promote discogenic differentiation of mesenchymal st...
Preprint
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Objective: To evaluate if back pain scores in morbidly obese patients change after bariatric surgery. Summary Background Data: Obese patients often complain of low back pain (LBP), however the underlying mechanism is not fully understood. Recent research shows that, next to mechanical loading, the chronic low-grade inflammation that arises in obese...
Article
Objective: The objective of this systematic review was to synthesize the best available evidence relating to the measurement properties of the multidimensional pain assessment tools used to assess postoperative pain in adults. Introduction: Pain is a common and poorly managed occurrence in patients during the postoperative period. Currently, pos...
Article
Introduction It is undetermined whether using sensors for knee balancing in total knee arthroplasty (TKA) improves patient outcomes. The purpose of this study was to compare clinical outcomes of sensor balance (SB) to manual balance (MB) TKA with a minimum two-year follow-up. Methods A consecutive series of 207 MB TKAs was compared to 222 SB TKAs...
Preprint
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Background Multiple components of the lumbar spine interact during the normal and pathological function. Bony stress in the lumbar spine is recognised as a factor in the development of pars defects and stress fractures, but its relationship with intervertebral disc (IVD) degeneration is not well understood. Therefore, a translational review encompa...
Article
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Damage to the annulus fibrosus (AF), the outer region of the intervertebral disc (IVD), results in an undesirable condition that may accelerate IVD degeneration causing low back pain. Despite intense research interest, attempts to regenerate the IVD have failed so far and no effective strategy has translated into a successful clinical outcome. Of p...
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PurposeThis meta-analysis aims to compare the complication rates of discectomy/microdiscectomy (OD/MD), microendoscopic discectomy (MED), percutaneous endoscopic lumbar discectomy (PELD), percutaneous laser disc decompression (PLDD), and tubular discectomy for symptomatic lumbar disc herniation (LDH) using general classification and modified Clavie...
Article
There has been no study to describe the ultrastructural organization of elastic fibers at the interface of the nucleus pulposus and annulus fibrosus of the intervertebral disc (IVD), a region called the transition zone (TZ). A previously developed digestion technique was optimized to eliminate cells and non-elastin ECM components except for the ela...
Article
The increasing prevalence of low back pain has imposed a heavy economic burden on global healthcare systems. Intense research activities have been performed for the regeneration of the Nucleus Pulposus (NP) of the IVD; however, tissue-engineered scaffolds have failed to capture the multi-scale structural hierarchy of the native tissue. The current...
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Purpose Animal models are frequently used to elucidate pathomechanism and pathophysiology of various disorders of the human intervertebral disc (IVD) and also to develop therapeutic approaches. Here we report morphological characteristics of the kangaroo lumbar IVDs and compare them with other animal models used in spine research. Methods Twenty-f...
Article
Background The accuracy of surgeon-defined assessment (SDA) of soft tissue balance in total knee arthroplasty (TKA) is poorly understood despite balance being considered a significant determinant of surgical success. The study’s hypothesis was that intra-operative SDA is a poor predictor of coronal balance in TKA.MethodsA prospective, multicenter s...
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Purpose: Existing automated spine alignment is based on original X-rays that are not applicable for teleradiology for spinal deformities patients. We aim to provide a novel automated vertebral segmentation method enabling accurate sagittal alignment detection, with no restrictions imposed by image quality or pathology type. Methods: A total of 4...
Article
Real-time health monitoring systems are emerging in diverse medical fields, tracking biological and physiological signals for direct feedback to the user. Orthopaedics is yet to adapt to innovative trends in health monitoring. Despite an evident entry point during orthopaedic surgeries, clinicians remain unable to objectively examine the structural...
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Aims: It is unknown whether kinematic alignment (KA) objectively improves knee balance in total knee arthroplasty (TKA), despite this being the biomechanical rationale for its use. This study aimed to determine whether restoring the constitutional alignment using a restrictive KA protocol resulted in better quantitative knee balance than mechanica...
Article
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Purpose: The aim of this network meta-analysis (NMA) was to compare the complication rates of discectomy/microdiscectomy, percutaneous laser disc decompression (PLDD), percutaneous endoscopic lumbar discectomy (PELD), microendoscopic discectomy (MED), and tubular discectomy for symptomatic lumbar disc herniation (LDH). Methods: We searched three...
Article
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Purpose Abnormal stress in the lumbar vertebra, also known as bony stress, can be a precursor to degenerative changes which may manifest as low back pain (LBP). However, the prevalence of bony stress in the lumbar spine and its relationship with degenerative changes and LBP is unclear. The purpose of this study was to evaluate the prevalence of bon...
Preprint
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Study design A retrospective cross-sectional study. Objective To assess the sensitivity to change and reliability of various mid-sagittal and axial plane metrics in the assessment of patients with single-level degenerative cervical stenosis on T2-weighted MR imaging. Setting A diagnostic MR imaging facility in Sydney (Australia). Methods We retrosp...
Chapter
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Replacing the Nucleus Pulposus for Degenerative Disc Disease and Disc Herniation: Disc Preservation Following Discectomy
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A retrospective cross-sectional study. To assess the sensitivity to change and reliability of various mid-sagittal and axial plane metrics in the assessment of patients with single-level degenerative cervical stenosis on T2-weighted MR imaging. A diagnostic MR imaging facility in Sydney (Australia). We retrospectively reviewed T2-weighted MR images...
Conference Paper
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In treating recalcitrant low back pain, extreme lateral lumbar interbody fusion (XLIF) with a large cage is reported to have better stability compared to approach of transforaminal lumbar interbody fusion (TLIF) using a small cage. In addition, bilateral pedicle screw fixation (PSF) in comparison with unilateral fixation achieved no inferior fusion...
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Abstract Introduction Estimation of intervertebral disc degeneration on magnetic resonance imaging (MRI) is challenging. Qualitative schemes used in clinical practice correlate poorly with pain and quantitative techniques have not entered widespread clinical use. Methods As part of a prior study, 25 New Zealand white rabbits underwent annular punc...
Article
Low back pain (LBP)varies over time. Consumers, clinicians, and researchers use various terms to describe LBP fluctuations, such as episodes, recurrences and flares. Although “flare” is use commonly, there is no consensus on how it is defined. This study aimed to obtain consensus for a LBP flare definition using a mixed-method approach. Step 1 invo...
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Intervertebral disc (IVD) degeneration is a major contributing factor to chronic low back pain and disability, leading to imbalance between anabolic and catabolic processes, altered extracellular matrix (ECM) composition, loss of tissue hydration, inflammation and impaired mechanical functionality. Current treatments aim to manage symptoms rather t...
Article
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PDMS is widely used for prosthetic device manufacture. Conventional ion implantation is not a suitable treatment to enhance the biocompatibility of poly dimethyl siloxane (PDMS) due to its propensity to generate a brittle silicon oxide surface layer which cracks and delaminates. To overcome this limitation, we have developed new plasma based proces...
Article
Objective: The objective of this review is to evaluate the measurement properties of multidimensional pain assessment tools for postoperative pain in adults. Introduction: Effective postoperative pain management increases patient safety and satisfaction, and reduces healthcare costs. The most commonly used postoperative pain assessment tools onl...
Article
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Background: Lumbar intervertebral disc herniation is a common cause of lower back and leg pain, with surgical intervention (e.g. discectomy to remove the herniated disc) recommended after an appropriate period of conservative management, however the existing or increased breach of the annulus fibrosus persists with the potential of reherniation. S...
Data
Supplemental Material, Supplemantary_Information_20170809 - The Role of Sacral Slope in the Progression of a Bilateral Spondylolytic Defect at L5 to Spondylolisthesis: A Biomechanical Investigation Using Finite Element Analysis
Article
Full-text available
Chronic back and neck pain is a prevalent disability, often caused by degeneration of the intervertebral disc. Because current treatments for this condition are less than satisfactory, a great deal of effort is being applied to develop new solutions, including regenerative strategies. However, the path from initial promising idea to clinical use is...
Article
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Purpose: The relationship between biomechanical instability and degenerative changes in the lumbar spine in chronic low back pain (CLBP) patients remains controversial. The main objective of this retrospective radiographical study was to evaluate changes in kinematics at different lumbar levels (in particular the L5-S1 level) with progressive grad...
Article
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Background: Spondylolytic (or lytic) spondylolisthesis is often associated with disc degeneration at the index-level; however, it is not clear if disc degeneration is the cause or the consequence of lytic spondylolisthesis. The main objective of this computed tomography based finite element modelling study was to examine the role of different grade...
Article
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PurposeTo elucidate the effects of growth differentiation factor-6 (GDF6) on: (i) gene expression of inflammatory/pain-related molecules and structural integrity in the rabbit intervertebral disc (IVD) degeneration model, and (ii) sensory dysfunction and changes in pain-marker expression in dorsal nerve ganglia (DRGs) in the rat xenograft radiculop...
Article
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This study investigated current trends in spine publications of the membership of Orthopaedic Research Society Spine Section (ORS3) and the more global and clinically focused International Society for the Study of the Lumbar Spine (ISSLS). The PubMed database was probed to quantify trends in the overall number of articles published, the number of j...
Data
Table S1 Journals that published from ORS3 members' articles from 2007 to 2016 (sorted by publication count).
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Table S4 Journals that published from ISSLS members' articles from 2007 to 2016 (sorted by impact factor).
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Table S5 Most productive individual authors in ORS3 and ISSLS from 2007 to 2016.
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Table S2 Journals that published from ORS3 members' articles from 2007 to 2016 (sorted by impact factor).
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Table S3 Journals that published from ISSLS members' articles from 2007 to 2016 (sorted by publication count).
Article
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Study Design: A biomechanical study using finite element (FE) analysis. Objective: The main objective of this study was to investigate the role of sacral slope in the progression of a L5 bilateral spondylolytic defect to spondylolisthesis. Materials and Methods: A three-dimensional model of lumbosacral spine was built using computed tomography (...
Article
Background: Lumbar discectomy has been shown to be clinically beneficial in numerous studies for appropriately selected patients. Some patients, however, undergo revision discectomy, with previously reported estimates of revisions ranging from 5.1% to 7.9%. No study to date has been able to precisely quantify the rate of revision surgery over nume...
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Study Design: A systematic review Objective: The objective of this study was to determine the safety and efficacy of standalone Anterior Lumbar Interbody Fusio