Sritharan, K, Chamoli, U, Kuan, J & Diwan, AD 2020, 'Assessment of degenerative cervical stenosis on T2-weighted MR imaging: sensitivity to change and reliability of mid-sagittal and axial plane metrics.', Spinal cord.View/Download from: Publisher's site
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 retrospectively reviewed T2-weighted MR images of 85 consecutive patients (48 M and 37 F) with single-level degenerative cervical stenosis. Canal compromise and cord compression were evaluated using three mid-sagittal plane metrics (M1, M2, and M3) and two axial plane metrics (M4 and M5), at the level of stenosis and nonstenotic cephalad and caudal levels (controls). Sensitivity to change (SC) for each metric was evaluated as the percentage deviation of the measured value from the estimated normal value based on cephalad and caudal controls. Reliability for each metric was evaluated using intraclass correlation coefficients. RESULTS:Degenerative cervical stenosis showed a bimodal distribution peaking at C5-6 (n = 32) and C3-4 (n = 29) levels. The changes in the canal and cord geometry along the rostrocaudal axis were inconsistent. Across all individual subjects (reflecting a range of stenosis severity), M3 (-32.87% ± 10.60%) was more sensitive to change compared with M1 (16.64% ± 16.48%) and M2 (-23.95% ± 11.12%). Similarly, M4 (-24.62% ± 12.17%) was more sensitive to change compared with M5 (-6.71% ± 11.08%). The level of reliability was "moderate" to "excellent" for mid-sagittal plane measurements, and "poor" to "excellent" for axial plane measurements. CONCLUSION:Changes in canal dimensions in the mid-sagittal plane and cord shape in the axial plane are sensitive indicators of degenerative cervical stenosis on T2-weighted MR images.
Chamoli, U, Umali, J, Kleuskens, MWA, Chepurin, D & Diwan, AD 2019, 'Morphological characteristics of the kangaroo lumbar intervertebral discs and comparison with other animal models used in spine research', European Spine Journal.View/Download from: Publisher's site
© 2019, Springer-Verlag GmbH Germany, part of Springer Nature. 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-five fresh-frozen cadaveric lumbar spines (T12–S1) derived from kangaroo carcases (Macropus giganteus) of undetermined age were first scanned in a C-Arm X-ray machine. A photograph of the axial section of the disc including a calibrated metric scale was also acquired. The digital radiographs and photographs were processed in ImageJ to determine the axial and sagittal plane dimensions for the whole disc (WD) and the nucleus pulposus (NP) and the mid-sagittal disc height for all the lumbar levels. Results: Our results suggest that the L6–S1 IVD in kangaroos is distinctly large compared with the upper lumbar IVDs. Based on previously published data, human lumbar IVDs are the largest of all the animal IVDs used in spine research, with camelid cervical IVDs being the closest relative in absolute dimensions (llamas: 78% in disc height, 40% in WD volume, and 38% in NP volume). Kangaroo L6–S1 IVD was approximately 51% in height, 20% in WD volume, and 20% in NP volume of the human lumbar IVD. Conclusions: We conclude that morphological similarities exist between a kangaroo and human lumbar IVD, especially with the lima bean shape in the axial plane, wedge shape in the sagittal plane, convexity at the cephalad endplates, and percentage volume occupied by the NP in the IVD. Graphic abstract: These slides can be retrieved under Electronic Supplementary Material. [Figure not available: see fulltext.].
Chen, X, Chamoli, U, Lapkin, S, Castillo, JV & Diwan, AD 2019, 'Complication rates of different discectomy techniques for the treatment of lumbar disc herniation: a network meta-analysis.', European spine journal : official publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society, vol. 28, no. 11, pp. 2588-2601.View/Download from: UTS OPUS or Publisher's site
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 online databases for randomized controlled trials (RCTs). Overall complication rates, complication rates per general and modified Clavien-Dindo classification schemes, and reoperation rates were considered as primary outcomes. Odds ratio with 95% confidence intervals for direct comparisons and 95% credible intervals for NMA results were reported. Surface under cumulative ranking curve (SUCRA) was used to estimate ranks for each discectomy technique based on the complication rates. RESULTS:In total, 18 RCTs with 2273 patients were included in this study. Our results showed that there was no significant difference in any of the pairwise comparisons. PELD (SUCRA: 0.856) ranked the lowest for overall complication rates. Discectomy/microdiscectomy (SUCRA: 0.599) and PELD (SUCRA: 0.939) ranked the lowest for intraoperative and post-operative complication rates, respectively. Concerning modified Clavien-Dindo classification scheme, PELD (SUCRA: 0.803), MED (SUCRA: 0.730), and PLDD (SUCRA: 0.605) ranked the lowest for the occurrence of type I, II, and III complications, respectively. Tubular discectomy (SUCRA: 0.699) ranked the lowest for reoperation rates. CONCLUSIONS:The results of this NMA suggest that discectomy/microdiscectomy and PELD are the safest procedures for LDH with minimal intraoperative and post-operative complications, respectively. PELD, MED, and PLDD are the safest procedures for LDH in terms of minimal rates for complications necessitating conservative, pharmacological, and surgical treatment, respectively. These slides can be retrieved under Electronic Supplementary Material.
Chepurin, D, Chamoli, U, Sheldrick, K, Lapkin, S, Scott, D, Kuan, J & Diwan, AD 2019, 'Bony stress in the lumbar spine is associated with intervertebral disc degeneration and low back pain: a retrospective case-control MRI study of patients under 25 years of age.', European spine journal : official publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society, vol. 28, no. 11, pp. 2470-2477.View/Download from: UTS OPUS or Publisher's site
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 bony stress in the lumbar spine and its relationship with intervertebral disc (IVD) degeneration, facet osteoarthritis and LBP in patients under 25 years of age. METHODS:A retrospective case-control study of 130 patients under 25 years of age was conducted from a population of 493 patients who had lumbar MRI across three imaging centres over three years. A cohort of 55 consecutive patients with bony stress was identified. A control group of consecutive patients (n = 75) without bony stress was also selected from the population. RESULTS:Bony stress was prevalent in 11% (95% CI [8.4-14.5%]) of patients and was not diagnosed in 36% (95% CI [22-55%]) of these cases. Patients with bony stress had over twofold (OR 2.3, 95% CI [1.1-4.8]) and fivefold (OR 5.3, 95% CI [2.11-13.3]) higher likelihood of having IVD degeneration and LBP, respectively, when compared with the control group. Bony stress was not found to be associated with facet osteoarthritis. CONCLUSION:Bony stress in the lumbar spine was prevalent in 11% of patients under 25 years of age. It was commonly undiagnosed in radiology reports (not reported in 36% of the cases). Being significantly associated and with an increased likelihood of IVD degeneration and LBP, we posit that bony stress is likely a symptomatic and clinically meaningful diagnostic entity in the assessment of LBP. These slides can be retrieved under Electronic Supplementary Material.
Ni, J, Bongers, A, Chamoli, U, Bucci, J, Graham, P & Li, Y 2019, 'In Vivo 3D MRI Measurement of Tumour Volume in an Orthotopic Mouse Model of Prostate Cancer', CANCER CONTROL, vol. 26, no. 1.View/Download from: UTS OPUS or Publisher's site
Sabnis, AB, Chamoli, U & Diwan, AD 2019, 'Answer to the Letter to the Editor of Miao Yu et al. concerning "Is L5-S1 motion segment different from the rest? A radiographic kinematic assessment of 72 patients with chronic low back pain" by AB Sabnis et al. (Eur. Spine J; 27(5):1127-1135)', EUROPEAN SPINE JOURNAL, vol. 28, no. 5, pp. 1249-1249.View/Download from: Publisher's site
Ramakrishna, VAS, Chamoli, U, Viglione, LL, Tsafnat, N & Diwan, AD 2018, 'Mild (not severe) disc degeneration is implicated in the progression of bilateral L5 spondylolysis to spondylolisthesis.', BMC musculoskeletal disorders, vol. 19, no. 1.View/Download from: UTS OPUS or Publisher's site
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 grades of disc degeneration in the progression of a bilateral L5-lytic defect to spondylolisthesis. METHODS:High-resolution computed tomography data of the lumbosacral spine from an anonymised healthy male subject (26 years old) were segmented to build a 3D-computational model of an INTACT L1-S1 spine. The INTACT model was manipulated to generate four more models representing a bilateral L5-lytic defect and the following states of the L5-S1 disc: nil degeneration (NOR LYTIC), mild degeneration (M-DEG LYTIC), mild degeneration with 50% disc height collapse (M-DEG-COL LYTIC), and severe degeneration with 50% disc height collapse(S-COL LYTIC). The models were imported into a finite element modelling software for pre-processing, running nonlinear-static solves, and post-processing of the results. RESULTS:Compared with the baseline INTACT model, M-DEG LYTIC model experienced the greatest increase in kinematics (Fx range of motion: 73% ↑, Fx intervertebral translation: 53%↑), shear stresses in the annulus (Fx anteroposterior: 163%↑, Fx posteroanterior: 31%↑), and strain in the iliolumbar ligament (Fx: 90%↑). The S-COL LYTIC model experienced a decrease in mobility (Fx range of motion: 48%↓, Fx intervertebral translation: 69%↓) and an increase in normal stresses in the annulus (Fx Tensile: 170%↑; Fx Compressive: 397%↑). No significant difference in results was noted between M-DEG-COL LYTIC and S-COL LYTIC models. CONCLUSIONS:In the presence of a bilateral L5 spondylolytic defect, a mildly degenerate index-level disc experienced greater intervertebral motions and shear stresses compared with a severely degenerate index-level disc in ...
Ramakrishna, VAS, Chamoli, U, Viglione, LL, Tsafnat, N & Diwan, AD 2018, 'The Role of Sacral Slope in the Progression of a Bilateral Spondylolytic Defect at L5 to Spondylolisthesis: A Biomechanical Investigation Using Finite Element Analysis', GLOBAL SPINE JOURNAL, vol. 8, no. 5, pp. 460-470.View/Download from: UTS OPUS or Publisher's site
Sabnis, AB, Chamoli, U & Diwan, AD 2018, 'Is L5-S1 motion segment different from the rest? A radiographic kinematic assessment of 72 patients with chronic low back pain', EUROPEAN SPINE JOURNAL, vol. 27, no. 5, pp. 1127-1135.View/Download from: Publisher's site
Viglione, LL, Chamoli, U & Diwan, AD 2017, 'Is Stand-Alone Anterior Lumbar Interbody Fusion a Safe and Efficacious Treatment for Isthmic Spondylolisthesis of L5-S1?', GLOBAL SPINE JOURNAL, vol. 7, no. 6, pp. 587-595.View/Download from: Publisher's site
Chamoli, U, Korkusuz, MH, Sabnis, AB, Manolescu, AR, Tsafnat, N & Diwan, AD 2015, 'Global and segmental kinematic changes following sequential resection of posterior osteoligamentous structures in the lumbar spine: An in vitro biomechanical investigation using pure moment testing protocols', PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART H-JOURNAL OF ENGINEERING IN MEDICINE, vol. 229, no. 11, pp. 812-821.View/Download from: Publisher's site
Chamoli, U, Chen, AS & Diwan, AD 2014, 'Interpedicular kinematics in an in vitro biomechanical assessment of a bilateral lumbar spondylolytic defect', CLINICAL BIOMECHANICS, vol. 29, no. 10, pp. 1108-1115.View/Download from: Publisher's site
Chamoli, U, Chen, AS & Diwan, AD 2014, 'Re: Cook DJ, Yeager MS, Cheng BC. Interpedicular travel in the evaluation of spinal implants: an application in posterior dynamic stabilization. Spine 2012; 37: 923-31', SPINE, vol. 39, no. 11, pp. 921-921.View/Download from: Publisher's site
Chamoli, U, Diwan, AD & Tsafnat, N 2014, 'Pedicle screw-based posterior dynamic stabilizers for degenerative spine: In vitro biomechanical testing and clinical outcomes', JOURNAL OF BIOMEDICAL MATERIALS RESEARCH PART A, vol. 102, no. 9, pp. 3324-3340.View/Download from: Publisher's site
Aquilina, P, Chamoli, U, Parr, WCH, Clausen, PD & Wroe, S 2013, 'Finite element analysis of three patterns of internal fixation of fractures of the mandibular condyle', BRITISH JOURNAL OF ORAL & MAXILLOFACIAL SURGERY, vol. 51, no. 4, pp. 326-331.View/Download from: Publisher's site
Parr, WCH, Chamoli, U, Jones, A, Walsh, WR & Wroe, S 2013, 'Finite element micro-modelling of a human ankle bone reveals the importance of the trabecular network to mechanical performance: New methods for the generation and comparison of 3D models', JOURNAL OF BIOMECHANICS, vol. 46, no. 1, pp. 200-205.View/Download from: UTS OPUS or Publisher's site
Wroe, S, Chamoli, U, Parr, WCH, Clausen, P, Ridgely, R & Witmer, L 2013, 'Comparative Biomechanical Modeling of Metatherian and Placental Saber-Tooths: A Different Kind of Bite for an Extreme Pouched Predator', PLOS ONE, vol. 8, no. 6.View/Download from: Publisher's site
Oldfield, CC, McHenry, CR, Clausen, PD, Chamoli, U, Parr, WCH, Stynder, DD & Wroe, S 2012, 'Finite element analysis of ursid cranial mechanics and the prediction of feeding behaviour in the extinct giant Agriotherium africanum', JOURNAL OF ZOOLOGY, vol. 286, no. 2, pp. 163-170.View/Download from: Publisher's site
Parr, WCH, Wroe, S, Chamoli, U, Richards, HS, McCurry, MR, Clausen, PD & McHenry, C 2012, 'Toward integration of geometric morphometrics and computational biomechanics: New methods for 3D virtual reconstruction and quantitative analysis of Finite Element Models', JOURNAL OF THEORETICAL BIOLOGY, vol. 301, pp. 1-14.View/Download from: Publisher's site
Attard, MRG, Chamoli, U, Ferrara, TL, Rogers, TL & Wroe, S 2011, 'Skull mechanics and implications for feeding behaviour in a large marsupial carnivore guild: the thylacine, Tasmanian devil and spotted-tailed quoll', JOURNAL OF ZOOLOGY, vol. 285, no. 4, pp. 292-300.View/Download from: Publisher's site
Chamoli, U & Wroe, S 2011, 'Allometry in the distribution of material properties and geometry of the felid skull: Why larger species may need to change and how they may achieve it', JOURNAL OF THEORETICAL BIOLOGY, vol. 283, no. 1, pp. 217-226.View/Download from: Publisher's site
Wroe, S, Chamoli, U, Parr, W, Ridgely, RC & Witmer, LM 2012, '3D BIOMECHANICAL MODELLING OF MARSUPIAL AND PLACENTAL SABRE-TOOTHS: A DIFFERENT KIND OF BITE FOR AN EXTREME POUCHED PREDATOR', JOURNAL OF VERTEBRATE PALEONTOLOGY, 72nd Annual Meeting of the Society-of-Vertebrate-Paleontology, TAYLOR & FRANCIS INC, N Carolina Museum Nat Sci, Raleigh, NC, pp. 196-196.