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PURPOSE: Identification of adolescent idiopathic scoliosis (AIS) patients with mild curvatures who pose significant risk of progressing to severe levels of curvatures is of paramount importance for clinical care. This study aimed to compare segmental deformity changes in AIS sub-cohorts that are dichotomised by progression status. METHODS: Thirty-six female participants with Lenke 1 AIS curves were investigated with sequential MRIs during growth. Scans were reformatted to measure orthogonal segmental parameters, including sagittal/coronal wedging angles and axial rotation angles. Participants were dichotomised by progression. Two-tailed, independent sample t-tests were used to compare sub-cohort multi-segmental and segmental deformity parameters. Measurements were compared at each scan number and variable rates of change were determined using actual time between measures. RESULTS: AIS progression status sub-cohorts were comparable at scan 1 for multi-segmental deformity parameters (e.g. major thoracic curve angle, rib hump, kyphosis) (P > 0.05). However, apical measures of coronal IVD wedging, axial IVD rotation and axial vertebral rotation were segmental parameters at scan 1 which were larger for participants whose AIS would later go on to clinically progress (all P < 0.05). Measures of segmental hypokyphosis were comparable between groups. As development was tracked at each subsequent scan, coronal and axial plane differences between groups increased in both magnitude and number of differences. CONCLUSION: Initial disparity and then subsequent increasing magnitude of change of axial rotation may indicate a higher propensity to clinically progress in the future. This knowledge hopes to provide useful management information for AIS care providers and prognostic education for patients alike. LEVEL OF EVIDENCE: II.
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PURPOSE: To understand how the axial plane deformity contributes to progression of the three-dimensional spinal deformity of Adolescent Idiopathic Scoliosis (AIS), with a main thoracic curve type, using a series of sequential magnetic resonance images (MRI). METHODS: Twenty-seven AIS patients (at scan 1: mean 12.4 years (± 1.5), mean Cobb angle 29.1°(± 8.8°)) had 3 MRI scans (T4-L1) performed at intervals of mean 0.7 years (± 0.4). The outer profile of the superior and inferior endplates were traced on a reformatted axial image using ImageJ (NIH). Endplate AVR, and intravertebral rotation (IVR), defined as the difference between superior and inferior endplate AVR, was calculated for each vertebral level. RESULTS: For all patients and scans, the mean AVR was greatest at the curve apex, with AVR diminishing in a caudal and cephalic direction from the apex. At scan 3 the mean apical AVR was 15.1°(± 4.6°) with a mean change in apical AVR between MRI 1 and 3 of 2.7°(± 2.9°). The increase in standing height between MRI 1 and 3 was mean 7.4 cm (± 4.6). Linear regression showed a positive correlation between apical AVR and Cobb angle (R2 = 0.57, P < 0.001), and a positive correlation between apical AVR and rib hump (R2 = 0.54, p < 0.001). The mean change in IVR was greater 3 vertebral levels cephalic and caudal to the apex (1.4°(± 4.1°) and 1.2°(± 2.0°), respectively), compared to the apex (0.4°(± 3.1°)). CONCLUSIONS: AVR increased, during curve progression, most markedly at the curve apex. The greatest IVR was observed at the periapical levels, with the apex by contrast having only a modest degree of rotation, suggesting the periapical vertebral levels of the scoliosis deformity may be a significant driver in the progression of AIS.
Subject(s)
Scoliosis , Humans , Adolescent , Scoliosis/diagnostic imaging , Body Height , Linear Models , Magnetic Resonance Imaging , RotationABSTRACT
BACKGROUND: Adolescents with disabilities have fewer opportunities to participate in community-based fitness programmes. The purpose of this study was to examine the impact of a school-based running programme at a local middle school in Lebanon, Pennsylvania, on fitness and quality of life (QoL) in children with physical and cognitive disabilities in a life-skills classroom. METHODS: Nineteen adolescents with diagnosed disabilities including intellectual disability (ID), autism spectrum disorder and Down syndrome were recruited from three life-skills classrooms to participate in a school-based running programme. The programme was designed to be implemented two times/week for 6 weeks by classroom teachers/aides. Physical therapy faculty and students developed the programme and assisted with implementation. Each session lasted 30 min, consisting of a warm-up and cooldown, relay races, games and timed runs. Pre- and post-test measures included physiological cost index (PCI) and Paediatric Quality of Life Inventory™ (PedsQL™). Pre- and post-test data were compared using Wilcoxon signed rank tests. Each week participants also completed a training log to reflect on the activity for the day. RESULTS: Participants demonstrated significant improvements in PCI (P = 0.028) and the PedsQL™ (P = 0.008) following the running programme. CONCLUSIONS: Results of this study suggest that participation in a 6-week school-based running programme may improve fitness and QoL in adolescents with disabilities.
Subject(s)
Autism Spectrum Disorder , Disabled Persons , Humans , Child , Adolescent , Quality of Life , Exercise , Schools , Physical FitnessABSTRACT
Two high-intensity interval training (HIIT) regimens are often used in research and clinical settings. Yet, there has been no direct comparison to determine if one can improve glucose control and variability to a greater extent in individuals living with type 2 diabetes (T2D). Fourteen older females with T2D participated in a semi-randomized control trial where HIIT10 (10 × 1-min intervals at 90% heart rate max; HRmax) and HIIT4 (4 × 4-min intervals at 90% of HRmax) were compared to a control condition (CON; no exercise). Continuous glucose monitoring was used to assess glucose control and variability over 24 h after each condition. Both HIIT10 (-2.1 ± 1.1 mmol/L) and HIIT4 (-2.1 ± 1.3 mmol/L) acutely lowered glucose compared to CON (-0.7 ± 0.8 mmol/L; p = 0.001), with no difference between exercise conditions. This glucose-lowering effect did not persist over the 24-h post-exercise period, as both mean glucose (p = 0.751) and glucose variability (p = 0.168) were not significantly different among conditions. However, exploratory analyses focusing on individuals with less optimal glucose control (above median 24-h mean glucose in the CON condition; n = 7) revealed that 24-h mean glucose (7.4 [7.14-8.92] vs. 8.4 [7.5-9.9] mmol/L; p = 0.048), glucose variability (p = 0.010), and peak glucose (p = 0.048) were lower following HIIT10 compared to CON, while HIIT4 reduced time spent in moderate hyperglycemia compared to CON (p = 0.023). Both HIIT10 and HIIT4 acutely lower glycemia, but the effect does not persist over 24 h. However, in individuals with worse glucose control, HIIT10 may improve mean 24-h glucose and glycemic variability, while HIIT4 may reduce time spent in moderate hyperglycemia.
Subject(s)
Diabetes Mellitus, Type 2 , High-Intensity Interval Training , Hyperglycemia , Humans , Female , Blood Glucose , Diabetes Mellitus, Type 2/therapy , Blood Glucose Self-Monitoring , GlucoseABSTRACT
BACKGROUND: With increasing global interest in sleep hygiene, sleep ergonomics is an area that has been largely understudied. During sleep individuals turn over during the night to restore blood flow in occluded blood vessels, indicating that control of local tissue pressure may play a role in improving sleep comfort. This study investigates the influence of mattress stiffness on tissue compressive stresses during supine lying. METHODS: A subject-specific 3D finite element (FE) model of the pelvis area has been developed to simulate supine lying on substrates of varying firmness. Constitutive parameters for the adipose-skin tissue and muscle-organ tissue were calibrated using a novel application of the inverse finite element method. FINDINGS: The compressive stress was consistently greatest in the muscle interfacing the sacrum at 18.5 kPa on the soft foam, and 30.9 kPa on the firm foam. From soft to firm, the compressive stress increased by 67% at the sacrum, 20% at the ischium, 42% at the lesser trochanter, and 50% at the skin. INTERPRETATION: The non-linearity of the foam substrate had a pressure distributing effect, relieving the peak compressive stresses at the sacrum, indicating that it may be possible to design arrays of foam substrates that can provide most efficient pressure relief.
Subject(s)
Pressure Ulcer , Skin , Humans , Skin/blood supply , Pressure Ulcer/prevention & control , Pressure , Sacrum , Sacrococcygeal Region , Finite Element AnalysisABSTRACT
STUDY DESIGN: A prospective cohort study. OBJECTIVE: Detail typical three-dimensional segmental deformities and their rates of change that occur within developing adolescent idiopathic scoliosis (AIS) spines over multiple timepoints. SUMMARY OF BACKGROUND DATA: AIS is a potentially progressive deforming condition that occurs in three dimensions of the scoliotic spine during periods of growth. However, there remains a gap for multiple timepoint segmental deformity analysis in AIS cohorts during development. MATERIALS AND METHODS: Thirty-six female patients with Lenke 1 AIS curves underwent two to six sequential magnetic resonance images. Scans were reformatted to produce images in orthogonal dimensions. Wedging angles and rotatory values were measured for segmental elements within the major curve. Two-tailed, paired t tests compared morphologic differences between sequential scans. Rates of change were calculated for variables given the actual time between successive scans. Pearson correlation coefficients were determined for multidimensional deformity measurements. RESULTS: Vertebral bodies were typically coronally convexly wedged, locally lordotic, convexly axially rotated, and demonstrated evidence of local mechanical torsion. Between the first and final scans, apical measures of coronal wedging and axial rotation were all greater in both vertebral and intervertebral disk morphology than nonapical regions (all reaching differences where P <0.05). No measures of sagittal deformity demonstrated a statistically significant change between scans. Cross-planar correlations were predominantly apparent between coronal and axial planes, with sagittal plane parameters rarely correlating across dimensions. Rates of segmental deformity changes between earlier scans were characterized by coronal plane convex wedging and convexly directed axial rotation. The major locally lordotic deformity changes that did occur in the sagittal plane were static between scans. CONCLUSIONS: This novel investigation documented a three-dimensional characterization of segmental elements of the growing AIS spine and reported these changes across multiple timepoints. Segmental elements are typically deformed from initial presentation, and subsequent changes occur in separate orthogonal planes at unique times.
Subject(s)
Kyphosis , Lordosis , Scoliosis , Humans , Adolescent , Female , Scoliosis/pathology , Prospective Studies , Thoracic Vertebrae/pathology , Lumbar Vertebrae/pathology , Magnetic Resonance Imaging/methods , Lordosis/pathology , Kyphosis/pathology , Imaging, Three-Dimensional/methodsABSTRACT
PURPOSE: Vertebral body tethering (VBT) is a recent procedure to correct and reduce spinal curves in skeletally immature patients with adolescent idiopathic scoliosis (AIS). The purpose of this systematic review and meta-analysis is to determine the expected curve reduction and potential complications for adolescent patients after VBT. METHODS: PubMed, Embase, Google Scholar and Cochrane databases were searched until February 2022. Records were screened against pre-defined inclusion and exclusion criteria. Data sources were prospective and retrospective studies. Demographics, mean differences in Cobb angle, surgical details and complication rates were recorded. Meta-analysis was conducted using a random-effects model. RESULTS: This systematic review includes 19 studies, and the meta-analysis includes 16 of these. VBT displayed a statistically significant reduction in Cobb angle from pre-operative to final (minimum 2 years) measurements. The initial mean Cobb angle was 47.8° (CI 95% 42.9-52.7°) and decreased to 22.2° (CI 95% 19.9-24.5°). The mean difference is - 25.8° (CI 95% - 28.9-22.7) (p < 0.01). The overall complication rate was 23% (CI 95% 14.4-31.6%), the most common complication was tether breakage 21.9% (CI 95% 10.6-33.1%). The spinal fusion rate was 7.2% (CI 95% 2.3-12.1%). CONCLUSION: VBT results in a significant reduction of AIS at 2 years of follow-up. Overall complication rate was relatively high although the consequences of the complications are unknown. Further research is required to explore the reasons behind the complication rate and determine the optimal timing for the procedure. VBT remains a promising new procedure that is effective at reducing scoliotic curves and preventing spinal fusion in the majority of patients. LEVEL OF EVIDENCE: Systematic review of Therapeutic Studies with evidence level II-IV.
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STUDY DESIGN: This is a case-control study of prospectively collected data. OBJECTIVE: To quantify paraspinal muscle size asymmetry in adolescent idiopathic scoliosis (AIS) and determine if this asymmetry is (i) greater than observed in adolescent controls with symmetrical spines; and (ii) positively associated with skeletal maturity using Risser grade, scoliosis severity using the Cobb angle, and chronological age in years. SUMMARY OF BACKGROUND DATA: AIS is a three-dimensional deformity of the spine which occurs in 2.5% to 3.7% of the Australian population. There is some evidence of asymmetry in paraspinal muscle activation and morphology in AIS. Asymmetric paraspinal muscle forces may facilitate asymmetric vertebral growth during adolescence. METHODS: An asymmetry index [Ln(concave/convex volume)] of deep and superficial paraspinal muscle volumes, at the level of the major curve apex (Thoracic 8-9 th vertebral level) and lower-end vertebrae ( LEV , Thoracic 10-12 th vertebral level), was determined from three-dimensional Magnetic Resonance Imaging of 25 adolescents with AIS (all right thoracic curves), and 22 healthy controls (convex=left); all female, 10 to 16 years. RESULTS: Asymmetry index of deep paraspinal muscle volumes was greater in AIS (0.16±0.20) than healthy spine controls (-0.06±0.13) at the level of the apex ( P <0.01, linear mixed-effects analysis) but not LEV ( P >0.05). Asymmetry index was positively correlated with Risser grade ( r =0.50, P <0.05) and scoliosis Cobb angle ( r =0.45, P <0.05), but not age ( r =0.34, P >0.05). There was no difference in the asymmetry index of superficial paraspinal muscle volumes between AIS and controls ( P >0.05). CONCLUSIONS: The asymmetry of deep apical paraspinal muscle volume in AIS at the scoliosis apex is greater than that observed at equivalent vertebral levels in controls and may play a role in the pathogenesis of AIS.
Subject(s)
Kyphosis , Scoliosis , Humans , Adolescent , Female , Scoliosis/diagnostic imaging , Scoliosis/pathology , Case-Control Studies , Australia , Magnetic Resonance Imaging , Kyphosis/pathology , Muscles/pathology , Imaging, Three-Dimensional , Thoracic Vertebrae/pathologyABSTRACT
BACKGROUND: A limitation of current facelift techniques is the early postoperative reappearance of anterior midcheek laxity associated with recurrence of the nasolabial fold (NLF). OBJECTIVES: This study was undertaken to examine the regional anatomy of the anterior midcheek and NLF with a focus on explaining the early recurrence phenomenon and to explore the possibility of alternative surgical methods that prolong NLF correction. METHODS: Fifty cadaver heads were studied (16 embalmed, 34 fresh; mean age, 75 years). Following preliminary dissections and macrosectioning, a series of standardized layered dissections were performed, complemented by histology, sheet plastination, and microcomputed tomography. Mechanical testing of the melo fat pad (MFP) and skin was performed to gain insight on which structure is responsible for transmission of the lifting tension in a composite facelift procedure. RESULTS: Anatomic dissections, sheet plastination, and microcomputed tomography demonstrated the 3-dimensional architecture and borders of the MFP. Histology of a lifted midcheek demonstrated that a composite MFP lift causes a change in connective tissue organization from a hanging-down pattern into a pulled-upward pattern, suggesting traction on the skin. Mechanical testing confirmed that, in a composite lift, despite the sutures being placed directly into the deep aspect of the MFP, the lifting tension distal to the suture is transmitted through the skin and not through the MFP. CONCLUSIONS: The usual method of performing a composite midcheek lift results in the skin, and not the MFP itself, bearing the load of the nondissected tissues distal to the lifting suture. For this reason, early recurrence of the NLF occurs following skin relaxation in the postoperative period. Accordingly, specific surgical procedures for remodeling the MFP should be explored, possibly in combination with volume restoration of the fat and bone, for more lasting improvement of the NLF.
Subject(s)
Nasolabial Fold , Rhytidoplasty , Aged , Humans , Adipose Tissue/surgery , Nasolabial Fold/surgery , Rhytidoplasty/methods , X-Ray MicrotomographyABSTRACT
Adolescent Idiopathic Scoliosis (AIS) is a 3D spine deformity that also causes ribcage and torso distortion. While clinical metrics are important for monitoring disorder progression, patients are often most concerned about their cosmesis. The aim of this study was to automate the quantification of AIS cosmesis metrics, which can be measured reliably from patient-specific 3D surface scans (3DSS). An existing database of 3DSS for pre-operative AIS patients treated at the Queensland Children's Hospital was used to create 30 calibrated 3D virtual models. A modular generative design algorithm was developed on the Rhino-Grasshopper software to measure five key AIS cosmesis metrics from these models-shoulder, scapula and hip asymmetry, torso rotation and head-pelvis shift. Repeat cosmetic measurements were calculated from user-selected input on the Grasshopper graphical interface. InterClass-correlation (ICC) was used to determine intra- and inter-user reliability. Torso rotation and head-pelvis shift measurements showed excellent reliability (> 0.9), shoulder asymmetry measurements showed good to excellent reliability (> 0.7) and scapula and hip asymmetry measurements showed good to moderate reliability (> 0.5). The ICC results indicated that experience with AIS was not required to reliably measure shoulder asymmetry, torso rotation and head-pelvis shift, but was necessary for the other metrics. This new semi-automated workflow reliably characterises external torso deformity, reduces the dependence on manual anatomical landmarking, and does not require bulky/expensive equipment.
Subject(s)
Cosmetics , Kyphosis , Scoliosis , Child , Humans , Adolescent , Scoliosis/surgery , Reproducibility of Results , Torso , ShoulderABSTRACT
INTRODUCTION: 3D Non-Contact surface scanning (3DSS) is used in both biomechanical and clinical studies to capture accurate 3D images of the human torso, and to better understand the shape and posture of the spine-both healthy and pathological. This study sought to determine the efficacy and accuracy of using 3DSS of the posterior torso, to determine the curvature of the spinal column in the lateral lying position. METHODS: A cohort of 50 healthy adults underwent 3DSS and Magnetic Resonance Imaging (MRI) to correlate the contours of the external spine surface with the internal spinal column. The correlation analysis was composed of two phases: (1) MRI vertebral points vs MRI external spine surface markers; and (2) MRI external spine surface markers vs 3DSS external spine surface markers. The first phase compared the profiles of fiducial markers (vitamin capsules) adhered to the skin surface over the spinous processes against the coordinates of the spinous processes-assessing the linear distance between the profiles, and similarity of curvature, in the sagittal and coronal planes. The second phase compared 3DSS external spine surface markers with the MRI external spine surface markers in both planes, with further qualitative assessment for postural changes. RESULTS: The distance between the MRI vertebral points and MRI external spine surface markers showed strong statistically significant correlation with BMI in both sagittal and coronal planes. Kolmogorov-Smirnov (KS) tests showed similar no significant difference in curvature, k, in almost all participants on both planes. In the second phase, the coronal 3DSS external spine surface profiles were statistically different to the MRI external spine surface markers in 44% of participants. Qualitative assessment showed postural changes between MRI and 3DSS measurements in these participants. CONCLUSION: These study findings demonstrate the utility and accuracy of using anatomical landmarks overlaid on the spinous processes, to identify the position of the spinal bones using 3DSS. Using this method, it will be possible to predict the internal spinal curvature from surface topography, provided that the thickness of the overlaying subcutaneous adipose layer is considered, thus enabling postural analysis of spinal shape and curvature to be carried out in biomechanical and clinical studies without the need for radiographic imaging.
Subject(s)
Scoliosis , Spinal Curvatures , Adult , Humans , Scoliosis/diagnostic imaging , Spine/diagnostic imaging , Spinal Curvatures/diagnostic imaging , Radiography , TorsoABSTRACT
This study compares the effectiveness of pharmacological treatments to develop guidelines for the management of acute pain after tooth extraction. We searched Medline, EMBASE, CENTRAL, and US Clinical Trials registry on November 21, 2020. We included randomized clinical trials (RCTs) of participants undergoing dental extractions comparing 10 interventions, including acetaminophen, nonsteroidal anti-inflammatory drugs (NSAIDs), opioids, and combinations to placebo. After duplicate screening and data abstraction, we conducted a frequentist network meta-analysis for each outcome at 6 h (i.e., pain relief, total pain relief [TOTPAR], summed pain intensity difference [SPID], global efficacy rating, rescue analgesia, and adverse effects). We assessed the risk of bias using a modified Cochrane RoB 2.0 tool and the certainty of evidence using the Grading of Recommendations, Assessment, Development, and Evaluation approach. We implemented the analyses in RStudio version 3.5.3 and classified interventions from most to least beneficial or harmful. We included 82 RCTs. Fifty-six RCTs enrolling 9,095 participants found moderate- and high-certainty evidence that ibuprofen 200 to 400 mg plus acetaminophen 500 to 1,000 mg (mean difference compared to placebo [MDp], 1.68; 95% confidence interval [CI], 1.06-2.31), acetaminophen 650 mg plus oxycodone 10 mg (MDp, 1.19; 95% CI, 0.85-1.54), ibuprofen 400 mg (MDp, 1.31; 95% CI, 1.17-1.45), and naproxen 400-440 mg (MDp, 1.44; 95% CI, 1.07-1.80) were most effective for pain relief on a 0 to 4 scale. Oxycodone 5 mg, codeine 60 mg, and tramadol 37.5 mg plus acetaminophen 325 mg were no better than placebo. The results for TOTPAR, SPID, global efficacy rating, and rescue analgesia were similar. Based on low- and very low-certainty evidence, most interventions were classified as no more harmful than placebo for most adverse effects. Based on moderate- and high-certainty evidence, NSAIDs with or without acetaminophen result in better pain-related outcomes than opioids with or without acetaminophen (except acetaminophen 650 mg plus oxycodone 10 mg) or placebo.
Subject(s)
Acetaminophen , Acute Pain , Adult , Humans , Acetaminophen/therapeutic use , Ibuprofen/therapeutic use , Oxycodone/therapeutic use , Network Meta-Analysis , Anti-Inflammatory Agents, Non-Steroidal/therapeutic use , Pain, Postoperative/drug therapy , Pain, Postoperative/etiology , Analgesics, Opioid/therapeutic use , Tooth Extraction/adverse effects , Acute Pain/drug therapy , Acute Pain/etiologyABSTRACT
In spine research, two possibilities to generate models exist: generic (population-based) models representing the average human and subject-specific representations of individuals. Despite the increasing interest in subject specificity, individualisation of spine models remains challenging. Neuro-musculoskeletal (NMS) models enable the analysis and prediction of dynamic motions by incorporating active muscles attaching to bones that are connected using articulating joints under the assumption of rigid body dynamics. In this study, we used forward-dynamic simulations to compare a generic NMS multibody model of the thoracolumbar spine including fully articulated vertebrae, detailed musculature, passive ligaments and linear intervertebral disc (IVD) models with an individualised model to assess the contribution of individual biological structures. Individualisation was achieved by integrating skeletal geometry from computed tomography and custom-selected muscle and ligament paths. Both models underwent a gravitational settling process and a forward flexion-to-extension movement. The model-specific load distribution in an equilibrated upright position and local stiffness in the L4/5 functional spinal unit (FSU) is compared. Load sharing between occurring internal forces generated by individual biological structures and their contribution to the FSU stiffness was computed. The main finding of our simulations is an apparent shift in load sharing with individualisation from an equally distributed element contribution of IVD, ligaments and muscles in the generic spine model to a predominant muscle contribution in the individualised model depending on the analysed spine level.
Subject(s)
Intervertebral Disc , Lumbar Vertebrae , Humans , Lumbar Vertebrae/physiology , Weight-Bearing/physiology , Biomechanical Phenomena , Ligaments/physiology , Intervertebral Disc/physiology , Muscles/physiology , Rotation , Models, Biological , Finite Element AnalysisABSTRACT
Solid-phase red cell adherence (SPRCA) is a sensitive platform for antibody detection, but nonspecific reactions may occur. One pattern of apparent nonspecific reactivity is a panagglutinin with a negative direct antiglobulin test (DAT). The purpose of this study was to define the clinical characteristics of patients with these nonspecific reactions and their associated serologic findings. Twenty patients with panreactive SPRCA testing results were identified between November 2022 and May 2023. In addition to panagglutinins, these patients had (1) a negative polyethylene glycol (PEG) antibody detection test, (2) a negative PEG autocontrol, and (3) a negative DAT. The strength of SPRCA panreactivity and the results of eluate testing (by tube and SPRCA) were studied. Clinical characteristics of patients included age, sex, and primary diagnosis. Each patient was also assessed for evidence of hemolysis. Fourteen female and six male patients were evaluated (average age 44 years). Primary diagnoses included pregnancy (n = 10), acute bleeding (n = 4), orthopedic (n = 3), and other (n = 3). There was no clinical or laboratory evidence of hemolysis. The predominant strength of SPRCA panreactivity was evenly distributed across reaction grades (1+ to 3+). Fifty-five percent of the eluates tested in PEG showed panreactivity, consistent with warm-reactive autoantibodies, while 85 percent of eluates tested by SPRCA were panreactive. Six discrepant cases, in which PEG eluate testing was negative and solid-phase eluate testing showed panreactivity, were associated with weak solid-phase plasma panreactivity (1+). In addition, the reactivity strengths of the eluates tested by SPRCA were invariably more strongly reactive than those eluates tested in PEG. Panagglutination is a distinct SPRCA-only plasma reactivity pattern. Despite a negative PEG tube and DAT, most panagglutinins are warm-reactive autoantibodies. Fortunately, these "interfering" panagglutinins do not appear to be clinically significant and are easily managed by an alternative testing method such as PEG.
Subject(s)
Autoantibodies , Hemolysis , Humans , Male , Female , Adult , Coombs Test/methods , Erythrocytes , Antibodies, Anti-IdiotypicABSTRACT
Prior studies have demonstrated Finite Element (FE) analysis is a useful tool when analysing the complex interplay of tissue and body loads which act through the human pelvis in a subject lying supine. The computational accuracy and efficiency of FE models that contain complex non-linear geometric interfaces between different anatomical and tissue regions can be compromised by superfluous node interactions and contact penetrations. This study proposes a method for the development of efficient contact definitions using shared topology. The Shared Topology Finite Element Model (FEM) resulted in a 37% reduction in solution time compared to an equivalent FEM defined with Bonded contact. At all tissue interfaces, contact penetration occurred in the Bonded FEM, with subsequent under-prediction of peak compressive strains and stresses by 1-7% compared to the Shared Topology FEM. Simulating supine lying of a 19-year-old male, the Shared Topology FEM predicted peak compressive stress in the muscle interfacing the sacrum of 29.4 kPa, and peak compressive strain of 50%. The proposed methodology can be applied for any medical imaging derived FEM where there are multiple congruent 3D geometries with negligible sliding across interfaces.
Subject(s)
Pelvis , Adult , Biomechanical Phenomena , Finite Element Analysis , Humans , Male , Pressure , Stress, Mechanical , Young AdultABSTRACT
Despite optimistic reports about the results of amputation for advanced vascular disease, the patient's assessment of advantages and disadvantages is seldom acknowledged. A detailed social study of 67 amputees has revealed considerable disparity between the patient's views and those of the medical staff. About a third of the patients are forced to retire from active work by the amputation; about three-quarters report a serious decline in their social activities; only about half are really independent with prostheses in the long term; a quarter report severe and intractable symptoms related to their amputation stumps; only about a quarter feel that the amputation was definitely beneficial; and only about one in five feel that the medical staff have provided adequate support during their hospital stay. Amputees face physical and financial disability, isolation, and discomfort. Every effort must be made to explain the implications of amputation honestly and realistically and to ensure continuing patient assessment and support.
Subject(s)
Amputees , Artificial Limbs , Amputation, Surgical , Amputation Stumps , Emotions , HumansABSTRACT
PURPOSE: There has been a recent shift toward the analysis of the pathoanatomical variation of the adolescent idiopathic scoliosis (AIS) spine with the three dimensions, and research of level-wise vertebral body morphology in single anatomical planes is now replete within the field. In addition to providing a precise description of the osseous structures that are the focus of instrumented surgical interventions, understanding the anatomical variation between vertebral bodies will elucidate possible pathoaetiological mechanisms of the onset of scoliotic deformity. METHODS: This review aimed to discuss the current landscape of AIS segmental vertebral morphology research and provide a comprehensive report of the typical patterns observed at the individual vertebral level. RESULTS: We have detailed how these vertebrae are typically characterised by lateral wedging to the convexity, have a marked degree of anterior overgrowth, are rotated towards the convexity, have inherent gyratory mechanical torsion created within them and are associated with pedicles on the concave side being narrower, longer and more laterally angled. For the most part, these findings are most pronounced at and around the apex of a scoliotic curve, with these deformations reducing towards junctional vertebrae. We have also summarised a nomenclature defined by the Scoliosis Research Society, highlighting the need for more consistent reporting of these level-wise dimensional anatomical changes. CONCLUSION: Finally, we emphasised how a marked degree of heterogeneity exists between the included investigations, namely in scoliotic curve-type inclusion, imaging modality and timepoint of analysis within scoliosis' longitudinal development, and how improvement in these study design characteristics will enhance ongoing research.
Subject(s)
Kyphosis , Scoliosis , Adolescent , Humans , Longitudinal Studies , Scoliosis/diagnostic imaging , Scoliosis/surgery , Thoracic Vertebrae , Vertebral BodyABSTRACT
Patient specific finite element (FE) modeling of the pediatric spine is an important challenge which offers to revolutionize the treatment of pediatric spinal pathologies, for example adolescent idiopathic scoliosis (AIS). In particular, modeling of the intervertebral disc (IVD) is a unique challenge due to its structural and mechanical complexity. This is compounded by limited ability to non-invasively interrogate key mechanical parameters of a patient's IVD. In this work, we seek to better understand the link between mechanical properties and mechanical behavior of patient specific FE models of the pediatric lumbar spine. A parametric study of IVD parameter was conducted, coupled with insights from current knowledge of the pediatric IVD. In particular, the combined effects of parameters was investigated. Recommendations are made toward areas of importance in patient specific FE modeling of the pediatric IVD. In particular, collagen fiber bundles of the IVD are found to dominate IVD mechanical behavior and are thus recommended as an area of primary focus for patient specific FE models. In addition, areas requiring further experimental research are identified. This work provides a valuable building block toward the development of patient specific models of the pediatric spine.