3D Printing of Bone Spurs Before Surgical Removal During Total Knee Arthroplasty

Project Background: In the United States, total knee arthroplasty (TKA) is the most performed orthopaedic operation. Among the 700,00 patients who received TKA, 21-25% underwent revision due to knee instability. Proper stability of a TKA depends on soft tissue balance for proper alignment in flexion and extension, and improper soft tissue modification is the primary cause of early implant failure. Soft tissue balancing can be complicated by presence of osteophytes on the distal femur or proximal tibia, which may require removal. The three-dimensional structure of osteophytes is often difficult to visualize with imaging, which could cause incomplete removal. Utilizing 3D models of these osteophytes may mitigate the risk of complication after implantation by enabling more efficient and effective soft tissue adjustment for knee tracking and balancing. Proposed Methods: We are writing a research proposal for the Rothman Institute to engage in a pilot study. We will use de-identified MRI or CT imaging to print the distal femoral and proximal tibial components of the knee, including osteophytes. The surgeon will use the model preoperatively or during surgery to gain a more comprehensive visual understanding of factors which may affect soft tissue balancing. After approximately 10 trials, we will ask the surgeons for feedback in addition to measuring outcomes such as change in OR time or revision rate. We aim to apply for IRB approval for a larger study. Results: The 3D model concept is supported by orthopaedic surgeons and residents who perform TKA. We anticipate reduced OR time. Conclusions: Feedback from orthopaedic surgeons suggests potential utility for 3D models in the OR. Although CT is a better imaging modality than MRI for 3D printing the models, CT scans are not commonly performed prior to TKA. Our next steps include IRB approval and determination of whether the models will be best utilized preoperatively or during surgery

Automated Neuromelanin Imaging as a Diagnostic Biomarker for Parkinson's Disease

Published onlineWe aimed to analyze the diagnostic accuracy of an automated segmentation and quantification method of the SNc and locus coeruleus (LC) volumes based on neuromelanin (NM)-sensitive MRI (NM-MRI) in patients with idiopathic (iPD) and monogenic (iPD) Parkinson's disease (PD). Thirty-six patients (23 idiopathic and 13 monogenic PARKIN or LRRK2 mutations) and 37 age-matched healthy controls underwent 3T-NM-MRI. SNc and LC volumetry were performed using fully automated multi-image atlas segmentation. The diagnostic performance to differentiate PD from controls was measured using the area under the curve (AUC) and likelihood ratios based on receiver operating characteristic (ROC) analyses. We found a significant reduction of SNc and LC volumes in patients, when compared to controls. ROC analysis showed better diagnostic accuracy when using SNc volume than LC volume. Significant differences between ipsilateral and contralateral SNc volumes, in relation to the more clinically affected side, were found in patients with iPD (P=0.007). Contralateral atrophy in the SNc showed the highest power to discriminate PD subjects from controls (AUC, 0.93-0.94; sensitivity, 91%-92%; specificity, 89%; positive likelihood ratio: 8.4-8.5; negative likelihood ratio: 0.09-0.1 at a single cut-off point). Interval likelihood ratios for contralateral SNc volume improved the diagnostic accuracy of volumetric measurements. SNc and LC volumetry based on NM-MRI resulting from the automated segmentation and quantification technique can yield high diagnostic accuracy for differentiating PD from health and might be an unbiased disease biomarker.Supported by the Fund for Health Research Foundation (FIS-ISCIII), Spanish Ministry of Economy and Competitiveness (reference: PI 13/02211); Spanish Ministry of Science and Innovation SAF2006-10126 (2006-2009), SAF2010-22329-C02-01 (2011-2013), and SAF2013-47939-R (to P.P.); project 061131 from the “Fundació La Marató de TV3” and by the UTE project FIMA, Spain (to P.P.). C.O.d.S. and A.M.B. were supported by Spanish Ministry of Economy and Competitiveness DPI2012-38090-C03-02 and TEC2013-48552-C2-1-R, respectively.Publicad

Alterations in the microstructure of white matter in children and adolescents with Tourette syndrome measured using tract-based spatial statistics and probabilistic tractography

Tourette syndrome (TS) is a neurodevelopmental disorder characterised by repetitive and intermittent motor and vocal tics. TS is thought to reflect fronto-striatal dysfunction and the aetiology of the disorder has been linked to widespread alterations in the functional and structural integrity of the brain. The aim of this study was to assess white matter (WM) abnormalities in a large sample of young patients with TS in comparison to a sample of matched typically developing control individuals (CS) using diffusion MRI. The study included 35 patients with TS (3 females; mean age: 14.0 ± 3.3) and 35 CS (3 females; mean age: 13.9 ± 3.3). Diffusion MRI data was analysed using tract-based spatial statistics (TBSS) and probabilistic tractography. Patients with TS demonstrated both marked and widespread decreases in axial diffusivity (AD) together with altered WM connectivity. Moreover, we showed that tic severity and the frequency of premonitory urges (PU) were associated with increased connectivity between primary motor cortex (M1) and the caudate nuclei, and increased information transfer between M1 and the insula, respectively. This is to our knowledge the first study to employ both TBSS and probabilistic tractography in a sample of young patients with TS. Our results contribute to the limited existing literature demonstrating altered connectivity in TS and confirm previous results suggesting in particular, that altered insular function contributes to increased frequency of PU

3D Printing of Bone Spurs Before Surgical Removal During Total Knee Arthroplasty

Background: In the United States, total knee arthroplasty (TKA) is the most common performed orthopedic surgery, with over 700,000 cases per year. Overall, 21-25% underwent revision due to instability. Incorrect soft tissue balancing during the procedure can lead to improper alignment, flexion, and extension. Visualization of osteophytes in a 3D manner prior to removal is difficult and poses significant risks for improper balancing on TKA. The purpose of the study is to determine whether the utilization of 3D osteophyte models is beneficial to Orthopaedic surgeons in the course of care, specifically with regard to improving outcomes, decreasing complication rates, and decreasing OR time. Methods: A pilot study will be performed pending the approval of the IRB and research proposal by the Rothman Institute. Deidentified 3D models for upcoming procedures will be printed utilizing patient CT scans prior to date of operation. The models will be provided to Orthopaedic Surgeons at the Rothman Institute prior to the procedure. Data from at least 10 cases will be collected post-operatively, in which operating surgeons will be interviewed assess beliefs on utility of models, OR times, and rates of revision. Results: Direct interviews with Orthopaedic surgeons and residents of the Rothman Institute demonstrate early interest and support of the utilization of 3D models in the OR. Lack of IRB prevents the utilization of models in the OR, but we anticipate decrease OR time and increased satisfaction by involved surgeons. Conclusions: Initial feedback from Orthopaedic surgeons suggest a space for the utility of 3D models in the OR. A significant limitation may be accessing CT images of patients and they are often not performed prior to operations. Next steps include IRB approval and finalizing a logistical blueprint for utilization for the models in the OR, specifically whether the models will be use preoperatively or perioperatively

3D Printing of Bone Spurs Before Surgical Removal

Project Background: In the US alone, total knee arthroplasty is the most common performed orthopedic surgery, with over 700,000 cases per year.1 Overall, 21-25% underwent revision due to instability.2 The stability of a TKA depends largely on soft tissue balance for proper alignment in flexion and extension. Soft tissue balancing in TKA depends on posterior femoral condylar osteophytes, which prevent full extension of the knee and increase tension posteriorly. Pre-operative soft tissue visualization is difficult and this leaves an increased chance for implant failure and revision surgery. Having a 3D model of the bone spur before and during the surgery may decrease risk of complication and enhance soft tissue modification for proper knee balancing post TKA. Proposed Methods: We will 3D print a knee via MRI or CT that has been de-identified and provided by our mentor. The orthopedic surgeon will use this print out before or during surgery to address any concerns they have during the surgery in terms of proper balancing of the soft tissue of the knee. After approximately 10 uses within the OR, we will interview the surgeons and patients for their feedback. Patients undergoing total knee arthroplasty using the 3D printed knee will be matched with historic records of those who had undergone TKA. Rates of revision, patient satisfaction, and OR time will be compared across groups using chi-square and t-tests where appropriate. Results: We anticipate reduced OR time, increased patient satisfaction and decreased rates of revision. Conclusions: Our study demonstrates an initial use for 3D models as an aid or guide for total knee arthroplasty. Using a 3D model for TKA helps the surgeon visualize osteophytes and reduces the need for revision surgery. A larger study will need to be conducted in order to test the feasibility and practicality of 3D printing for surgery

3D Printing of Knee Models to Decrease OR Time and Reduce Revisional Surgery in Total Knee Arthroplasty (TKA)

Project Background: Osteophytes are a common problem, affecting 2% of the United States population. For many elderly people, these osteophytes will cause them to seek medical attention. Due to the 2-D nature of MRIs and CT scans, it can be difficult to gain a complete understanding of the complicated soft tissue structures surrounding the joint when performing a Total Knee Arthroplasty(TKA). Without proper removal of osteophytes and correct soft tissue balancing, there is an increased rate of revisional surgery. By utilizing a 3-D model preoperatively and within the OR, surgeons can visualize various aspects of the knee to determine what may be contributing to a soft tissue imbalance. Proposed Methods: We plan to conduct a prospective cohort study at the Rothman Institute. We will use CT images to create 3-D printed models of knees complicated with osteophytes. The surgeon will have the model to reference both preoperatively and during the surgery. We will measure the effectiveness of model by collecting data on the total procedural time, the rate of revisional surgery within the next year, and through feedback from the surgeons. Results: Although we do not currently have any results, we anticipate approval for our project shortly. We hope to have data collected within the next few months supporting our hypothesis that 3-D models will decrease both OR time and revisional surgeries. Conclusions: While the literature shows that these 3-D models may help with OR time, we have been unable to verify this yet. Additionally, revisional surgery can happen months later, so this data may be more difficult to collect in our time frame. After the pilot study has been completed, if we have promising results we hope to expand the project to include other types of surgeries affected by soft tissue balancing

Progressive Resistance Exercise and Parkinson's Disease: A Review of Potential Mechanisms

This paper reviews the therapeutically beneficial effects of progressive resistance exercise (PRE) on Parkinson's disease (PD). First, this paper discusses the rationale for PRE in PD. Within the first section, the review discusses the central mechanisms that underlie bradykinesia and muscle weakness, highlights findings related to the central changes that accompany PRE in healthy individuals, and extends these findings to individuals with PD. It then illustrates the hypothesized positive effects of PRE on nigro-striatal-thalamo-cortical activation and connectivity. Second, it reviews recent findings of the use of PRE in individuals with PD. Finally, knowledge gaps of using PRE on individuals with PD are discussed along with suggestions for future research

Morphometric and gene expression analyses of stromal expansion during development of the bovine fetal ovary

During ovarian development stroma from the mesonephros penetrates and expands into the ovarian primordium and thus appears to be involved, at least physically, in the formation of ovigerous cords, follicles and surface epithelium. Cortical stromal development during gestation in bovine fetal ovaries (n = 27) was characterised by immunohistochemistry and by mRNA analyses. Stroma was identified by immunostaining of stromal matrix collagen type I and proliferating cells were identified by Ki67 expression. The cortical and medullar volume expanded across gestation, with the rate of cortical expansion slowing over time. During gestation, the proportion of stroma in the cortex and total volume in the cortex significantly increased (P  0.05). The expression levels of 12 genes out of 18 examined, including osteoglycin (OGN) and lumican (LUM), were significantly increased later in development (P < 0.05) and the expression of many genes was positively correlated with other genes and with gestational age. Thus, the rate of cortical stromal expansion peaked in early gestation due to cell proliferation, whilst late in development expression of extracellular matrix genes increased.M.D. Hartanti, A K. Hummitzsch, H.F. Irving-Rodgers, W.M. Bonner, K.J. Copping, R.A. Anderson, I.C. McMillen, V.E.A. Perry and R.J. Rodger

Human-Mediated Emergence as a Weed and Invasive Radiation in the Wild of the CD Genome Allotetraploid Rice Species (Oryza, Poaceae) in the Neotropics

BACKGROUND: The genus Oryza is being used as a model in plant genomic studies although there are several issues still to be resolved regarding the spatio-temporal evolution of this ancient genus. Particularly contentious is whether undated transoceanic natural dispersal or recent human interference has been the principal agent determining its present distribution and differentiation. In this context, we studied the origin and distribution history of the allotetraploid CD rice genome. It is endemic to the Neotropics but the genus is thought to have originated in the Paleotropics, and there is relatively little genetic divergence between some orthologous sequences of the C genome component and their Old World counterparts. METHODOLOGY/PRINCIPAL FINDINGS: Because of its allotetraploidy, there are several potential pitfalls in trying to date the formation of the CD genome using molecular data and this could lead to erroneous estimates. Therefore, we rather chose to rely on historical evidence to determine whether or not the CD genome was present in the Neotropics before the arrival of Columbus. We searched early collections of herbarium specimens and studied the reports of explorers of the tropical Americas for references to rice. In spite of numerous collectors traveling inland and collecting Oryza, plants determined as CD genome species were not observed away from cultivated rice fields until 1869. Various arguments suggest that they only consisted of weedy forms until that time. CONCLUSIONS/SIGNIFICANCE: The spatio-temporal distribution of herbarium collections fits a simple biogeographical scenario for the emergence in cultivated rice fields followed by radiation in the wild of the CD genome in the Neotropics during the last four centuries. This probably occurred from species introduced to the Americas by humans and we found no evidence that the CD genome pre-existed in the Old World. We therefore propose a new evolutionary hypothesis for such a recent origin of the CD genome. Moreover, we exemplify how an historical approach can provide potentially important information and help to disentangle the timing of evolutionary events in the history of the Oryza genomes