Background: Abnormal knee mechanics may contribute to early cartilage degeneration following anterior cruciate ligament reconstruction. Anterior cruciate ligament graft geometry has previously been linked to abnormal tibiofemoral kinematics, suggesting this parameter may be important in restoring normative cartilage loading. However, the relationship between graft geometry and cartilage contact is unknown.
Methods: Static MR images were collected and segmented for eighteen subjects to obtain bone, cartilage, and anterior cruciate ligament geometries for their reconstructed and contralateral knees. The footprint locations and orientation of the anterior cruciate ligament were calculated. Volumetric, dynamic MR imaging was also performed to measure tibiofemoral kinematics, cartilage contact location, and contact sliding velocity while subjects performed loaded knee flexion-extension. Multiple linear regression was used to determine the relationship between non-anatomic graft geometry and asymmetric knee mechanics.
Findings: Non-anatomic graft geometry was related to asymmetric knee mechanics, with the sagittal plane graft angle being the best predictor of asymmetry. A more vertical sagittal graft angle was associated with greater anterior tibial translation (β = 0.11mmdeg, P = 0.049, R = 0.22), internal tibial rotation (β = 0.27degdeg, P = 0.042, R = 0.23), and adduction angle (β = 0.15degdeg, P = 0.013, R = 0.44) at peak knee flexion. A non-anatomic sagittal graft orientation was also linked to asymmetries in tibial contact location and sliding velocity on the medial (β = -4.2mmsdeg, P = 0.002, R = 0.58) and lateral tibial plateaus (β = 5.7mmsdeg, P = 0.006, R = 0.54).
Interpretation: This study provides evidence that non-anatomic graft geometry is linked to asymmetric knee mechanics, suggesting that restoring native anterior cruciate ligament geometry may be important to mitigate the risk of early cartilage degeneration in these patients.
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http://dx.doi.org/10.1016/j.clinbiomech.2018.05.008 | DOI Listing |
Sci Rep
January 2025
Department of Oral and Maxillofacial Surgery, RWTH Aachen University Hospital, Pauwelsstraße 30, 52074, Aachen, Germany.
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View Article and Find Full Text PDFBioengineering (Basel)
November 2024
Singapore National Eye Center, Singapore 168751, Singapore.
We describe retrospectively the indications and outcomes of nine patients who present with varying degrees of deep posterior stromal scarring or endothelial failure following deep anterior lamellar keratoplasty (DALK). These patients underwent a surgical strategy coined Intraoperative Optical Coherence Tomography Guided Femtosecond Laser-Assisted Descemet Membrane Endothelial Keratoplasty (iFAD). This strategy can be used to address suboptimal visual outcomes following primary DALK.
View Article and Find Full Text PDFBiomaterials
December 2024
School of Biological and Health Systems Engineering, Arizona State University, 550 East Orange St., Tempe, AZ, 85281, USA. Electronic address:
Insulin-secreting allogeneic cell therapies are a promising treatment for type 1 diabetes, with the potential to eliminate hypoglycemia and long-term complications of the disease. However, chronic systemic immunosuppression is necessary to prevent graft rejection, and the acute risks associated with immunosuppression limit the number of patients who can be treated with allogeneic cell therapies. Islet macroencapsulation in a hydrogel biomaterial is one proposed method to reduce or eliminate immune suppression; however, macroencapsulation devices suffer from poor oxygen transport and limited efficacy as they scale to large animal model preclinical studies and clinical trials.
View Article and Find Full Text PDFNano Lett
January 2025
State Key Laboratory of Solidification Processing, Center of Advanced Lubrication and Seal Materials, School of Materials Science and Engineering, Northwestern Polytechnical University, Xi'an 710072, P.R. China.
Plasmonic superlattices enable the precise manipulation of electromagnetic fields at the nanoscale. However, the optical properties of static lattices are dictated by their geometry and cannot be reconfigured. Here, we present a surface-interface engineered plasmonic superlattice with confined polyelectrolyte-functionalized metal-organic framework (MOF) hybrid layers to tune plasmon resonance for ultrafast chemical sensing.
View Article and Find Full Text PDFComput Biol Med
December 2024
Faculty of Chemical & Petroleum Engineering, University of Tabriz, Tabriz, Iran. Electronic address:
Background And Objectives: The liver, a vital metabolic organ, is always susceptible to various diseases that ultimately lead to fibrosis, cirrhosis, acute liver failure, chronic liver failure, and even cancer. Optimal and specific medicine delivery in various diseases, hepatectomy, shunt placement, and other surgical interventions to reduce liver damage, transplantation, optimal preservation, and revival of the donated organ all rely on a complete understanding of perfusion and mass transfer in the liver. This study aims to simulate the computational fluid dynamics of perfusion and the temporal-spatial distribution of a medicine in a healthy liver to evaluate the hemodynamic characteristics of flow and medicine transport with the purpose of more effective liver treatment.
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