A numerical investigation of the infrapatellar fat pad

Abstract

<jats:p> The infrapatellar fat pad is an adipose tissue in the knee that facilitates the distribution of synovial fluid and absorbs impulsive actions generated through the joint. The correlation between morphological configuration and mechanical properties is analyzed by a computational approach. The microscopic anatomy of the infrapatellar fat pad is studied aiming to measure the dimension of adipose lobules and the thickness of connective septa. Results from histomorphometric investigations show that the infrapatellar fat pad is an inhomogeneous tissue, constituted by large lobules in the superficial part and smaller lobules in the deepest one. Finite element models of the infrapatellar fat pad are developed. The first model considers the inhomogeneous conformation of the infrapatellar fat pad, composed of micro- and macro-chambers, while the second model considers a homogeneous distribution of adipose lobules with similar dimensions. Computational analyses are performed considering the static standing configuration and the passive flexion–extension movement. The computational results allow us to identify the different stress and strain fields within the tissue and to appreciate the variation of the mechanical performance of the overall system considering the distribution of adipose lobules. Results show that the distribution of adipose lobules in macro- and micro-chambers allows major deformation of the infrapatellar fat pad, decreasing the stress inside the tissues. </jats:p>

Age-Dependent Remodeling in Infrapatellar Fat Pad Adipocytes and Extracellular Matrix: A Comparative Study

“…These data are in accordance with previous findings by Macchi et al ( 8 ) where a reduction in elastic fibers was ascribed to old donors age. A focus on the dynamic role of the IFP in knee kinematics is appropriate to understand the significance of these data; IFP deforms considerably in knee flexo-extension, as previously assessed by ultrasound analysis ( 22 ) and by data on finite element analysis ( 16 , 53 , 54 ). Thus, the higher elastic fibers content in ACL-patients may likely represent the resulting expression of higher dumping requirements due to more repetitive and intensive solicitation in young-age; a sort of non-pathogenic adaptive mechanism to loading, like for collagen III.…”

Increased signal intensity, not volume variation of infrapatellar fat pad in knee osteoarthritis: A cross-sectional study based on high-resolution magnetic resonance imaging

“…Recently, the function of IPFP in OA is known as structural-related and metabolism-related. [6][7][8][9][10] The main structural-related functions of the IPFP include the distribution of mechanical load, 11 filling the extra space of joints, limiting overactivity of knees, 12 stabling the patella, 13 and promoting synovial fluid distribution. 14 Meanwhile, metabolism-related functions of IPFP include the releasing of paracrine inflammatory mediators, which reach the articular cartilage and aggravate cartilage degeneration, 15,16 and secretion of proteins by mesenchymal stem cells from IPFP to lubricate and protect knees.…”

Difference in Movement between Superficial and Deep Parts of the Infrapatellar Fat Pad during Knee Extension

“…The superficial and deep parts of the IFP have different morphological and functional characteristics [7,9], and the functional and morphological characteristics of both need to be evaluated separately when considering the problems that arise in the IFP.…”