# Early removal of the infrapatellar fat pad as a novel treatment for osteoarthritis

> **NIH NIH R21** · COLORADO STATE UNIVERSITY · 2020 · $180,621

## Abstract

PROJECT SUMMARY/ABSTRACT
This proposal was crafted to fast-track an improved understanding of the initiation and development of
osteoarthritis (OA). Specifically, this work is designed to tease out the inflammatory and biomechanical
contributions linking the infrapatellar fat pad (IFP) to knee degeneration. The central premise of this
proposal is that early removal of the IFP beneficially alters the pathogenesis of primary OA in
individuals susceptible to disease. In support of this theory, we have striking data in a rodent model that
surgical removal of the IFP coincident with the onset of OA significantly decreased the short-term (4 month)
progression of disease in the treated knee. We then demonstrated that this improvement may be related to the
formation of a thick band of fibrous connective tissue (FCT) in the space previously occupied by the IFP. We
postulate that there are two related, but potentially distinct, explanations for our findings: (1) removal of the IFP
abrogated a critical source of detrimental inflammatory mediators not supplied by the replacement FCT; and/or
(2) the development of the FCT in place of a comparatively lax IFP provided enhanced joint stability not
present in its native state. To test our conjectures, experiments (as per our preliminary studies) will be
performed in a translational guinea pig model that predictably develops primary OA with pathology identical to
humans. The objective of the current project is to determine the benefits of the FCT versus IFP in
minimizing/reducing knee OA. Our long-term goal is to identify explicit contributions of the IFP to OA so that
interventional strategies can be strategized for prevention and/or treatment. Two Subaims are proposed: (1) to
correlate the presence and severity of OA to the temporal expression and tissue distribution of inflammatory
mediators in the IFP versus the FCT; and (2) to assess the contribution of the FCT versus the IFP on joint
tissue biomechanical properties and joint biomechanics. Subaim 1 will use a combination of structural
(histology and microcomputed tomography) and molecular (transcript and protein expression) outcomes to
characterize OA and correlate it to catabolic cytokines/chemokines and adipokines. Subaim 2 will utilize cranial
drawer tests, material property tests, and computer-aided gait analysis to determine tissue behavior and joint
kinematics. This work is significant because it will make strides towards providing convincing evidence that the
resident IFP is a contributor to joint deterioration, thus filling a void in the current understanding of OA
pathogenesis. The proposed research is innovative because it will: (a) support early removal of the IFP in
specific patients with an identified predisposition for OA; (b) elucidate properties of the IFP, which have been
minimally documented in any species; and (c) discover changes in functional movement and symptom
modification related to IFP removal that would not be highlighted by focusin...

## Key facts

- **NIH application ID:** 9996486
- **Project number:** 5R21AR073972-02
- **Recipient organization:** COLORADO STATE UNIVERSITY
- **Principal Investigator:** KELLY S SANTANGELO
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $180,621
- **Award type:** 5
- **Project period:** 2019-08-15 → 2022-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9996486

## Citation

> US National Institutes of Health, RePORTER application 9996486, Early removal of the infrapatellar fat pad as a novel treatment for osteoarthritis (5R21AR073972-02). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/9996486. Licensed CC0.

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