# Simultaneous Imaging of Tissue Biochemistry and Metabolism associated with Biomechanics in Patella Femoral Joint Osteoarthritis

> **NIH NIH R01** · UNIVERSITY OF CALIFORNIA, SAN FRANCISCO · 2022 · $707,133

## Abstract

ABSTRACT
Knee osteoarthritis (OA) is the leading cause of disability in adults, with a substantial fiscal impact. Furthermore,
patellofemoral joint OA is a major source of pain and dysfunction. A hypothetical model for OA pathogenesis has
been proposed whereby repetitive joint loading causes an initial increase in bone remodeling, which is associated
with increased vascular invasion of the deep layers of cartilage. Emerging Proton Emission Tomography and
Magnetic Resonance Imaging simultaneous systems (PET-MRI) offer an exciting new modality to simultaneously
acquire numerous functional measures as well as high-resolution morphology to study this complex
phenomenon. Joint loading is integral to OA progression yet currently, very little is known regarding the
biomechanical factors associated with PFJOA progression. Therefore, our overall goal is to: (i) identify cross-
sectional and longitudinal local patterns of cartilage and bone interactions unique to PFJOA, and (ii) determine
the mediation effects of gait biomechanics and bone morphology on PFJOA progression. We will conduct a
longitudinal cohort study investigating 100 people with isolated PFJOA, followed for 2 time points. Simultaneous
PET-MRI and gait biomechanics will be collected for all subjects at baseline and 2-year follow-up. Aim 1: To
study the cross-sectional relationships between bone and cartilage imaging biomarkers and to
investigate how the patterns of interactions are mediated by gait biomechanics and bone morphology.
Hypothesis 1: Elevated SUV in subjects with PFJOA will be colocalized with prolongation of T1ρ and T2 relaxation
times. Complex bone-cartilage interactions mediated by change in loading as a result of abnormal gait
biomechanics and bone morphology will show non-colocalized associations between bone and cartilage.
Aim 2: To study the longitudinal relationships between bone and cartilage imaging biomarkers and to
investigate how the patterns of interactions are mediated by gait biomechanics and morphology:
Hypothesis 2: Early changes in bone metabolic activity (SUV) are a precursor to cartilage compositional changes
(T1ρ and T2). Subjects with specific abnormal gait biomechanics and bone shape features will show accelerated
compositional changes. Aim 3: To determine the ability of bone-cartilage interactions to predict
longitudinal trajectories of structural and symptomatic PFJOA progression. Hypothesis 3: Both colocalized
and non-colocalized bone-cartilage interaction patterns mediated by joint biomechanics and bone shape will be
significant predictors of structural and symptomatic PJOA progression. Cross-sectional and longitudinal
evaluations of cartilage composition and bone remodeling mediated by gait biomechanics as likely contributors
to PFJOA progression, are vital to determine the individual and combined effects of the disease.

## Key facts

- **NIH application ID:** 10443016
- **Project number:** 1R01AR079647-01A1
- **Recipient organization:** UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
- **Principal Investigator:** Sharmila Majumdar
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $707,133
- **Award type:** 1
- **Project period:** 2022-03-15 → 2027-02-28

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10443016

## Citation

> US National Institutes of Health, RePORTER application 10443016, Simultaneous Imaging of Tissue Biochemistry and Metabolism associated with Biomechanics in Patella Femoral Joint Osteoarthritis (1R01AR079647-01A1). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10443016. Licensed CC0.

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