# Early Detection and Monitoring of Osteonecrosis of the Femoral Head

> **NIH NIH R56** · UNIVERSITY OF MINNESOTA · 2021 · $541,108

## Abstract

PROJECT SUMMARY: Osteonecrosis of the femoral head [ONFH] is a serious hip disorder affecting both
children and adults that can lead to collapse of the femoral head and osteoarthritis. ONFH is the cause for
approximately 10% of total hip replacements in the United States (25,000/year). Clinical management of ONFH
focuses on preventing femoral head collapse, but the primary treatment for ONFH, core decompression
surgery, fails to prevent disease progression in 30-50% of patients. This can be attributed in part to delayed
diagnosis and limited ability to predict clinical outcome, monitor disease progression, and evaluate response to
treatment using current clinical imaging methods (radiographs and traditional T1- and T2-weighted magnetic
resonance imaging [MRI]). Our long-term goal is to improve clinical outcomes for patients with or at risk for
ONFH by advancing imaging techniques to enable earlier detection and more precise treatment. The objective
of this R01 proposal is to characterize quantitative, non-contrast-enhanced MRI techniques to detect ischemic
injury to the femoral head, monitor disease progression, and assess treatment response. Our central
hypothesis is that quantitative MRI can detect disease earlier than traditional MRI techniques, at a potentially
reversible stage, and better predict and monitor treatment response. We will build upon our promising work
using a pig model of ischemic ONFH, which demonstrated that quantitative relaxation time mapping and
diffusion imaging techniques are very sensitive in detecting acute ischemic injury to the femoral head. In Aim 1,
we will identify the cellular changes driving the sensitivity of the quantitative MRI methods using the pig model
of ischemic ONFH. Animals will be imaged in vivo at 3T MRI, and the femoral heads will subsequently be
studied ex vivo using high-resolution 9.4T MRI and histology. In Aim 2, we will characterize the response of the
quantitative MRI methods to progression and repair of steroid-induced ONFH, which is the most common
cause of ONFH (30% of cases). For this aim, we will use a rabbit model of steroid-induced ONFH, which has a
different pathogenesis than the pig model used in Aim 1. Animals will be longitudinally imaged in vivo at 3T
MRI, and the imaging findings will be validated by ex vivo analysis of the proximal femurs using histology. In
Aim 3, we will take the first step toward clinically translating the quantitative MRI techniques by conducting an
exploratory study to detect early-stage injury and monitor response to treatment in patients with ONFH
undergoing core decompression surgery. Patients will be imaged before surgery and serially after surgery, for
up to two years, to study how the quantitative MRI measures respond in patients whose treatment fails to
prevent femoral head collapse versus patients who do not have disease progression. The contralateral femoral
head will also be evaluated for early-stage ONFH. Collectively, our project has the potentia...

## Key facts

- **NIH application ID:** 10485553
- **Project number:** 1R56AR078315-01
- **Recipient organization:** UNIVERSITY OF MINNESOTA
- **Principal Investigator:** Casey Peter Johnson
- **Activity code:** R56 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $541,108
- **Award type:** 1
- **Project period:** 2021-09-22 → 2024-01-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10485553

## Citation

> US National Institutes of Health, RePORTER application 10485553, Early Detection and Monitoring of Osteonecrosis of the Femoral Head (1R56AR078315-01). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/10485553. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*