# QUANTIFICATION OF BONE RESPONSE TO POROUS FEMORAL STEMS

> **NIH NIH R01** · UNIVERSITY OF CALIFORNIA LOS ANGELES · 1987 · $192,041

## Abstract

This study is being undertaken in response to the current wave of
worldwide enthusiasm for using porous coated implants.  This
enthusiasm is growing despite the fact that very little
fundamental information is available on the actual process of
biological ingrowth.  This study will use two configurations of
porous coating on cylindrical femoral total hip replacements in a
canine model.  The overall goals of this project are to: a)
determine the percent, extent, and viability of bone ingrowth into
the porous regions of the implant, b) determine the mechanical
properties of the bone-prosthesis interface and c) to relate the
density changes in the bone to the changes in stress computed
from finite element models of the canine femur.

Specially bred dogs (black labrador) will receive bilateral porous
acetabular and femoral components.  These animals will be
followed for 6, 12 and 18 months.  Four animals will be involved in
each of the followup periods.  Each animal will have one fully
coated femoral prosthesis (100%) in one hip and a proximally
coated device (50%) in the contralateral hip an conjunction with a
chamfered cylinder acetabular component.  After sacrifice push
out tests will be performed on the femoral specimens at
predetermined levels to determine the shear stiffness and
strength at the interface.  Image processing techniques will be
used to quantify the density changes, cortical dimension
alternations, and the amount of bone present within the porous
layer at the time of sacrifice.  Thin sections above and below the
mechanical test section will provide the best representation of
the material which is present in these interfaces.  Finite Element
Models will be constructed to determine the state of stress in the
bone with and without implants.  Microradiographs and calcified
tissue histology will be used to quantify the bone ingrowth
response.

The information obtained from this study will provide
fundamental insight into the factors affecting the remodeling
response to porous implants in a full weightbearing situation.  The
information obtained will be quantitative rather than the
qualitative assessments that have been reported previously.

## Key facts

- **NIH application ID:** 3157952
- **Project number:** 1R01AR037103-01A1
- **Recipient organization:** UNIVERSITY OF CALIFORNIA LOS ANGELES
- **SAM.gov UEI:** RN64EPNH8JC6
- **Principal Investigator:** HARLAN C AMSTUTZ
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1987
- **Award amount:** $192,041
- **Award type:** 1
- **Project period:** 1987-08-01 → 1990-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3157952

## Citation

> US National Institutes of Health, RePORTER application 3157952, QUANTIFICATION OF BONE RESPONSE TO POROUS FEMORAL STEMS (1R01AR037103-01A1). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3157952. Licensed CC0.

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