# TOTAL SURGICAL REPLACEMENT OF THE HUMAN HIP JOINT

> **NIH NIH R01** · RUSH UNIVERSITY MEDICAL CENTER · 1993 · $204,569

## Abstract

This proposal is concerned with certain design variables affecting bone
remodeling following primary cementless total hip arthroplasty.  The use of
cementless techniques in total hip arthroplasty heightens concern with
stress-induced bone remodeling, fixation, and long term biocompatibility.
Proximal cortical resorption of varying severity has been reported with a
variety of cementless femoral stems, made from CoCr or from Ti6Al4V.
Cortical resorption can lead to failure of the host bone, failure of the
prosthetic device, and presents enormous problems for further
reconstruction.  The purpose of this proposal is to gain a better
understanding of the relationship between stress-induced bony changes in
the proximal femur following cementless total hip arthroplasty (THA) and
implant design.  We propose to investigate this relationship by studying
bone remodeling as a function of cross-sectional stiffness related to stem
modulus and stem geometry.

Two hypotheses will be tested.  (1) The elastic modulus and geometry of the
femoral stem can be modulated to minimize long-term femoral remodeling
changes.  (2) The relationship between prosthetic-induced changes in the
femur's mechanical environment and adaptive changes in cortical morphology
is non-linear.  Specifically, we plan to evaluate the effect of large
variations in stem (i) elastic modulus and (ii) geometry (in this study,
the location of the implant's centroids and bending axes relative to those
of the femur) on changes in bone morphology in a canine model, while
accounting for individual variation in the position of the stem within the
femoral canal.  These data will be used to determine if the relationship
between the prosthesis-induced changes in femoral stress/strain and the
changes in bone morphology is linear or non-linear.

Thus, two key clinical questions are (i) how does bone remodeling vary over
the range of relative stem stiffness of potential clinical feasibility and
(ii) does stem geometry influence proximal bone loss following cementless
THA?  To address these issues, a canine primary THA model will be used in
which stem stiffness will be varied over a 10-fold range.  In a separate
experiment, stem shape will be varied.  The experimental endpoints will be
the structural responses to the treatments (e.g., change in cortical area,
thickness and porosity and medullary bone density).  The data will be
analyzed to test for the effects of the design variables on the remodeling
response and to determine mechanistically how the prosthesis-induced
changes in the mechanical environment of the femur correspond to the bony
adaptive response.  The goal of these experiments is to derive principles
which will have clinical implications.

## Key facts

- **NIH application ID:** 3154911
- **Project number:** 5R01AR016485-20
- **Recipient organization:** RUSH UNIVERSITY MEDICAL CENTER
- **SAM.gov UEI:** C155UU2TXCP3
- **Principal Investigator:** JORGE O GALANTE
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1993
- **Award amount:** $204,569
- **Award type:** 5
- **Project period:** 1979-05-01 → 1996-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3154911

## Citation

> US National Institutes of Health, RePORTER application 3154911, TOTAL SURGICAL REPLACEMENT OF THE HUMAN HIP JOINT (5R01AR016485-20). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3154911. Licensed CC0.

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