# MECHANICAL BEHAVIOR OF CARTILAGE TO DYNAMIC LOADS

> **NIH NIH R01** · HOSPITAL FOR SPECIAL SURGERY · 1987 · $143,482

## Abstract

This application proposes to study the mechanical behavior of normal
articular cartilage to different dynamic load conditions and to determine
any changes that occur after the tissue has been physically changed.
Recent evidence suggests that ultrastructural alterations in the dense
collagenous surface layer causes mechanical softening of the tissue due to
increased fluid transport across the articular surface.  This could lead to
proteoglycan depletion and further tissue softening.  The specific aim of
this proposal is to test this hypothesis by studying the mechanical
behavior of the tissue to different mechanical factors, including the type,
magnitude and frequency of load application (dead weight creep, cyclic
creep, unloaded recovery and cyclic recovery), and different morphological
factors, including surface removal and proteoglycan removal.

One-dimensional confined compression tests will be performed on whole plugs
of adult bovine articular cartilage.  A specific sequence of mechanical
tests will be performed on each intact specimen and repeated after tissue
alteration.  The biphasic creep model of Mow and coworkers will be used
(when applicable) to determine the intrinsic aggregate elastic modulus and
average permeability for each specimen and test.  In addition, the amount
of fluid exuded and imbibed during each phase of the cyclic experiments
will be determined as a function of loading time.  After each test is
completed the plug will be serially sliced on a microtome and the aggregate
modulus, permeability and fluid content determined as a function of depth.
A layered mathematical model and a multivariate regression model will be
developed to predict overall tissue behavior.

The results from this study will yield vital information concerning the
dynamic mechanical behavior of healthy (normal) articular cartilage, the
factors controlling this behavior and how their interaction contributes in
producing an altered mechanical behavior in pathological tissue.  Since the
mechanical and morphological configurations proposed in this research
application are similar to those experienced and exhibited in diarthrodial
joints, this information will provide useful insight into the physiology of
the degenerative joint disease process.

## Key facts

- **NIH application ID:** 3156979
- **Project number:** 5R01AR034870-03
- **Recipient organization:** HOSPITAL FOR SPECIAL SURGERY
- **Principal Investigator:** PETER A TORZILLI
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1987
- **Award amount:** $143,482
- **Award type:** 5
- **Project period:** 1985-09-20 → 1988-12-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3156979

## Citation

> US National Institutes of Health, RePORTER application 3156979, MECHANICAL BEHAVIOR OF CARTILAGE TO DYNAMIC LOADS (5R01AR034870-03). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3156979. Licensed CC0.

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