# BIOMECHANICS OF LOCAL ARTICULAR INCONGRUITIES

> **NIH NIH R01** · UNIVERSITY OF IOWA · 1988 · $103,449

## Abstract

Despite the general belief that cartilage contact pressures are
elevated near articular surface incongruities, there are no data
which directly link the degree of geometric incongruity with the
degree of pressure elevation.  Nor are there data linking the
degree of pressure elevation with the quality of defect repair.
The governing hypothesis of our application is that the ability of
hyaline cartilage to repair and/or avoid degeneration, due to local
defect, progressively diminishes in accordance with the severity
of elevations of contacts pressure (and/or pressure gradient) near
the defect.

To date, techniques have been lacking for measuring cartilage
contact stresses at spatial resolutions appropriate for the high-
gradient regions that often surround local incongruities.  Recent
success with digital image scanning of magnified Fuji-film
recordings now makings such measurements feasible.

After briefly expanding upon our preliminary studies to further
document the reliability and precision of the new pressure
mapping technique, we first propose (specific Aim 1) to perform
in-vitro pressure mappings for three established human intra-
articular fracture models (tibial plateau, acetabulum, and ankle).
The objective of this part of the study is to show that despite
substantial differences in the amount of geometric incongruity
that can be tolerated clinically, these functions involve
approximately equivalent local pressure elevations near their
respective geometric tolerance limits.

We also propose to study the influence of local pressure
aberrations on the quality of cartilage repair, using a canine
model with full-thickness circular defects in the femoral condyle.
We will perform in-vitro pressure mapping studies (Aim 2) to
determine the specific defect sizes necessary to achieve three
specific levels of pressure elevation at the defect rim.  We then
will conduct a prospective in-vivo study (Aim 3), in which each of
our three graded local pressure elevations is created in a group of
eight dogs, all of which will be allowed to heal their defects over
a ten-month period.  The success of defect repair in these 24 dogs
will be assessed by numerical histomorphic grading, supplemented
by indentation testing.

## Key facts

- **NIH application ID:** 3158958
- **Project number:** 1R01AR038916-01A1
- **Recipient organization:** UNIVERSITY OF IOWA
- **SAM.gov UEI:** Z1H9VJS8NG16
- **Principal Investigator:** THOMAS DUDLEY BROWN
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1988
- **Award amount:** $103,449
- **Award type:** 1
- **Project period:** 1988-08-01 → 1991-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3158958

## Citation

> US National Institutes of Health, RePORTER application 3158958, BIOMECHANICS OF LOCAL ARTICULAR INCONGRUITIES (1R01AR038916-01A1). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3158958. Licensed CC0.

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