# SURFACE FAILURE IN UHMWPE JOINT COMPONENTS

> **NIH NIH R01** · HOSPITAL FOR SPECIAL SURGERY · 1992 · $162,936

## Abstract

The continuing purpose of this research is to establish failure criteria
for the articulating surfaces of polyethylene (UHMWPE) components used in
total joint replacement systems and to apply these criteria to optimize
implant design.  Observations of retrieved components revealed distinct
damage modes apparently caused by fatigue fracture mechanisms.  To date,
the design decisions for UHMWPE components have been based on the
assumption that the particular stresses and stress distribution (namely,
the maximum shear stress and the range of maximum principal stress)
discovered in our analytical models are indeed those responsible for
causing these damage modes.  To verify the direct relationship between
specific stress states and the production of surface damage, the conditions
under which growing fatigue cracks in UHMWPE will change direction must be
established which will cause small defects on and below the surface to
propagate and create the observed damage modes.  The approach is based upon
principles of fracture mechanics.  Fatigue crack propagation experiments
will be conducted on standardized UHMWPE specimens to determine the
relationship between the cyclic stress intensity and the crack growth rate
and direction.  Test variables will be the angle of inclination of the
crack relative to the direction of the applied loading and the state of
preconditioning of the material under uniaxial cyclic loading prior to
testing.  Tests will be conducted on specimens made from both conventional
UHMWPE and enhanced forms of UHMWPE.  The empirical relationship will be
used as input to a numerical method for predicting fatigue crack
propagation to demonstrate that the method correctly predicts fatigue crack
propagation in UHMWPE.  This will be accomplished by modelling the test
specimen geometry and loading conditions from the fatigue tests and
comparing the computed crack propagation rates and directions with those
measured experimentally.  If fatigue crack propagation in UHMWPE cannot be
described on the basis of linear elastic fracture mechanics, the analytical
method will be modified to include non-linear material behavior around the
crack tip.

## Key facts

- **NIH application ID:** 3158926
- **Project number:** 5R01AR038905-06
- **Recipient organization:** HOSPITAL FOR SPECIAL SURGERY
- **Principal Investigator:** TIMOTHY M. WRIGHT
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1992
- **Award amount:** $162,936
- **Award type:** 5
- **Project period:** 1987-09-01 → 1993-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3158926

## Citation

> US National Institutes of Health, RePORTER application 3158926, SURFACE FAILURE IN UHMWPE JOINT COMPONENTS (5R01AR038905-06). Retrieved via MORVS 2026-10-24 from https://api.morvs.ai/grant/nih/3158926. Licensed CC0.

---

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