# ALLOGRAFT BIOMECHANICS: DOSE RESPONSE FOR IRRADIATION

> **NIH NIH R01** · UNIVERSITY OF CINCINNATI · 1993 · $254,063

## Abstract

This renewal is designed to test our governing hypothesis that gamma
irradiation produces dose-dependent reductions in ligament allograft
biomechanics, but that these reductions are more significant before surgery
than 6 months after surgery.  While allografts have certain advantages,
surgeons remain concerned about how effectively methods like gamma
irradiation sterlize the graft against viral contaminants such as HIV-1 and
hepatitis.  Several authors have estimated, for example, that dosage levels
of 4 MRad or more might be needed to satisfactorily inactivate the HIV-1
virus in these grafts.  Unfortunately, such high levels of gamma
irradiation can compromise initial biomechanical properties of frozen
allograft tissues and may have deleterious effects on the structures after
surgery as well.  Furthermore the treatment may also reduce the
concentration of permanent, covalent hydroxypyridinium crosslinks [HP]
which likely transmit tissue forces.  In this grant, we test four
hypotheses related to these potential structural and material alterations
using goat patellar tendon-bone (PTB) allografts.

HYPOTHESIS 1.  Goat PTB allografts undergo significant, dose-dependent
reductions in initial mechanical and material properties up to 8 Mirads of
gamma irradiation.  The reductions in material properties are associated
with decreases in [HP].

HYPOTHESIS 2.  Increasing gamma irradiation level significantly increases
the knee's anterior motion limits by decreasing graft stiffness immediately
after surgery.  These changes are caused, in part, by unfolding of the
irradiated tissue substance and by increased motion at the graft's fixation
sites.

HYPOTHESIS 3.  Four megarads of gamma irradiation produces no significant
reductions in ACL allograft biomechanics 6 months postop.

These studies should permit the mechanical dose-dependent curve for
irradiation of ligament allograft tissues to be established and forum the
basis for immunological, ultrastructural, and biochemical studies of
grafted knees at various time intervals post surgery.

## Key facts

- **NIH application ID:** 3158746
- **Project number:** 5R01AR038719-05
- **Recipient organization:** UNIVERSITY OF CINCINNATI
- **SAM.gov UEI:** DZ4YCZ3QSPR5
- **Principal Investigator:** DAVID L BUTLER
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1993
- **Award amount:** $254,063
- **Award type:** 5
- **Project period:** 1989-05-20 → 1995-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3158746

## Citation

> US National Institutes of Health, RePORTER application 3158746, ALLOGRAFT BIOMECHANICS: DOSE RESPONSE FOR IRRADIATION (5R01AR038719-05). Retrieved via MORVS 2026-10-24 from https://api.morvs.ai/grant/nih/3158746. Licensed CC0.

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