# IN VIVO MEASUREMENT OF ANTERIOR CRUCIATE LIGAMENT STRAIN

> **NIH NIH R01** · UNIVERSITY OF VERMONT & ST AGRIC COLLEGE · 1992 · $176,144

## Abstract

Injuries to the anterior cruciate ligament (ACL) are occurring at epidermic
proportions from athletic endeavors.  The most common surgical treatment of
an ACL deficiency is ACL reconstruction using autogenous grafts.  Although
reconstructive techniques are commonly employed, graft implantation
variables and post-operative rehabilitation programs remain controversial
and unknown.  Since the goal of an ACL reconstruction is to restore the
normal biomechanics of the knee, it is important to understand the strain
behavior of the normal ACL.  We propose to continue our in vivo
investigation of strain in the normal ACL focusing on commonly prescribed
rehabilitation activities (Group #1).  In addition, we would like to
measure the stress and strain in two commonly used autografts (patellar
tendon and hamstrings tendon) during ACL reconstructive surgery (Group #2).
The group #1 volunteers are patients who are candidates for arthroscopic
meniscectomy.  After the routine surgical procedure, a Hall effect strain
transducer (HEST) will be implanted into the anteromedial band of the
normal ACL.  Patients will then perform different rehabilitation
activities; isotonic contractions, isometric contractions, squatting,
biking, and stair climbing.  Strain will be determined as a function of
flexion angle and compared with analytical predictions of the shear forces
at the knee during these activities.  The group #2 patients are volunteers
who are candidates for arthroscopic reconstruction of the knee.  Graft type
will be selected randomly.  During graft implantation, a tension measuring
device (tensiometer) will be used to document graft placement and set
initial graft tension.  A modified HEST which incorporates a pressure
sensor, calibrated to tensile stress, will be attached to the graft.
Stress, strain and laxity measurements will be performed to determine the
initial tension required to restore normal knee stability.  The graft will
then be fixed and the surgery completed.  The stress-strain biomechanics
will then be measured during anteroposterior shear loading and passive
flexion-extension of the knee.  Stress-strain comparisons will be made
between the two graft types and the normal ACL.  This will be the first
study to determine if the reconstructed ACL restores normal knee
biomechanics.  By using these experimental methods, the strain biomechanics
of the normal ACL will be characterized, the effects of initial graft
tension and graft replacement will be evaluated, and the stress-strain
biomechanics of different grafts will be determined.  The results of the
proposed study will assist the clinician in determining the best surgical
treatment and post-operative rehabilitation program for patients undergoing
reconstructive surgery.  These variables determine the long-term success of
the grafts and may reduce cartilage degeneration which has been shown to
persists after ACL reconstruction.

## Key facts

- **NIH application ID:** 3159191
- **Project number:** 2R01AR039213-05
- **Recipient organization:** UNIVERSITY OF VERMONT & ST AGRIC COLLEGE
- **SAM.gov UEI:** Z94KLERAG5V9
- **Principal Investigator:** MALCOLM H POPE
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1992
- **Award amount:** $176,144
- **Award type:** 2
- **Project period:** 1988-02-01 → 1996-01-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3159191

## Citation

> US National Institutes of Health, RePORTER application 3159191, IN VIVO MEASUREMENT OF ANTERIOR CRUCIATE LIGAMENT STRAIN (2R01AR039213-05). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3159191. Licensed CC0.

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