# Biomechanical Markers of PTOA after ACL Reconstruction and Meniscal Resection

> **NIH NIH R21** · UNIVERSITY OF VERMONT & ST AGRIC COLLEGE · 2021 · $261,884

## Abstract

Project Summary
An estimated 120,000 anterior cruciate ligament (ACL) tears are repaired surgically on an annual basis in the
United States. Surgical repair stabilizes the ACL-deficient knee, but a growing body of evidence suggests that
surgery does not alter the progression to early-onset osteoarthritis, known as post-traumatic osteoarthritis
(PTOA). Patients who undergo anterior cruciate ligament reconstruction (ACLR) are more likely to get PTOA,
especially those who sustained a meniscal injury at the same time as their ACL tear. Meniscal resection and
removal can have disastrous consequences for patients’ long-term knee joint health. Approximately 21%-48%
of patients who had all or part of their meniscus removed during ACLR go on to develop PTOA. Effective
treatments for stopping PTOA after meniscal resection have not been conceived because the reasons why the
disease develops are not well understood. The theorized mechanism speculates that, despite restoring overall
stability, surgical reconstruction of the ACL and resection of the meniscus alter the biomechanics of the knee
joint: changing the way cartilage responds to load, shifting the point of contact between tibial and femoral
cartilage, increasing the speed at which the tibia and femur bones move past one another during physical
activities, and decreasing in the distance between the bones. In turn, sections of cartilage experience
unaccustomed loads, and irreversible damage results. Central to this theory is the notion that the bones
articulate differently compared to non-surgical knees. While this argument makes sense conceptually, it’s
possible that the bones do not articulate differently during physical activity, but instead articular cartilage
damage at the time of injury starts a sequence of catabolic events culminating in loss of joint space width—the
hallmark outcome of osteoarthritis. The study team members possess the necessary skills, expertise and
equipment to support or refute the aforementioned hypothetical framework through direct measurements of
biomechanical factors. Specifically, high-speed dual fluoroscopy, an X-ray technique, will measure bone
motion with submillimeter and subdegree bias and precision; quantitative magnetic resonance imaging (qMRI)
will assess cartilage composition; traditional MRI will quantify three-dimensional cartilage structure. In the
current proposal, biomechanical markers for PTOA disease onset and progression will be measured at one
and two years after surgery. This longitudinal study will address the following two aims. Aim 1: To improve
understanding of PTOA pathogenesis by performing a side-to-side comparative analysis of in-vivo knee
mechanics (tibiofemoral cartilage strain and arthrokinematics) in patients one year after ACLR+M. Aim 2: To
improve understanding of PTOA pathogenesis by performing an image-based analysis of longitudinal changes
in cartilage after ACLR+M. Completion of the aims in this proposal will generate new and impactfu...

## Key facts

- **NIH application ID:** 10156542
- **Project number:** 1R21AR077371-01A1
- **Recipient organization:** UNIVERSITY OF VERMONT & ST AGRIC COLLEGE
- **Principal Investigator:** Niccolo M Fiorentino
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $261,884
- **Award type:** 1
- **Project period:** 2021-02-08 → 2023-01-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10156542

## Citation

> US National Institutes of Health, RePORTER application 10156542, Biomechanical Markers of PTOA after ACL Reconstruction and Meniscal Resection (1R21AR077371-01A1). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10156542. Licensed CC0.

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