# Knee Arthrosis after ACL Reconstruction: A Long-term Cohort Study with Matched Controls

> **NIH NIH R01** · RHODE ISLAND HOSPITAL · 2020 · $318,780

## Abstract

PROJECT SUMMARY/ABSTRACT
The objectives of this longitudinal outcome study are to evaluate the progression of post-traumatic
osteoarthritis (PTOA) following surgical reconstruction of the anterior cruciate ligament (ACL) in male and
female patients 15 years after surgery, and to determine if the initial tension applied to the graft at the time of
surgery and if sex influences long-term outcomes related to arthrosis. Disruption of the ACL is a common injury
that usually requires surgical reconstruction to restore function and prevent PTOA. The “initial graft tension”
applied at the time of surgery modulates joint contact mechanics, which in turn, may promote PTOA. However,
the effects of low- and high-initial graft tensions on PTOA development are unknown. It is also known that sex
is a risk factor for ACL injury and subsequent graft failure. Thus, it is likely that females are at increased risk for
PTOA following surgery. The proposed work will leverage a cohort of ACL reconstructed patients that were
previously enrolled in a randomized control trial to study the effects of initial graft tension. Patients, who were
candidates for ACL reconstruction with an autograft, were randomized into one of two treatment groups: 1)
initial graft tension set such that the anterior-posterior (AP) laxity of the reconstructed knee was equal to that of
the contralateral normal knee (the “low-tension” treatment; n=46), and 2) initial graft tension set to reduce AP
knee laxity by 2 mm relative to that of the contralateral knee (the “high-tension” treatment; n=44). An additional
group of subjects without evidence of knee injury (n=60) was recruited to serve as an uninjured control. In the
previous funding cycle, we found differences in several outcome measures starting to emerge between the two
initial graft tension groups at 7-year follow-up that were not present at 3-year follow-up. In this proposal, the
follow-up of this patient cohort and its matched control group will be extended to 15 years, a time point that will
enable us to clearly identify those patients who present with both radiographic and symptomatic PTOA. The
first hypothesis is that tibiofemoral joint space width of the reconstructed knees of the “high-tension” cohort will
be equal to that of the control group, while that of the “low-tension” cohort will be less than that of the control
group 15 years after ACL reconstruction. The second hypothesis is that decreases in medial joint space width
after ACL reconstruction will be greater in female patients compared to male patients. The comprehensive set
of outcomes to be used include imaging modalities to monitor PTOA development and other validated patient-
reported, clinical, and functional measures. X-ray measures of joint space width are considered the only
validated indicator of PTOA progression for clinical trials of the knee, and will serve as the primary outcome
measure for the proposed study. Radiographic assessment of joint health (OARSI score)...

## Key facts

- **NIH application ID:** 9928008
- **Project number:** 5R01AR074973-02
- **Recipient organization:** RHODE ISLAND HOSPITAL
- **Principal Investigator:** Braden C Fleming
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $318,780
- **Award type:** 5
- **Project period:** 2019-05-10 → 2023-04-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9928008

## Citation

> US National Institutes of Health, RePORTER application 9928008, Knee Arthrosis after ACL Reconstruction: A Long-term Cohort Study with Matched Controls (5R01AR074973-02). Retrieved via AI Analytics 2026-06-11 from https://api.ai-analytics.org/grant/nih/9928008. Licensed CC0.

---

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