NCT03652753

Brief Summary

High energy intra-articular fractures of the distal tibia, or Pilon fracture, is a devastating injury with multiple short and long term complications. The incidence of these injuries is increasing as survival rates after motor vehicle collisions increase. The current standard of care for high energy pilon fractures is to place an external fixator at the time of injury and then provide definitive internal fixation when the soft tissue envelope allows, which is usually around 10-14 days. Arguably, the most debilitating long term complication after a high energy pilon fracture is the development of post-traumatic osteoarthritis (PTOA), which occurs in 50% or more of pilon fractures within the first 2 years of surgery. The development of osteoarthritis occurs even in the presence of adequate restoration of the tibial plafond. Part of this issue lies in the fact that ankle joint cartilage is the thinnest of any major articular joint and sustains a great deal of damage at the time of injury. This impaction and injury initiates a cascade of events that ultimately result in cartilage cell death, or chondrolysis. Chondrolysis occurs via necrosis or apoptosis. Apoptosis occurs via a caspase pathway, while necrosis of chondrocytes likely occurs secondary to overproduction of reactive oxidant species (ROS). Recent animal models have demonstrated several things: chondrocyte death is highest along fracture lines, and likely undergo necrosis as opposed to apoptosis. The reason that PTOA likely occurs in such a high percentage of pilon fractures is because of this chondrolysis, and if a method can be developed to decrease the rate of chrondrocyte necrosis, then the rate of PTOA could potentially improve and improve patient outcomes overall. A recent bovine model examined the injection of N-acetylcysteine (NAC) after an intra-articular knee fracture and its effect on the cartilage cell viability. Their study demonstrated that chondrocyte cell viability after an injection of NAC within four hours of injury decreased chondrolysis from roughly 60% to about 30% at 48hrs. The effect was greater the closer to injury the injection occurred, and was statistically significant for 2 weeks. This indicates that free radical scavengers can potentially improve cartilage cell viability and help prevent the development of PTOA. No studies have been published on humans regarding injection of NAC after a fracture. However, a recent article examined the injection of NAC into osteoarthritic knees and found that it was effective in lowering certain cartilage degradation markers and was comparable to hyaluronic acid for both pain and function. NAC has been proven safe for both intra-articular injections and systemic injections in humans. Our study will focus on the improvement of cartilage cell viability with an injection of NAC. Our hypothesis is that the NAC intra-articular injection will increase the percentage of viable cartilage cell after sustaining a pilon fracture, when compared to a placebo injection of saline. The goal of this study is to examine the effects of an intra-articular injection of the amino acid NAC on cartilage cells after an intra-articular fracture of the ankle joint. The long-term clinical goal of this research is to reduce the incidence of post-traumatic osteoarthritis in the ankle joint after fracture.

Trial Health

77
On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
30

participants targeted

Target at below P25 for phase_4

Timeline
7mo left

Started Jan 2019

Longer than P75 for phase_4

Geographic Reach
1 country

1 active site

Status
recruiting

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

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Study Timeline

Key milestones and dates

Study Progress93%
Jan 2019Dec 2026

First Submitted

Initial submission to the registry

August 28, 2018

Completed
1 day until next milestone

First Posted

Study publicly available on registry

August 29, 2018

Completed
4 months until next milestone

Study Start

First participant enrolled

January 1, 2019

Completed
7.9 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

December 1, 2026

Expected
Same day until next milestone

Study Completion

Last participant's last visit for all outcomes

December 1, 2026

Last Updated

April 28, 2026

Status Verified

April 1, 2026

Enrollment Period

7.9 years

First QC Date

August 28, 2018

Last Update Submit

April 23, 2026

Conditions

Outcome Measures

Primary Outcomes (1)

  • Cartilage Cell Viability

    During the definitive surgery we will take a cartilage biopsy and analyze for cell viability.

    At time of definitive surgery

Study Arms (2)

N-acetylcysteine (NAC)

EXPERIMENTAL

Injection of N-acetylcysteine at the time of external fixation

Drug: N-acetylcysteine

Saline

PLACEBO COMPARATOR

Injection of saline at the time of external fixation

Drug: Saline

Interventions

4 mL of a 20% solution of NAC will be injected into the ankle of patients with pilon fractures at the time of their external fixator surgery

N-acetylcysteine (NAC)
SalineDRUG

4 mL of a 20% solution of saline will be injected into the ankle of patients with pilon fractures at the time of their external fixator surgery

Saline

Eligibility Criteria

Age18 Years+
Sexall
Healthy VolunteersNo
Age GroupsAdult (18-64), Older Adult (65+)

You may qualify if:

  • Closed high energy pilon fracture requiring a staged procedure

You may not qualify if:

  • Younger than 18
  • Open fracture
  • Intra-articular injury not requiring a staged procedure
  • Allergy to NAC
  • Wounds preventing safe intra-articular injection
  • Unwilling to participate in the study
  • Pregnancy

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

University of Missouri Health System

Columbia, Missouri, 65212, United States

RECRUITING

MeSH Terms

Interventions

AcetylcysteineSodium Chloride

Intervention Hierarchy (Ancestors)

CysteineAmino Acids, SulfurSulfur CompoundsOrganic ChemicalsAmino AcidsAmino Acids, Peptides, and ProteinsChloridesHydrochloric AcidChlorine CompoundsInorganic ChemicalsSodium Compounds

Central Study Contacts

Study Design

Study Type
interventional
Phase
phase 4
Allocation
RANDOMIZED
Masking
DOUBLE
Who Masked
PARTICIPANT, OUTCOMES ASSESSOR
Purpose
TREATMENT
Intervention Model
PARALLEL
Sponsor Type
OTHER
Responsible Party
PRINCIPAL INVESTIGATOR
PI Title
Assistant Professor

Study Record Dates

First Submitted

August 28, 2018

First Posted

August 29, 2018

Study Start

January 1, 2019

Primary Completion (Estimated)

December 1, 2026

Study Completion (Estimated)

December 1, 2026

Last Updated

April 28, 2026

Record last verified: 2026-04

Locations