The Effect of Early Saline Lavage on Synovial Fluid Composition Following Human Intra-Articular Ankle Fracture
Phase: NA
Conditions: Intra-Articular Fractures
Sponsor: Duke University

 
 
 
 
 
 
 
 
 
 
 
 
The Effect of Early Saline Lavage on Synovial Fluid Composition Following Human 
Intra-Articular Ankle Fracture 
 
Document Date: 12/12/2024 
 
NCT05465382 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

Purpose of the Study 
  
The purpose of this study is to examine the effect of early, percutaneous, intra-articular saline lavage on 
the undiluted synovial fluid microenvironment during the acute phase following intra-articular fracture 
of the human ankle. We hypothesize that early intervention with percutaneous joint lavage in the first 0-
48 hours after injury will attenuate the production of pro-inflammatory cytokines, MMP’s and cartilage 
breakdown products compared to non-lavaged control subjects at the time of surgical fixation. 
 
 
Background & Significance 
 
Post traumatic osteoarthritis (PTOA) is a frequent cause of disability in orthopaedic trauma patients. 
Post-traumatic etiologies represent a disproportionately high percentage of clinically significant 
osteoarthritis of the ankle (65-80%) as compared to the knee and hip (2-10%). Compared to other forms 
of arthritis, PTOA is unique in that the timing of onset is known. As a result, there is an opportunity for 
studying the underlying pathogenesis at the time of injury and targeting interventions aimed at treating 
early disease and preventing disease progression. 
 
Traditionally, the intraoperative restoration of anatomic joint congruity and balanced articular loading 
were thought to be the main factors involved in preventing the development of PTOA. However, even 
after anatomic reduction, intra-articular fractures of the lower extremity are still susceptible to the 
development of PTOA. Furthermore, the relationship between residual articular surface displacement 
and the development of PTOA is inconsistent in the literature. While the mechanical components of 
intra-articular fracture treatment have been well studied, more recent work has focused on better 
understanding the biological response within the joint that likely contributes to cartilage damage and 
the progression of PTOA. 
 
At the time of intra-articular ankle fracture, chondrocyte death and apoptosis occur locally along the 
fracture edges. However, immediately thereafter, the entire joint is exposed to the inflammatory 
environment created by injury to the periarticular soft tissues and fractured bone edges. This gives rise 
to the so-called “innocent bystander” phenomenon, whereby uninjured cartilage throughout the joint is 
subjected to the deleterious effects of the inflammatory burden created by the healing fracture site.  In 
2015, Adams et al. sought to better define this inflammatory environment, and demonstrated the 
presence of significantly elevated levels of pro-inflammatory cytokines and extracellular matrix-
degrading mediators present in the synovial fluid after intra-articular ankle fracture, which could play a 
role in the development of PTOA. Followup study here at Duke has demonstrated that the intra-articular 
composition of these inflammatory cytokines and matrix metalloproteinases (MMP’s) changes over 
time, with evidence of in-vivo cartilage degeneration present by 10 days post-injury. Furthermore, in-
vitro study has demonstrated the clear deleterious effect of synovial fluid fracture hematoma (SFFH) on 
chondrocyte viability on a time-based scale, with SFFH collected from 0-2 days post-injury 
demonstrating the greatest potential for cartilage damage. 
 
These studies suggest that early intervention to alter the composition of the intra-articular environment 
may attenuate the inflammatory response, diminishing the potential for “innocent bystander” cartilage 

damage and the subsequent development of PTOA. Currently, there are no therapeutics approved for 
the treatment of PTOA. Commercially available anti-inflammatory cytokine agents and 
metalloproteinase inhibitors have been shown to increase chondrocyte viability in animal and in-vitro 
models, however, their use is not yet approved for the treatment of PTOA in human subjects. 
 
Saline joint lavage represents a potentially simple, low-risk and minimal-cost intervention which has not 
been previously studied for this purpose in human subjects. Open joint lavage at the time of definitive 
surgical fixation is within the standard of care, but typically occurs greater than 10 days after injury by 
which time cartilage degradation has already begun.  Early, saline lavage during initial presentation to 
the clinic or emergency department may theoretically alter the progression of the intra-articular 
inflammatory response by evacuating the bulk of the developing synovial-fluid fracture hematoma. 
 
The vast majority of ankle fractures present to the ER or urgent care within a day of fracture. Moreover, 
a large subset of these fractures require reduction (fracture setting) that is painful. It is our standard of 
care to perform an intra-articular lidocaine injection before reduction. We will take advantage of this 
standard of care needle insertion to the fractured ankle to perform saline joint lavage to diminish this 
early inflammatory burden. 
 
Design & Procedures 
 
This is a prospective randomized control trial which will be performed exclusively at Duke University 
Hospital (DUH). We plan to enroll 60 patients with the hopes to have 40 evaluable subjects. 
 
After informed consent is obtained, subjects will be randomized into one of two groups as listed below.  
Group 1: intra-articular saline lavage (n=30) 
Group 2: no intra-articular saline lavage (n=30) 
 
Randomization will occur by the opening of pre-prepared envelopes which will be stored in the 
orthopaedic resident office (HAFS Building, Room 1661). Envelopes will be labeled #1-#60. Thirty 
envelopes will contain a note card labeled “Group 1” and Thirty envelopes will contain a note card 
labeled “Group 2”. Envelopes will be pre-prepared by key study personnel not involved in the consent or 
randomization process.  
 
Upon informed consent, subjects will undergo physical examination, medical history assessment, vital 
sign measurements, and x-rays of the injured and/or contralateral ankle as part of their standard clinical 
care. After initial evaluation, subjects will undergo aspiration of the injured ankle joint via the standard 
anteromedial arthroscopy portal approach. This will be performed with sterile technique using a 16-
guage needle attached to a 10cc syringe.  As previously mentioned, this standard of care needle 
insertion is used independent of the current study for the administration of intra-articular lidocaine for 
patient pain relief. The aspirate will be immediately transported to Dr. Adam’s lab (LSRC Building, Room 
B331) aliquoted and stored at -80 degrees Celsius for batch analysis.  
 
Subjects in Group 1 will then undergo saline joint lavage as follows:  
Three 10cc syringes will be filled with 10cc of sterile 0.9% normal saline.  

One 10cc normal saline syringe will be injected into the ankle joint through the previously placed 
anteromedial 16-gauge needle.  
Saline will be withdrawn from the joint into the attached 10cc syringe.  
The needle will be left in place, the syringe detached, and the lavage repeated with the remaining two 
10cc normal saline syringes.  
After three rounds of lavage, 10cc of 1% lidocaine without epinephrine will be injected into the joint via 
the existing anteromedial 16-gauge needle. This will serve as an intra-articular hematoma block for 
patient comfort during fracture reduction and splinting. 
This intra-articular lidocaine block is routinely performed as standard of care for ankle fractures 
presenting to the emergency department. As described, only one needle stick will be performed which 
will facilitate sample aspiration, lavage and lidocaine block, thus causing minimal to no additional 
discomfort to the patient.   
 
Subjects in group 2 will not undergo normal saline lavage. After synovial fluid aspiration as described 
above, they will undergo intra-articular injection of 10cc of 1% lidocaine without epinephrine via the 
existing anteromedial 16-gauge needle. This will serve as an intra-articular hematoma block for patient 
comfort during fracture reduction and splinting.  
 
The aspiration and lavage protocol as described above will take place in the DUH ED and be performed 
only by approved key study personnel.   
 
After the initial aspiration +/- lavage and stabilization of the ankle joint, subjects will undergo a period of 
soft tissue rest to allow for the resolution of soft tissue swelling. This is standard of care in the treatment 
of periarticular lower extremity fractures. Subjects will then undergo surgical fixation when it is deemed 
appropriate by the Orthopaedic Trauma team, independent of this study. At the time of surgery, after 
tourniquet inflation, all subjects will again undergo intra-articular aspiration of the injured ankle joint. 
This will be performed using a 16-gauge needle attached to a 10cc syringe via a standard anteromedial 
arthroscopy portal approach. The aspirate will be immediately aliquoted, transported to Dr. Adam’s lab 
(LSRC building B331) and stored at -80 degrees Celsius for batch analysis.  
 
 
Selection of Subjects 
  
Adult subjects (over 18 years of age) presenting to the DUH Emergency Department with an intra-
articular fracture of the ankle joint between 0-48 hours from the time of injury will be eligible for 
inclusion. Intra articular fracture (IAF) is defined as any fracture of the fibula or tibia in which the 
fracture line(s) exit into the cartilage surface of the ankle joint. Exclusion criteria include: 1) age <18yo, 
2) open fracture, 3) subjects presenting >48 hours from the time of injury, 4) nonoperatively treated 
fractures.   
 
 
Subject Recruitment and Compensation 
 

Upon evaluation by the orthopaedic surgery team in the Duke University Hospital Emergency 
Department, subject eligibility will be confirmed and the study will be introduced to the subject by their 
treating physician. Key personnel with role of "Collaborator"  will review the study in detail with the 
subject. Paper consent forms will be signed and stored in a key-locked file cabinet within the study 
coordinators office (Duke Orthopaedics Arringdon, 3rd Floor, Room 3262).   
 
We plan to enroll 60 subjects to capture 40 participants as determined by our power analysis which is 
detailed below. All patients who meet the above inclusion criteria will be eligible for the study. In this 
way, enrollment will be equitable across all demographic groups.  
 
 
Risk/Benefit Assessment 
 
As described above, this study represents minimal risk and discomfort to subjects. It is standard of care 
to administer an intra-articular lidocaine injection during the emergency department management of 
ankle fractures. We will utilize this standard of care needle insertion to the fractured ankle to perform 
our study related aspiration and saline lavage. In this way, no additional risk or discomfort will be 
incurred by the subject as a result of participation. Patients choosing not to participate will receive the 
normal standard of care for treatment of their injury independent of this study. Furthermore, 
consenting to participate in this study in no way obligates subjects to undergo surgical fixation of their 
ankle fracture. This decision will be made in consultation with their treating surgeon.  
 
Risk is involved to the extent that privacy and confidentiality may be compromised. However, every 
reasonable effort will be made to limit breaches of privacy and confidentiality.  
 
Subjects will not benefit directly from this study. However, data and conclusions derived from this study 
may improve the current understanding of post traumatic arthritis and possibly influence future patient 
care or study designs.  
 
 
Data Analysis & Statistical Considerations 
 
Sample Size Estimate 
 
The study was powered (a-priori) for randomized between group differences in the primary outcome 
measures of Cytokines and Matrix Metalloproteinase levels collected during standardized aspirations. 
The study will involve two independent groups: 1) individuals with intra-articular fractures of the ankle 
who receive saline lavage (experimental) and 2) individuals with intra-articular fractures of the ankle 
who do not receive lavage (control). Differences between groups will be evaluated with a fixed effects 
repeated measures, analysis of covariance (RM-ANCOVA) with three dedicated time points ([1.] 
baseline, [2.] in the OR after anesthesia is induced (generally within 24 hours of lavage), and [3] 1 to 2 
weeks post-injury). Baseline cytokines and Matrix Metalloproteinase levels will be used as a covariate 
control. Assuming a normal distribution for the cytokines and Matrix Metalloproteinase levels and 
assuming a partial theta squared effect size of 0.40 (large effect*, primarily occurring at the second time 

point), we constructed a sample size estimation estimating for between groups’ comparisons. With an 
expected 80% power, 2 time intervals*, 1 control interval, two independent groups, and a standard 
error of probability of 0.05, we estimated the need for a minimum sample size of 40 for statistical 
significance (~20 per group). We will employ intention to treat and chains equation imputation and will 
not oversample each group for drop outs. 
 
Statistical Analyses 
 
The primary outcome measure will be cytokines and Matrix Metalloproteinase levels measured at two 
distinct time points after injury. We will use a between groups, repeated measures Analysis of 
Covariance (RM-ANCOVA) to measure differences between the two designated groups. A RM-ANCOVA is 
used in examining the differences in the mean values of the dependent variables that are related to the 
effect of the controlled independent variables while taking into account the influence of the 
uncontrolled independent variables (baseline) over more than one time point. A p value of 0.05 will be 
used to measure statistical significance.  
 
*Medium effect size required a sample size of 98 
+Three time intervals would only require a sample size of 36.  
 
Data & Safety Monitoring 
 
The only major risk involved is the loss of confidentiality and every effort will be made to ensure this 
does not happen by the research staff. No followup contact with subjects will be necessary after their 
ankle aspirations. The results of this research will not be placed in their medical record. No PHI will leave 
Duke.  It will not be necessary to specifically provide the subjects with any additional information, as 
their involvement ends with their ankle joint aspiration at the time of surgery and does not influence 
their longitudinal care.  Furthermore, any research findings will be made available through publication. 
Research records containing MRN will be kept in an electronic spreadsheet on the Duke server of which 
access is limited to the PI and his research staff.  Any electronic information will be stored on a 
computer that is password protected. After data collection and prior to statistical analysis, a case 
number will be assigned to the data and the medical record number (the only identifying data collected) 
will be stripped from the database.  After the review is complete, publication has been accepted and all 
revisions have been made to the manuscript, then the study will be closed in the eIRB.