A Prospective Clinical Trial Comparing Serum Mast Cell Tryptase (SMCT) Levels to Arthrofibrosis Rates Among Primary Total Knee Arthroplasty (TKA) Patients

December 10, 2025 updated by: Matthew P. Abdel, M.D., Mayo Clinic
This research is being done to see if the amount of an enzyme in blood (called serum mast cell tryptase) changes before and after surgery. The investigators would like to see if these amounts are related to knee stiffness and pain in subjects that undergo a total knee replacement.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Arthrofibrosis (AF), characterized by pain and limited mobility, affects a notable percentage of patients post-total knee arthroplasty (TKA). Despite various treatment advancements, the condition remains challenging to manage. Prior research has indicated a relationship between elevated serum mast cell tryptase (SMCT) levels and increased fibrosis in animal models, suggesting that SMCT could serve as a biomarker for arthrofibrosis in humans. This study aims to 1) assess pre- and postoperative SMCT levels in TKA patients, 2) evaluate SMCT's association with arthrofibrosis and clinical outcomes, and 3) determine the impact of allergic or inflammatory co-morbidities on SMCT levels.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Observational

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
219

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • Minnesota
      • Rochester, Minnesota, United States, 55905
        • Mayo Clinic

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

20 years to 100 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

Males or females between the ages of 20 to 100 years who are surgical candidates for primary total knee replacement.

Description

Inclusion Criteria:

  • Investigators will include all patients with osteoarthritis who are surgical candidates for primary TKA. Investigators will include all eligible male or female patients between the ages of 20 years to 100 years old. All included study participants must be able to give an informed consent.

Exclusion Criteria:

  • Significant femoral or tibial deformity due to congenital or traumatic etiologies, inflammatory arthritis, post-septic arthritis, osteomyelitis, prior infection of knee joint, osteoporosis, dislocated or fragmented patella
  • Patients taking mast cell inhibitors and/or degranulation inhibitors for any reason.
  • The presence of infections, highly communicable diseases (e.g. AIDS), active tuberculosis, venereal disease, hepatitis.
  • Significant neurological or musculoskeletal disorders or disease that may adversely affect normal gait or weight bearing.
  • Presence of previous prosthetic knee replacement devices (of any type)
  • Metastatic disease
  • Psychiatric illness
  • Drug or alcohol abuse
  • Inability to participate in standard postoperative rehabilitation protocol

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort

Group / Cohort

A group or subgroup of participants in an observational study that is assessed for biomedical or health outcomes.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Primary Total Knee Arthroplasty
All patients enrolled in this study were part of the same recruitment group who whose SMCT levels will be observed pre and postoperatively. Primary TKA patients are having their native knee replaced.
Diagnostic test: Tryptase, Serum test
Blood draw lab test which measures concentration of Tryptase in the sample. Tryptase is the one of the primary secretions of active mast cells and is used as a measure of inflammatory activity. Normal Reference Value: <11.5 ng/mL
Other Names:
  • Serum Tryptase
  • Tryptase, S
  • TRYPT
  • Mast Cell Tryptase
  • CPT Code 83520

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Serum mast cell tryptase values
Time Frame: 1 year
Serum mast tryptase values will be assessed pre and postoperatively to evaluate changes that can be expected in patients who are undergoing total knee replacement.
1 year
Evaluate serum mast cell tryptase association with arthrofibrosis
Time Frame: 1 year
For patients who developed arthrofibrosis after total knee replacement, we will examine if a significant change in serum mast cell tryptase accompanies this outcome. This will help evaluate if tryptase levels may be useful as a marker of risk for arthrofibrosis.
1 year

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Evaluate the impact of allergic or inflammatory co-morbidities on serum mast cell tryptase levels
Time Frame: 1 year
We will aim to examine to what extent allergic or inflammatory conditions influence changes in serum mast cell tryptase levels for patients undergoing total knee replacement. This aids in determining if underlying patient health affects how useful tryptase measurements could be as a marker for risk of arthrofibrosis, or if there is an association between these conditions and increased risk for arthrofibrosis.
1 year

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Mayo Clinic

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Matthew Abdel, M.D., Mayo Clinic

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

Helpful Links

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
July 1, 2018

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
November 15, 2023

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
November 15, 2023

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
July 3, 2018

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
July 24, 2018

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
July 26, 2018

Study Record Updates

Last Update Posted (Estimated)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
December 18, 2025

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
December 10, 2025

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
December 1, 2025

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 18-004103

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

IPD will not be shared, as Mayo Clinic is the only institution involved in this research study and results reporting will be done via summary metrics and statistical analysis. Research participants did not consent for IPD to be shared outside of Mayo Clinic.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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