Knee OsteoarthritisNCT03598829
A Prospective Clinical Trial Comparing Serum Mast Cell Tryptase (SMCT) Levels to Arthrofibrosis Rates Among Primary Total Knee Arthroplasty (TKA) Patients
An observational study of Knee Osteoarthritis and Arthropathy of Knee, run by Mayo Clinic at 1 site in United States.
Trial summary
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. Read more about this study
- Who is it for?
- Ages 20 to 100 years
- Conditions the study is for
- Knee Osteoarthritis, Arthropathy of Knee, Arthrofibrosis
- What is being tested?
- Tryptase, Serum test
- How many people
- 219 participants
- Where
- 1 siteUnited States
- Study dates
- 1 Jul 2018to 15 Nov 2023
- Phase
- Observational
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 20 to 100 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: Males or females between the ages of 20 to 100 years who are surgical candidates for primary total knee replacement.
Who may be able to join
- 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.
Who cannot join
- 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
Show all 9Show fewer
- Psychiatric illness
- Drug or alcohol abuse
- Inability to participate in standard postoperative rehabilitation protocol
Trial locations and contacts
1 site in 1 country.
About this study
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.
Read the 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.
- Conditions
- Knee Osteoarthritis, Arthropathy of Knee, Arthrofibrosis
- Being tested
- Tryptase, Serum test
- Medical subject headings
- Osteoarthritis, Knee
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Tryptase, Serum testDiagnostic test
Also called Serum Tryptase, Tryptase, S, TRYPT, Mast Cell Tryptase
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
| Study group | Role | What they receive |
|---|---|---|
| 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. Receives: Diagnostic Test: Tryptase, Serum test |
What is being measured
The primary outcome is the main question the study is designed to answer.
Serum mast cell tryptase values
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.
Measured: 1 year
Evaluate serum mast cell tryptase association with arthrofibrosis
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.
Measured: 1 year
Secondary outcomes (1)
Evaluate the impact of allergic or inflammatory co-morbidities on serum mast cell tryptase levels
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.
Measured: 1 year
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted26 Jul 2018
- Study start1 Jul 2018
- Primary completion15 Nov 2023
- Study completion15 Nov 2023
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Knee OsteoarthritisStudies of the same condition, open and under way.
- More trials run by Mayo ClinicThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 219 participants (actual)
Sponsor and investigators
- Lead sponsor
- Mayo Clinic
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Matthew P. Abdel, M.D., Mayo Clinic
- Investigators
- Matthew Abdel, M.D., Principal investigator, Mayo Clinic
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT03598829
- Sponsor's protocol ID
- 18-004103
- Status last verified
- Dec 2025
- First submitted
- 3 Jul 2018
- Last updated
- 18 Dec 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: 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.
Study at a glance
From the registry record, last updated by the sponsor on 18 Dec 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Prospective Clinical Trial Comparing Serum Mast Cell Tryptase (SMCT) Levels to Arthrofibrosis Rates Among Primary Total Knee Arthroplasty (TKA) Patients
- ClinicalTrials.gov ID
- NCT03598829
- Acronym / sponsor ID
- 18-004103
- Conditions
- Knee Osteoarthritis, Arthropathy of Knee, Arthrofibrosis
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 219 participants (actual)
- Lead sponsor
- Mayo ClinicUniversity, hospital or other
- Study start
- 1 Jul 2018 (actual)
- Primary completion
- 15 Nov 2023 (actual)
- Study completion
- 15 Nov 2023 (actual)
- First posted
- 26 Jul 2018 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
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 design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Primary Total Knee Arthroplasty | – | Diagnostic Test: Tryptase, Serum testAll 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. |
Who may qualify
- Ages
- 20 to 100 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Males or females between the ages of 20 to 100 years who are surgical candidates for primary total knee replacement.
Key inclusion criteria (1 listed)
- 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.
Key exclusion criteria (9 listed)
- 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)
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Tryptase, Serum testAlso: Serum Tryptase, Tryptase, S, TRYPT, Mast Cell TryptaseBlood 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 | Diagnostic test | Primary Total Knee Arthroplasty |
Primary outcome
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.
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 secondary outcome
Evaluate the impact of allergic or inflammatory co-morbidities on serum mast cell tryptase levels
Time frame: 1 year
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 18 Dec 2025.
- Mayo Clinic Clinical TrialsLink provided by the sponsor.
- Individual participant dataSharing planned: No. 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.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Matthew Abdel, M.D. principal investigator
Mayo Clinic
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Knee Osteoarthritis and Arthropathy of Knee, run by Mayo Clinic at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 1 inclusion and 9 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 18 Dec 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Serum mast cell tryptase values (time frame: 1 year). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 18 Dec 2025.