Osteoarthritis, KneeNCT07766330
Effect of Nonsteroidal Anti-Inflammatory Drug Restriction on the Efficacy of Platelet-Rich Plasma in Knee Osteoarthritis
A study testing Leukocyte-Rich Platelet-Rich Plasma, ibuprofen and Acetaminophen in people with Osteoarthritis, Knee, run by Federal University of São Paulo at 1 site in Brazil.
Trial summary
The goal of this randomized clinical trial is to learn whether taking ibuprofen, a nonsteroidal anti-inflammatory drug, after a platelet-rich plasma (PRP) injection changes pain relief and knee function in adults with knee osteoarthritis. Read more about this study
- Who is it for?
- Ages 18 to 80 years
- Conditions the study is for
- Osteoarthritis, Knee
- What is being tested?
- Leukocyte-Rich Platelet-Rich Plasma, ibuprofen and Acetaminophen
- Type of treatment
- Pill or oral medicine, Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 90 participants
- Where
- 1 siteBrazil
- Study dates
- 1 Oct 2026to Oct 2028
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
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 18 to 80 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Age between 18 and 80 years
- Knee pain for at least 3 months
- Radiographic evidence of knee osteoarthritis classified as Kellgren-Lawrence grade I, II, or III
- Ability and willingness to provide written informed consent
Who cannot join
- Body mass index of 35 kg/m2 or higher
- Pregnancy or breastfeeding
- Diabetes mellitus with glycated hemoglobin greater than 6.5%
- Hematologic disease, including anemia, coagulopathy, or thrombophilia
- Hemoglobin below 11 g/dL
- Hematocrit below 33%
Show all 21Show fewer
- Platelet count below 150,000/mm3
- Advanced knee osteoarthritis
- Rheumatologic disease
- Chronic kidney disease
- Respiratory disease, including rhinitis, asthma, or chronic obstructive pulmonary disease
- Active or previous oncologic disease, as defined in the protocol
- Fibromyalgia
- Psychiatric disorder currently under treatment
- Substance dependence, including smoking, harmful alcohol use, or other substance use
- Use of nonsteroidal anti-inflammatory drugs within the previous 30 days
- Use of systemic, intra-articular, topical, or inhaled glucocorticoids within the previous 3 months
- Current use of anticoagulant or antiplatelet medication
- American Society of Anesthesiologists physical status classification of 3 or higher
- Currently receiving disability or sickness-related social security benefits
- Inability or unwillingness to provide informed consent or complete the required patient-reported outcome measures
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Brazil1 site
Disciplina de Medicina Esportiva da UNIFESP
São Paulo, São Paulo, 04022-002
About this study
The goal of this randomized clinical trial is to learn whether taking ibuprofen, a nonsteroidal anti-inflammatory drug, after a platelet-rich plasma (PRP) injection changes pain relief and knee function in adults with knee osteoarthritis.
The main questions it aims to answer are:
Read more
Does ibuprofen change the improvement in knee pain six months after a PRP injection compared with acetaminophen?
Does ibuprofen change knee function or the need for additional pain medicine during follow-up?
Researchers will compare PRP followed by ibuprofen with PRP followed by acetaminophen. Participants will receive one ultrasound-guided PRP injection and take the assigned medication every eight hours for five days. They will complete assessments of pain, knee function, additional pain medicine use, and safety. Participants and the physician performing the injection will not know which medication was assigned.
Read the detailed description
Platelet-rich plasma (PRP) has shown promising results for reducing pain and improving function in people with knee osteoarthritis. However, it is unclear whether the use of nonsteroidal anti-inflammatory drugs after PRP may affect the clinical response. This study will compare ibuprofen, a nonsteroidal anti-inflammatory drug, with acetaminophen, which has no clinically relevant anti-inflammatory effect at the study dose.
This is a randomized, controlled, parallel-group, double-blind clinical trial. Ninety adults with knee osteoarthritis will be randomly assigned in a 1:1 ratio to one of two groups. All participants will receive a single ultrasound-guided intra-articular injection of leukocyte-rich PRP. After the injection, participants will receive either ibuprofen 400 mg every eight hours or acetaminophen 500 mg every eight hours for five consecutive days. The medications will be provided in visually identical capsules. Participants and the physician performing the injection will remain unaware of the assigned medication.
The primary outcome will be the change in knee pain measured using a visual analog scale six weeks after the injection. Secondary assessments will include knee function measured using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and the use of additional pain medication during follow-up.
Adverse events will be monitored through digital questionnaires at 24 hours, 48 hours, and seven days after the intervention, as well as during scheduled follow-up visits. Adverse events will be classified according to the Common Terminology Criteria for Adverse Events, version 5.0.
- Conditions
- Osteoarthritis, Knee
- Being tested
- Leukocyte-Rich Platelet-Rich Plasma, ibuprofen, Acetaminophen
- Keywords
- Platelet-Rich Plasma, Nonsteroidal Anti-Inflammatory Drugs, Intra-Articular Injection, Knee Pain
- Medical subject headings
- Osteoarthritis, Knee
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Leukocyte-Rich Platelet-Rich PlasmaBiological
Also called LR-PRP, Platelet-Rich Plasma, PRP
A single 12 mL intra-articular injection of autologous leukocyte-rich platelet-rich plasma, prepared from 54 mL of peripheral venous blood using a standardized single-centrifugation protocol without anticoagulants or exogenous activators. The injection will be performed using a lateral suprapatellar approach under ultrasound guidance.
ibuprofenDrug
Ibuprofen 400 mg oral capsules administered every eight hours for five consecutive days, starting immediately after the platelet-rich plasma injection. Capsules will be visually identical to the acetaminophen capsules.
AcetaminophenDrug
Also called Paracetamol
Acetaminophen 500 mg oral capsules administered every eight hours for five consecutive days, starting immediately after the platelet-rich plasma injection. Capsules will be visually identical to the ibuprofen capsules.
| Study group | Role | What they receive |
|---|---|---|
| Platelet-Rich Plasma Plus Ibuprofen | Experimental | Participants will receive a single ultrasound-guided intra-articular injection of leukocyte-rich platelet-rich plasma, followed by ibuprofen 400 mg orally every eight hours for five consecutive days. Receives: Biological: Leukocyte-Rich Platelet-Rich Plasma; Drug: ibuprofen |
| Platelet-Rich Plasma Plus Acetaminophen | Active comparator | Participants will receive a single ultrasound-guided intra-articular injection of leukocyte-rich platelet-rich plasma, followed by acetaminophen 500 mg orally every eight hours for five consecutive days. Receives: Biological: Leukocyte-Rich Platelet-Rich Plasma; Drug: Acetaminophen |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change From Baseline in Knee Pain Measured by a Visual Analog Scale
Knee pain will be measured using a 100-mm visual analog scale ranging from 0 mm (no pain) to 100 mm (worst imaginable pain). Change from baseline will be calculated, with a negative change indicating improvement.
Measured: Baseline and 6 months after the intervention
Secondary outcomes (2)
Change From Baseline in Western Ontario and McMaster Universities Osteoarthritis Index Total Score
The Western Ontario and McMaster Universities Osteoarthritis Index questionnaire includes 24 items assessing pain, stiffness, and physical function. Each item is scored from 0 to 4, resulting in a total score from 0 to 96. Higher scores indicate worse symptoms and greater functional limitation. Change from baseline will be calculated.
Measured: Baseline and 3, 6, and 12 months after the intervention
Additional Analgesic Consumption
The number of additional analgesic doses used after the intervention will be recorded using a standardized participant form. Higher values indicate greater use of rescue analgesic medication.
Measured: 1 week, 3 weeks and 3 months after the intervention
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted14 Aug 2026
- Study start1 Oct 2026 (estimated)
- Primary completionJun 2028 (estimated)
- Study completionOct 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Osteoarthritis, KneeStudies of the same condition, open and under way.
- 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
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- Two-arm, parallel-group trial with 1:1 random allocation. Both groups will receive a single platelet-rich plasma injection and will differ only in the post-procedure medication assigned for five days: ibuprofen or acetaminophen.
- Masking
- Double blind
- Who is masked
- Participant, Care provider
- Enrolment
- 90 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Federal University of São Paulo
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Paulo Santoro Belangero, Federal University of São Paulo
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07766330
- Sponsor's protocol ID
- 99121626.1.0000.5505
- Status last verified
- Aug 2026
- First submitted
- 11 Aug 2026
- Last updated
- 14 Aug 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: Deidentified individual participant data are not currently planned to be shared because an IPD-sharing procedure was not included in the approved protocol and informed consent process. Aggregate study results will be disseminated through scientific publications and presentations.
Study at a glance
From the registry record, last updated by the sponsor on 14 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effect of Nonsteroidal Anti-Inflammatory Drug Restriction on the Efficacy of Platelet-Rich Plasma in Knee Osteoarthritis
- ClinicalTrials.gov ID
- NCT07766330
- Acronym / sponsor ID
- 99121626.1.0000.5505
- Conditions
- Osteoarthritis, Knee
- Keywords
- Platelet-Rich Plasma, Nonsteroidal Anti-Inflammatory Drugs, Intra-Articular Injection, Knee Pain
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 90 participants (estimated)
- Lead sponsor
- Federal University of São PauloUniversity, hospital or other
- Study start
- 1 Oct 2026 (estimated)
- Primary completion
- Jun 2028 (estimated)
- Study completion
- Oct 2028 (estimated)
- First posted
- 14 Aug 2026 (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.
The goal of this randomized clinical trial is to learn whether taking ibuprofen, a nonsteroidal anti-inflammatory drug, after a platelet-rich plasma (PRP) injection changes pain relief and knee function in adults with knee osteoarthritis.
The main questions it aims to answer are:
Does ibuprofen change the improvement in knee pain six months after a PRP injection compared with acetaminophen?
Does ibuprofen change knee function or the need for additional pain medicine during follow-up?
Researchers will compare PRP followed by ibuprofen with PRP followed by acetaminophen. Participants will receive one ultrasound-guided PRP injection and take the assigned medication every eight hours for five days. They will complete assessments of pain, knee function, additional pain medicine use, and safety. Participants and the physician performing the injection will not know which medication was assigned.
Detailed description
Platelet-rich plasma (PRP) has shown promising results for reducing pain and improving function in people with knee osteoarthritis. However, it is unclear whether the use of nonsteroidal anti-inflammatory drugs after PRP may affect the clinical response. This study will compare ibuprofen, a nonsteroidal anti-inflammatory drug, with acetaminophen, which has no clinically relevant anti-inflammatory effect at the study dose.
This is a randomized, controlled, parallel-group, double-blind clinical trial. Ninety adults with knee osteoarthritis will be randomly assigned in a 1:1 ratio to one of two groups. All participants will receive a single ultrasound-guided intra-articular injection of leukocyte-rich PRP. After the injection, participants will receive either ibuprofen 400 mg every eight hours or acetaminophen 500 mg every eight hours for five consecutive days. The medications will be provided in visually identical capsules. Participants and the physician performing the injection will remain unaware of the assigned medication.
The primary outcome will be the change in knee pain measured using a visual analog scale six weeks after the injection. Secondary assessments will include knee function measured using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and the use of additional pain medication during follow-up.
Adverse events will be monitored through digital questionnaires at 24 hours, 48 hours, and seven days after the intervention, as well as during scheduled follow-up visits. Adverse events will be classified according to the Common Terminology Criteria for Adverse Events, version 5.0.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (participant, care provider)
- Number of arms
- 2
- Model description
- Two-arm, parallel-group trial with 1:1 random allocation. Both groups will receive a single platelet-rich plasma injection and will differ only in the post-procedure medication assigned for five days: ibuprofen or acetaminophen.
| Arm | Type | Receives |
|---|---|---|
| Platelet-Rich Plasma Plus Ibuprofen | Experimental | Biological: Leukocyte-Rich Platelet-Rich Plasma, Drug: ibuprofenParticipants will receive a single ultrasound-guided intra-articular injection of leukocyte-rich platelet-rich plasma, followed by ibuprofen 400 mg orally every eight hours for five consecutive days. |
| Platelet-Rich Plasma Plus Acetaminophen | Active comparator | Biological: Leukocyte-Rich Platelet-Rich Plasma, Drug: AcetaminophenParticipants will receive a single ultrasound-guided intra-articular injection of leukocyte-rich platelet-rich plasma, followed by acetaminophen 500 mg orally every eight hours for five consecutive days. |
Who may qualify
- Ages
- 18 to 80 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- Age between 18 and 80 years
- Knee pain for at least 3 months
- Radiographic evidence of knee osteoarthritis classified as Kellgren-Lawrence grade I, II, or III
- Ability and willingness to provide written informed consent
Key exclusion criteria (21 listed)
- Body mass index of 35 kg/m2 or higher
- Pregnancy or breastfeeding
- Diabetes mellitus with glycated hemoglobin greater than 6.5%
- Hematologic disease, including anemia, coagulopathy, or thrombophilia
- Hemoglobin below 11 g/dL
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 |
|---|---|---|
| Leukocyte-Rich Platelet-Rich PlasmaAlso: LR-PRP, Platelet-Rich Plasma, PRPA single 12 mL intra-articular injection of autologous leukocyte-rich platelet-rich plasma, prepared from 54 mL of peripheral venous blood using a standardized single-centrifugation protocol without anticoagulants or exogenous activators. The injection will be performed using a lateral suprapatellar approach under ultrasound guidance. | Biological | Platelet-Rich Plasma Plus Acetaminophen, Platelet-Rich Plasma Plus Ibuprofen |
| ibuprofenIbuprofen 400 mg oral capsules administered every eight hours for five consecutive days, starting immediately after the platelet-rich plasma injection. Capsules will be visually identical to the acetaminophen capsules. | Drug | Platelet-Rich Plasma Plus Ibuprofen |
| AcetaminophenAlso: ParacetamolAcetaminophen 500 mg oral capsules administered every eight hours for five consecutive days, starting immediately after the platelet-rich plasma injection. Capsules will be visually identical to the ibuprofen capsules. | Drug | Platelet-Rich Plasma Plus Acetaminophen |
Primary outcome
Change From Baseline in Knee Pain Measured by a Visual Analog Scale
Time frame: Baseline and 6 months after the intervention
Knee pain will be measured using a 100-mm visual analog scale ranging from 0 mm (no pain) to 100 mm (worst imaginable pain). Change from baseline will be calculated, with a negative change indicating improvement.
2 secondary outcomes
Change From Baseline in Western Ontario and McMaster Universities Osteoarthritis Index Total Score
Time frame: Baseline and 3, 6, and 12 months after the intervention
Additional Analgesic Consumption
Time frame: 1 week, 3 weeks and 3 months after the intervention
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 14 Aug 2026.
- Individual participant dataSharing planned: No. Deidentified individual participant data are not currently planned to be shared because an IPD-sharing procedure was not included in the approved protocol and informed consent process. Aggregate study results will be disseminated through scientific publications and presentations.
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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.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Leukocyte-Rich Platelet-Rich Plasma, ibuprofen and Acetaminophen in people with Osteoarthritis, Knee, run by Federal University of São Paulo at 1 site in Brazil.
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 4 inclusion and 21 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: opening soon, as of the sponsor's last update on 14 Aug 2026. 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 Brazil. 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?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Guilherme Moury Fernandes, MD (+55 11 3385-4343, guilherme.moury@unifesp.br), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change From Baseline in Knee Pain Measured by a Visual Analog Scale (time frame: Baseline and 6 months after the intervention). 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 14 Aug 2026.