An interventional study of Leukocyte-Rich Platelet-Rich Plasma and ibuprofen in Osteoarthritis, Knee, sponsored by Federal University of São Paulo. Not yet recruiting at 1 site in Brazil. Open to participants aged 18 Years to 80 Years. Per ClinicalTrials.gov, last updated 2026-08-14.
Sponsored by Federal University of São Paulo · Not applicable, Interventional, and Treatment
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.
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.
3,292 studies on the registry are indexed under Osteoarthritis, Knee; 623 are open to participants now.
This study's planned enrollment of 90 is above the median of 68 across 2,714 interventional studies indexed under Osteoarthritis, Knee.
Browse Osteoarthritis, Knee studies →Federal University of São Paulo is the lead sponsor of 439 studies on the registry; 23 are open to participants now.
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Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
A blood test of average blood sugar over the past two to three months, given as a percentage or in mmol/mol. 6.5% (48 mmol/mol) or more is the usual threshold for diabetes, normally confirmed by a second test.
The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
Chronic obstructive pulmonary disease: long-term lung disease that makes it hard to breathe out, including emphysema and chronic bronchitis.
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
The anaesthetists’ scale of health before surgery: I is healthy, II has a mild illness that is under control, III a severe one, IV a severe illness that is a constant threat to life. V and VI are used for the critically ill and for organ donors.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HbA1c
A blood test of average blood sugar over the past two to three months, given as a percentage or in mmol/mol. 6.5% (48 mmol/mol) or more is the usual threshold for diabetes, normally confirmed by a second test.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hemoglobin (Hb)
The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Platelets
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
COPD
Chronic obstructive pulmonary disease: long-term lung disease that makes it hard to breathe out, including emphysema and chronic bronchitis.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Corticosteroids (steroids)
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ASA physical status
The anaesthetists’ scale of health before surgery: I is healthy, II has a mild illness that is under control, III a severe one, IV a severe illness that is a constant threat to life. V and VI are used for the critically ill and for organ donors.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
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.
Biological: Leukocyte-Rich Platelet-Rich Plasma · Drug: ibuprofen
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.
Biological: Leukocyte-Rich Platelet-Rich Plasma · Drug: Acetaminophen
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.
Also known as: LR-PRP, Platelet-Rich Plasma, PRP
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.
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.
Also known as: Paracetamol
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.
Time frame: Baseline and 6 months after the intervention
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.
Time frame: 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.
Time frame: 1 week, 3 weeks and 3 months after the intervention
Incidence and Severity of Adverse Events
The number of participants experiencing adverse events will be recorded. Events will be classified according to the Common Terminology Criteria for Adverse Events, version 5.0, from grade 1 (mild) to grade 5 (death).
Time frame: 24 hours, 48 hours, 7 days, and through 12 months after the intervention
Plan to share: 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.
No publications or documents are linked to this record.
Start is estimated for Oct 2026; primary completion for Jun 2028, 20 months later.
Of 1,111 non-industry interventional studies with no phase under Osteoarthritis, Knee, half reached primary completion within 18 months of starting (the median), counting those still running; a quarter within 8 and three quarters within 36. This study's planned 20 months is above that.
Counting every sponsor, half of 1,251 studies reached it within 18 months; a quarter within 8 and three quarters within 36.
How these figures are worked out, and which studies are left out of them.
This study is not yet recruiting, as verified in Aug 2026. You cannot join it, but the record below documents what was studied.
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Federal University of São Paulo →