Effect of Nonsteroidal Anti-Inflammatory Drug Restriction on the Efficacy of Platelet-Rich Plasma in Knee Osteoarthritis

N/ANot Yet RecruitingNCT07766330

Federal University of São Paulo90 enrolled

Overview

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.

Study Type

INTERVENTIONAL

Interventions

Leukocyte-Rich Platelet-Rich PlasmaBIOLOGICAL

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

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.

Eligibility

Sex: ALLMin age: 18 YearsMax age: 80 Years

Medical Language ↔ Plain English

Inclusion Criteria: * 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 Exclusion Criteria: * 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% * 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

Outcomes

Primary Outcomes

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

Secondary Outcomes

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