This study investigates the safety and combined effect of Turmeric, Black Seeds, Flaxseed, and Medicago Sativa for relieving symptoms of knee osteoarthritis compared to the placebo group.

The present double-blind, randomized and placebo-controlled study will be conducted on patients with knee osteoarthritis to evaluate the safety and efficacy of a combined cream of Turmeric, Black Seeds, Flaxseed, and Medicago Sativa for relieving symptoms of knee osteoarthritis. The primary endpoints will be the pain, stiffness, and physical function subscales of the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) criteria, subject global evaluation (SGE), and the overall WOMAC score. Also, the secondary endpoints of this study include an evaluation of the quality of life, quality of sleep, and Functional Capacity Classification.

A pilot study with 30 participants per arm will be conducted to estimate the final sample size. Adults over 40 years of age who have had OA for at least 6 months, and whose OA diagnosis meets the American College of Rheumatology criteria will be eligible to participate in the present study. Participants will be randomized in the intervention or placebo group to use a cream containing 95% vaseline and 5% mixed extract of Turmeric, Black Seeds, Flaxseed, and Medicago Sativa as intervention or cream of vaseline solely as a placebo. The cream will be administrated topically three times daily (9 AM, 3 PM, and 9 PM) for up to 12 weeks. The efficacy and safety of the creams will be measured during visits on days 30, 60, and 90 (final visit). Also, the complications and adherence of patients to intervention will be checked on days 15, 45, and 75 by telephonic discussion. The analysis will be performed based on the intent-to-treat method.

Inclusion Criteria:

• At least 6 months of diagnosis of knee osteoarthritis, and whose OA diagnosis meets the American College of Rheumatology criteria,
• Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain subscale baseline value of ≥ 9 (0-20 scale),
• Functional Capacity Classification of I-III,
• Radiograph evidence of OA in the target knee with a Kellgren-Lawrence score of 2 or 3,
• Morning stiffness of <30 min duration or crepitus on active motion, which are present upon examination.

Exclusion Criteria:

• Evidence of other conditions or diseases of the skin or joints,
• Evidence of partial or complete knee joint replacement or anticipated joint replacement in the target knee,
• Contraindications to the use of non-steroidal anti-inflammatory drugs (NSAIDs) or who use anticoagulant therapy that prohibits them from using NSAIDs,
• Pregnancy, planning to become pregnant or breastfeeding during the study period,
• Ischemic heart disease, heart failure, end-stage cirrhosis, end-stage renal failure, or psychiatric conditions that prevent an adequate evaluation of the study outcomes,
• Insufficient cognitive functioning to participate and complete the questionnaires,
• Unable or unwilling to follow up and complete the study pathway,
• Having active cancer undergoing treatment that prevents the evaluation of the outcome measures,
• A history or diagnosis of other arthritic conditions, such as rheumatoid arthritis, joint and bone deformities, fibromyalgia, and/or other inflammatory and immune system disorders,
• Type I or II diabetes or obesity (body mass index ≥ 39),
• Suffering from painful conditions or frequent headaches requiring the use of systemic opiates or derivatives, or the need for additional NSAID or COX-2 inhibitors,
• Receiving systemic or intra-articular corticosteroid injections.