Do Platelet-Rich Plasma Injections for Knee Osteoarthritis Work?

Area of Science:

• Orthopedics
• Regenerative Medicine
• Rheumatology

Background:

• Platelet-rich plasma (PRP) injections are increasingly considered for managing mild to moderate knee osteoarthritis (OA), with anecdotal reports of pain and stiffness reduction.
• Limited high-quality evidence, specifically level-one randomized controlled trials (RCTs), exists to definitively support the long-term efficacy of PRP for knee OA.
• Existing research often relies on a few key RCTs, necessitating further investigation into the true benefits of PRP therapy.

Purpose of the Study:

• To evaluate the clinical outcomes and therapeutic benefits of administering PRP injections over a six to eight-week period in patients diagnosed with knee OA.
• To assess changes in pain, stiffness, and physical function following a series of PRP treatments.

Main Methods:

• A cohort of 31 patients with knee OA received three PRP injections spaced two to three weeks apart.
• The Western Ontario and McMaster Universities Arthritis Index (WOMAC) was administered before each injection and at a six-week follow-up post-final treatment.
• Key outcome measures included WOMAC scores for pain, stiffness, physical function, and overall joint status.

Main Results:

• A statistically significant reduction in total WOMAC scores, pain, stiffness, and physical function was observed after the third PRP injection.
• Specifically, total WOMAC score decreased by 16.36%, pain by 16.37%, stiffness by 5.12%, and physical function by 18.03%.
• However, all measured WOMAC scores reverted to near baseline levels by the six-week follow-up assessment.

Conclusions:

• While a trend towards WOMAC score reduction was noted, the results suggest that the observed benefits may be attributed to a placebo effect.
• The temporary nature of symptom relief indicates a need for more robust research to establish genuine therapeutic value.
• Future studies should investigate the influence of osteoarthritis severity (grade) and patient body mass index (weight) on PRP treatment outcomes.