Platelet-rich plasma (PRP) injections are a common treatment for a variety of orthopedic conditions, including knee osteoarthritis, tendinitis, and ligament injuries. PRP therapy involves drawing a patient’s own blood, processing it to concentrate the platelets, and then injecting the resulting plasma into the affected joint or tissue. The platelets contain growth factors and other proteins that can help promote healing and reduce inflammation.
While PRP therapy has shown promising results in many cases, the optimal frequency of injections remains a topic of debate among healthcare professionals. Some doctors recommend a single injection, while others suggest a series of injections over several weeks or months.
There is currently no consensus on the ideal frequency of PRP injections for knee osteoarthritis, which is a common condition that affects millions of people around the world. However, several studies have suggested that multiple injections may be more effective than a single injection. As a patient and an interventional pain physician, I have successfully treated my own Knee OA with a PRP injection and now perform prophylactic PRP injections to maintain the effects and hopefully reduce the risk of progressing to severe osteoarthritis and needing a knee replacement.
A 2017 study published in the Journal of Bone and Joint Surgery compared the outcomes of patients with knee osteoarthritis who received a single PRP injection with those who received three weekly injections. The researchers found that patients who received three injections had greater improvements in pain and function than those who received only one injection.
Similarly, a 2018 study published in the Journal of Orthopaedic Surgery and Research found that multiple PRP injections were more effective than a single injection in reducing pain and improving function in patients with knee osteoarthritis.
One must be cautioned and note that more injections may not always be better. A 2020 review published in the Journal of Clinical Medicine concluded that there is insufficient evidence to support the use of multiple PRP injections for knee osteoarthritis. The authors noted that while some studies have shown that multiple injections can be beneficial, others have not found any significant difference between multiple injections and a single injection. My criticism to this idea is that studies rarely use the same PRP kits and preparation methods, platelet counts do vary so read the fine print.
Ultimately, the frequency of PRP injections for knee osteoarthritis should be determined on a case-by-case basis, taking into account factors such as the severity of the condition, the patient’s age and overall health, and the response to previous treatments.
For an objective view of the evidence, lack of evidence, pros, cons and technical aspects of utilizing ultrasound to guide PRP into various tissues of the body, join me at one of our upcoming ultrasound courses or regenerative medicine course where we provide a certificate of completion, practical training and CME credits.
David Rosenblum, MD
Regenerative Pain Medicine Training