This guest post comes from David Vizurraga, MD in response to a study in JAMA investigating platelet-rich plasma vs. placebo in the treatment of knee osteoarthritis. The study was also featured in a recent Medpage Today article.
According to a 2020 meta-analysis by Cui et al., an estimated 654.1 million individuals worldwide have knee osteoarthritis (OA)¹. Given the prevalence of knee OA and the knowledge of the havoc it can wreak on a patient’s quality of life, it is no wonder that we, and our patients, are constantly and sometimes desperately seeking a solution to provide relief. Many a patient and surgeon attempt a myriad of interventions, such as weight loss, physical therapy, oral medications, and intra-articular injections, until their efficacy decreases and the specter of surgery reveals itself as a last resort. Yet, while there are those who eagerly pursue surgical reconstruction, not all patients share the same level of interest nor are even appropriate candidates for such. So, in the spirit of Ponce de León and his quest for the Fountain of Youth, we, as scientists, have sought alternate solutions and have developed various biologic options. Platelet-rich plasma (PRP) is but one of these, and its effectiveness in our fight against knee OA pain remains debatable and under scrutiny.
In the RESTORE trial published in JAMA², Bennell et al. provide a data point that demonstrates no significant difference between PRP and placebo in the treatment of knee OA in terms of both pain and radiographic appearance. Under randomized and triple-blinded (participant, injector, assessor) conditions, their study evaluated 288 community-based patients who were ≥50 years old and had symptomatic, medial knee OA that was rated as Kellgren-Lawrence Grade 2 or 3. Each patient underwent 3 weekly injections of either leukocyte-poor PRP or saline (n =144 in each group) and were followed for 12 months. Primary outcomes for treatment with PRP vs. placebo injection were limited to 12-month change in overall average knee pain scores (−2.1 vs. −1.8; p =0.17) and percentage change in medial tibial cartilage volume as assessed by MRI (−1.4% vs. −1.2%; p = 0.81). There were 31 secondary outcomes that evaluated pain, function, quality of life, global change, and joint structures at 2 and/or 12-month follow-up. Of these, the only outcomes that demonstrated a clinically notable difference of PRP vs. placebo injection were global improvement overall at 2 months (48.2% vs. 36.2%; p =0.02), global improvement in function at 12 months (42.8% vs. 32.1%; p =0.05), and ≥3 areas of cartilage thinning (17.1% vs. 6.8% [PRP vs. placebo]; p = 0.02).
While this study demonstrated trends, it failed to show any clinically notable difference in primary outcomes between PRP and placebo injections. Regarding the secondary outcomes in which clinical importance was shown, we aren’t given enough detail to attempt to apply the results to the patient-at-large. As the study cites, the cost per injection of PRP is $2,032 per injection, leading to a total cost of $6,096 for a complete series. Additionally, it is known that repeat intra-articular procedures create potential infection risks to patients. These, combined with the lack of clinical superiority, makes the use of PRP in the setting of knee OA highly debatable. This further validates and potentially expands the American Association of Hip and Knee Surgeons, Hip Society, and Knee Society position statement on the use of biologics in advanced hip and knee arthritis, in which they state that PRP injections cannot be recommended, and that they do not support its routine clinical use3.
While the trends and statistics may be viewed from countless perspectives, we must always take the one view that is of ultimate concern: that of our patient. Whether this intervention is offered or not in one’s clinic, we must act as responsible stewards of the data and resources, counseling our patients so that they are aware of the options that they have and can make their own decisions based on our best recommendations and their own life’s circumstances.
David Vizurraga, MD is a San Antonio-based orthopaedic surgeon specializing in adult hip and knee reconstruction and a member of the JBJS Social Media Advisory Board.
- Cui A, Li H, Wang D, Zhong J, Chen Y, Lu H. Global, regional prevalence, incidence and risk factors of knee osteoarthritis in population-based studies. EClinicalMedicine. 2020;29:100587.
- Bennell KL, Paterson KL, Metcalf BR, Duong V, Eyles J, Kasza J, Wang Y, Cicuttini F, Buchbinder R, Forbes A, Harris A, Yu SP, Connell D, Linklater J, Wang BH, Oo WM, Hunter DJ. Effect of intra-articular platelet-rich plasma vs placebo injection on pain and medial tibial cartilage volume in patients with knee osteoarthritis: the RESTORE randomized clinical trial. JAMA. 2021;326(20):2021-30.
- Browne JA, Nho SJ, Goodman SB, Della Valle CJ. American Association of Hip and Knee Surgeons, Hip Society, and Knee Society position statement on biologics for advanced hip and knee arthritis. The Journal of Arthroplasty. 2019;34(6):1051-2. Epub 2019 Apr 1.