Why should PRP be considered for knee osteoarthritis?
Pain and loss of function are characteristic of osteoarthritis of the knee. Knee osteoarthritis is expected to increase in prevalence due to a significant number of older persons with a body mass index greater than 24. Traditional measures such as NSAIDs, corticosteroids, and surgery can have adverse effects and are not always as effective as one would like. PRP is a newer treatment option that has a high safety profile and emerging evidence suggests that it is effective in treating OA and painful conditions.
PRP is harvested from the patient’s own blood and contains a high volume of a number of different growth factors. These growth factors are believed to modulate the inflammation that contributes to cartilage degradation.
What type of studies have been done?
A prospective study by Moretti and colleagues (2022) was designed to assess the clinical effects of PRP in knee osteoarthritis on pain, range of motion, and functional ability. One hundred and fifty-three patients with mild to moderate knee osteoarthritis were enrolled in the study. Patients were evaluated for pain, stiffness, range of motion, knee stability, alignment, and functional ability to walk and limb stairs. Five milliliters of a 5% concentrate of PRP were injected for a total of three times at one-week intervals. Interestingly, all patients received antibiotics post-procedure even though there was no evidence of infection reported. Ice and Tylenol were prescribed for local pain. No adverse effects were reported.
What were the results of this study?
Patients experienced improved function and decreased pain of approximately 8% at one month, 12% at three months, and 19% at six months. Stiffness, range of motion, knee stability, alignment, and functional ability to walk and climb stairs improved at all evaluation points: 1.2% improvement at one month, 6.17% improvement at three months, and 8.64% improvement at six months. A second measure of pain (visual analog scale) showed decreased pain at all evaluation points with an approximately 39% improvement at six months. MRI scans showed tibial and femoral plate increased thickness at six months, although the increase was not significant.
The authors suggest that triple PRP injections are more effective than one or two injections in treating knee osteoarthritis. Best results were seen at six months.
Reference
Moretti, L., Maccagnano, G., Coviello, M. et al. (2022). Platelet-rich plasma injections for knee osteoarthritis treatment: A prospective clinical study. J. Clin. Med. 11, 2640. https://doi.org/10.3390/jcm11092640
