Osteoarthritis: The Problem
Osteoarthritis, a leading cause of disability, affects the knee more than any other joint. The incidence of osteoarthritis is increasing dramatically, this may be due to the increasingly aged population and the obesity epidemic. The number of knee replacements has significantly increased, and this is concerning because this is a costly procedure and is a difficult procedure to recover from.
Osteoarthritis is the result of an imbalance between the breakdown and repair of joint tissue along with cellular and biochemical changes within the joint. It is now understood that there are metabolic pathways that can be targeted for biologic intervention. PRP is one such intervention.
PRP Described
PRP is an autologous preparation, that is, it is derived from the patient’s own tissue, and as such there is virtually no risk of immunologic reactions or infectious disease transfer. PRP has a high concentration of platelets in a small volume of plasma. The concentration of platelets may be as high as five times the levels found in blood.
PRP has been shown to have a regenerative effect on tissue and is at least as effective, if not more effective as hyaluron and steroid injections for symptom control. However, steroids have the potential to negatively affect cartilage health.
PRP contains growth factors and 70% of these are released in the first ten minutes after administration and the remaining growth factors are released within the first hour. These growth factors Link to GF section are responsible for tissue healing and cartilage regeneration.
The Current National Institute for Health Care Excellence confirms that PRP injections for knee osteoarthritis pose no major safety concerns. The application of this therapy in a clinic setting has the potential of eliminating the expense of hospital care and potentially avoiding the need for joint surgery.
The Study
This study was designed to test the feasibility of administering PRP in a clinic setting. The treatment protocol consisted of three injections given one month apart. PRP was prepared using a two-spin centrifuge process with anticoagulation agents added. Twelve patients participated in the study. Injections were well tolerated with the only adverse event reported as pain and stiffness for two days in one patient.
Results
Patient outcome goals included being pain-free, decreased knee stiffness, prevention of surgical knee replacement, and improved mobility.
At the end of four months:
Seven patients (58.3%) were very satisfied, four patients (33.3%) were satisfied, and one patient (8.3%) was not satisfied.
In terms of goal achievement:
Five patients (45.5%) felt they had fully met their goals, five patients (45.5%) felt they had partially met their goals, and one patient (9%) felt they had not met their goals.
The later patient was the one reporting pain and stiffness for two days after the procedure. Two patients reported complete resolution of pain at four months, two patients reported persistence of constant pain and the remaining four patients reported intermittent pain, but the intermittent pain score was 24.7 points versus 53.8 points at baseline. Mean self-reported health utility increased at follow up.
Discussion
The authors chose goal-oriented outcomes rather than universally applied outcomes because they feel it reflects patients’ priorities and simplifies patient decision making. The outcomes of this study align with findings from medical literature.
It should be noted that the follow up period in this study was four months, which is too short a period to determine if the goal of avoiding surgery was met.
Summary
This study supports the feasibility, safety, and efficacy of clinic based PRP administration. PRP is associated with significant improvement in pain, health utility and patient satisfaction.
Reference
Glynn, LG, Mustafa, A, Casey, M, et al. (2018). Platelet-rich plasma (PRP) therapy for knee arthritis: A feasibility study in primary care. BMC, 4:93
https://doi.org/10.1186/s40814-018-0288-2
