Background: While severe knee osteoarthritis (OA) requires surgery, most patients suffering mild OA symptoms need only medical management. Evidence of intra-articular injection with autologous photo-activated platelet-rich plasma (PA-PRP) has been limited to the findings from a pilot study in a controlled setting with a small sample size. The authors reported a 2-year experience with the use of PA-PRP in patients with OA of the knee.

Objective: To report the clinical outcomes of PA-PRP injection in treatment of OA of the knee.

Materials and Methods: Demographic and clinical data of all patients with knee OA that received PA-PRP injection at Bumrungrad International Hospital between May 2014 and May 2016 were analyzed. Clinical outcome was assessed at baseline before the first, second, and third dose, and 1, 3, 6, 9, 12, 18, 24 months after the PA-PRP injection using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC).

Results: Thirty-two patients received PA-PRP during the study period. Forty percent of these patients had OA of both knees. Baseline WOMAC score of 39.2 on average was reduced by one-third after the first dose of PA-PRP. Three months after the full course of three doses, WOMAC score was improved by 80% from baseline. Six patients (5.3%) got worse WOMAC scores after their first dose of PA-PRP, but insisted on completing the course and eventually saw clinical improvement.

Conclusion: Clinical benefits of PA-PRP injection could last for approximately three months after a full course of injection. Worse WOMAC score after the first injection might occur in 5% of the patients.

Keywords: Knee osteoarthritis, Platelet rich plasma

Received 3 May 2017 | Revised 1 Sep 2017 | Accepted 4 Sep 2017