Efficacy of PRP versus hyaluronic acid in obese individuals with knee osteoarthritis: a retrospective study.

INTRODUCTION: Obesity is a common comorbidity in patients with knee osteoarthritis (KOA). Both viscosupplementation and platelet-rich plasma (PRP) intra-articular injections may alleviate KOA symptoms. To better guide patient selection for PRP therapy, we compared the outcomes of these treatments in obese individuals. MATERIALS AND METHODS: This retrospective study included 99 obese patients who received intra-articular injections of either PRP (n = 43) or hyaluronic acid (HA, n = 56) between January 2014 and October 2017. The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), visual analogue scale (VAS), and range of motion (ROM) were assessed before the injection and at 15 days, 6 months, 12 months, and the final follow-up. Outcomes were then compared between the two treatment groups. RESULTS: Obese patients treated with HA had a higher rate of arthroplasty (35.7% vs. 9.3%, p = 0.002), reduced ROM, poorer VAS and WOMAC scores, and a higher overall risk of arthroplasty (log-rank p = 0.177) compared with those treated with PRP. Cox proportional hazards analysis indicated a non-significant trend toward a reduced risk of knee arthroplasty in the PRP group (HR = 0.46, 95% CI 0.15-1.42, p = 0.176) over average follow-up of 16.5 month for all patients. CONCLUSIONS: Intra-articular PRP injections were associated with better outcomes than HA in obese patients with KOA. PRP may delay the need for arthroplasty and could serve as a valuable therapeutic option for selected patients who do not respond to conventional treatments. Due to several limitations, further large-scale studies are warranted to confirm the effectiveness of this promising approach in this high-risk population.