The Efficacy of Platelet-Rich Plasma Injection Therapy in Obese versus Non-Obese Patients with Knee Osteoarthritis: A Comparative Study

Abstract

<p><strong>Background/Objectives</strong>: Obesity is a common comorbidity in knee osteoarthritis (KOA) patients. Platelet-Rich Plasma (PRP) injection therapy may mitigate KOA. To further clarify potential patient selection for PRP injection therapy, we compared the outcomes in patients with different body mass index (BMI). <br></p><p><strong>Methods</strong>: A total of 91 patients with mild to moderate KOA were treated with three intra-articular PRP injections at 10 to 14-day intervals. Range of motion (ROM), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and Visual Analogue Scale (VAS) were documented before and after the injections at 15 days, 6 months, 12 months, and at the last follow-up. Outcomes were compared between patients with a BMI over 30 kg/m² (obese, n = 34) and under 30 kg/m² (non-obese, <em>n</em> = 57). <br></p><p><strong>Results</strong>: Significant difference during the follow-up was detected in WOMAC score at the last follow-up favouring BMI under 30 group [17.8 ± 18.8 versus 10.5 ± 11.7, <em>p</em> = 0.023]. The odds ratio (OR) in BMI over 30 kg/m² group for total knee arthroplasty was 3.5 (95% CI 0.3-40.1, <em>p</em> = 0.553), and OR for any arthroplasty was 7.5 (95% CI 0.8-69.8, <em>p</em> = 0.085) compared to non-obese patients. <br></p><p><strong>Conclusions</strong>: Obese patients benefitted from PRP injections in KOA but there is a minimal difference favouring non-obese patients in symptom alleviation in follow-up stages after 12 months. The risk of arthroplasty is higher for obese KOA patients.</p>