One-Year Clinical Outcomes of GPS Leukocyte-Rich Platelet-Rich Plasma Injection for Kellgren-Lawrence Grade II and III Knee Osteoarthritis: A Real-World Case Series

Abstract Background Knee osteoarthritis (OA) is a major cause of pain, impaired walking ability, locomotive dysfunction, and future care dependency in older adults. Although medication, intra-articular hyaluronic acid injection, and rehabilitation are commonly used, some patients have persistent symptoms and may ultimately require total knee arthroplasty. However, surgery may not be feasible or acceptable for older patients because of age, comorbidities, surgical risk, or personal preference. Methods This retrospective real-world case series evaluated 15 patients with symptomatic Kellgren-Lawrence (KL) grade II or III knee OA who underwent a single intra-articular GPS leukocyte-rich platelet-rich plasma (L-PRP) injection and completed baseline and 1-year assessments. Knee OA was evaluated using radiography and magnetic resonance imaging. Pain was assessed using the numeric rating scale (NRS), knee-related symptoms and function using the Knee injury and Osteoarthritis Outcome Score (KOOS), and locomotive function using the 25-question Geriatric Locomotive Function Scale. Patient satisfaction and adverse events were recorded. Paired baseline and 1-year outcomes were compared using Wilcoxon signed-rank tests. Results The cohort included 15 knees from 5 male and 10 female patients. Among men, 2 had KL grade II and 3 had grade III disease; among women, 7 had KL grade II and 3 had grade III disease. Mean NRS pain score improved significantly from 4.6 +/- 2.4 at baseline to 2.7 +/- 2.1 at 1 year (P = 0.015). The KOOS quality-of-life subscale also improved significantly (30.0 +/- 17.1 to 45.4 +/- 23.8; P = 0.010). A satisfaction score of 5 was reported by 74% of patients, and 81% reported a score of 4 or higher. Three patients reported transient injection-site pain; no serious adverse events occurred. Conclusions GPS L-PRP injection was associated with significant 1-year improvement in pain and knee-related quality of life in patients with KL grade II or III knee OA, with high satisfaction and no serious adverse events. These preliminary findings support GPS L-PRP as a potential self-funded nonoperative option for selected patients who wish to avoid or delay surgery.