66 patients with Kellgren-Lawrence grade II–III knee osteoarthritis compared four intra-articular injection strategies: platelet-rich plasma (PRP) Plasma Gel combined with hyaluronic acid (HA) and corticosteroid, HA + corticosteroid, PRP Plasma Gel + corticosteroid, and corticosteroid alone. Outcomes of interest included pain, function, fatigue, activity level, patient perception of improvement, and quality-of-life measures. All treatment groups demonstrated clinical improvement at 1 month, though the combination of PRP Plasma Gel, HA, and corticosteroid produced the greatest and most sustained improvements at 3 months. PRP Plasma Gel + corticosteroid and HA + corticosteroid showed intermediate benefits, whereas corticosteroid alone demonstrated the least durable response. These findings suggest that combining PRP Plasma Gel with HA and corticosteroid may provide superior short-term outcomes for patients with knee osteoarthritis.