Ultrasound-Guided Aspiration of Baker’s Cyst Combined With Intracystic Platelet-Rich Plasma Injection in Knee Osteoarthritis

Objective: The aim of the study was to evaluate whether ultrasound (US)-guided aspiration of Baker’s cyst (BC) followed by intracystic platelet-rich plasma (PRP) injection reduces pain, improves functional outcomes, and decreases cyst size. Design: Thirty-six patients with Kellgren-Lawrence grade 1-3 knee osteoarthritis (KOA) and BC were randomized into two groups. Group A underwent cyst aspiration alone, while Group B received aspiration followed by intracystic PRP injection. Assessments were performed at baseline, 6 weeks, and 12 weeks using the Numerical Rating Scale (NRS), the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and ultrasonographic cyst measurements. Results: In Group A, WOMAC pain, function, and total scores improved at both follow-ups, whereas NRS and WOMAC stiffness improved only at 6 weeks; cyst size remained unchanged. In Group B, significant improvements were found in NRS, all WOMAC subscales, and cyst size at both evaluations. At week 12, between-group analysis demonstrated greater pain relief and superior WOMAC scores in Group B, although cyst size reduction was similar between groups. Conclusion: US-guided aspiration combined with intracystic PRP provided superior pain relief and functional improvement compared to aspiration alone in KOA patients with BC.