Ultrasound-Guided Aspiration of Baker's Cyst Combined With Intracystic Platelet-Rich Plasma Injection in Knee Osteoarthritis: A Randomized Controlled Trial.

Abstract

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. 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. 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. US-guided aspiration combined with intracystic PRP provided superior pain relief and functional improvement compared to aspiration alone in KOA patients with BC.