Posteromedial Arthroscopic Treatment of a Persistent Baker's Cyst Following Total Knee Arthroplasty: A Case Report.

CASE: A 55-year-old man underwent total knee arthroplasty (TKA) for advanced osteoarthritis. A small preoperative Baker's cyst enlarged postoperatively, causing progressive posterior knee swelling and restricted flexion. Conservative treatment, including aspiration and corticosteroid injection, failed. Posteromedial arthroscopic decompression was performed. At 14-month follow-up, the patient was pain-free with full range of motion and no clinical evidence of recurrence. CONCLUSION: Posteromedial arthroscopy is an effective minimally invasive option for persistent symptomatic Baker's cysts following TKA.