Bilateral knee pigmented villonodular synovitis in a young adult: Radiologic diagnosis and surgical approach.

Pigmented villonodular synovitis is a rare proliferative disorder of the synovial joints, characterized by synovial thickening and hemosiderin deposition. It predominantly affects the knee joint, with bilateral involvement being exceedingly rare. We present a case of diffuse bilateral pigmented villonodular synovitis in a 20-year-old female, initially presenting with left knee pain and swelling, diagnosed via MRI. Following an open total synovectomy, the patient developed postoperative stiffness, requiring arthroscopic arthrolysis. Subsequently, similar symptoms emerged in the right knee, leading to a second synovectomy and subsequent arthrolysis. Despite the challenges associated with managing this condition, including a high recurrence rate and postoperative stiffness, the patient showed significant improvement 1 year postoperatively. This case underscores the importance of thorough synovectomy and highlights the potential need for further surgical intervention to address complications such as stiffness.