Interdisciplinary Management of an Intra-Articular Venous Malformation of the Left Knee in a Pediatric Patient

Intra-articular venous malformations of the knee are rare congenital vascular lesions that frequently present with nonspecific symptoms, leading to diagnostic delays and an increased risk of joint damage. We report the case of a 13-year-old girl with progressive knee pain, swelling, and restricted mobility. Magnetic resonance imaging revealed a venous malformation involving both intra-articular and juxta-articular structures of the left knee. Management consisted of ultrasound-guided sclerotherapy with polidocanol and bleomycin performed by vascular surgery, followed by arthroscopic debridement and synovectomy by the orthopedic surgery team. The patient experienced an uncomplicated recovery with decreased knee volume, significant pain reduction, and improved gait. Histopathology confirmed a venous malformation with reactive hemosiderotic synovitis. This case highlights the importance of considering venous malformations in pediatric patients with unexplained knee symptoms and demonstrates the effectiveness of a minimally invasive, multidisciplinary approach in preventing long-term joint damage.