A Case of an Aggressive Intraosseous Arteriovenous Malformation in the Lower Extremity: Special Considerations for Diagnosis and Management

Background: Arteriovenous malformations (AVMs) are rare, congenital vascular anomalies. Intraosseous AVMS most frequently arise in the head and neck, with only a small fraction occurring in the extremities. Herein, we report the findings of a combined soft tissue and intraosseous AVM involving the lower extremity of a 13-year-old child. This case highlights the necessity of an interdisciplinary approach for the effective treatment and management of these rare vascular anomalies. Case Description: A 13-year-old female presented with a 4-year history of intermittent pain and swelling over her right lateral malleolus. The patient was evaluated with radiologic imaging revealing an AVM involving the right distal leg, ankle, and hindfoot with intraosseous involvement of the distal tibia and talus. She was then referred to Vascular and Plastic Surgery and an angiogram was performed demonstrating shunting from the anterior tibial, peroneal, and posterior tibial arteries to the AVM. Venous drainage was to the anterior tibial and greater saphenous veins. Three embolizations were performed over the course of 6 months. Following the third embolization, the patient was taken to the operating room where Plastic and Orthopedic Surgery performed total resection of the nidus and involved bone which was then grafted with injectable synthetic bone graft. Results: Successful resection of the nidus was achieved, and the patient had an uncomplicated recovery. Within 6 months postoperatively, the patient demonstrated full range of lower extremity motion and was able to participate in age appropriate gross motor activities. Radiologic evaluation 7 months postoperatively showed no evidence of nidus recurrence. Conclusion: Intraosseous involvement of AVMS is rare and presents a therapeutic challenge due to its invasive potential and high incidence of recurrence. Wide local excision with bone grafting and interdisciplinary management are paramount for complete resection.