Successful Management of Radiation-Associated Insufficiency Fracture of the Tibial Plateau with Low-Intensity Pulsed Ultrasound

Objective: Unusual or unexpected effect of treatment Background: Clinical management of radiation-associated pathological fracture is challenging because of a high nonunion rate and potential for morbidity. We report a case of radiation-associated insufficiency fracture of the tibial plateau after surgery, perioperative chemotherapy, and adjuvant radiation therapy for synovial sarcoma of the proximal calf that was successfully treated with low-intensity pulsed ultrasound (LIPUS). Case Report: A healthy 52-year-old Japanese woman presented with a slowly growing, painful soft tissue mass over her proximal calf. Histological examination of core needle biopsy specimens led to a pathological diagnosis of synovial sarcoma. After perioperative ifosfamide and doxorubicin chemotherapy and surgical resection, adjuvant radiation therapy was administered, with a total of 60 Gy in 30 fractions. At 5 months after surgery and 2 months after the completion of radiation therapy, she developed an insufficiency pathological fracture of the proximal tibia without any apparent trauma. The patient was treated with LIPUS for 1 year. There was no collapse or deformity of the knee joint. The patient remained free of symptoms and had no recurrences for 2 years after surgery. Conclusions: This is the first report of radiation-associated pathological fracture that was successfully treated with LIPUS. LIPUS could be a safe and effective treatment option in the management of radiation-associated pathological fractures.