Abstract
BACKGROUND: Aneurysmal bone cyst (ABC) is a benign but locally aggressive bone tumor. Involvement of the proximal fibula is uncommon and represents a unique surgical challenge due to the proximity of the common peroneal nerve (CPN) and the lateral stabilizing structures of the knee. The optimal surgical management of ABC in this location remains controversial. METHODS: A retrospective case series was conducted including patients with histologically confirmed ABC of the proximal fibula treated with proximal fibulectomy between October 2018 and November 2023. All patients had a minimum follow-up of 24 months. Clinical and functional outcomes were evaluated using the Musculoskeletal Tumor Society (MSTS) score. Secondary outcomes included recurrence, peroneal nerve–related complications, knee instability, and other procedure-related complications. RESULTS: Nine patients with proximal fibular ABC were included. The mean follow-up duration was 26.8 ± 2.8 months. Proximal fibulectomy achieved local tumor control in all patients, with no local recurrence observed during the follow-up period. The mean MSTS score at final follow-up was 25.3 ± 1.8. Transient peroneal nerve palsy occurred in three patients and resolved spontaneously, while one patient had persistent weakness in ankle and great toe dorsiflexion at final follow-up. No patient developed clinically significant knee instability. CONCLUSION: Proximal fibulectomy is a safe and effective treatment option for ABC of the proximal fibula, providing excellent local control with satisfactory functional outcomes and should be considered in selected cases.