Surgical treatment and long-term results of single-center unicameral bone cysts and aneurysmal bone cysts wi̇th long and medium bone localization

Although various treatment modalities have been described for aneurysmal bone cysts (ABCs) and unicameral bone cysts (UBCs), there is currently no consensus regarding the optimal approach. The primary goals of treatment are cyst decompression, early mobilization of the affected extremity, and prevention of complications. This study aims to present the long-term clinical, radiological, functional, and oncological outcomes, as well as complication rates, of patients who underwent surgical treatment for ABCs and UBCs. Between January 2011 and December 2024, a total of 73 patients, including 47 with UBC and 26 with ABC localized in long or mid-diaphyseal bones, underwent surgical treatment at the Department of Orthopedics and Traumatology, Fırat University Medical Faculty. Patients with a minimum of one year of follow-up were retrospectively analyzed. Preoperative magnetic resonance imaging (MRI), surgical records, clinical history, biopsy results, and postoperative radiographs were reviewed. Patients were evaluated in terms of healing time, clinical and radiological improvement, and complications. The mean age at diagnosis among the 26 ABC patients was 14 years, with 14 females and 12 males. The most frequently applied surgical methods were allograft with plate fixation (38.5%) and allograft alone (34.6%). These were followed by autograft with plate (7.7%) and allograft with intramedullary nailing (7.7%). The average healing time was 9.62 months. Recurrence occurred in 3 patients (11.5%), with lesions localized to the humerus and tibia. Among the 47 UBC patients, the mean age at diagnosis was 21 years; 28 were male and 19 female. The most commonly used treatments included allograft (19.1%), steroid injection (17%), and allograft with plate (14.9%). According to the modified Neer scoring system, complete healing was observed in 78.7% of patients, partial healing in 14.9%, and poor healing in 6.4%. The average healing time was calculated as 8.96 months. Recurrence was noted in 9 patients (14.9%), 5 of whom had humeral involvement. No statistically significant difference was found between the type of surgical technique and recurrence rates in ABC cases. Surgical modalities performed in conjunction with extended curettage appear to yield similarly favorable long-term outcomes. Additionally, the presence of pathological fractures did not significantly affect the healing time. In UBC cases, no reoperation was required in patients treated with allograft or autograft, suggesting that these methods may be more effective. Furthermore, patients treated with autograft demonstrated a statistically shorter healing time. Recurrence occurred in 4 of 8 patients who received steroid injections, indicating moderate efficacy. Healing time was also found to be statistically shorter in UBC patients with pathological fractures. Keywords: unicameral bone cyst, aneurysmal bone cyst, surgical treatment, recurrence