Treatment of aneurysmal bone cysts of the pelvis and sacrum

Background: Aneurysmal bone cysts are benign, non-neoplastic, highly vascul ar bone lesions. The purpose of this study was to describe the prevalence, the clinical presentation, and the recurrence rate of aneurysmal bone cysts of the pelvis and sacrum and to examine the diagnostic and therapeutic opt ions and prognosis for patients with this condition. Methods: Forty consecutive patients with an aneurysmal bone cyst of the pel vis and/or sacrum were treated from 1921 to 1996. Their medical records and radiographic and imaging studies were reviewed, and histological sections from the cysts were examined. Seventeen lesions were iliosacral, sixteen we re acetabular, and seven were ischiopubic. Seven involved the hip joint, an d two involved the sacroiliac joint. All twelve sacral lesions extended to more than one sacral segment and were associated with neurological signs an d symptoms. Destructive acetabular lesions were associated with pathologica l fracture in five patients and with medial migration of the femoral head, hip subluxation, and hip dislocation in one patient each. The mean duration of follow-up was thirteen years (range, three to fifty-three years). Results: Thirty-five patients who were initially treated for a primary lesi on had surgical treatment (twenty-one had excision-curettage and fourteen h ad intralesional excision); two patients also had adjuvant radiation therap y. Of the thirty-five patients, five (14%) had a local recurrence noted les s than eighteen months after the operation. Of five patients initially trea ted for a recurrent lesion, one had a local recurrence. At the latest follo w-up examination, all forty patients were disease-free and twenty-eight (70 %) were asymptomatic. There were two deep infections. Conclusion: Aneurysmal bone cysts of the pelvis and sacrum are usually aggr essive lesions associated with substantial bone destruction, pathological f ractures, and local recurrence. Current management recommendations include preoperative selective arterial embolization, excision-curettage, and bone- grafting.