Background: Aneurysmal bone cysts are benign,
non-neoplastic, highly vascular 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 options and prognosis
for patients with this condition.
Methods: Forty consecutive patients with an aneurysmal
bone cyst of the pelvis 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 were acetabular,
and seven were ischiopubic. Seven involved the hip joint, and two
involved the sacroiliac joint. All twelve sacral lesions extended
to more than one sacral segment and were associated with neurological
signs and symptoms. Destructive acetabular lesions were associated
with pathological 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 lesion had surgical treatment (twenty-one
had excision-curettage and fourteen had intralesional excision);
two patients also had adjuvant radiation therapy. Of the thirty-five
patients, five (14%) had a local recurrence noted less
than eighteen months after the operation. Of five patients initially
treated for a recurrent lesion, one had a local recurrence. At the
latest follow-up examination, all forty patients were disease-free
and twenty-eight (70%) were asymptomatic. There were two
Conclusion: Aneurysmal bone cysts of the pelvis
and sacrum are usually aggressive lesions associated with substantial
bone destruction, pathological fractures, and local recurrence.
Current management recommendations include preoperative selective arterial
embolization, excision-curettage, and bone-grafting.