title: Treatment of aneurysmal bone cysts of the pelvis and sacrum.
abstract: 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 deep infections.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Mayo Clinic and Mayo Foundation, Rochester, Minnesota 55905, USA.
authors.forename: P J
authors.initials: PJ
authors.lastname: Papagelopoulos
authors.forename: S N
authors.initials: SN
authors.lastname: Choudhury
authors.forename: F J
authors.initials: FJ
authors.lastname: Frassica
authors.forename: J R
authors.initials: JR
authors.lastname: Bond
authors.forename: K K
authors.initials: KK
authors.lastname: Unni
authors.forename: F H
authors.initials: FH
authors.lastname: Sim
mesh_terms: D000293:Adolescent; D000328:Adult; D017824:Bone Cysts, Aneurysmal / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000532:radiotherapy / Q000601:surgery*; D002648:Child; D002675:Child, Preschool; D003131:Combined Modality Therapy; D005260:Female; D006801:Humans; D008297:Male; D010388:Pelvis / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D011183:Postoperative Complications / Q000453:epidemiology; D015995:Prevalence; D011859:Radiography; D012008:Recurrence; D012447:Sacrum / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D016896:Treatment Outcome