title: Treatment of unicameral bone cysts in pediatric patients with an injectable regenerative graft: a preliminary report.
abstract: BACKGROUND
  Multiple treatment modalities exist for unicameral bone cysts (UBC), including steroid injection, autologous bone marrow injection, mechanical decompression, intramedullary fixation, curettage, and bone grafting. All have their own potential limitations such as high recurrence rates, cyst persistence, need for multiple procedures, and prolonged immobilization. A minimally invasive regimen consisting of curettage, decompression, and injection of a calcium sulfate-calcium phosphate (CaSO4-CaPO4) composite has been utilized at our institution in an attempt to obtain optimal results for the treatment of UBCs in the pediatric population.
  
  
  METHODS
  We retrospectively evaluated 16 patients with pathologically confirmed UBC who were treated with curettage, decompression, and injection of a calcium sulfate-calcium phosphate composite between April 2006 and August 2010 at a single institution. The average age of the patients at time of surgical intervention was 9.4 years of age (range, 3 to 16 y). Average follow-up was 16 months (range, 6 to 36 mo). Radiographic healing, clinical outcomes, and complications were evaluated.
  
  
  RESULTS
  Final follow-up radiographs demonstrated healing in 93.7% (15 of 16) of patients after a single procedure. Complete healing was observed in 14 of 16 patients and partially healed with a defect in 1 of 16 patients. One patient had a persistent cyst but did not wish to receive further treatment. All patients returned to full activities including sports on average at 3.1 months (range, 1 to 6 mo) and were asymptomatic on most recent follow-up. No postoperative complications, including refracture, were observed.
  
  
  CONCLUSIONS
  Curettage, decompression, and injection of a calcium sulfate-calcium phosphate composite for UBC in the pediatric population demonstrates encouraging results with low recurrence rates and complications compared with conventional methods.
  
  
  METHODS
  Case series, Level of Evidence IV.
authors.affiliation: Department of Orthopaedics, Riverside County Regional Medical Center, Moreno Valley, CA 92555, USA. johnnygentile@hotmail.com
authors.forename: John V
authors.initials: JV
authors.lastname: Gentile
authors.forename: Carl R
authors.initials: CR
authors.lastname: Weinert
authors.forename: John A
authors.initials: JA
authors.lastname: Schlechter
mesh_terms: D000293:Adolescent; D001845:Bone Cysts / Q000473:pathology / Q000628:therapy*; D001861:Bone Regeneration; D002130:Calcium Phosphates / Q000008:administration & dosage*; D002133:Calcium Sulfate / Q000008:administration & dosage*; D002648:Child; D002675:Child, Preschool; D003131:Combined Modality Therapy; D003475:Curettage; D005260:Female; D006801:Humans; D007267:Injections; D008297:Male; D012189:Retrospective Studies
chemical_list: D002130:Calcium Phosphates; C020243:calcium phosphate; D002133:Calcium Sulfate