title: Hydroxyapatite crystals as a bone graft substitute in benign lytic lesions of bone.
abstract: BACKGROUND
  Bone grafts are required to fill a cavity created after curettage of benign lytic lesions of the bone. To avoid the problems associated at donor site with autologous bone graft, we require allograft or bone graft substitutes. We evaluated the healing of lytic lesions after hydroxyapatite (HA) grafting by serial radiographs.
  
  
  METHODS
  Forty cases of benign lytic lesions of bone were managed by simple curettage and grafting using HA blocks. Commercially available HA of bovine origin (Surgiwear Ltd., Shahjahanpur, India) was used for this purpose. Mean duration of followup was 34.8 months (range 12-84 months). Mean patient age was 19.05 years (range 3-55 years). Radiological staging of graft incorporation was done as per criteria of Irwin et al. 2001.
  
  
  RESULTS
  In our series, two cases were in stage I. A total of 11 cases were in stage II and 27 were in stage III. Graft incorporation was radiologically complete by 15 months. Clinical recovery was observed before radiological healing. The average time taken to return to preoperative function was 3 months. Recurrence was observed in giant cell tumor (n = 3) and chondromyxoid fibroma (n = 1). There was no incidence of graft rejection, collapse, growth plate disturbances or antigenic response.
  
  
  CONCLUSIONS
  We conclude that calcium HA is biologically acceptable bone graft substitute in the management of benign lytic lesions of bone.
authors.affiliation: Department of Orthopaedics, G.S.V.M. Medical College, Kanpur, Uttar Pradesh, India.
authors.forename: Anil Kumar
authors.initials: AK
authors.lastname: Gupta
authors.affiliation: Department of Orthopaedics, G.S.V.M. Medical College, Kanpur, Uttar Pradesh, India.
authors.forename: Praganesh
authors.initials: P
authors.lastname: Kumar
authors.affiliation: Department of Orthopaedics, G.S.V.M. Medical College, Kanpur, Uttar Pradesh, India.
authors.forename: Kumar
authors.initials: K
authors.lastname: Keshav
authors.affiliation: Department of Orthopaedics, G.S.V.M. Medical College, Kanpur, Uttar Pradesh, India.
authors.forename: Anant
authors.initials: A
authors.lastname: Singh
keywords: Benign lytic lesions of bone; Grafts; bone graft substitute; bone neoplasms; hydroxyapatite; hydroxyapatite crystals