title: Clinical and radiological results of impaction bone allograft technique in acetabular revisions associated with massive bone stock deficiencies: Four to seven years follow-up study.
abstract: BACKGROUND
  We conducted this retrospective study to evaluate the medium- term results of impaction bone allograft technique when used on its own with cemented cups in acetabular revisions associated with massive bone loss.
  
  
  METHODS
  This study involved 28 hips in 27 patients classified as severe acetabular deficiencies (Paprosky type 3) secondary to aseptic loosening. All were revised with impacted morsellised bone allograft using fresh-frozen and freeze-dried bone together with cemented rim bearing UHMWP (28 mm I.D.) cups and followed for an average of 72 months (range 48 to 91 m). Clinical assessment was based on the Harris Hip Score (HHS). Radiological assessment included measurement of cup migration using image analysis computer software as well as assessment of graft incorporation.
  
  
  RESULTS
  Clinically, HHS improved from pre-operative average of 24.9 to average of 78 at the last follow-up. One hip was revised at 12 months postoperatively due to aseptic loosening. Survivorship for the cup with endpoint revision for any reason was 96.4%. Radio-logically, the average of superior migration was 1.53 mm; average of medial migration was 0.59 mm. 92.8% of hips showed radiographic evidence of graft incorporation. Cup survival rate with aseptic loosening as endpoint was 92.85%.
  
  
  CONCLUSIONS
  The technique of impaction bone grafting using morsellised fresh frozen bone allograft appears to be a valuable biological option in such patients, with encouraging results, but further follow-up is required to establish the longer term outcome of these reconstructions. (Hip International 2005; 15: 46-51).
authors.affiliation: Joint Replacement Research Unit, East Surrey Hospital Redhill, Surrey - UK.
authors.forename: S
authors.initials: S
authors.lastname: El-Kawy
authors.forename: D
authors.initials: D
authors.lastname: Hay
authors.forename: K
authors.initials: K
authors.lastname: Drabu