title: Contoured iliac crest allograft interposition for pericapsular acetabuloplasty in developmental dislocation of the hip: technique and short-term results.
abstract: BACKGROUND
  Pericapsular acetabuloplasty procedures have been widely used as an integral component of combined surgery to treat developmental hip dislocation after walking age. The stability of the acetabuloplasty and the maintenance of the acetabular correction will depend on the structural integrity of the iliac crest autograft, which, traditionally, has been inserted as the interposition material. Problems related to the use of an autograft have been encountered by various surgeons-including the authors-namely, graft displacement and resorption, which may necessitate internal fixation or result in revision surgery. To overcome autograft failure, the use of an allograft as the interposition material has been introduced by some surgeons. This study describes the radiologic results of 147 hips treated for developmental hip dislocation by means of a standard protocol of open hip reduction and pericapsular acetabuloplasty with a contoured iliac crest allograft as the interposition material.
  
  
  METHODS
  This retrospective study reviewed the radiographs of 147 hips presenting with late developmental dislocation which were treated by open reduction and a concomitant pericapsular acetabuloplasty using a contoured iliac crest allograft as the interposition material. The minimum follow up period was 2 years. Measurement of the acetabular index (AI) was the main variable. The efficacy of the interposed iliac crest allograft as the main stabiliser of the acetabuloplasty was reflected by the maintenance of the corrected AI during the follow up period. Loss of acetabular correction, graft extrusion or resorption, the need for osteotomy internal fixation, delayed or non union, infection, hip redislocation and avascular necrosis (AVN) as possible complications were documented.
  
  
  RESULTS
  The treatment protocol of a combined open reduction of the hip and pericapsular acetabuloplasty, inserting a contoured iliac crest allograft as the interposition material, resulted in concentrically reduced and stable hips in 96.6% of our cases. The redislocation rate was 3.4%. All of the allografts were completely incorporated at 6 months post-surgery with no graft-related infections. In only two hips was the acetabular correction not maintained. None of the osteotomies required internal fixation for stability, even in older children.
  
  
  CONCLUSIONS
  We believe that a contoured iliac crest allograft as the pericapsular acetabuloplasty interposition material renders excellent osteotomy stability that eliminates the need for internal fixation and-in the short-term-maintains the correction of the acetabulum achieved intra-operatively.
authors.affiliation: King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia.
authors.forename: William J
authors.initials: WJ
authors.lastname: Wade
authors.forename: Thamer S
authors.initials: TS
authors.lastname: Alhussainan
authors.forename: Zayed
authors.initials: Z
authors.lastname: Al Zayed
authors.forename: Nezar
authors.initials: N
authors.lastname: Hamdi
authors.forename: Dalal
authors.initials: D
authors.lastname: Bubshait