title: Surgical management of hip subluxation and dislocation in children with cerebral palsy: isolated VDRO or combined surgery?
abstract: BACKGROUND
  Controversy exists regarding surgical treatment of hip subluxation/dislocation in children with cerebral palsy (CP). The purpose of this study was to compare isolated varus derotational osteotomy (VDRO) and VDRO combined with open hip reduction and/or pelvic osteotomy in children with CP and hip subluxation/dislocation.
  
  
  METHODS
  Retrospective review was performed of 75 patients with CP (116 hips) and hip subluxation/dislocation treated surgically, with a minimum of 2 years follow-up. Ninety-two hips had undergone VDRO alone, and 24 had undergone VDRO and open reduction and/or pelvic osteotomy (with the decision to proceed with open hip reduction and/or pelvic osteotomy made intraoperatively based on fluoroscopy and arthrogram). Clinical variables, functional level, radiographic variables, and complications/revisions were compared between groups.
  
  
  RESULTS
  Patients requiring combined surgery (VDRO+) had higher baseline migration percentages (MP) (84% ± 18 VDRO+, 51% ± 21 VDRO), higher acetabular indices (34 ± 10 VDRO+, 28 ± 7 VDRO), more negative center-edge angles (-36 ± 28 VDRO+, -0.3 ± 18 VDRO), and higher neck-shaft angles (162 ± 12 VDRO+, 157 ± 10 VDRO) (all P < 0.02). Postoperative radiographic variables were similar between groups. The percentage of patients with MP >30% at final follow-up was similar between groups (38% VDRO+, 33% VDRO). There were no differences in complications or revision rates between groups. Of the hips with MP >50% preoperatively and treated with VDRO alone, 41% developed postoperative MP of ≥ 30% and 21% developed a MP of ≥ 40%.
  
  
  CONCLUSIONS
  The study results confirm that combined procedures should be considered in patients with high MP. However, this study supports a sequential approach to surgical management of subluxated/dislocated hips in patients with CP as many hips with MP >50% were successfully managed with VDRO alone. We recommend performing VDRO and soft tissue release first, assessing reduction using fluoroscopy and arthrogram and proceeding with open reduction and/or pelvic osteotomy if reduction and/or femoral head coverage are inadequate.
  
  
  METHODS
  Level III, retrospective comparative study.
authors.affiliation: Starship Children's Hospital, Grafton, Auckland, New Zealand.
authors.forename: Kenneth
authors.initials: K
authors.lastname: Huh
authors.forename: Susan A
authors.initials: SA
authors.lastname: Rethlefsen
authors.forename: Tishya A L
authors.initials: TA
authors.lastname: Wren
authors.forename: Robert M
authors.initials: RM
authors.lastname: Kay
mesh_terms: D002547:Cerebral Palsy / Q000150:complications*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006617:Hip Dislocation / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D008297:Male; D010027:Osteotomy / Q000379:methods*; D017410:Practice Guidelines as Topic; D011859:Radiography; D016059:Range of Motion, Articular; D012189:Retrospective Studies; D016896:Treatment Outcome