title: A balanced approach for stable hips in children with cerebral palsy: a combination of moderate VDRO and pelvic osteotomy.
abstract: BACKGROUND
  Hip reconstructive surgery in cerebral palsy (CP) patients necessitates either femoral varus derotational osteotomy (VDRO) or pelvic osteotomy, or both. The purpose of this study is to review the results of a moderate varisation [planned neck shaft angle (NSA) of 130°] in combination with pelvic osteotomy for a consecutive series of patients.
  
  
  METHODS
  Patients with CP who had been treated at our institution for hip dysplasia, subluxation or dislocation with VDRO in combination with pelvic osteotomy between 2005 and 2010 were reviewed.
  
  
  RESULTS
  Forty patients with a mean follow-up of 5.4 years were included. The mean age at the time of operation was 8.9 years. The majority were non-ambulant children [GMFCS I-III: n = 11 (27.5 %); GMFCS IV-V: n = 29 (72.5 %)]. In total, 57 hips were treated with both femoral and pelvic osteotomy. The mean pre-operative NSA angle of 152.3° was reduced to 132.6° post-operatively. Additional adductor tenotomy was performed in nine hips (16 %) at initial operation. Reimers' migration percentage (MP) was improved from 63.6 % pre-operatively to 2.7 % post-operatively and showed a mean of 9.7 % at the final review. The results were good in 96.5 % (n = 55) with centred, stable hips (MP <33 %), fair in one with a subluxated hip (MP 42 %) and poor in one requiring revision pelvic osteotomy for ventral instability.
  
  
  CONCLUSIONS
  This approach maintains good hip abduction and reduces soft-tissue surgery. Moderate varisation in VDRO in combination with pelvic osteotomy leads to good mid-term results with stable, pain-free hips, even in patients with severe spastic quadriplegia.
authors.affiliation: Department of Orthopaedic Surgery, University Children's Hospital Zurich, Steinwiesstrasse 75, 8032, Zurich, Switzerland. kerstin.reidy@kispi.uzh.ch.
authors.forename: Kerstin
authors.identifier: http://orcid.org/0000-0002-1292-3000
authors.initials: K
authors.lastname: Reidy
authors.affiliation: Department of Orthopaedic Surgery, University Children's Hospital Zurich, Steinwiesstrasse 75, 8032, Zurich, Switzerland.
authors.forename: Christoph
authors.initials: C
authors.lastname: Heidt
authors.affiliation: Department of Orthopaedic Surgery, University Children's Hospital Zurich, Steinwiesstrasse 75, 8032, Zurich, Switzerland.
authors.forename: Stefan
authors.initials: S
authors.lastname: Dierauer
authors.affiliation: Department of Orthopaedic Surgery, Cantonal Hospital Winterthur, Brauerstrasse 15, 8401, Winterthur, Switzerland.
authors.forename: Hanspeter
authors.initials: H
authors.lastname: Huber
keywords: Cerebral palsy; Hip dysplasia; Hip reconstruction; Neck shaft angle; Pelvic osteotomy; VDRO