title: Triple innominate osteotomy for Legg-Calvé-Perthes disease in children: does the lateral coverage change with time?
abstract: BACKGROUND
  Triple innominate osteotomy (TIO) is one of the modalities of surgical containment in Legg-Calvé-Perthes disease (LCPD). However, overcoverage with TIO can lead to pincer impingement.
  
  
  OBJECTIVE
  We therefore asked (1) whether TIO contained the femoral head in Catterall Stages III and IV of LCPD; (2) whether the center-edge (CE) angle, acetabular roof arc angle (ARA), and Sharp's angle changed during the growing years; and (3) what percentage of patients had radiographic evidence of pincer impingement beyond a minimum followup of 3 years.
  
  
  METHODS
  We identified 19 children who had 20 TIOs performed for Catterall Stages III and IV LCPD. Two blinded observers assessed sequential radiographs. Each observer made two sets of readings more than 2 weeks apart. Femoral head extrusion index, CE angle of Wiberg, ARA, and Sharp's angle were measured. Minimum followup was 3 years to document continued acetabular growth (mean, 3.8 years; range, 3-7 years).
  
  
  RESULTS
  All patients exhibited femoral head containment at last followup. Eleven of 20 hips demonstrated no radiographic evidence of pincer morphology beyond a minimum followup of 3 years (mean, 3.8 years). Patients with CE angle corrected to 44° or less and an ARA of greater than -6° after TIO did not demonstrate a pincer morphology at last followup.
  
  
  CONCLUSIONS
  TIO resulted in femoral head containment in all cases. Lateral acetabular coverage changed during the growing years in all patients. Surgical correction beyond 44° of CE angle and -6° of ARA should be avoided to prevent pincer morphology later.
authors: Department of Orthopedic Surgery, Rady Children's Hospital, University of California-San Diego, 3030 Children's Way, Suite 410, San Diego, CA 92123, USA. hhosalkar@rchsd.org
authors: Harish
authors: H
authors: Hosalkar
authors: Ana Laura
authors: AL
authors: Munhoz da Cunha
authors: Keith
authors: K
authors: Baldwin
authors: Kai
authors: K
authors: Ziebarth
authors: Dennis R
authors: DR
authors: Wenger
mesh_terms: D000367:Age Factors; D002140:California; D002648:Child; D005260:Female; D005270:Femur Head / Q000000981:diagnostic imaging / Q000601:surgery*; D006801:Humans; D007873:Legg-Calve-Perthes Disease / Q000000981:diagnostic imaging / Q000601:surgery*; D008297:Male; D010027:Osteotomy / Q000009:adverse effects / Q000379:methods*; D026741:Physical Therapy Modalities; D011859:Radiography; D012720:Severity of Illness Index; D013997:Time Factors; D016896:Treatment Outcome