title: Analysis of segmental residual growth after progressive bone lengthening in congenital lower limb deformity.
abstract: BACKGROUND
  The issue of prognosis in limb length discrepancy in children affected by congenital abnormality remains a subject of concern. Therapeutic strategy must take length prediction into account, to adapt equalization techniques and the timing of treatment. Initial prognosis, however, may need revising after completion of one or several surgical interventions on the pathologic limb. The aim of this study was to determine the different types of growth response that a bone segment can present after progressive lengthening in case of congenital limb length discrepancy.
  
  
  METHODS
  A series of 114 bone lengthenings with external fixator, performed in 36 girls and 50 boys with congenital lower limb length discrepancy, was retrospectively analyzed. Bone segment growth rates were measured before lengthening, during the first year after frame removal and finally over long-term follow-up, calculating the ratios of radiological bone length to the number of months between two measurements. Mean follow-up was 4.54±0.2 years.
  
  
  RESULTS
  Changes in short- and long-term growth rate distinguished five patterns of bone behavior after lengthening, ranging from growth acceleration to total inhibition.
  
  
  CONCLUSIONS
  These five residual growth patterns depended on certain factors causing acceleration or, on the contrary, slowing down of growth: age at the lengthening operation, percentage lengthening, and minimal period between two lengthenings. These criteria help optimize conditions for resumed growth after progressive segmental lengthening, avoiding conditions liable to induce slowing down or inhibition, and providing a planning aid in multi-step lengthening programs.
  
  
  METHODS
  Level IV. Retrospective study.
authors.affiliation: Scientific and Clinical Laboratory for Deformity Correction and Limb Lengthening. Federal Russian State-Financed Ilizarov Scientific Center for Restorative Traumatology and Orthopaedics, 6, M.-Ulyanova Street, 640014 Kurgan, Russia.
authors.forename: D
authors.initials: D
authors.lastname: Popkov
authors.forename: P
authors.initials: P
authors.lastname: Journeau
authors.forename: A
authors.initials: A
authors.lastname: Popkov
authors.forename: B
authors.initials: B
authors.lastname: Pedeutour
authors.forename: T
authors.initials: T
authors.lastname: Haumont
authors.forename: P
authors.initials: P
authors.lastname: Lascombes
mesh_terms: D000293:Adolescent; D001852:Bone Lengthening / Q000379:methods*; D002648:Child; D002675:Child, Preschool; D005260:Female; D005269:Femur / Q000601:surgery*; D005500:Follow-Up Studies; D006132:Growth Plate / Q000502:physiology*; D006801:Humans; D038061:Lower Extremity Deformities, Congenital / Q000601:surgery*; D008297:Male; D012189:Retrospective Studies; D013977:Tibia / Q000601:surgery*; D013997:Time Factors; D016896:Treatment Outcome