title: The effects of patellar tendon advancement on the immature proximal tibia.
abstract: OBJECTIVE
  The aim of this study is to examine the short-term effects of patellar tendon advancement on the proximal tibial slope in the skeletally immature patient.
  
  
  METHODS
  A retrospective, non-randomized, comparative cohort design was used. Koshino indices and tibial slopes were assessed pre-operatively and post-operatively and compared with age- and sex-matched controls.
  
  
  RESULTS
  Nine children with 17 patellar tendon advancements were analyzed for changes in Koshino indices. Of these 17 tibiae, radiographs on changes in tibial slope were available for 16 tibiae which were also compared with controls. Children aged <11 years had a greater initial posterior tibial slope (69.8° ± 3.5°) than age-matched controls (80.3° ± 2.7°). A decrease in posterior slope was seen in these younger patients (average change 10.3° ± 4.8°) at an average of 1.6 years of follow-up. Of the nine apophyses in children aged <11 years of age, seven had undergone premature closure.
  
  
  CONCLUSIONS
  Patellar tendon advancement appears to have an unreported effect on the proximal tibial growth in the young patient (<11 years old). These patients appear to be susceptible to apophyseal closure, resulting in subsequent loss of posterior tibial slope. Surgeons should be aware of this effect and monitor younger patients with radiographs if performing this procedure.
authors.affiliation: College of Human Medicine, Michigan State University, Grand Rapids, MI USA.
authors.forename: Cameron
authors.initials: C
authors.lastname: Patthanacharoenphon
authors.affiliation: Helen DeVos Children's Hospital, Grand Rapids, MI USA.
authors.forename: Dayle L
authors.initials: DL
authors.lastname: Maples
authors.affiliation: College of Human Medicine, Michigan State University, Grand Rapids, MI USA.
authors.forename: Christina
authors.initials: C
authors.lastname: Saad
authors.affiliation: Helen DeVos Children's Hospital, Grand Rapids, MI USA.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Forness
authors.affiliation: American Family Children's Hospital, University of Wisconsin, Madison, WI USA ; Orthopaedics and Rehabilitation University of Wisconsin, UWMF Centennial Building, Rm 6170-12D, Madison, WI 53705 USA.
authors.forename: Matthew A
authors.initials: MA
authors.lastname: Halanski
keywords: Cerebral palsy; Crouched gait; Patellar tendon advancement; Physis; Single-event multilevel surgery