title: Effect of tibial slope on the stability of the anterior cruciate ligament-deficient knee.
abstract: OBJECTIVE
  We aimed to quantify the effect of changes in tibial slope on the magnitude of anterior tibial translation (ATT) in the anterior cruciate ligament (ACL)-deficient knee during the Lachman and mechanized pivot shift tests. We hypothesized that increased posterior tibial slope would increase the amount of ATT of an ACL-deficient knee, while leveling the slope of the tibial plateau would decrease the amount of ATT.
  
  
  METHODS
  Lachman and mechanized pivot shift tests were performed on hip-to-toe cadaveric specimens, and ATT of the lateral and the medial compartments was measured using navigation (n = 11). The ACL was then sectioned. Stability testing was repeated, and ATT was recorded. A proximal tibial osteotomy in the sagittal plane was then performed achieving either +5 or -5° of tibial slope variation after which stability testing was repeated (n = 10).
  
  
  RESULTS
  Sectioning the ACL resulted in a significant increase in ATT in both the Lachman and mechanized pivot shift tests (P < 0.05). Increasing or decreasing the slope of the tibial plateau had no effect on ATT during the Lachman test (n.s.). During the mechanized pivot shift tests, a 5° increase in posterior slope resulted in a significant increase in ATT compared to the native knee (P < 0.05), while a 5° decrease in slope reduced ATT to a level similar to that of the intact knee.
  
  
  CONCLUSIONS
  Tibial slope changes did not affect the magnitude of translation during a Lachman test. However, large changes in tibial slope variation affected the magnitude of the pivot shift.
authors.affiliation: Orthopaedic and Sports Medicine Clinic of Kansas City, Leawood, KS, USA.
authors.forename: James E
authors.initials: JE
authors.lastname: Voos
authors.forename: Eduardo M
authors.initials: EM
authors.lastname: Suero
authors.forename: Musa
authors.initials: M
authors.lastname: Citak
authors.forename: Frank P
authors.initials: FP
authors.lastname: Petrigliano
authors.forename: Marianne R F
authors.initials: MR
authors.lastname: Bosscher
authors.forename: Mustafa
authors.initials: M
authors.lastname: Citak
authors.forename: Thomas L
authors.initials: TL
authors.lastname: Wickiewicz
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Pearle
mesh_terms: D000070598:Anterior Cruciate Ligament Injuries; D001696:Biomechanical Phenomena; D006801:Humans; D007593:Joint Instability / Q000473:pathology*; D007719:Knee Joint / Q000033:anatomy & histology* / Q000502:physiology; D013977:Tibia / Q000033:anatomy & histology*