title: Effect of tibial tuberosity advancement on femorotibial shear in cranial cruciate-deficient stifles. An in vitro study.
abstract: OBJECTIVE
  This in vitro study compares the femorotibial shear in canine stifles with intact and transected cranial cruciate ligaments (CrCL), before and after tibial tuberosity advancement (TTA) by measuring the distance between origin and insertion of the cruciate ligaments.
  
  
  METHODS
  Radiodense markers were inserted into bones at the attachment sites of the cruciate ligaments in sixteen cadaveric stifles of adult dogs. Each stifle was then mounted in a testing apparatus. The distances between the markers were measured on mediolateral radiographs, performed on each stifle under three different situations: intact, after CrCL transection, and after performing a TTA. Stifles were loaded to create a constant tibiofemoral reaction force by maintaining the load parallel to the patellar ligament. Radiographs were taken in a preloaded and loaded state in the intact stifle and only in a loaded state after CrCL transection, and after performing a TTA.
  
  
  RESULTS
  Loading the stifle joints after transection of the CrCL resulted in a mean lengthening of the CrCL marker distance of 22.4%. Loading the transected CrCL stifles after performing a TTA resulted in a mean shortening of the CrCL marker distance by 3.0% compared to the loaded intact condition.
  
  
  CONCLUSIONS
  This study demonstrates that, in loaded stifles with transected CrCLs, TTA causes a caudal shift in the cranial shear force, counteracting cranial subluxation of the tibia.
authors.affiliation: Clinic for Small Animal Surgery, Vetsuisse Faculty University of Zurich, Winterthurerstrasse 260, CH-8057 Zurich, Switzerland. nkipfer@vetclinics.unizh.ch
authors.forename: N M
authors.initials: NM
authors.lastname: Kipfer
authors.forename: S
authors.initials: S
authors.lastname: Tepic
authors.forename: D M
authors.initials: DM
authors.lastname: Damur
authors.forename: T
authors.initials: T
authors.lastname: Guerrero
authors.forename: M
authors.initials: M
authors.lastname: Hässig
authors.forename: P M
authors.initials: PM
authors.lastname: Montavon
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D016118:Anterior Cruciate Ligament / Q000473:pathology / Q000601:surgery; D000070598:Anterior Cruciate Ligament Injuries; D001696:Biomechanical Phenomena; D002102:Cadaver; D004285:Dogs / Q000293:injuries* / Q000601:surgery; D005260:Female; D008297:Male; D013264:Stifle / Q000502:physiology / Q000601:surgery*; D013977:Tibia / Q000601:surgery*