title: The effect of tibial plateau leveling osteotomy position on cranial tibial subluxation: an in vitro study.
abstract: OBJECTIVE
  To compare centered versus distal tibial plateau leveling osteotomy (TPLO) position on cranial tibial subluxation, postoperative tibial plateau angle (TPA), and tibial long axis shift (TLAS).
  
  
  METHODS
  In vitro biomechanical evaluation.
  
  
  METHODS
  Six pairs of canine cadaveric hind limbs.
  
  
  METHODS
  One limb of each pair was randomly assigned to the distal (TPLO-D) or centered (TPLO-C) osteotomy group. Cranial tibial subluxation (CTS) under load was quantified sequentially under 3 conditions: intact, after cranial cruciate ligament transection, and after TPLO; a corrected CTS value was also calculated. Postoperative TPA and TLAS were measured. Comparisons were made using 1-way repeated measures ANOVA with a Tukey's multiple comparison post hoc test for CTS, and a Wilcoxon's sign rank test for TPA and TLAS. Significance was set at P<.05.
  
  
  RESULTS
  TPLO-C had a significantly lower mean CTS than TPLO-D (P<.01). Corrected CTS was also significantly lower in TPLO-C than in TPLO-D (P<.001). Postoperative TPA and TLAS were less in TPLO-C than in TPLO-D (P=.0312).
  
  
  CONCLUSIONS
  Our results confirm that distal centering of the TPLO leads to craniodistal translation of the tibial plateau, TLAS, and a postoperative TPA that is greater than expected. This geometric effect has the biomechanical effect expected of inadequate tibial plateau leveling, namely incomplete neutralization of cranial tibial thrust.
  
  
  CONCLUSIONS
  The centered osteotomy position is geometrically more precise, and biomechanically more effective than the distal position.
authors.affiliation: Department of Veterinary Clinical Sciences, The Ohio State University, Columbus, OH 43210, USA. kowaleski.6@osu.edu
authors.forename: Michael P
authors.initials: MP
authors.lastname: Kowaleski
authors.forename: Detlef
authors.initials: D
authors.lastname: Apelt
authors.forename: John S
authors.initials: JS
authors.lastname: Mattoon
authors.forename: Alan S
authors.initials: AS
authors.lastname: Litsky
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D016118:Anterior Cruciate Ligament / Q000601:surgery*; D000070598:Anterior Cruciate Ligament Injuries; D001696:Biomechanical Phenomena; D001835:Body Weight / Q000502:physiology*; D002102:Cadaver; D004285:Dogs / Q000293:injuries / Q000601:surgery*; D010027:Osteotomy / Q000379:methods / Q000662:veterinary*; D011183:Postoperative Complications / Q000662:veterinary; D018709:Statistics, Nonparametric; D013264:Stifle / Q000293:injuries / Q000601:surgery*; D013977:Tibia / Q000293:injuries / Q000601:surgery*; D016896:Treatment Outcome