title: Sagittal joint instability in the cranial cruciate ligament insufficient canine stifle. Caudal slippage of the femur and not cranial tibial subluxation.
abstract: OBJECTIVE
  This in vivo study qualitatively describes the sagittal motion pattern of the cranial cruciate ligament (CrCL) insufficient canine stifle in operated and unoperated joints with cranio-caudal laxity on palpation.
  
  
  METHODS
  Sagittal stifle kinematics were recorded in vivo in dogs (> 15 kg BW) with unilateral (n = 7) or bilateral (n = 6) complete CrCL rupture and positive cranial drawer test as well as two sound control dogs using uniplanar fluoroscopic kinematography with the dogs walking on a treadmill. Stifle stability and sagittal motion pattern of the femur and the tibia were determined by visual inspection of the fluoroscopic video sequences.
  
  
  RESULTS
  Control dogs showed no cranio-caudal instability, identical to the contralateral stifles of the dogs with unilateral rupture. All unoperated stifles with CrCL rupture (n = 6) showed caudal slippage of the femur at the beginning of the stance phase. Of the 13 operated stifles (TightRope: n = 1, tibial tuberosity advancement, TTA: n = 6, tibial plateau leveling osteotomy, TPLO: n = 5, cranial closing wedge osteotomy, CCWO: n = 1) nine were unstable, showing the same motion pattern as the unoperated stifles.
  
  
  CONCLUSIONS
  In the CrCL insufficient stifle with in vivo cranio-caudal instability caudal slippage of the distal femur at tow touch is the predominant motion pattern.
  
  
  CONCLUSIONS
  The discrepancy between in vivo motion pattern and in vitro simulation of CrCL insufficiency in which cranial tibial subluxation is the predominant sagittal motion pattern warrants further studies.
authors.forename: J
authors.initials: J
authors.lastname: Rey
authors.forename: M S
authors.initials: MS
authors.lastname: Fischer
authors.affiliation: Prof. Dr. Peter Böttcher, Klinik für Kleintiere, der Universität Leipzig, An den Tierkliniken 23, 04103 Leipzig, Germany, Email: boettcher@kleintierklinik.uni-leipzig.de.
authors.forename: P
authors.initials: P
authors.lastname: Böttcher
mesh_terms: D000818:Animals; D016118:Anterior Cruciate Ligament / Q000000981:diagnostic imaging / Q000503:physiopathology*; D001696:Biomechanical Phenomena; D004283:Dog Diseases / Q000000981:diagnostic imaging / Q000503:physiopathology*; D004285:Dogs; D005260:Female; D005269:Femur / Q000000981:diagnostic imaging / Q000503:physiopathology; D005471:Fluoroscopy / Q000662:veterinary; D007593:Joint Instability / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000662:veterinary*; D008297:Male; D013264:Stifle / Q000000981:diagnostic imaging / Q000503:physiopathology*; D013977:Tibia / Q000000981:diagnostic imaging / Q000503:physiopathology; D016138:Walking
keywords: Stifle; cranial cruciate ligament rupture; fluoroscopy; in vivo; kinematics