title: The effect of cranial cruciate ligament insufficiency on caudal cruciate ligament morphology: An experimental study in dogs.
abstract: OBJECTIVE
  To investigate the effect of cranial cruciate ligament (CrCL) insufficiency on morphology of the canine caudal cruciate ligament (CdCL).
  
  
  METHODS
  In vivo experimental study.
  
  
  METHODS
  Five adult foxhounds.
  
  
  METHODS
  Two years after CrCL transection, the histologic appearance of CdCLs from CrCL-deficient and unoperated contralateral control (CrCL-intact) stifle joints were evaluated using light and transmission electron microscopy.
  
  
  RESULTS
  CdCLs from CrCL-deficient joints had extracellular matrix changes, characterized by chondroid metaplasia and disruption of cell architecture. Percent of small-diameter fibrils in CdCLs from CrCL-deficient joints was significantly greater (P <.05) than that in CdCLs from CrCL-intact joints. Collagen fibril density in CdCLs from CrCL-deficient joints (41.09 +/- 5.39%) tended to be less than that in CdCLs from CrCL-intact joints (52.96 +/- 6.92%); however, this difference was not significant (P =.056). Mean eccentricity (ratio of minor to major diameters) of collagen fibrils was significantly (P <.0001) lower for CdCLs from CrCL-deficient joints (0.85 +/- 0.016) when compared with that for CdCLs from CrCL-intact joints (0.87 +/- 0.015).
  
  
  CONCLUSIONS
  Significant alterations were found in the morphology of CdCLs from CrCL-deficient joints. These changes may be associated with repetitive microtrauma to the CdCL secondary to instability or enzymatic degradation in the hostile synovial environment of an unstable joint.
  
  
  CONCLUSIONS
  Regardless of the cause, the switch to a predominantly small-diameter collagen fibril profile may reflect compromised material properties of the CdCL. This should be taken into account when considering surgical techniques that rely on the CdCL to stabilize CrCL-deficient stifles.
authors.affiliation: Laboratory for Comparative Orthopaedic Research, College of Veterinary Medicine, Michigan State University, East Lansing 48824, USA.
authors.forename: Terri A
authors.initials: TA
authors.lastname: Zachos
authors.forename: Steven P
authors.initials: SP
authors.lastname: Arnoczky
authors.forename: Michael
authors.initials: M
authors.lastname: Lavagnino
authors.forename: Scott
authors.initials: S
authors.lastname: Tashman
mesh_terms: D000818:Animals; D016118:Anterior Cruciate Ligament / Q000473:pathology* / Q000648:ultrastructure; D004283:Dog Diseases / Q000473:pathology*; D004285:Dogs; D007593:Joint Instability / Q000473:pathology / Q000662:veterinary*; D013264:Stifle / Q000473:pathology*