Average Tibial Plateau Angle of 3,922 Stifles Undergoing Surgical Stabilization for Cranial Cruciate Ligament Rupture

Introduction: At the author’s institution, it is noted that the majority of dogs that present with cranial cruciate ligament (CCL) insufficiency have a higher tibial plateau angle (TPA) than what is currently reported in the literature. The purpose of this study was to determine the average TPA in a large sample dogs with CCL insufficiency and to see if breed-specific TPAs could be determined. Our hypothesis is that the average TPA will be higher than what is reported, and that some breeds will have higher TPAs versus others.

Materials and Methods: Medical records from 2006 to 2015 were reviewed for dogs that were diagnosed with CCL rupture and underwent CCL stabilization. The patient’s signalment, weight, body condition score, examination findings, surgery report, and preoperative TPA were reviewed.

Results: 3,249 dogs underwent CCL stabilization surgery from 2006 to 2015. Of the 3,249 dogs, 3,054 dogs met the inclusion criteria for a total of 3,922 stifles to be evaluated. The overall average preoperative TPA was 29° (29 ± 3.683°). Average breed-specific preoperative TPAs (breeds consisting of 20 or more dogs) ranged from 27° to 35.1°.

Discussion/Conclusion: Our reported overall preoperative TPA in a large series of dogs is higher than what is currently published. In reviewing 3,922 stifles the average and median preoperative TPA was 29°. In addition, we report the average preoperative TPA in specific breeds. This updated information may guide clinicians in management decisions regarding treatment for CCL rupture.

Acknowledgement: There was no proprietary interested or funding provided for this project.