A Description of the Movement of the Canine Pelvic Limb in Three Dimensions Using an Inverse Dynamics Method, and a Comparison of Two Techniques to Surgically Repair a Cranial Cruciate Ligament Deficient Stifle

The purposes of the dissertation were: 1) to describe three-dimensional (3D) motion of the canine pelvic limb using an inverse dynamics method, and 2) to compare these motion patterns between normal, healthy dogs and those that have had their stifles stabilized by one of two surgical methods approximately five years earlier.

Twenty-five dogs were allocated to three groups; healthy control dogs, dogs that had received the tibial plateau leveling osteotomy (TPLO), and dogs that had received the lateral fabellar suture (LFS) stabilization technique. Both surgical techniques were performed approximately five years prior on stifles with surgically induced cranial cruciate ligament (CCL) rupture. A kinematic model was created so that virtual markers could be used to describe the pelvic limb motion in 3D. Kinetic, kinematic, and morphometric data were integrated so that an inverse dynamics method could be used to describe angular displacement, joint moment and power across the hock, stifle, and hip joints in the sagittal, frontal, and transverse planes. Discrete points and shapes of waveforms were analyzed for any differences among groups.

Motion and energy patterns were successfully determined in 3D for all three joints of the canine pelvic limb. There was similarity between all three groups for all variables studied in the three planes with the exception of two variables. In the sagittal plane, the TPLO group had a more extended hip at the beginning of stance phase compared to the control group. Also, in the frontal plane, the LFS group had a significantly larger maximum power across the stifle when compared to the normal group. Despite the differences between these two variables, there were no differences in gait patterns between these groups that would suggest that one surgical procedure is superior to the other. Both surgical groups moved similarly to the healthy control group. The method of collecting kinematic data in this study allowed for the description of motion of the canine pelvic limb in 3D using inverse dynamics. Comparison between normal controls and dogs that had two different methods of repair for stifle instability showed similar gait patterns for all three groups.