No abstract

The case records of 92 consecutive dogs that suffered sacroiliac fracture-separation were examined. Seventy-seven per cent (71 of 92) had unilateral sacroiliac injury and 23% (21 of 92) had bilateral sacroiliac injury. Of the unilateral cases, 93% (66 of 71) of the dogs had associated acetabular, ilial, femoral, or tibia1 fractures; coxofemoral luxations; or cruciate injuries. Eighty-five per cent (78 of 92) of the dogs had either bilateral sacroiliac injury or unilateral sacroiliac injury and other orthopedic injuries of the opposite limb, thus disabling both hind limbs.Sixty-five per cent (60 of 92) of the dogs received lag screw fixation of the sacroiliac joint. Of 29 dogs that were re-radiographed on an average of 437 days following fixation, 38% (11 of 29) showed evidence of loosening of the lag screw fixation.Screws that were placed in the body of the sacrum in some dogs resulted in the fewest loosened fixations (12%, 2 of 17), compared to other locations of screw placement. The fixation had loosened in 7% (1 of 14) of dogs that had a cumulative screw depth/sacral width of 60% or more, compared with 48% of dogs (10 of 21) where cumulative screw depth was less than 60%. The number of screws per fixation and whether the separation was fully reduced or not did not affect whether the fixation loosened.NJURY TO THE SACROILIAC joint in the dog com-

SummaryComputer aided kinematic and synchronized force plate gait analysis were used to characterize joint movement in 14 large mixed breed dogs at a trot. A curvilinear relationship of joint angle to time was described, for three forelimb and three hindlimb joints. Two peaks of maximum extension, one preceding the onset and at the end of stance phase were observed for the femorotibial, tarsus and cubital joints. The carpus, scapulohumeral and coxofemoral joint exhibited one peak of maximum extension. The variance in joint angle measurement was calculated for repeated trials for a given dog and for differences between dogs using a 2-factor repeated measures ANOVA. The mean variance for all joints except the carpal joint for trial repetition was 12.6 (degrees)2 (range, 2.6-23.9) and for differences between dogs 6.2 (degrees)2 (range, 1.0-11.3). The carpal joint exhibited greater variation with a mean variance, attributable to trial repetition, of 42.5 (degrees)2 (range, 39.4-44.3) and a variance between dogs of 52.4 (degrees)2 (range, 18.5-89.4).The results obtained would suggest that computer assisted kinematics is an accurate means of assessing joint angle movement in large mixed breed dogs with a low level of variance attributable to trial repetition and to differences between dogs, with the exception of the carpal joint. The sample of mixed breed dogs in this study is similar to dogs that would be seen in a clinical sample population. Our results suggest that computer assisted kinematics could be an important tool in providing objective information on gait, in clinical and research studies, using mixed breed dogs.This study describes the trot in 14 large mixed breed dogs using computer aided kinematic and force plate gait analysis techniques. Variances in fore and hindlimb joint angle measurements were deter-mined, for a given dog, by repeated trials and for differences between dogs. The measured variances were low in all joints except the corpus, despite diverse dog conformation in the study.

The L:P proved to be a repeatable measurement of vertical patellar position, which is independent of stifle angles from 75 degrees to 148 degrees. This measurement could be used as a quantitative method for diagnosing patella alta and patella baja in large-breed dogs.

TBR may help limit the development of stifle DJD in dogs treated for canine patellar luxation.