Evaluation of the Tekscan F-SCAN system for measurement of the kicking force in horses.

INTRODUCTION: The incidence of fractures after a kick, coupled with marked soft tissue trauma at the site of injury, suggests that the force of a kick from the hind limb of a horse is enormous. The goal of this study was to measure this force and to investigate whether the Tekscan F-SCAN in-shoe pressure measuring system is suitable for quantification of the impact strength of a kick from a horse. The system was tested in 6 horses that had undergone clinical examination and gait analysis. The sensor-shoe combination was attached to each hind foot and the horse was stimulated to kick against a wall. The F-SCAN system measured the maximum vertical and horizontal force (N), the main contact area (cm2) of the sole with the floor (stance phase limb) or wall (kicking limb) and the duration (sec) that the sole was in contact with the floor or wall. In addition, each kicking event was recorded with a video camera for subjective evaluation. The mean kicking force measured was lower than that recorded in horses trotting on a treadmill, where the forces exerted on one limb were similar to the horse's body weight. The results of this study indicate that the Tekscan F-SCAN system is not ideally suited to measure the force of a kick of a horse in vivo.

INTRODUCTION: La fréquence des fractures et les importants dégâts aux tissus mous consécutifs à des coups de pieds laissent à penser que la force de frappe transmise à cette occasion doit être très importante. Le but du présent travail était de mesurer cette force et de voir si le système F-Scan Tekscan est adapté pour quantifier la force de frappe d'un cheval. Après un examen clinique et orthopédique, le système a été utilisé sur 6 chevaux, en incluant le senseur dans une hipposandale et en stimulant ensuite le cheval pour qu'il rue contre une paroi. Le système F-Scan a mesuré lors de chaque coup de pied la force maximale verticale respectivement horizontale (N), la surface de contact (cm2) de la sole avec le sol (membre à l'appui) ou avec la paroi (membre donnant le coup) ainsi que la durée de contact avec le sol respectivement avec la paroi. Chaque coup de pied a simultanément été enregistré sur vidéo et le force du coup a été estimée subjectivement. Les forces mesurées étaient toutefois plus faibles que celles enregistrées chez des chevaux au trot sur un tapis roulant dans une étude précédente. Les forces exercées sur les membres étaient globalement égales au poids du cheval. Les résultats de notre étude laissent à penser que le système F-Scan Tekscan n'est pas idéal pour mesurer la force de frappe d'un cheval.

Retrospective analysis of factors associated with outcome of proximal interphalangeal joint arthrodesis in 82 horses including Warmblood and Thoroughbred sport horses and Quarter Horses (1992-2014).

REASONS FOR PERFORMING STUDY: Outcomes associated with arthrodesis of the proximal interphalangeal (PIP) joint in Quarter Horses used for Western performance activities are well documented but little is known regarding outcomes for other types of horses. OBJECTIVES: To identify factors associated with outcomes, including breed and activity, after arthrodesis of the PIP joint in Warmbloods, Thoroughbreds and Quarter Horses. STUDY DESIGN: Retrospective case series. METHODS: Surgical case records of 82 Quarter Horses principally engaged in Western performance and Thoroughbred or Warmblood breeds principally engaged in showing, showjumping and dressage, with arthrodesis of the PIP joint were reviewed. Arthrodesis was performed with either 3 transarticular cortex bone screws placed in lag fashion, a dynamic compression plate (DCP) with 2 transarticular cortex bone screws placed in lag fashion, or a locking compression plate (LCP) with 2 transarticular cortex bone screws placed in lag fashion. Demographic data, clinical presentation, radiographic findings, surgical technique, post operative treatment and complications were recorded. Long-term follow-up was obtained for all 82 horses. RESULTS: Osteoarthritis of the PIP joint was the most common presenting condition requiring arthrodesis, which was performed with either the 3 screw technique (n = 41), DCP fixation (n = 22), or LCP fixation (n = 19). Post operatively, 23/31 (74%) Warmbloods/Thoroughbreds and 44/51 (87%) Quarter Horses achieved successful outcomes. Thirteen of 23 (57%) Warmbloods/Thoroughbreds and 24 of 38 (63%) Quarter Horses, used for athletic performance, returned to successful competition. Within this subgroup of horses engaged in high-level activity, regardless of breed type, horses undergoing hindlimb arthrodesis were significantly more likely to return to successful competition (73%; 33/45) than those with forelimb arthrodesis (25%; 4/16, P = 0.002). CONCLUSIONS: Arthrodesis of the PIP joint in Warmbloods/Thoroughbreds and Quarter Horses results in a favourable outcome for return to their intended use and athletic competition.

Evaluation of an in-shoe pressure measurement system in horses.

OBJECTIVE: To develop an objective, accurate method for quantifying forelimb ground reaction forces in horses by adapting a human in-shoe pressure measurement system and determine the reliability of the system for shod and unshod horses. ANIMALS: 6 adult Thoroughbreds. PROCEDURE: Horses were instrumented with a human in-shoe pressure measurement system and evaluated at a trot (3 m/s) on a motorized treadmill. Maximum force, stance time, and peak contact area were evaluated for shod and unshod horses. Three trials were performed for shod and unshod horses, and differences in the measured values were examined with a mixed model ANOVA for repeated measures. Sensor accuracy was evaluated by correlating measured variables to clinically observed lameness and by a variance component analysis. RESULTS: 4 of 6 horses were determined to be lame in a forelimb on the basis of clinical examination and measured values from the system. No significant differences were observed between shod and unshod horses for maximum force and stance time. A significant decrease in peak contact area was observed for shod and unshod horses at each successive trial. Maximum force measurements provided the highest correlation for detecting lameness (r = 0.91, shod horses; r = 1.0, unshod horses). A variance component analysis revealed that 3 trials provided a variance of 35.35 kg for maximum force (+/- 5.78% accuracy), 0.007 seconds for stance time (+/- 2.5% accuracy), and 8.58 cm2 for peak contact area (+/- 11.95% accuracy). CONCLUSIONS AND CLINICAL RELEVANCE: The in-shoe pressure measurement system provides an accurate, objective, and effective method to evaluate lameness in horses.

Empyema of the guttural pouch (auditory tube diverticulum) in horses: 91 cases (1977-1997).

OBJECTIVE: To identify features of guttural pouch (auditory tube diverticulum) empyema in horses and compare findings of uncomplicated guttural pouch empyema with guttural pouch empyema complicated by chondroids. DESIGN: Retrospective study. ANIMALS: 91 horses with guttural pouch empyema. PROCEDURE: Medical records of horses with guttural pouch empyema were reviewed. RESULTS: The most common owner complaint and abnormal finding was persistent nasal discharge. Chondroids were detected in 21% (19/91) of affected horses. Streptococcus equi was isolated from the guttural pouch in 14 of 44 horses; for Streptococcus spp, in vitro resistance to sulfadimethoxine and trimethoprim-sulfamethoxazole was detected. Retropharyngeal swelling and pharyngeal narrowing were significantly more prevalent in horses with chondroids, compared with horses with uncomplicated empyema. Ninety-three percent of affected horses were discharged from the hospital; at time of discharge, 66% had complete resolution of disease, 19% had improvement without resolution, and 15% did not have improvement. CONCLUSIONS AND CLINICAL RELEVANCE: Horses with persistent nasal discharge should be examined endoscopically for guttural pouch empyema. Treatment with lavage offers a good prognosis for resolution of uncomplicated guttural pouch empyema. Aggressive treatment with lavage and endoscopic snare removal of chondroids offers a good prognosis and may make surgical intervention unnecessary.