Standing osteosynthesis of an accessory carpal bone fracture in a Warmblood mare with a 6‐hole 3.5 talonavicular fusion plate and 3.5‐mm screws

A 9-year-old Warmblood, high-level showjumping mare sustained an acute, closed, vertical, comminuted fracture of the left accessory carpal bone (ACB) during a fall. The fracture was repaired under standing sedation and local anaesthesia, using a 6-hole APTUS® 3.5 TFP and 5 × 3.5-mm self-tapping TriLock© screws. The mare recovered from surgery without complications. Upon follow-up examination 9 months post-operatively the mare was sound in all gaits and back to full athletic activity. The ACB fracture had completely healed. The displaced dorsoproximal fracture fragment was in a stationary position and there was evidence of mild nonprogressive osteoarthritis of the antebrachiocarpal joint

Differences of morphological attributes between 62 proximal and distal subchondral cystic lesions of the proximal phalanx as determined by radiography and computed tomography

OBJECTIVE: To determine morphological characteristics of subchondral cystic lesions (SCLs) in the proximal phalanx (PP) of adult horses. SAMPLE: Radiographs and/or CT scans of PP from 46 horses. PROCEDURES: There were horses with a SCL in PP, which was diagnosed by radiography and/or computed tomography, included. Additional data (signalment, history, orthopedic examination) were collected retrospectively for each case. RESULTS: Forty-six horses met the required inclusion criteria, with a total of 62 SCLs. Forty-three SCLs (70.5%) were located in the proximal PP (group A). Forty-four percent of these were associated with short, incomplete fractures, while 30 of the proximal PP SCLs (69.7%) were found mid sagittal. Proximal SCLs mostly showed a blurred, irregular shape (62.8%) and long, as well as wide, but shallow shapes in CT. Eighteen SCLs (29.5%) were found in the distal PP, near the proximal interphalangeal joint (group B). In contrast to the described proximal SCLs, the distal SCLs were of circular or oval shape, well delineated (77.8%), and distinctly larger. Horses of group A were significantly older (mean age, 11.47 years) than horses of group B (mean age, 6.72 years). CLINICAL RELEVANCE: The distribution and morphological attributes of proximal PP SCLs as well as their association to subchondral bone lesions and short, incomplete proximal fractures indicate more recently developed lesions due to chronic stress factors, such as repetitive trauma to the cartilage and subchondral bone. In contrast, morphology and distribution of distal SCLs showed high accordance with developmental bone cysts originating from a failure of endochondral ossification

Bending and torsional stiffness measurements of equine radii and tibiae

This study was a re-evaluation of static mechanical testing of equine long bones as part of a larger study on impact failure modes and strength of the same bones. Supplementary to other morphological and mechanical tests, static stiffness properties of these long bones were non-destructively determined. The goal was to quantify stiffness properties of the diaphysis of equine radii and tibiae in quasi-static bending as well as when loaded in torsion and to check for possible age and gender effects on these properties. Fifty-six equine bones (tibiae and radii) from fifteen horses were first tested in a torsion machine and subsequently fifty-five of them investigated using a 3-point-bending test-setup. A maximum torque of 150 N*m and a maximum bending moment of 920 N*m were applied in steps. Loading and unloading was performed in order to check for hysteresis effects. The outcome for both type of bones (tibiae and radii) was described statistically in relation to age (young, middle aged, and old) and gender (geldings and mares). Additional information on the side (left and right), breed and use of the horse (competition versus ‘other’, such as pleasure) was excluded from statistical modelling after preliminary analysis. While the loading-unloading cycles in bending showed some hysteresis due to localized deformation, the unloading curve followed the loading curve in torsional loading. Bending stiffness of tibiae is on average 6’813 N/mm and of radii 6’130 N/mm. Torsional stiffness of tibiae is 2.36*106 N*m(rad/mm), and of radii 1.90*106 N*m(rad/mm). Tibiae were clearly stiffer than radii. A trend of higher bone stiffness for geldings compared with mares and for younger horses could be found, although not statistically significant

Traffic accident-related injuries in horses

Horses involved in road traffic accidents (RTAs) are commonly presented to veterinarians with varying types of injuries. The aim of this study was describe the pattern and severity of traffic accident-related injuries in horses in a single hospital population. Medical records of horses either hit by a motorized vehicle or involved in RTAs whilst being transported from 1993 to 2015 were retrospectively reviewed and the following data was extracted: Signalement, hospitalisation time, month in which the accident happened, cause of the accident, place of the accident and type of vehicle hitting the horse. Further the different body sites injured (head, neck, breast, fore limb, abdomen, back and spine, pelvis and ileosacral region, hind limb, tail and genital region), the type of injury (wounds, musculoskeletal lesions and internal lesions) and the presence of neurological signs were retrieved from the medical records. 34 horses hit by motorized vehicles and 13 horses involved in RTAs whilst being transported were included in the study. Most of the accidents where horses were hit by motorized vehicles occurred during December (14.7%) and October (14.7%), horses were most commonly hit by cars (85.3%) and the majority of accidents occurred on main roads (26.5%). In 29.4% of the cases, horses had escaped from their paddock and then collided with a motorized vehicle. Most of the accidents with horses involved in RTAs whilst being transported occurred during April (30.8%) and June (23.1%). In 76.9% of the cases the accident happened on a freeway. In the horses hit by motorized vehicles the proximal hind limbs were the body site most commonly affected (44.1%), followed by the proximal front limbs (38.2%) and the head (32.4%). When horses were involved in RTAs whilst being transported the proximal fore limbs (61.5%), the proximal hind limbs (53.8%) and the distal hind limbs, back and head (38.5% each) were the most common injured body sites. Wounds were the most common type of injury in both groups(85.3% hit by motorized vehicle, 76.9% transported ones). In horses hit by a motorized vehicle 35.3% suffered from fractures, in 20.6% a synovial structure was involved and in 5.9% a tendon lesion was present. 14.7% suffered from internal lesions and 14.7% showed neurologic symptoms (40% peripheral, 60% central neurologic deficits). On the other hand, in horses involved in a RTA whilst being transported 30.8% suffered from fractures. There were no synovial structures injured and no tendon injuries were present. Furthermore there were no internal lesions present and only one horse involved in a RTA showed central neurologic symptoms. Injuries of horses being hit by a motorized vehicle were more severe than when horses were protected by a trailer and involved in an RTA whilst being transported. The study has been able to identify the different injury types of traffic accident-related injuries in horses. Awareness of the nature of these injuries is important, to avoid underestimation of their severity

Mikroskopische Untersuchung der Pferdezähne und ihrer Umgebung – Teil 1: Allgemeines und Histologie der Schneidezähne

In Ergänzung zu den bildgebenden Verfahren soll die vorliegende Arbeit Bilder zur Histologie der Zähne des Pferdes samt ihrer Umgebung vermitteln. Teil 1 der Arbeit umfasst die Methodik und die Histologie der Schneidezähne, Teil 2 befasst sich mit der Histologie der Backenzähne. Aus den Gebissen von 3 Pferden verschiedenen Alters wurden nach der Fixation ganze Zähne oder Teile der Gebisse ohne Entkalkung in Methyl-Methacrylat (MMA) eingebettet. Daraus wurden um 500 μm dicke Hartschnitte bis zu einer Grösse von 60 × 110 mm hergestellt und vorwiegend nach Giemsa gefärbt. Die Oberflächen der Schnitte ergaben sowohl Übersichtsbilder als auch Details der Zahnsubstanzen und der sie bildenden Zellen mitsamt ihrer Umgebung in hoher Auflösung. Die Bilddokumentation umfasst eingehend das 5-jährige Pferd, da bei dieser Altersgruppe über lange Zeit wenig Veränderungen vorkommen. In Längs- und Querschnitten werden die Pulpahöhle, die Zahnsubstanzen und die Schmelzbecher, (Kunden) bis ins Detail gezeigt. An den unentkalkten Präparaten blieb insbesondere der Schmelz vollständig erhalten. In der Umgebung der Zähne sind im ca. 500 μm starken Periodontium neben den gegen apikal gerichteten Fasern vor allem zirkulär um den Zahn verlaufende Faserbündel vorhanden. Der Kieferknochen enthält viel lockere Spongiosa, in der die inneren, an das Periodontium angrenzenden Lamellen, mit einer Stärke bei nur 200 μm sehr dünn sind. Beim 2-jährigen Pferd sieht man im Längsschnitt durch den 1. Schneidezahn des Oberkiefers im Ersatzzahn (I1, 101) die Bildung der Zahnsubstanzen sowie den Schmelzbecher in seiner Entstehung. Außerdem erkennt man an den Wurzeln des Milchzahnes Zeichen des aktiven Abbaus der Zahnsubstanzen. An den Schneidezähnen des 13-jährigen Pferdes fallen im Unterkiefer die starke Schrägstellung der Schneidezähne auf sowie die gegen apikal größeren Zwischenräume zwischen den Zähnen. Die durch das Periodontium und die lockere Struktur der Kieferknochen weiten Zwischenräume sind mit dafür verantwortlich, dass es mit zunehmendem Alter oft zu einer Auflockerung zwischen den Schneidezähnen bis zu deren Ausfall kommen kann. Die Bilddokumentation der Pferdezähne samt ihrer Umgebung möchte für Diagnostik und Therapie Kenntnisse zur Struktur der Gewebe an den verschiedenen Lokalisationen der Gebisse vermitteln

Messung von Herzfrequenzen und Kotcortisolmetaboliten bei Pferden am Zürcher Sechseläuten

The Zurich’s Sechseläuten is a traditional festival of the Zurich guilds, in which around 500 horses take part. After a parade through the old town of Zurich, the riders gather at a big square to canter around a burning woodpile topped with an exploding effigy (the «Böögg»). The level of stress experienced by the horses partaking in this event is subjected to increasing scrutiny. The aim of this study was to evaluate the stress load of the horses participating in the Sechseläuten procession more objectively by measuring heart rate and faecal cortisol metabolites. Twenty-three horse-rider pairs were voluntarily recruited from the guilds for participation in the study. For comparison purposes, three sections of the procession were simulated in terms of gait and distance travelled in a normal riding environment during a test day and observed during the Sechseläuten itself 16 days later: Counter march Bahnhofstrasse, parade Limmatquai and parade around the burning «Böögg». All horses were equipped with a heart rate measuring system with GPS tracking (Polar Team Pro®, Polar Electro Oy, Finland). Faecal samples for measuring cortisol metabolites were taken rectally immediately before and 24 hours after the events. Thirteen of the 23 horses were sedated during the Sechseläuten (Acepromazine, 0,1–0,2 mg/kg p.o.). The differences between the observation periods and groups (sedated/unsedated) were tested by analysis of variance (P<0,05). Walking and cantering speeds in the three sections did not differ between the test day and the Sechseläuten itself. Compared to the test day, the average heart rate was increased in all sections of the real event. However, neither the initial cortisol metabolite value nor the increase after the events showed a significant difference between the test day and the Sechseläuten. The average heart rate of the sedated group did not differ from the unsedated group during the walking sections but was elevated during canter around the Böögg. The increase in heart rate at the Sechseläuten indicated a stress load, but together with the unchanged cortisol responses, this can be classified as moderate. The influence of a sedation were inconclusive and should be further investigated

Density functional theory based screening of ternary alkali-transition metal borohydrides: A computational material design project

The dissociation of molecules, even the most simple hydrogen molecule, cannot be described accurately within density functional theory because none of the currently available functionals accounts for strong on-site correlation. This problem led to a discussion of properties that the local Kohn-Sham potential has to satisfy in order to correctly describe strongly correlated systems. We derive an analytic expression for the nontrivial form of the Kohn-Sham potential in between the two fragments for the dissociation of a single bond. We show that the numerical calculations for a one-dimensional two-electron model system indeed approach and reach this limit. It is shown that the functional form of the potential is universal, i.e., independent of the details of the two fragments.We acknowledge funding by the Spanish MEC (Grant No. FIS2007-65702-C02-01), “Grupos Consolidados UPV/EHU del Gobierno Vasco” (Grant No. IT-319-07), and the European Community through e-I3 ETSF project (Grant Agreement No. 211956).Peer reviewe