SONOGRAPHY OF THE EQUINE PALMAR METACARPAL SOFT TISSUES

It was hypothesized that ultrasonography may be a sensitive method for identifying pathologic changes in the tendons and ligaments of the palmar metacarpus of the horse. The palmar meta-carpi of equine cadavers and live horses were examined sonographically. The advantages and disadvantages of various ultrasound scanning techniques and the normal appearance of longitudinal and transverse palmar metacarpal sonograms are described.     

山羊实验性骨折愈合的X线观察

利用X线诊断技术,观察山羊的掌骨骨折愈合情况.结果表明:骨折愈合过程各期出现骨痂的最早时间,纤维性骨痂期平均为13d(最早者12d);骨性骨痂形成期平均为15.5d(最早者14d);骨性接合期平均为44d(最早者38d);骨痂改建期平均为72.5d(最早者70d).同时表明,同一骨骼的骨折,因骨折部位上下不同,达到各期愈合所经历的时间的差异明显,即掌骨上1/3组比掌骨下1/3组分别提前2,3,12和5d.     

Foetal Growth in the Reindeer

In connection with reindeer, slaughter 348 foetuses were collected at different foetal developmental stages and studied together with 20 full-term newborn calves with respect to weight, crown-rump length, metacarpal bone length and appearance of ossification foci. On the basis of these measurements polynomial growth curves were constructed. Weight gain was most rapid during the last trimester of gestation, but total and metacarpal bone length gain showed only minor acceleration towards the end of pregnancy. Ossification was apparent at an age of about 6 weeks. Undernutrition during late winter was observed to retard the foetal growth.     

Transverse stress fracture of the distal diaphysis of the third metacarpus in six Thoroughbred racehorses

Fractures involving the fetlock region are encountered commonly in Thoroughbred racehorses. Condylar fractures of the distal metacarpus/metatarsus and mid‐sagittal fractures of the proximal phalanx account for the majority of fetlock injuries during both racing and training and clinical features, management and outcome of these injuries have been well described. Transverse fractures of the distal diaphysis of the third metacarpus, however, are seldom observed and have received little attention in the literature. This paper describes clinical and radiological findings associated with 6 cases encountered in first opinion racehorse practice over a 3 year period. Transverse third metacarpal fractures vary in presentation but typically have clinical signs referable to the fetlock region and may, on occasion, be life‐threatening. They are therefore an important differential diagnosis when a fracture involving the fetlock is suspected.     

COMPARISON OF FLAT-PANEL DIGITAL TO CONVENTIONAL FILM-SCREEN RADIOGRAPHY IN DETECTION OF EXPERIMENTALLY CREATED LESIONS OF THE EQUINE THIRD METACARPAL BONE

Radiographic diagnosis of equine bone disease using digital radiography is prevalent in veterinary practice. However, the diagnostic quality of digital vs. conventional radiography has not been compared systematically. We hypothesized that digital radiography would be superior to film-screen radiography for detection of subtle lesions of the equine third metacarpal bone. Twenty-four third metacarpal bones were collected from horses euthanized for reasons other than orthopedic disease. Bones were dissected free of soft tissue and computed tomography was performed to ensure that no osseous abnormalities were present. Subtle osseous lesions were produced in the dorsal cortex of the third metacarpal bones, and the bones were radiographed in a soft tissue phantom using indirect digital and conventional radiography at standard exposures. Digital radiographs were printed onto film. Three Diplomates of the American College of Veterinary Radiology evaluated the radiographs for the presence or absence of a lesion. Receiver operator characteristic curves were constructed, and the area under these curves were compared to assess the ability of the digital and film-screen radiographic systems to detect lesions. The area under the ROC curves for film-screen and digital radiography were 0.87 and 0.90, respectively ( P =0.59). We concluded that the digital radiographic system was comparable to the film-screen system for detection of subtle lesions of the equine third metacarpal bone.     

The Arterial Supply of the Metacarpophalangeal Joint in the Bactrian Camel (Camelus bactrianus)

The arterial supply of the six metacarpophalangeal joints was studied in Bactrian camels. The arterial branches supplying the metacarpophalangeal joints were derived from the metacarpal distal perforating, medial and lateral branches of the palmar metacarpal artery III, medial and lateral branches of the palmar common digital artery III and the abaxial palmar proper digital arteries III and IV. These arterial branches were the proximal dorsoaxial distal metacarpal, distal dorsoaxial distal metacarpal, abaxial distal metacarpal, palmar distal metacarpal, interosseous distal metacarpal, dorsoaxial proximal proximal phalangeal, palmoaxial proximal proximal phalangeal, palmoabaxial proximal proximal phalangeal and dorsoabaxial proximal proximal phalangeal branches. They linked with each other around the metacarpophalangeal joint.     

Scintigraphic Appearance of the Dorsal Cortex of the Third Metacarpus and Third Metatarsus in the Horse

The lack of "standard uptake pattern" to refer to when interpreting scintigraphic images poses a problem to anyone working with skeletal scintigraphy. An article written by Koblik et al. stated that in the normal scintigraphic image of older horses, the dorsal cortex of the metacarpus and metatarsus is not identifiable, whereas it can be identified in younger horses. In this retrospective study we evaluated the association between the age of a horse and visibility of the dorsal cortex of the metacarpus and metatarsus. We found that dorsal cortical uptake can be seen in the normal adult horse. The population in the study consisted of 139 horses scanned under general anesthesia in lateral recumbency. Scintigraphic images of 202 limbs were examined visually and by using a profile image tool. In almost all limbs the dorsal cortex was identifiable (82%); only 7% of the dorsal cortices were not identifiable; and 11% of the scintigraphic images were not interpretable.     

ULTRASONOGRAPHIC MEASUREMENT OF PALMAR METACARPAL TENDON AND LIGAMENT STRUCTURES IN THE HORSE

An ultrasonographic study was made at several levels of the palmar metacarpal region of 23 horses (Anglo-Arabian-Andalusian) aged over three years. Lateromedial and palmodorsal measurements were made of tendons and ligaments, following clinical examination to confirm the absence of pathology in this region. Dissection was performed on 23 forelimbs, and these were measured at the same levels to establish a base of reference for the study. These measurements should prove useful in the evaluation of possible pathology in this region.