Ultrastructural immunolocalisation of bone sialoprotein in the osteocartilagenous interface of the equine third carpal bone

REASONS FOR PERFORMING STUDY: One of the most common causes of lameness in racehorses is osteoarthritis (OA). Pathogenesis is not clear and pathological processes of the different joint tissues interact in often progressive events. The interface between cartilage and newly synthesised bone has been shown to be particularly enriched in bone sialoprotein (BSP), a cell-binding matrix protein. OBJECTIVES: To establish whether changes in the concentration of BSP may serve as a marker for early biochemical changes of the subchondral bone. METHODS: Articular cartilage, cartilage/bone interface and subchondral bone of the proximal third carpal bone from 3 Standardbred trotters were analysed ultrastructurally for the presence of BSP in normal and degenerative areas. RESULTS: A marked increase of BSP in the cartilage/bone interface with degenerative changes of the bone and cartilage compared to the morphologically intact cartilage/bone interface was noted, but levels of the protein were distinctly lower in the distal bone. CONCLUSIONS: The results indicate that BSP has the potential to be used as a marker for changes in bone metabolism in the subchondral bone. POTENTIAL RELEVANCE: Tools to monitor early biochemical changes within the connective tissues of the joint in vivo are essential in studies of the pathogenesis of OA. These could be used to monitor and understand such changes in relation to load, exercise, training programmes, inflammation and the development of OA.     

Radiographic bone surveys in the evaluation of primary bone tumors in dogs

Forty-two dogs with primary bone tumors underwent radiographic bone surveys. The use of radiographic bone surveys led to a higher yield in finding other nonclinically detectable neoplastic sites (7.1%) than did thoracic radiographs (4.7%). Multicentric bone tumors accounted for 9.5% of total cases. Bone infarcts were identified in 3 dogs (7.1%).     

Radiological interpretation of the navicular bone

Acquisition of a sufficient number of high quality radiographic views is an essential prerequisite to accurate radiological interpretation of the navicular bone. This requires appropriate preparation of the foot, careful attention to limb position and to both centring and direction of the x‐ray beam, according to hoof capsule conformation. Artefacts are easily created. Potentially significant radiological abnormalities include: entheseiophytes at the proximomedial and proximolateral aspect of the bone; proximal or distal extension of the flexor border of the bone, distal border fragments, 8 or more large and variably shaped distal border radiolucent zones; discrete radiolucent areas in the spongiosa with or without detectable communication with the flexor cortex; new bone at the sagittal ridge; increased thickness of the flexor cortex; sclerosis of the spongiosa; and a bipartite bone.     

Haemangiosarcoma of bone in the dog

Twenty-two dogs with osseous haemangiosarcoma were examined in the University of Pennsylvania School of Veterinary Medicine from July 1952 to September 1972. A detailed case report of a primary haemangiosarcoma of the proximal humerus in a 21/2-year old spayed Irish Setter is given along with the salient features of twenty-one other cases. The three breeds most commonly involved were Boxers, Great Danes and German Shepherd Dogs. The ages ranged from 2–11 years with a median age of 6 years. The male to female ratio was 1·6:1·0. The proximal humerus and ribs were the bones most commonly affected. The long bone to flat bone ratio was 1·0:1·33. In some cases it was difficult or impossible to ascertain whether the haemangiosarcoma in bone was primary or metastatic. Histological grading appeared of little or no prognostic value. Résumé. De juillet 1952 à septembre 1972, on a examiné à l'Ecole de Médicine Vétérinaire de l'Université de Pennsylvanie, vingt-deux chiens atteints d'hémangiosarcome osseux. On donne un protocole détaillé d'observation d'un cas d'hémangiosarcome primaire de l'humérus proximal chez un setter irlandais châtré avec les traits caractéristiques saillants de vingt et un autres cas. Les trois races les plus communes dont il s'agissait, étaient les Boxers, les Grands Danois et les Bergers Allemands. Les âges variaient de deux à onze ans avec une moyenne d'âge de six ans. La proportion mâle à femelle était de 1·6:1·0. L'humérus proximal et les côtes étaient les os lesplus communément affectés La proportion de l'os long à l'os plat était de 1·0:1·33. Dans certains cas, il était difficile ou impossible de constater si l'hémangiosarcome de l'os était primaire ou métastatique. Une gradation histologique a semblé n'avoir que peu ou pas de valeur prognostique. Zusammenfassung. Zweiundzwanzig Hunde mit ossalen Hämangiosarkomen wurden in der Universität der Pennsylvanischen Schule für Veterinäre Medizin in der Zeit von Juli 1952 bis September 1972 untersucht. Ein in Einzelheit gehender Krankenbefund von einem primären Hämangiosarkom des Humerus proximalis in einem zweiundhalbjährigen irischen Setter (dem die Eierstöcke entfernt waren) wurde, zusammen mit den hervorstechenden Merkmalen von zweiundzwanzig anderen Fällen, veröffentlicht. Die drei Rassen, am Meisten einbegriffen, waren Boxer, dänische Doggen und deutsche Schäferhunde. Ihr Alter belief sich von zwei bis elf Jahren mit einem Durchschnittsalter von sechs Jahren. Das männliche zum weibliche Verhältnis stand bei 1·6:1·0. Der Humerus proximalis und die Rippen waren die Knochen, welche am Meisten befallen waren. Die Röhrenknochen standen zu den Plattenknochen im Verhältnis von 1·0:1·33. In einigen Fällen war es schwierig oder unmöglich zu ermitteln ob das Hämangiosarkom in Knochen primär oder metastatisch war. Histologische Einstufung schien von wenig oder keinem prognostischem Wert.     

Canine osteosarcoma of the penile bone

A 13-year-old mixed breed dog was presented with difficulties to urinate, blood in the urine and a nodule at the root of the penis. The penis was completely resected, and an osteosarcoma of the penile bone was diagnosed. Radiographically, there was no evidence to suggest tumours in other bones or distant metastases. The dog was euthanized as a consequence of tumour recurrence after 2 months. This is believed to be the first reported case of a primary osteosarcoma of the penile bone.     

Radiological interpretation of the navicular bone

Accurate radiological interpretation of a navicular bone requires at least a true lateromedial (LM) image, dorsoproximal‐palmarodistal oblique (DPr‐PaDiO) and palmaroproximal‐palmarodistal oblique (PaPr‐PaDIO) images. Additional information is sometimes acquired from a weightbearing dorsopalmar (DPa) image. The LM image is used to assess thickness of the palmar cortex, proximal or distal extension of the palmar cortex, demarcation between the cortex and spongiosa and the presence of periarticular osteophytes. The number, size, shape and position of radiolucent zones along the distal borders of the navicular bone are assessed in a PaPr‐PaDiO image, together with the presence of central or acentric radiolucent osseous cyst‐like lesions in the spongiosa, proximal or distal border entheseophytes, distal or proximal border fragments and a fracture. The PaPr‐PaDiO image is used to identify radiolucent lesions in the palmar cortex and to confirm the thickness of the palmar cortex and the presence of a fracture, and to assess the trabecular architecture of the spongiosa. The presence of a bipartite or tripartite navicular bone is determined from DPr‐PaDiO, PaPr‐PaDiO and DPa images.     

Comparison of bone healing by demineralized bone matrix and autogenous cancellous bone in horses

OBJECTIVE: The purpose of this study was to compare bone healing induced by equine demineralized bone matrix (DBM) to autogenous cancellous bone graft (ACB) or no graft (control) in a rib-defect model in horses. STUDY DESIGN: The osteogenic properties of ACB and DBM were evaluated in bilateral 19-mm circular defects created in the outer cortex of the 6th and 8th ribs of each horse. ANIMALS OR SAMPLE POPULATION: Eight mature horses. METHODS: Three rib defects in each horse were randomly treated with each of the 3 treatment groups, and the fourth rib defect received a random treatment. Rib sections, including the defects, were harvested 56 days after implantation and examined for bone mineral density, percent ash and calcium and graded for signs of radiographic and histological healing. RESULTS: All ribs were fractured at the defect site and were classified as nonunion fractures 56 days after implantation. There were no significant differences among groups in bone mineral density and signs of radiographic or histological healing. There was an increased volume of bone in control and ACB-treated sites compared with DBM-treated sites. Rib defects treated with ACB were significantly higher in percent ash and calcium than those treated with DBM. DBM elicited no inflammatory reaction, and remodeling occurred around the periphery and within vascular channels of the decalcified particles. CONCLUSION: DBM particles remodel from the periphery, which may explain the significantly lower percent ash, calcium, and bone when compared with ACB, because 2- to 4-microL pieces of DBM may act as space-occupying masses until completely mineralized. There was no evidence of enhanced healing associated with the use of DBM in this model. CLINICAL RELEVANCE: Particles of 2 to 4 mm DBM should not be used as an aid to fracture repair because particles of this size interfere with normal mineralization. However, our model of nonunion fracture healing may be useful in future studies.     

Fracture of the canine tibial tarsal bone

Fracture of the tibial tarsal bone was encountered in two dogs. In one case, coaptation in flexion resulted in joint stiffness and persistent lameness. In the other, open reduction and transverse pinning of each fragment to the adjacent fibular tarsal bone was followed by uncomplicated healing and normal function of the tarsus. Résumé. On a rencontré, chez deux chiens, un cas de fracture de l'os tibiotarsien. Dans un cas, la coaptation de flexion a résulté en raidure de l'articulation et en claudication persistante. Dans l'autre cas, une réduction ouverte et un épinglage transversal de chaque fragment à l'os adjacent péronéotarsien e été suivi d'une guérison sans complications et d'un fonctionnement normal du tarse. Zusammenfassung. Bruch des Schienbien-Fusswurzel Knochens kamen in zwei Hunden vor. In einem Fall hatte das Aufeinanderpassen in Biegung Gelenksteifheit und anhaltende Lahmheit zur Folge. In dem anderen folgte blutigem Knochenbruchreposition und querlaufencer Nage-lung von jedem Fragment an den benachbarten Wadenbein-Fusswurzel Knochen, eine unkom-plizierte Heilung und Normale Funktion des Tarsus.     

Bending properties of cortical bone of the horse

Bending properties of samples of cortical bone taken from the cranial, caudal, medial, and lateral quadrants of the midshaft of the radius, femur, and metacarpus of 12 ponies, 18 months old, were determined by 4-point loading at a rate of 10 mm/minute. The elastic modulus for all samples was between 16.2 and 20.2 GN/m2, and the ultimate breaking strength, between 204 and 255 MN/m2. There was greater variation in these properties between bone quadrants than between bones. Samples from the cranial and medial quadrants of both femur and radius were stiffer and had greater ultimate breaking strength than caudal or lateral samples. All samples of radius deformed more and absorbed more energy before reaching the greatest load than did samples of femur. The elastic modulus and the ultimate breaking strength of radius within any quadrant were highly correlated to specific gravity. However, at any specific gravity, caudal and lateral samples were not as strong as cranial and medial samples. Samples taken from exercised ponies, male ponies, or those fed diets containing 0.7% Ca,0.6% P or 2.7% Ca,1.1% P tended to be stiffer and have a greater ultimate breaking strength than samples taken from unexercised ponies, females, or those fed diets containing 0.7% Ca,1.4% P.     

Fractures of the accessory carpal bone in the horse

The clinical signs and radiographic appearance of 19 cases of fracture of the accessory carpal bone of horses are described. In 17 cases the fractures were in the frontal plane and occurred palmar to the groove on the lateral aspect of the bone. In six cases radiographs taken six months to three years after the fracture occurred showed no evidence of bony union; nevertheless, these and five other horses for which follow-up information was available for up to seven years all became sound, and seven of them returned to competitive activity.     

Use of bone morphogenetic proteins for augmentation of bone regeneration

A large body of preclinical and clinical data now documents that recombinant BMPs can be used for skeletal regeneration in humans and animals. Recombinant human BMP-2 and BMP-7 have been approved for use in human patients with long-bone fractures and nonunions and in patients undergoing lumbar fusion or various maxillofacial and dental regenerative procedures. These products have also been made available for veterinary use.