A standardized cortical defect was created on the caudal cortex of the proximal portion of each ulna in 5 adult mixed-breed dogs. One gram of autogenous cancellous bone graft (ACBG) was obtained from the greater tubercle of the ipsilateral humerus. The cortical defect in the ulna of 1 limb was filled with 1 g of ACBG that had been compressed with 2-MPa pressure for 30 seconds. One gram of noncompressed ACBG was placed into the contralateral ulnar cortical defect. The compressed and noncompressed ACBG recipient sites were radiographed at weekly intervals. Dogs were euthanatized 8 weeks after surgery, and the ACBG recipient sites were harvested for histomorphometric analysis. Optical densitometry was performed on all radiographs. There was no significant difference between compressed and noncompressed ACBG with optical densitometry or histomorphometric analysis for total bone area. We concluded that there was no difference in osteogenic capability between compressed and noncompressed ACBG of equal mass.

Cortical bone screws were implanted into the proximal portion of the right and left radius and ulna of 6 newborn Quarter Horse foals as radiographic markers for measurement of growth. Distance between markers on a lateral radiographic view was measured. Radiographs were taken at 2-week intervals until the horses were 8 weeks old, at 4-week intervals until they were 48 weeks old, and at 12-week intervals until they were 72 weeks old. The proximal radius and ulna grew at similar rates during the 72-week period of evaluation, and growth continued throughout 72 weeks. The proximal radius grew 3.5 cm, and the ulna grew 3.4 cm. Although the rates of growth were similar, growth from the ulnar physis contributed only to the length of the olecranon; growth was not transmitted to the ulnar diaphysis distal to the cubital joint. The proximal radius slid distally in relation to the ulna as growth occurred at the proximal radial physis. These findings suggest that transfixing the ulna to the radius while growth is occurring at the proximal radial physis impedes the natural shifting process, and subluxation of the elbow can result. Severity of subluxation would be inversely related to the age of the horse at the time of transfixation.

Spinal-evoked potentials were recorded from 2 litters of clinically normal mixed-breed dogs between 35 and 300 days of age. Summated responses to tibial nerve stimulation were recorded from percutaneous needle electrodes placed at L7-S1, L4-5, T13-L1, C7-T1, and the cisterna cerebellomedullaris. The ulnar nerve was stimulated with recordings at C7-T1 and the cisterna cerebellomedullaris. Amplitudes did not change significantly with age, but were significantly (P < 0.05) different between various recording sites. On day 35, segmental and overall (L7-cisterna cerebellomedullaris) conduction velocities were less than half of the adult values. Spinal cord conduction velocities increased with age, reaching adult values at approximately 9 months of age. It was determined that quadratic equations best predicted the conduction velocities during maturation.

Objective—To investigate topographic and age-dependent adaptation of subchondral bone density in the elbow joints of healthy dogs by means of computed tomographic osteoabsorptiometry (CTOAM). Animals—42 elbow joints of 29 clinically normal dogs of various breeds and ages. Procedures—Subchondral bone densities of the humeral, radial, and ulnar joint surfaces of the elbow relative to a water-hydroxyapatite phantom were assessed by means of CTOAM. Distribution patterns in juvenile, adult, and geriatric dogs (age, < 1 year, 1 to 8 years, and > 8 years, respectively) were determined and compared within and among groups. Results—An area of increased subchondral bone density was detected in the humerus distomedially and cranially on the trochlea and in the olecranon fossa. The ulna had maximum bone densities on the anconeal and medial coronoid processes. Increased bone density was detected in the craniomedial region of the joint surface of the radius. A significant age-dependent increase in subchondral bone density was revealed in elbow joint surfaces of the radius, ulna, and humerus. Mean subchondral bone density of the radius was significantly less than that of the ulna in paired comparisons for all dogs combined and in adult and geriatric, but not juvenile, dog groups. Conclusions and Clinical Relevance—An age-dependent increase in subchondral bone density at the elbow joint was revealed. Maximal relative subchondral bone densities were detected consistently at the medial coronoid process and central aspect of the humeral trochlea, regions that are commonly affected n dogs with elbow dysplasia.

OBJECTIVE To perform 3-D inverse dynamics analysis of the entire forelimb of healthy dogs during a walk and trot. ANIMALS 5 healthy adult Beagles. PROCEDURES The left forelimb of each dog was instrumented with 19 anatomic markers. X-ray fluoroscopy was used to optimize marker positions and perform scientific rotoscoping for 1 dog. Inverse dynamics were computed for each dog during a walk and trot on the basis of data obtained from an infrared motion-capture system and instrumented quad-band treadmill. Morphometric data were obtained from a virtual reconstruction of the left forelimb generated from a CT scan of the same dog that underwent scientific rotoscoping. RESULTS Segmental angles, torque, and power patterns were described for the scapula, humerus, ulna, and carpus segments in body frame. For the scapula and humerus, the kinematics and dynamics determined from fluoroscopy-based data varied substantially from those determined from the marker-based data. The dominant action of scapular rotation for forelimb kinematics was confirmed. Directional changes in the torque and power patterns for each segment were fairly consistent between the 2 gaits, but the amplitude of those changes was often greater at a trot than at a walk. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that control of the forelimb joints of dogs is similar for both a walk and trot. Rotation of the forelimb around its longitudinal axis and motion of the scapula should be reconsidered in the evaluation of musculoskeletal diseases, especially before and after treatment or rehabilitation.

Foram analisadas 528 radiografias simples de fraturas de rádio e ulna do arquivo do Serviço de Diagnostico por Imagem do Departamento de Cirurgia junto ao Hospital Veterinário da Faculdade de Medicina Veterinária e Zootecnia da Universidade de São Paulo realizadas no período de julho de 1999 a dezembro de 2005, selecionando-se os meses para análise de forma randomizada. Os principais resultados encontrados foram: Fraturas de rádio e ulna representam 20,9% do total encontradas, destas o tipo mais observado foi a transversal, tanto no rádio (75,5%) quanto na ulna (76,6%). 87,1% das fraturas acometeram o rádio e a ulna. O terço distal foi o mais acometido foi o distal, tanto do rádio quanto da ulna (72,9% e 70,1%, respectivamente). Esquírolas ósseas foram observadas em 13,8% e desvio de eixo ósseo em 94,9% dos casos. 40,2% dos cães não possuíam raça definida. 34,3% dos cães possuíam idade entre seis meses a um ano. | Survey of 528 radiographs of radius and ulna fractures selected from archive of Radiology Service of the Surgery Department into the Veterinary Hospital of Veterinary College of the University of Sao Paulo from July 1999 December 2005 we randomly selected the months to analyze. Radius and ulna fractures represent 20.9% of total fractures. 87.1% of these fractures attacked both bones. Transversal fractures were the most common type even in radius (75.5%) than ulna (76.6%), which occurred mainly at distal third radius (72.9%) and ulna (70.1%). Mix-breed dogs (40.2%), between the ages of six months and one year (34.3%), with displacement of axis bone (94.9%) were the most frequent types observed.

The aims and difficulties in small breed dogs radius and ulna fracture repair are known, frequently occurring cases of nonunionn principally in distal part of these bones, by their inherent anatomical characteristics, as poor muscular recovering, small medullar channel and less vascular aport, that are the principal causes of complication in post surgical or conservative procedures. By this reality, the comparison between treatment with bone plate and screws, with and without addition of bone morphogenetic protein (BMP), in distal fracture of radius and ulna in a Doberman Pinscher, cared in HOVET surgical area is described. It was evaluated the bone callus formation, by radiographic examination in 30th, 60th, 90th and 120th day of surgical procedure, being visualized total consolidation after 90 days in the control member and after 30 days in the BMP member, showing all the beneficial possibilities of the BMP use in cases of distal fractures in small breed dogs. | Os cuidados e dificuldades em reparação de fraturas de rádio-ulna de cães de porte pequeno são conhecidos, com a ocorrência freqüente de não-união óssea, principalmente no que tange as fraturas distais, relacionadas a características anatômicas inerentes, como pouco recobrimento de tecido muscular, canal medular de diâmetro reduzido, e pouca vascularização. Tendo em vista esta realidade, descreve-se a comparação entre o tratamento com placa e parafuso e placa e parafuso com adição de proteína morfogenética óssea em fratura completa transversa de terço distal bilateral de rádio-ulna, de semelhante apresentação em cão da raça Pinscher, atendido no Serviço de Cirurgia de Pequenos Animais do HOVET/USP. Avaliou-se, comparativamente, o tempo de formação de calo ósseo, por exames radiográficos, aos 30, 60, 90 e 120 dias de pós-operatório, onde foi encontrado tempo de cicatrização de 90 dias no membro controle enquanto que, no membro tratado com a proteína morfogenética óssea, o tempo de cicatrização foi de 30 dias, demonstrando a possibilidade de incremento que o uso de fatores de crescimento podem trazer ao tratamento de fraturas em cães de pequeno porte.