Categorization of the pelvic limb standing posture in nine breeds of dogs.

The objective of the study was to categorize objectively nine breeds of healthy dogs according to pelvic limb standing posture. A total of 135 dogs from different breeds were used and the standing angles of the hip, stifle, and tarsal joints, together with the percentages of the greater trochanter, patella and tuber calcanei heights, with respect to crista iliaca height, were used as discriminant variables for the categorization of pelvic limb posture. All included breeds were allocated to three groups of the standing pelvic limb posture. The best discriminant variables between the three groups were the percentage of patellar height, and the standing angles of the stifle and tarsal joints. German shepherds, Anatolian shepherds, golden retrievers, Rottweilers, Belgian Malinois and Dobermann pinschers were well separated between 89% and 100% success rate for the categorization. The minimal success rate was determined in Berner sennenhunds as the ratio of 75%. It was also determined that Dobermann pinschers had the straightest pelvic limbs, while German shepherds had the most angulated pelvic limbs. Further studies are required to document the impact of postural differences in active and passive structure diseases of the locomotor system of the pelvic limb among dog breeds.

Anterior Femoral Bow and Possible Effect on the Stifle Joint: A Comparison between Humans and Dogs.

The aim of the study was to compare the anterior bow of the femur between dogs and humans in terms of the possible impact on the stifle joint. The femoral radiographs obtained retrospectively were used to determine the angles and positions of the anterior bow in both dogs (n = 135) and humans (n = 57). Descriptive statistics and Pearson's correlation analysis were used for the statistical analyses of the variables. The mean anterior bow angle (ABA) was 18.3 ± 2.02° and 4.88 ± 1.24° in dogs and humans, respectively. The bow position was at the distal shaft in dogs (64.9 ± 2.04%) and almost at the mid-shaft of the bone (46.5 ± 5.52%) in humans. The ABA was related to the bow position in both humans and dogs. Additionally, the angle correlated with age in humans, while it was correlated with weight and breed in dogs. In conclusion, it is suggested that the anterior bow should be used as a landmark on the femoral axis for the biomechanical research of stifle joint, and dog stifle could be used as a suitable model for human knee in experimental studies for clinicians, while making sure that ethical principles are fully respected.

Lateral and medial tibial plateau angles in normal dogs. An osteological study.

OBJECTIVES: To measure lateral and medial tibial plateau angle values in isolated canine tibiae and to compare lateral and medial tibial plateau angle values between dogs based on sex and breed. METHODS: Tibiae of 90 dogs from 24 different breeds were used. Photographs were taken of the medial and lateral aspects of the tibiae for measurement of the medial and lateral tibial plateau angles. Additionally, the medial tibial plateau angle was measured from radiographs of the tibiae. Two-way analysis of variance was used to test the effects of side, sex and breed on the medial and lateral tibial plateau angles as measured from photographs as well as the medial tibial plateal angles as measured from radiographs. The photographic and radiographic medial tibial plateau angles were compared by paired t-test, whereas the medial and lateral photographic tibial plateau angles were compared by t-test. RESULTS: When all dogs were included in the analysis, the difference between the mean medial tibial plateau angle (24.0 ± 3.19°) and the mean lateral tibial plateau angle (25.5 ± 3.84°) as measured from photographs was significant (p <0.05). The difference in the photographic medial tibial plateau angle between male and female dogs was significant (p <0.05), whereas the difference in the photographic lateral tibial plateau angle between sexes was not significant. There was a significant difference between the medial and lateral tibial plateau angles as measured from photographs in male dogs (p <0.05) but not in female dogs. Breed comparisons also showed significant differences for the photographic lateral tibial plateau angle (p <0.05). CLINICAL SIGNIFICANCE: The axial rotation of the femoral condyles on the tibial plateau is probably affected by the discrepancy between the medial and lateral tibial plateau angles, and this difference in certain breeds might influence the prevalence of cranial cruciate ligament disease.

Effect of anatomic variation in caudal tibial plateau on the tibial plateau angle in dogs: a cadaveric study.

OBJECTIVES: To determine the effect of using two different landmarks to identify the caudal point on the joint orientation line in the sagittal plane in tibial plateau angle measurement in dogs: the caudal margin of the medial condyle as the anatomic tibial plateau angle and the tibial insertion of the caudal cruciate ligament as the conventional tibial plateau angle. METHODS: A total of 170 tibiae from 85 mid- and large-breed dogs were used. The two joint orientation lines were drawn on photographic images of the bones. The angles between the line perpendicular to the tibial axis and the two lines were then measured as the anatomic and conventional tibial plateau angle. RESULTS: The mean conventional tibial plateau angle (25·2 ±2·60°) and anatomic tibial plateau angle (23·5 ±2·59°) differed significantly (P<0·001), and the degree of this difference varied significantly among seven breeds (P<0·01). CLINICAL SIGNIFICANCE: The results of this study suggest that the locations of the caudal margin of the medial condyle and the tibial insertion of the caudal cruciate ligament differed, leading to inconsistent identification of the joint orientation line depending on the landmark used.

Variation of tibial plateau geometry and cruciate ligament coordinates in six breeds of dogs.

OBJECTIVES: The first aim of this study was to examine whether or not variations concerning the conformational characteristics of the proximal surface of the tibial plateau exist among six different dog breeds as well as within the same breed. The second aim of this study was to determine the coordinates of the cruciate ligaments. METHODS: One hundred and four tibias of 52 mature dogs from six different breeds were used. Photographs of the proximal surface of tibial plateau were taken, and measurements for the length, width and area of the tibial plateau, and the lateral and medial condyles were taken. In addition, the intercondylar width, height of Gerdy's tubercle, popliteal notch depth, and extensor groove depth were measured and recorded. The quotients from these measurements were calculated and compared amongst the dog breeds. The coordinates of the cruciate ligaments, according to the centre of tibial plateau, were also determined. RESULTS: Based on the calculated quotients, variations in the geometry of the tibial plateau geometry were common among the breeds. Within the same breed, on the other hand, length and width measurements of the tibial plateau were the least variable parameters among the other parameters examined. The cranial cruciate ligament was located in front of the surface centre of tibial plateau in all breeds. The position of cranial cruciate ligament was more variable in the craniocaudal direction than that observed in the mediolateral direction; this was the exact opposite of caudal cruciate ligament. CLINICAL SIGNIFICANCE: The inter-breed variations of the quotients determined in the present study may facilitate attempts aimed to assess the risk factors of stifle joint injury and to design total knee prostheses.

Effects of triple pelvic osteotomy on anatomic structures of the pelvic region in the dog.

Triple pelvic osteotomy has been used in dogs to maintain normal form and anatomical function of the hip in canine hip dysplasia. Pelves subjected to triple pelvic osteotomy undergo several architectural changes of different magnitudes. The aim of this study was to determine the positional changes of the anatomical structure of the pelvis after unilateral triple pelvic osteotomy in five mongrel dogs. Atrophy of the middle gluteal muscle, reduction in tension of the external and internal obturator muscles, compression on the caudal gluteal vein and entrapment of the sciatic nerve at the level of the ilial body were the most remarkable findings in the study. From an anatomical standpoint, it is suggested that the lateral rotation of the acetabulum should be kept minimal to guarantee least alterations in the normal anatomic architecture of the pelvic region.

A morphometric study on the cross-sections of the scapular spine in dogs.

In cases of unstable scapular body fractures, the base of the scapular spine is one of the sites where there is adequate bone for the application of plate fixation in dogs. In this type of fixation, the amount of bone is an important factor with regard to the holding power of the screw from the biomechanical viewpoint. Therefore, the aim of this paper is to present the detailed quantitative features of the sectional area of the scapular spine in dogs. A total of 28 scapulas from 14 dogs were used, and each was divided into 10 equal slices The height of the scapular spine, depths of the supra-spinous and infraspinus fossae were measured from the scanned images with the aid of a computer program. The results showed that the depth of the supraspinous fossa was greater in the ventral half of the spine, while the depth of the infraspinous was greater in the dorsal half. The differences between the depths of the two fossae were noticeable in the ventral half of the scapular spine.

Cross-sectional geometry of the metapodial bones in the calf and ox.

The purpose of this study was to present a detailed description of the cross-sectional geometry at three levels of the metapodial bones and to assess the bone strength from the bone geometry in calf and ox. For this purpose, 20 metapodial bones from five calves and 40 metapodial bones from ten oxen were used. Sections were made at 25, 50 and 75% of the bone length and scanned. The cortical thickness, endosteal and periosteal diameters, cortical and medullar areas as well as second moment of area and section modulus were obtained from the images with the aid of a computer program. The cortical thickness and area values were higher in the metatarsus than that those in the metacarpus. The smallest cortical area and the thinnest cortical thickness were found at the distal level of metapodial bone in both calf and ox. When compared with the calf, relative increases in cortical area were seen at the proximal and distal levels, and the increases in cortical thickness were pronounced in the medial, lateral and dorsal sides in the metacarpus of the ox. With respect to the second moment of area and the polar moment, significant differences between metacarpus and metatarsus were found at the distal half of the bones in the calf while these differences were at the proximal half in the ox. The results of the current study indicated that there were important differences between the metacarpus and metatarsus as well as between the levels of the same bone with regard to the values of the geometric and strength parameters.

Computed tomographic measurements of the hip morphology of 10 healthy German shepherd dogs.

Linear measurements were made by computed tomography of the diameter of the femoral head, the width and depth of the acetabulum and the dorsal and ventral acetabular rim distances in 10 healthy German shepherd dogs, and angular measurements were made of the axial acetabular index, acetabular anteversion, and the dorsal and ventral centre-edge angles. There were no significant differences between the measurements made on the left and right sides. The width of the acetabulum was about twice its depth, and was a little larger than the diameter of the femoral head. The mean values of the axial acetabular index, acetabular anteversion, and ventral and dorsal centre-edge angles were 100.9 degrees, 25.1 degrees, 48.0 degrees and 12.2 degrees, respectively.

Morphometry of the thoracic spine in German shepherd dog: a computed tomographic study.

Computed tomographic images of the thoracic spine of 13 German shepherd dogs were examined in order to determine the thoracic spine morphometry. Examinations were carried out in the transverse plane both intervertebral and mid-vertebral levels of the each thoracic vertebrae. The dorsoventral and interpedicular diameters of the spinal canal, the dorsoventral and transverse diameters of the vertebral body, the dorsoventral and transverse diameters of the spinal cord and also the cross-section area of the spinal canal were measured. The maximum values were found to be at the level of C7-T1. The shapes of the spinal canal and cord were circular in middle part, the shape became transverse oval in the cranial and caudal parts of the thoracic spine. The most significant correlation between the diameters was found to be in male dogs, except between dorsoventral diameters of the spinal canal and that of the vertebral body and between dorsoventral diameters of the spinal canal and transverse diameters of the vertebral body.

Computed tomographic pelvimetry in German shepherd dogs.

Pelvimetry was performed on a computed tomographic scanner using dorsal and lateral scout-view images of 10 adult German shepherd dogs. The vertical and transverse diameters of the pelvis were measured and the pelvic inlet and pelvic outlet areas were also calculated. No significant correlations between the pelvic measurements and body weight, age and sex were found. Although the conjugata vera, diameter verticalis, diameter sacralis, sagittal diameter and the distance between the two medial tubera ischiadica were longer in females, no significant statistical difference was found between male and female animals for all measurements. It is proposed that the computed tomographic pelvimetry should be preferred for the sensitive measurements when the normal standards are determined for different animal species and the cost is reduced to an acceptable level.

Computed tomographic measurements of the trachea in dog.

Computed tomographic examination of the trachea was performed on 18 mix-breed dogs. The measurements were taken from 5 segments from which the first 3 segments were extrathoracic trachea, 1 segment at the level of thoracic inlet and 1 segment intrathoracic trachea. The inner and outer transverse and vertical diameters were measured at each of the segments. The cross-sectional area of the lumen, ratio of the inner and outer transverse and vertical diameters were also calculated. It was seen that the diameters and cross-sectional area of the lumen decreased gradually in the extrathoracic trachea from larynx to thoracic inlet but these values showed an increase in the intrathoracic trachea. Correlation coefficients between the inner diameters, cross-sectional lumen areas and the body weight was calculated and a high correlation was found between the inner transverse and vertical diameters and the cross-sectional area of the lumen except between the inner transverse and vertical diameters at the level of S5 segment.

A quantitative study on the trachea of the dog.

This study was carried out to record the detailed morphometric structure of the trachea in dogs using 15 female and four male healthy adult mongrel dogs. The diameter and thickness of each tracheal ring were measured, the number of tracheal rings varying from 36 to 45. All data were subjected to statistical analysis which was carried out on individual sections of the trachea, i.e. the cranial cervical, middle cervical, thoracic inlet and the intrathoracic tracheal regions, which consisted of 12, 12, nine and 12 tracheal rings, respectively. Fusion of the tracheal rings was especially obvious in the cranial cervical and thoracic inlet regions as a result of neck movements. The diameter and thickness of the tracheal rings are smallest at the thoracic inlet level because the direction of the trachea changes at this point where the thoracic inlet is relatively small and surrounded by bone. The ratios of inner transverse to inner vertical and outer transverse to outer vertical diameters were almost the same, between 1.14 and 1.25 in all regions, which indicated that the trachea is near-circular in shape in the dog. At the thoracic inlet level cross-sectional lumen areas are 7 and 6% smaller than those in the middle cervical and intrathoracic regions, respectively. The thinnest cartilage was seen at the thoracic inlet level where there is a risk of tracheal collapse.

Classification of the vascular patterns of the pelvic limb muscles of cats.

The vascular patterns of the pelvic limb muscles were studied in 20 limbs of 10 cats. Gross dissection and radiography were used to identify the vascular pedicles. It is proposed that the tensor fascia lata, the rectus femoris, the superficial gluteal, the biceps femoris, the sartorius, the gracilis and the lateral digital extensor muscles are suitable for making muscular and musculocutaneous flaps in cat.

A quantitative study of the circulus arteriosus cerebri of the camel (Camelus dromedarius).

The afferent vessels of the circulus arteriosus cerebri in the camel were studied quantitatively. It was found that the diameters of the arteries did not differ significantly on the left and right sides. An interesting observation was that the basilar artery contributed to the blood supply of the brain in the camel, in contrast to the situation in other ruminants.

A quantitative study on the retial arteries in one-humped camels.

The brain arteries of camels were injected with latex and the rostral epidural rete mirabile, which is situated inside the cavernous sinus at the base of the brain, was studied both grossly and quantitatively. The rostral epidural rete mirabile is formed by the retial branches of the maxillary and external ophthalmic arteries and also the internal carotid artery. When the ratio of the blood supply to the rete was estimated from the diameter of each vessel, it was found that the branches of the maxillary artery carried 76.41%, the branches of the external ophthalmic artery carried 10.26% and the internal carotid artery carried 13.33%.

A quantitative study of the aorta of the chicken (Gallus domesticus).

The different segments of the aorta were studied quantitatively in five age groups of chicken. It was observed that the widest diameter and the thickest media occur on the 56th day in each segment, except for the thoracic aorta, which had the widest diameter on the 42nd day and the thickest media on the 70th day. The percentage of the intima, media and the adventitia, as compared with the total wall thickness, was determined and it was found that this value was quite similar in age group, but the differences were significant from one segment to another. The ratio between the total wall thickness and the lumen diameter was also calculated in each segment.

Classification of the vascular patterns of the thoracic limb muscles of cats.

The vascular patterns of the thoracic limb muscles were studied in 20 limbs of 10 cats. Gross dissection and radiography were used to identify the vascular pedicles. It is proposed that the latissimus dorsi, the cervical portion of the trapezius, the caudal portion of the omotransversarius, the deep pectoral, the deltoid, the biceps brachii, the lateral digital extensor and the extensor carpi ulnaris muscles are suitable for making muscular and musculocutaneous flaps in cat.

A quantitative study on the retial arteries in the bovine fetus.

The rostral epidural rete mirabile was injected with latex and the retial arteries were studied quantitatively in three groups of bovine fetuses. It was seen that the differences between the diameters of the right and left retial arteries were not significant. An interesting observation was that the diameter of the internal carotid artery decreased gradually with an increase in the gestational age, but this reduction was made up for the maxillary artery via the rostral rete branches. The proportion of the blood supply to the rete was also determined in three groups of fetuses.