Comparison of the large muscle group widths of the pelvic limb in seven breeds of dogs.

Orthopaedic diseases are common in the pelvic limbs of dogs, and reference values for large muscle groups of the pelvic limb may aid in diagnosis such diseases. As such, the objective of this study was to compare the large muscle groups of the pelvic limb in seven breeds of dogs. A total of 126 dogs from different breeds were included, and the widths of the quadriceps, hamstring and gastrocnemius muscles were measured from images of the lateral radiographies. The width of the quadriceps was not different between the breeds, but the widths of the hamstring and gastrocnemius muscles were significantly different between the breeds. The widest hamstring and gastrocnemius muscles were seen in the Rottweilers and the Boxers, respectively. The narrowest hamstring and gastrocnemius muscles were seen in the Belgian Malinois and the Golden retrievers, respectively. All ratios between the measured muscles differed significantly between the breeds. Doberman pinschers and Belgian Malinois had the highest ratio of gastrocnemius width:hamstring width. Doberman pinschers had also the highest ratio of quadriceps width:hamstring width. German shepherds had the highest ratio of gastrocnemius width:quadriceps width. The lowest ratios of quadriceps width:hamstring width were determined in the German shepherds. The ratios of the muscle widths may be used as reference values to assess muscular atrophy or hypertrophy in cases of bilateral or unilateral orthopaedic diseases of the pelvic limbs. Further studies are required to determine the widths and ratios of the large muscle groups of the pelvic limbs in other dog breeds.

Rotational deformities of the long bones can be corrected with rotationally guided growth during the growth phase.

Background and purpose - Coronal and sagittal plane long bone deformities can be corrected with guided growth, whereas transverse plane rotational deformities require osteotomy and internal or external fixation. We investigated whether rotational changes can be introduced with the plating technique. Methods - 45 rabbits (6 weeks old) were divided into 3 groups. The unoperated right tibia was used as control. In groups 1 and 3, two plates were placed obliquely to the long axis and in different directions. In group 2, a sham operation was performed with screws. Animals in groups 1 and 2 were followed for 4 weeks. In group 3 the implants were removed 4 weeks after the operation to observe rebound effect, and the animals were followed for another 4 weeks. The tibial torsion was assessed on computed tomography (CT). External rotation was accepted as a negative value. Results - In group 1, mean torsion was -20° (SD 7.9) in the right tibia and -2.9° (SD 7.2) in the left tibia (p < 0.001). In group 2, mean torsion was -23° (SD 4.9) in the right tibia and -26° (SD 6.5) in the left tibia (p = 0.2). In group 3, mean torsion was -21° (SD 6.3) in the right tibia and -9.5° (SD 5.3) in the left tibia (p < 0.001). Intergroup evaluation for left torsion showed a significant difference between group 2 and the other groups (p < 0.001). When the rebound effect was evaluated, there was no statistically significant difference between groups 1 and 3 (p = 0.08). Interpretation - A rotational change was attained with this technique. Although a rebound effect was seen after implant removal, it did not reach statistical significance. The final rotational change remained constant.

Effect of triple pelvic osteotomy on the proximal femoral geometry in dysplastic dogs.

Triple pelvic osteotomy (TPO) is one of the surgical procedures for use to try to reduce subsequent degenerative joint disease or modify the progress of hip dysplasia in young dogs. Joint force and pressure distribution were changed by this procedure. Therefore, the aim of this study was to find out whether the remodeling of proximal femur exists or not after TPO in dysplastic dogs. Ten femora from five young dysplastic mongrel dogs, treated unilaterally with TPO using 20° canine pelvic osteotomy plates, were used. One year after TPO, neck-proximal shaft angle, femoral head, neck, diaphyseal and mid-shaft diameters, total femoral, femoral neck axis, and intertrochanteric, femoral head offset lengths as well as the lengths from head center to lateral margin of greater trochanter and to proximal femoral axis were measured from the bone. The significant differences between treatment and control side were determined in Norberg angle, neck-proximal shaft angle, neck diameter, diaphyseal diameter, mid-shaft diameter, length from head center to proximal femoral axis and femoral head offset length. In conclusion, although small number of cases was used, it was determined that the aforementioned variables are affected by TPO. So, these variables may be supply additional information about the changes to the joint following TPO in dysplastic dogs.

Geometry of the femoral condyles in dogs.

The stifle joint is one of the most important joints in dogs from the orthopaedic point of view. The aim of this study was to document the morphometric values of femoral condyles, given the close relationship between the shape and function of an anatomic structure. The left femora of 16 mid-sized dogs were used, and diameter and nine radii as well as cranial and caudal bow lengths from each condyle were measured. The photographs were taken of the distal femora from both sides. All measurements were obtained from these images by using software. Additionally, the rotation angle was calculated from the intercondylar distance and the difference between lateral and medial bow lengths. In addition to the rotation angle, the difference of diameter and nine radii between the lateral and medial condyles was determined. All radii except getting at 90° were significantly different between the medial and lateral condyles. The greatest values were determined in the caudal part of the medial condyle. This results the smaller contact area and a greater pressure on the underlying surface, and therefore the meniscus and articular cartilage of the caudal part of the medial side suggests the possibility of a risk of injury as the stifle joint flexes. The mean rotational angle of the femur was also calculated to be 2.18° laterally and 1.02° medially in the caudal and cranial parts of condyles, respectively. The result of this study showed that the lateral and medial condyles had different shapes in canine femur.

A quantitative study on the sacrum of the dog.

The aim of this study was to record sacral bone morphometry that may help in selection of the implant type and proper size in sacroiliac separation. For this reason, sacral lengths and width, the length of each sacral vertebrae, distances between cranial and caudal articular processes, vertical and transversal diameters of the cranial endplate, sacral tuberositas and articular surface areas were obtained from 11 dogs. Additionally, the transverse and vertical diameters of the bony structure and sacral canal were measured from six cross-sections. The data of the study were determined to be representative of the sacral values for average-sized dogs, which was confirmed statistically. The highest value was the sacral width among the linear measurements. The ventral sacral length was longer than the dorsal sacral length. The total lateral area of the sacral wing was measured as 677.46 (142.1)mm2. The transverse diameters of the first sacral vertebra important for screw implantation were 46.02 (4.33)mm and 44.18 (5.29)mm in the first and second cross-sections, respectively.

Computed tomographic assessment of the trachea in the German shepherd dog.

Computed tomographic (CT) examination of the trachea was performed in 10 German shepherd dogs to determine the normal value of some tracheal measurements under general anesthesia and in sternal recumbence position. Measurements obtained from nine segments were evaluated in four groups as the cranial cervical, caudal cervical, thoracic inlet and the thoracal tracheas. The inner transverse (T) and vertical (V) diameters were measured with the aid of electronic calipers from the software of the CT scanner. The cross-sectional lumen area (CSA) was calculated by using vertical and transverse diameters. The ratio of the transverse and vertical diameters (T/V) was also calculated. There was not any significant difference between thoracic inlet and thoracic tracheas, however, the mentioned regions were found to be significantly different from both cranial and caudal cervical regions in all measurements except the ratio of T/V. The ratio of T/V between 0.92 and 1.06 gradually changed and there was not any statistical difference between subsequent regions while differences were found among further regions. The largest CSA, seen in cranial cervical trachea was as 364.62 mm2 and decreased gradually to 309.29, 245.69 and 226.50 mm2 in caudal cervical, thoracic inlet and thoracic tracheas, respectively. From the point of view of technique, CT examination of the dog trachea was very easy and it was possible to take sensitive and repeated measurements. It, however, may be accepted as expensive and that it is disadvantageous to require general anesthesia. The data presented in this study represent tracheal values in the healthy German shepherd dog under the conditions of the study.

A quantitative study on the digital bones of cattle.

The bones of 64 digits from eight Holstein male cattle were studied quantitatively to determine whether any differences existed respective on the corresponding bones of the different digits. For this purpose, the greatest and abaxial greatest lengths, the smallest diaphysial breadths, the breadths of proximal and distal ends of the proximal and middle phalanges, the lengths of dorsal surfaces, the heights of extensor processes, the greatest diagonal lengths and the middle breadths of the soles from the distal phalanges were measured. Comparison showed that measurements between the right and left sides did not differ significantly. However, differences were found for almost all measurements between the forelimb and hindlimb. The proximal and middle phalanges were found to be shorter and broader in the forelimb and the broadness was more noticeable than the length. The distal phalanx of the medial forefoot had the greatest value in four measurements while the smallest values were found in the lateral hind foot. The results indicated that the morphometry of the digital bones could be important from both phylogenetic and clinical aspects.