OBJECTIVE To describe methods to measure the 3-D orientation of the proximal, diaphyseal, and distal segments of the canine radius by use of computer-aided design software (CADS) and to compare the repeatability and reliability of measurements derived by those methods. SAMPLE 31 canine radii with biapical deformities and 24 clinically normal (control) canine radii. PROCEDURES Select CT scans of radii were imported into a CADS program. Cartesian coordinate systems for the humerus and proximal, diaphyseal, and distal radial segments were developed. The orientation of each radial segment in the frontal, sagittal, and transverse planes was measured in triplicate by 3 methods. The repeatability and reliability of those measurements were calculated and compared among the 3 measurement methods. RESULTS The mean ± SD within-subject repeatability of radial angular measurements for all 3 methods was 1.40 ± 0.67° in the frontal plane, 3.17 ± 2.21° in the sagittal plane, and 3.01 ± 1.11° in the transverse plane for control radii and 2.56 ± 1.95° in the frontal plane, 3.59 ± 2.39° in the sagittal plane, and 3.47 ± 1.19° in the transverse plane for abnormal radii. Mean ± SD bias between radial measurement methods was 1.88 ± 2.07° in the frontal plane, 6.44 ± 6.80° in the sagittal plane, and 2.27 ± 2.81° in the transverse plane. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that use of CADS to assess the 3-D orientation of the proximal, diaphyseal, and distal segments of normal and abnormal canine radii yielded highly repeatable and reliable measurements.

This study aimed to determine the numbers, directions, localizations, diameters, morphometric values of the nutrient foramina (NF) in humerus of domestic mammals and to reveal the differences between the right and left humerus in animal species. In the study, a total of 223 humerus, large ruminants (56), small ruminants (60), equidae (29), sus (24), carnivora-dog (42), and carnivora-cat (12), were examined in the Department of Anatomy, Faculty of Veterinary Medicine, Van Yuzuncu Yil University. The numbers, shapes, directions, localization sites and localized surfaces of the NF’s were observed with the naked eye, and recorded. The locations of the NF’s were confirmed by calculating the Foraminal Index (FI). The diameters of the NF’s were measured using 1.2 mm (18 Gauge: G), 0.9 mm (20 G), 0.7 mm (22 G), 0.55 mm (24 G), and 0.1 mm (34 G) needles. In animal species, morphometric measurements were taken such as total length of the humerus (TLH), distance between the NF with the proximal end of the humerus (NFP), distance between the NF with the distal end of the humerus (NFD), FI and performed statistical analysis of the measured values.There was found a single NF in 99% of the examined humerus in the study. In general, it was seen that the NF’s were directed downwards, and located in the middle 1/3 with lower 1/3 segments. NF’s were determined to be localized to the facies caudalis in 100% of sus, in 93% of large ruminants and carnivoradogs, and in 85% of small ruminants; however, in equidae and carnivora-cats were all localized to the margo medialis. According to the statistics, no statistically significant difference (p>0.05) was observed between the right and left humerus NF measurement values in terms of morphometric properties. But only, the diameter of the NF in the small ruminants was statistically significant (p<0.05).It was found that the morphological and morphometric differences of NF’s in right and left humerus of domestic mammals. Moreover, in these animals, it is thought that the study may help veterinary clinicians and surgeons in evaluating of the pathological conditions related to humeral NF and planning of the operative applications to be performed in this region.

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.

Objective-To assess gait abnormalities associated with selective anesthesia of the suprascapular nerve (SSN) achieved by use of perineural catheterization and thereby determine the function of that nerve as it relates to gait in horses. Animals-3 adult horses with no preexisting clinically apparent lameness at a walk. Procedure-Each horse was anesthetized; the right SSN was exposed surgically for placement of a perineural catheter to permit delivery of 1 mL of 2% mepivacaine hydrochloride. Six hours after recovery from anesthesia, each horse was videotaped while walking (50-step data acquisition period) before and after administration of mepivacaine. Videotapes were reviewed and the proportion of abnormal steps before and after selective SSN anesthesia was assessed. A step was considered abnormal if a marked amount of scapulohumeral joint instability (ie, lateral luxation of the proximal portion of the humerus) was observed during the weight-bearing phase of the stride. Results-Clinically apparent gait dysfunction was detected in all 3 horses following perineural administration of the local anesthetic agent. Anesthesia of the SSN resulted in scapulohumeral joint instability as evidenced by consistent lateral excursion of the shoulder region during the weight-bearing phase of gait at a walk. The proportion of abnormal steps before and after SSN anesthesia was significantly different in all 3 horses. Conclusions and Clinical Relevance-These data support the role of the SSN in shoulder joint stability in horses and define SSN dysfunction as 1 mechanism by which the syndrome and gait dysfunction clinically referred to as sweeny may develop.

We evaluated the single-cycle structural properties for axial compression, torsion, and 4-point bending with a central load applied to the caudal or lateral surface of a diaphyseal segment from the normal adult equine humerus, radius, third metacarpal bone, femur, tibia, and third metatarsal bone. Stiffness values were determined from load-deformation curves for each bone and test mode. Compressive stiffness ranged from a low of 2,690 N/mm for the humerus to a high of 5,670 N/mm for the femur. Torsional stiffness ranged from 558 N.m/rad for the third metacarpal bone to 2,080 N.m/rad for the femur. Nondestructive 4-point bending stiffness ranged from 3,540 N.m/rad for the radius to 11,500 N.m/rad for the third metatarsal bone. For the humerus, radius, and tibia, there was no significant difference in stiffness between having the central load applied to the caudal or lateral surface. For the third metacarpal and metatarsal bones, stiffness was significantly (P < 0.05) greater with the central load applied to the lateral surface than the palmar or plantar surface. For the femur, bones were significantly (P < 0.05) stiffer with the central load applied to the caudal surface than the lateral surface. Four-point bending to failure load-deformation curves had a bilinear pattern in some instances, consisting of a linear region at lower bending moments that corresponded to stiffness values from the nondestructive tests and a second linear region at higher bending moments that had greater stiffness values. Stiffness values from the second linear region ranged from 4,420 N.m/rad for the humerus to 13,000 N.m/rad for the third metatarsal bone. Differences in stiffness between nondestructive tests and the second linear region of destructive tests were significant (P < 0.05) for the radius, third metacarpal bone, and third metatarsal bone. Difference between stiffness values of paired left and right bones was not detected for any test. Four-point bending ultimate failure bending moments ranged from 260 N.m for the femur to 940 N.m for the third metatarsal bone. There was no difference in failure bending moment between the directions of applied central load for a given bone.

As more sophisticated research is performed to refine fracture fixation techniques for horses, it is important that normal values for the geometric properties of the bones of the appendicular skeleton be determined and that suitable controls be available. We evaluated the geometric properties of total bone width, cortical bone width, and medullary canal/trabecular bone width measured from 2 radiographic projections of equine long bones (humerus, radius, third metacarpal bone, femur, tibia, and third metatarsal bone) obtained from a general population of horses. Measurements were performed on slices separated by intervals equal to 5% of the bone's length. Slices were then grouped into 5 regions: proximal epiphysis, proximal part of the metaphysis, diaphysis, distal part of the metaphysis, and distal epiphysis. Results validated use of the contralateral bone as a control for assessing experimental models or clinical cases. Of 858 homotypic slice comparisons between left and right bones, significant (P less than or equal to 0.05) differences were detected in 31 (3.6%) of the comparisons. Of 168 homotypic region comparisons, significant differences were observed in 3 (1.8%) of the comparisons. The greatest variation between left and right bones was observed in metaphyseal regions, areas with bony protuberances, and regions with prominent bone superimposition. At a power of 0.8 for the statistical tests performed in this study, the mean homotypic variation of bones in each region is < 5.8% for the proximal epiphysis, 11.3% for the proximal part of the metaphysis, 6.8% for the diaphysis, 12.2% for the distal part of the metaphysis, and 5.2% for the distal epiphysis.

The ability of IV administered hydroxyethyl-starch-deferoxamine to attenuate radical production in freshly procured cancellous bone specimens was investigated, using spin-trapping and electron spin resonance (ESR) techniques. A core cancellous bone specimen 10 mm long and 5.6 mm in diameter was obtained, using aseptic technique, from the proximal portion of the humerus of 30 adult mixed-breed dogs. After procurement of the initial bone specimen, 10 dogs received a 10% solution of hydroxyethyl-starch-deferoxamine in 0.9% NaCl (50 mg/kg of body weight, IV), 10 dogs received an equivalent volume (5 ml/kg, IV) of a 10% solution of hydroxyethyl-starch in 0.9% NaCl, and 10 dogs received 0.9% saline solution (5 ml/kg, IV). A second core cancellous bone specimen was obtained from the contralateral humerus of each dog 45 minutes after treatment. All specimens were individually incubated in the spin trap alpha-phenyl-N-tert-butylnitrone in Eagle's minimum essential medium, at 26 C for 45 minutes, then were frozen at -20 C until they were prepared for analysis by ESR spectroscopy. Each specimen was thawed, homogenized, and extracted in a low-dielectric organic solvent prior to obtaining an ESR spectrum, which was analyzed for hyperfine splitting constants for radical identification. Each first-derivative spectrum was digitally double-integrated to obtain an area; these areas were used to compare intensities of the spin adducts. Difference in the area obtained before and after treatment for each dog was expressed as a ratio of that dogs pretreatment area ([pretreatment - posttreatment]/pretreatment). The calculated ratios for saline-, hydroxyethyl-starch-, and hydroxyethyl-starch-deferoxamine-treated dogs were compared, using a Kruskal-Wallis (KW) nonparametric test for multiple comparisons of ranked data. Significance was determined at P less than or equal to 0.05. Ad hoc comparisons were performed, using the KW procedure for individual comparisons, with alpha set at 0.05. The mean +/- SD and median ratio for each of the treatment groups were: saline-treated dogs, 0.005 +/- 0.40 and 0.045; hydroxyethyl-starch-treated dogs, -0.063 +/- 0.27 and -0.025; hydroxyethyl-starch-deferoxamine-treated dogs, 0.261 +/- 0.278 and 0.335, respectively. There was a significant (P < 0.01, KW) difference in the ratios between treatment groups. Ratios for hydroxyethyl-starch-deferoxamine-treated dogs were significantly (P < 0.05, KW) higher than that for hydroxyethyl-starch-treated dogs but not for saline-treated dogs. The ratios for saline- and hydroxyethyl-starch-treated dogs were not significantly different. We could not associate significant attenuation of radical generation in freshly harvested core cancellous bone specimens with IV administration of hydroxyethyl-starch-deferoxamine. The potential for unconjugated hydroxyethyl-starch to function as an oxidant must considered.

Dogs have been used extensively as an experimental model for studying musculoskeletal disorders. Many of these studies incorporated sequential radiography to quantitate a particular treatment's effect, using the contralateral bone as the control condition. The contralateral bone can be used as a control only if there is bilateral symmetry between right and left limbs. We performed radiography (craniocaudal and lateromedial views) on 10 pairs of humeri, radii, femora, and tibiae from dogs, using an alignment jig, to radiographically determine homotypic geometric variations of long bones. The bones were divided into 5 regions: proximal epiphysis, proximal metaphysis, diaphysis, distal metaphysis, and distal epiphysis. The total bone diameter, medullary diameter, and cortical width (total of medial + lateral cortex or total of cranial + caudal cortex) were measured at specified slices throughout each of these regions. Fourteen of 540 homotypic comparisons revealed significant differences between right and left bones at either a slice or region. Although there were only 14 significant differences between right and left bones at any region or slice, measurements were more precise with lower coefficients of variation in the diaphyseal and epiphyseal regions. Homotypic differences in diaphyseal and epiphyseal regions were < 5.3 and 7.5%, respectively power = 0.8). In metaphyseal regions, however, homotypic differences were larger; these differences could have been as large as 11.5% for total bone diameter, 15.6% for medullary diameter, and 80.0% for cortical width without achieving significant differences between populations (power = 0.8). This study validated the concept of using the contralateral limb as the control condition in orthopedic studies using dogs, particularly when evaluating the geometric properties of long bones radiographically.

A percutaneous biopsy technique for the study of endochondral bone formation in the dog was developed. With the dogs under general anesthesia or sedated with a combination of a tranquilizer and a local anesthetic, biopsy specimens were obtained from the proximal growth plate of the humerus with the use of a Jamshidi bone biopsy needle. Biopsy specimens were structurally intact, and contained epiphysis, growth plate, and metaphysis. The procedure proved to be a simple, safe technique, which caused minimal discomfort for the patient and did not affect the growth of the proximal end of the humerus, even after multiple biopsies.

OBJECTIVE To assess 3-D geometry of the humerus of dogs and determine whether the craniocaudal canal flare index (CFI) is associated with specific geometric features. SAMPLE CT images (n = 40) and radiographs (38) for 2 groups of skeletally mature nonchondrodystrophic dogs. PROCEDURES General dimensions (length, CFI, cortical thickness, and humeral head offset), curvature (shaft, humeral head, and glenoid cavity), version (humeral head and greater tubercle), and torsion were evaluated on CT images. Dogs were allocated into 3 groups on the basis of the craniocaudal CFI, and results were compared among these 3 groups. The CT measurements were compared with radiographic measurements obtained for another group of dogs. RESULTS Mean ± SD humeral head version was −75.9 ± 9.6° (range, −100.7° to −59.4°). Mean mechanical lateral distal humeral angle, mechanical caudal proximal humeral angle, and mechanical cranial distal humeral angle were 89.5 ± 3.5°, 50.2 ± 4.5°, and 72.9 ± 7.8°, respectively, and did not differ from corresponding radiographic measurements. Mean humeral curvature was 20.4 ± 4.4° (range, 9.6° to 30.5°). Mean craniocaudal CFI was 1.74 ± 0.18 (range, 1.37 to 2.10). Dogs with a high craniocaudal CFI had thicker cranial and medial cortices than dogs with a low craniocaudal CFI. Increased body weight was associated with a lower craniocaudal CFI. Radiographic and CT measurements of craniocaudal CFI and curvature differed significantly. CONCLUSIONS AND CLINICAL RELEVANCE CT-based 3-D reconstructions allowed the assessment of shaft angulation, torsion, and CFI. Radiographic and CT measurements of shaft curvature and CFI may differ.