Assessment of overall thoracic limb axial alignment in dogs with antebrachial deformity.

OBJECTIVE: To assess overall thoracic limb axial alignment in dogs with and without angular limb deformity (ALD). STUDY DESIGN: Ex vivo and retrospective observational clinical study. ANIMALS: Forty canine thoracic limbs from bilateral normal specimens (10 pairs) and unilateral antebrachial ALD (10 uniapical and 10 biapical deformities). METHODS: Computed tomography images of the entire thoracic limb were collected for multiplanar reconstruction. Baseline limb axis was defined by the humeral anatomic axis. Axial alignment of the distal humerus, proximal and distal radius, and metacarpal bones were obtained and compared among levels and groups. RESULTS: The mean overall thoracic limb rotation of normal dogs was 35.4 ° (95% CI, 27.2 °, 43.6 °). Mean overall limb rotation in uniapical and biapical deformity was 41.6 ° (95% CI, 33.0 °, 50.1 °) and 54.4 ° (95% CI, 45.8 °, 62.9 °), respectively, but was not statistically different (P = .096). Only overall limb rotation in limbs with biapical ALD was different from normal limbs (P = .008). Rotation at the level of the elbow was 77% and 85% of overall limb rotation in normal and deformity limbs, respectively, and was increased from normal in limbs with ALD (both P < .05). Radial torsion did not differ among groups but was moderately correlated with overall limb rotation. CONCLUSION: Rotation arising in the elbow of limbs with ALD was higher than in normal limbs and accounted for the greatest contribution of overall limb rotation. CLINICAL SIGNIFICANCE: Assessment of radial torsion alone is insufficient to understand overall limb axial alignment in dogs with antebrachial bone deformity.

Assessment of radial torsion using computed tomography in dogs with and without antebrachial limb deformity.

OBJECTIVE: To evaluate the reliability of radial torsion assessment in dogs using computed tomography (CT). STUDY DESIGN: Cadaveric and retrospective observational clinical study. ANIMALS: Thoracic limbs (n = 40) from bilateral normal cadaveric canine specimens (10 pairs) and unilateral antebrachial angular limb deformity (ALD) dogs (10 uniapical and 10 biapical deformities). METHODS: Limbs were evaluated using CT. Frontal, sagittal, and axial plane (torsion) values were obtained using published guidelines and compared between groups and limbs. Radial torsion reliability was assessed among 3 observers using intraclass correlation coefficients (ICC). RESULTS: The mean (±SD) radial torsion of normal dogs was 3.6° ± 6.4° and contained a significant right to left limb variation of 2.6°. Mean radial torsion in uniapical ALD limbs (3.6° ± 18.7°) was not significantly different from biapical ALD limbs (8.9° ± 17.9°). There was a wide range of torsion values in normal and ALD limbs. The interobserver reliability was excellent (ICC > 0.8) for normal dogs, good (0.73) for uniapical, and excellent (0.89) for biapical ALD limbs. The intraobserver reliability was excellent (>0.8) for all groups. CONCLUSION: There was a small side-to-side variation of radial torsion in normal dogs. With directed training, torsion assessment using CT is reliable in dogs with and without antebrachial bone deformity.

Inflow Venous Occlusion for Intracardiac Resection of an Occluding Right Ventricular Tumor.

Use of normothermic venous inflow occlusion enabled removal of an intracardiac tumor in a 4 yr old, 27 kg, spayed female Airedale terrier with a history of appendicular osteosarcoma and recent exertional syncope. Inflow venous occlusion via a median sternotomy thoracotomy without hypothermia was used to access the mineralized mass within the right ventricular outflow tract. Duration of circulatory arrest was 70 s for this beating heart surgery. A circumscribed intracardiac chondrosarcoma tumor was marginally resected in this dog, successfully alleviating exertional syncope and restoring a normal echogenic appearance of the right heart. Asymptomatic intracardiac chondrosarcoma recurrence and pulmonary metastasis was detected at 309 days and cardiopulmonary arrest occurred 372 days following intracardiac surgery. Use of inflow occlusion is a viable technique for select intracardiac tumors in dogs with preoperative planning.

Update on Surgical Principles and Equipment.

The diversity implicit in exotic animal surgery requires a tailored approach to optimize successful outcomes. Outlined is information on patient preparation, instrumentation, hemostatic techniques, and magnification as it pertains to the exotic animal. Application of topical antiseptic solutions and judicious removal of pelage and feathers will decrease bacterial load during patient preparation. The use of specific barrier protection ensures proper aseptic technique and enables optimal patient monitoring. Magnification combined with a focal light source enhances visual acuity, allowing for better use of delicate instrumentation and identification of anatomic structures.

Radiographic risk factors for contralateral rupture in dogs with unilateral cranial cruciate ligament rupture.

BACKGROUND: Complete cranial cruciate ligament rupture (CR) is a common cause of pelvic limb lameness in dogs. Dogs with unilateral CR often develop contralateral CR over time. Although radiographic signs of contralateral stifle joint osteoarthritis (OA) influence risk of subsequent contralateral CR, this risk has not been studied in detail. METHODOLOGY/PRINCIPAL FINDINGS: We conducted a retrospective longitudinal cohort study of client-owned dogs with unilateral CR to determine how severity of radiographic stifle synovial effusion and osteophytosis influence risk of contralateral CR over time. Detailed survival analysis was performed for a cohort of 85 dogs after case filtering of an initial sample population of 513 dogs. This population was stratified based on radiographic severity of synovial effusion (graded on a scale of 0, 1, and 2) and severity of osteophytosis (graded on a scale of 0, 1, 2, and 3) of both index and contralateral stifle joints using a reproducible scoring method. Severity of osteophytosis in the index and contralateral stifles was significantly correlated. Rupture of the contralateral cranial cruciate ligament was significantly influenced by radiographic OA in both the index and contralateral stifles at diagnosis. Odds ratio for development of contralateral CR in dogs with severe contralateral radiographic stifle effusion was 13.4 at one year after diagnosis and 11.4 at two years. Odds ratio for development of contralateral CR in dogs with severe contralateral osteophytosis was 9.9 at one year after diagnosis. These odds ratios were associated with decreased time to contralateral CR. Breed, age, body weight, gender, and tibial plateau angle did not significantly influence time to contralateral CR. CONCLUSION: Subsequent contralateral CR is significantly influenced by severity of radiographic stifle effusion and osteophytosis in the contralateral stifle, suggesting that synovitis and arthritic joint degeneration are significant factors in the disease mechanism underlying the arthropathy.