Radiographic and Histologic Changes After Thoracolumbar Disc Curettage

Forty-eight thoracolumbar disc spaces were approached by a dorsolateral muscle-separating technique in six mature dogs. Twenty-four of the discs were fenestrated and curetted, and the changes were followed radiographically and histologically for 16 weeks. Disc space collapse was visible radiographically immediately after the surgical procedure, and those disc spaces remained narrow throughout the observation period. Histologically, there was evidence of chondrocyte activation within 2 weeks in the excavated disc spaces. By 16 weeks, fibrocartilage had filled the void in the curetted disc spaces.     

Fibrotic Myopathy of the Semitendinosus Muscle in Four Dogs

Fibrosis of the semitendinosus muscle resulted in a characteristic gait abnormality in four male German shepherd dogs. Blood chemistry, electrophoresis, and electromyographic studies were performed. Surgery was undertaken in each case to relieve the restricting fibrous tissue. The lameness returned with reappearance of the fibrous band within six months. The etiology of fibrotic myopathy is unknown, but electromyographic studies and electrophoresis results suggest a myopathy due to chronic inflammation. Histopathologic exam reveals replacement of degenerating muscle fibers with connective tissue.     

Limb Salvage Surgery for Osteosarcoma of the Proximal Humerus: Outcome in 17 Dogs

Objective —To describe function and identify factors that affect outcome in dogs undergoing limb salvage surgery for osteosarcoma (OS) of the proximal humerus.
Study Design —A retrospective study of dogs in which OS of the proximal humerus was treated with limb salvage surgery.
Animals —17 client-owned dogs.
Methods: Records were analyzed for functional outcome, recurrence, metastasis, and survival.
Results —Outcome was good to excellent in 12% of dogs. Recurrence, metastasis, and survival were significantly affected by completeness of surgical margins. Double plating of the distal allograft-host junction significantly reduced frequency of biomechanical failure.
Conclusions —Limb salvage surgery for OS of the proximal humerus did not result in acceptable function and was fraught with postoperative complications. Outcome was significantly affected by completeness of surgical margins.
Clinical Relevance —Limb salvage surgery for OS of the proximal humerus in dogs cannot be recommended until improvement in functional outcome and reduction in postoperative complications can be achieved. The dependence of outcome on completeness of surgical margins supports aggressive en bloc resection and marking and evaluating surgical margins.     

MAGNETIC RESONANCE IMAGING CHARACTERISTICS OF PERIPHERAL NERVE SHEATH TUMORS OF THE CANINE BRACHIAL PLEXUS IN 18 DOGS

Magnetic resonance imaging (MRI) examinations from 18 dogs with a histologically confirmed peripheral nerve sheath tumor (PNST) of the brachial plexus were assessed retrospectively. Almost half (8/18) had a diffuse thickening of the brachial plexus nerve(s), six of which extended into the vertebral canal. The other 10/18 dogs had a nodule or mass in the axilla (1.2-338 cm3). Seven of those 10 masses also had diffuse nerve sheath thickening, three of which extended into the vertebral canal. The majority of tumors were hyperintense to muscle on T2-weighted images and isointense on T1-weighted images. Eight of 18 PNSTs had only minimal to mild contrast enhancement and many (13/18) enhanced heterogeneously following gadolinium DTPA administration. Transverse plane images with a large enough field of view (FOV) to include both axillae and the vertebral canal were essential, allowing in-slice comparison to detect lesions by asymmetry of structures. Higher resolution, smaller FOV, multiplanar examination of the cervicothoracic spine was important for appreciating nerve root and foraminal involvement. Short tau inversion recovery, T2-weighted, pre and postcontrast T1-weighted pulse sequences were all useful. Contrast enhancement was critical to detecting subtle diffuse nerve sheath involvement or small isointense nodules, and for accurately identifying the full extent of disease. Some canine brachial plexus tumors can be challenging to detect, requiring a rigorous multiplanar multi-pulse sequence MRI examination.     

Industrial Development Groups,Organizational Resources,and the Prospects for Effecting Growth in Local Economies

Using data from a survey of directors of not-for-profit industrial development groups in the United States and from a variety of secondary sources, we test the hypothesis that the presence of an active industrial development group was a significant factor in the economic growth of its service area over the 1977-to-1982 period. The data permit us to control for different levels of organizational resources among growth promotion groups as well as other traditional factors of local economic change in a regression analysis. While growth promotion groups are judged to be effective in terms of the number of jobs that are created or preserved relative to their direct expenditures of resources, neither their presence nor the levels of their organizational resources are significantly related to service area net employment change. The efforts of growth promotion groups are simply overwhelmed in importance by factors such as population size, metropolitan accessibility, location in a growth region, and manufacturing wage rates that characterize the respective service areas.     

Clinical Effects of Longitudinal Division of the Corpus Callosum in Normal Dogs

Longitudinal division of the corpus callosum was performed in six normal beagles to determine surgical morbidity. The corpus callosum was divided sagittally on the midline and the effect on neurological function was determined. Five of six dogs were clinically normal within 14 days or less after surgery. One dog had persistent but improving clinical signs consistent with a forebrain disturbance at 30 days after surgery. Overall, minimal morbidity and no mortality was associated with this surgical procedure. Further study is indicated to determine the efficacy of this surgical treatment for seizure control in dogs with idiopathic epilepsy.     

Combined Resection of the Nasal Planum and Premaxilla in Three Dogs

Surgical techniques for removal of tumors that affect the nasal planum or the premaxilla have been described. For extensively invasive malignancies, these techniques may be inadequate if used alone to achieve wide surgical margins. An operative technique that combines resection of the nasal planum and premaxilla has been developed for extensive malignant tumors of the nasal planum or premaxilla. This technique was used in three dogs and resulted in an acceptable cosmetic appearance and good function and tumor control. Complications after surgery included minor bleeding and partial dehiseence of the suture lines in two dogs and stenosis of the nasal orifice in one dog.