Effects of Plate Luting on Cortical Vascularity and Development of Cortical Porosity in Canine Femurs

A 4.5 mm, six hole dynamic compression plate was applied to the lateral aspect of one femur in 16 dogs. The plate was luted with polymethylmethacrylate (PMMA) in eight dogs. Four dogs each from the luted and nonluted groups were euthanatized at weeks 5 and 10. Plated femurs were sectioned and processed for microradiography, microangiography, and correlated histology. At week 5, there was decreased vascularity in the outer one third of the cortex beneath luted plates and normal to increased vascularity in the inner two thirds of the cortex. Increased cortical porosity and a decreased percentage of osteocyte-filled lacunae were found in the cortex beneath luted plates at week 5. At week 10, vascularity was increased throughout the cortex under luted plates. Under nonluted plates, there was normal to increased vascularity at both time periods. Luting a bone plate with PMMA decreased vascularity to the outer one third of the cortex beneath the plate at week 5, and resulted in accelerated resorption of bone.     

Effects of Immobilization on Cartilage Formation after Periosteal Grafting in the Rabbit Stifle

Autogenous periosteal grafts were harvested and placed in the trochlear grooves of the stifles of 32 rabbits. Postoperative immobilization periods of 0, 7, and 14 days were compared. Grafted areas were evaluated for gross appearance, histologic morphology, attachment of cartilage to subchondral bone, cartilage depth, chondrocyte density, proteoglycan presence, collagen fiber orientation, and mitotic activity. Nonimmobilized stifles had increased gross coverage of subchondral bone, better histologic quality, increased safranin O stain uptake, and more normal collagen fiber orientation at 60 days than stifles immobilized for 7 ir 14 days. Postoperative immobilization did not affect attachment of the graft to the subchondral bone.     

The Power of a Statistical Test What Does Insignificance Mean?

In statistical testing of data, the p value is a standard measure for reporting quantitative results. When a significant difference is reported, (e.g., P less than .05), most readers understand that there is less than a 5% chance that the authors have made a type I error (false positive or alpha) with their conclusion. In contrast, when nonsignificant differences between treatments, groups, or parameters of interest are reported (e.g., P greater than .05), many investigators and readers incorrectly interpret the 95% confidence interval for this conclusion as a 95% chance of making the correct decision. In fact, the alpha level of significance (in this example, .05) is only one of the parameters that determines the probability of committing a type II error (false negative or beta) when concluding statistical insignificance. Statistical power is the probability of having made a correct decision when the statistical tests reveal insignificance (P greater than .05) and the null hypothesis is true. The higher the power, the greater the chance that the decision is correct. Power depends on the alpha level of significance, the sample size, the standard deviation of the population or the sample, and the magnitude of the difference the investigators are trying to demonstrate.     

Morphological Effects of Arthroscopic Partial Synovectomy in Horses

Gross and microscopic effects of arthroscopic partial synovectomy on synovium and articular cartilage of middle carpal joints were studied in 15 horses. A 7-mm diameter motorized synovial resector was inserted into each middle carpal joint and arthroscopic partial synovectomy and lavage or arthroscopic lavage alone was performed. Study periods were 0 (three horses), 16 (three horses), and 30 days (six horses). No gross evidence of degenerative joint disease was observed at day 16 or 30. At 30 days, resected areas lacked villi and there was deposition of fibrin on the synovial surface with varying amounts of newly formed fibrovascular tissue. Thirty days after arthroscopic synovectomy, normal synovium had not formed in equine middle carpal joints.     

The Intercondylar Fossa of the Normal Canine Stifle: An Anatomic and Radiographic Study

The intercondylar fossa (ICF) in dogs consists of a cranial outlet, intercondylar shelf, caudal arch, caudal outlet, a medial wall, and a lateral wall. The normal cranial outlet is bell-shape and, in mixed-breed dogs (mean body weight 19.2 kg, N = 21), measured 5.8 mm cranially, 8.1 mm centrally, and 10.3 mm caudally. The ICF is oriented 12° from the dorsal plane of the femoral diaphysis and obliqued 7°, proximolateral to distomedial, in the sagittal plane. To adjust for dog size, a fossa width index (FWI) was calculated by dividing the cranial outlet width by the distance between epicondyles. The normal FWI as determined in this study was 0.18 cranially, 0.25 centrally, and 0.32 caudally. The fossa height index was 0.31. Contact between the ICF and the cranial cruciate ligament began at about 115° of extension. The contact area moved cranially in the intercondylar fossa as the stifle was extended. Evaluation of the ICF can be performed radiographically but positioning is critical.     

Intrahepatic Portosystemic Venous Anomaly in the Dog Perioperative Management and Complications

Hypotension, hemorrhage, and acute hepatic congestion were common complications during surgical correction of intrahepatic portosystemic venous anomalies in 13 dogs. Acute splanchnic congestion and hyperthermia were the most serious postoperative complications. Three dogs died within 24 hours; 10 dogs are alive and well after 12 to 46 months.     

Permanent Tracheostomy in Standing Horses: Technique and Results

Permanent tracheal stomas were created in seven sedated, standing horses with severe upper airway obstruction. After local anesthesia, a 3-cm by 6-cm rectangle of skin was removed from the ventral surface of the neck, 3 cm distal to the cricoid cartilage. The sternothyrohyoideus muscles were clamped proximally and distally, then transected to expose the tracheal rings. The ventral third of four tracheal rings was dissected from the tracheal mucosa that was then incised in a double "Y." Two layers of suture were used to achieve mucocutaneous closure. Stomas healed without serious complications; two mares subsequently foaled, and three horses were used for riding.     

Urinary Bladder Incisions in Dogs Comparison of Ventral and Dorsal

The occurrence of postoperative adhesions following ventral (20 dogs) or dorsal (12 dogs) urinary bladder incisions was evaluated. The bladder incisions were sutured with 3–0 polydioxanone suture material in a two-layer closure. Laparotomy (no urinary bladder incision) was performed in four dogs, which served as controls. The surgical sites were examined 1 (30 dogs) and 2 weeks (6 dogs) after surgery. Omental adherence to the urinary bladder was a frequent finding, but none of the urinary bladders was adhered to the ventral abdominal wall incision.     

Locking Loop Tendon Suture Use in Repair of Five Calcanean Tendons

The locking loop tendon suture is demonstrated. Five cases of its use in both acute and chronic lacerations of the calcanean tendon are presented. The results in all five cases were excellent. Advantages of this suture pattern include preservation of the intrinsic blood supply of the tendon, gap formation produced only with extreme load, simple and rapid placement of the suture, and reduction in adhesions. This suture pattern also can be used for other tendons.