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81.
Smooth and partially threaded 3.12 mm (1/8 inch) trochar-tipped Steinmann pins were inserted transversely through both diaphyseal cortices of eight mature canine tibias using five methods. Angular velocity (revolutions per minute) during insertion and temperature elevation due to friction during penetration of the second cortex were recorded. The force required for extraction of the pins from the bone and the histologic appearance of the bone-pin interface were determined for one-half of the pins 2 days after insertion and for one-half of the pins 56 days after insertion. The increase in temperature was similar for all methods of insertion except high speed power, which was significantly greater (p < 0.05). The force required for axial pin extraction was similar for pins inserted by hand chuck, predrilled, and low speed power methods after both 2 and 56 days. Pins inserted by high speed power and hand drill required force similar to the others for extraction after 2 days but significantly less force (p < 0.05) for extraction after 56 days. The partially threaded pins required significantly greater force (p < 0.01) extraction after both 2 and 56 days. Histologic examination revealed increased mechanical bone damage surrounding hand chuck inserted pins, increased bone necrosis surrounding high speed power inserted pins, and increased inflammatory changes surrounding hand drill inserted pins.  相似文献   
82.
Transphyseal freezing of the canine distal femur was evaluated to determine its effect on physeal growth and closure. A specially designed cryoprobe was used to freeze the distal right femoral physis in 17 immature dogs. The left distal femoral physis was sham operated to serve as a control. Dogs were radiographed weekly and euthanized from 2 days to 8 weeks following surgery. The rate of long bone growth decreased in all dogs, and the physis was closed at 6 to 8 weeks.
Histologic studies on the distal femoral physes revealed that immediately after freezing, there was extensive hemorrhage in the epiphysis and metaphysis with disruption of the physis. Inflammation and death of the physeal cartilage followed. Blood vessels invaded the physis, and eventually bone was formed between the epiphysis and metaphysis, resulting in complete and premature physeal closure.  相似文献   
83.
A caudal approach to the scapulohumeral joint for treatment of osteochondritis dissecans of the humeral head was performed in seven dogs. By 14 days after surgery, three of the seven dogs were walking normally. At 6 weeks after surgery, all dogs were considered sound. Visualization was adequate for curettage of the osteochondritis dissecans lesions. Access to the medial joint compartment also was afforded.  相似文献   
84.
As part of a study of possible causes of postoperative pulmonary complications of general anesthesia in the horse, lateral cervical radiographs were taken after endotracheal intubation in nine randomly selected horses. The epiglottis was found to be retroverted in three. Subsequently, the effects of epiglottic retroversion during anesthesia on postoperative laryngeal function were investigated experimentally in three horses by fluoroscopy. No untoward sequelae were observed. Prophylaxis and potential adverse effects of this previously unreported complication of endotracheal intubation in the horse are discussed.  相似文献   
85.
Deep digital flexor tendon transection at the mid-metacarpus was performed in 20 horses with severe acute or chronic laminitis that was not responsive to conventional treatment. Sixteen horses improved within 72 hours, one horse worsened, and two horses were unaffected by the surgery. Eleven horses survived less than 1 month after surgery and six horses survived longer than 6 months. Three horses surviving longer than 6 months have remained lame and no horse has returned to athletic performance. Transection of the deep digital flexor tendon at the mid-metacarpus may decrease the pain associated with the acute refractory stage of laminitis and may be useful as an immediate salvage procedure; however, despite the early clinical improvement observed after tenotomy, the survival rate of affected horses may not be altered.  相似文献   
86.
Videorecordings of the laryngeal activity of 108 unsedated horses were obtained at rest by passing a flexible videoendoscope into the nasopharynx through the right ventral meatus. All videotaped images were reviewed once, and 72 were reviewed twice, by three veterinarians. Laryngeal cartilage movement was assessed subjectively with a five-tier grading system. The mean intraobserver agreement was 83.3% (range, 75.0%-90.2%) with a kappa statistic of .65 to .98. The mean interobserver agreement was 79.0% (range, 70.4%-80.6%) with a kappa statistic of .51 to .90. A computer program was developed to measure the left:right ratio of the rima glottidis. The mean left:right ratio for horses assigned a median laryngeal grade of I was 0.84 (range, 0.55-1.03); for grade II, 0.82 (0.50-1.12); for grade III, 0.59 (0.39-0.91); and for grade IV, 0.24 (0.07-0.35).  相似文献   
87.
Six fractures of the midshaft or distal third of the humerus were repaired through a modified craniolateral approach in which the brachialis muscle was transected rather than retracted to improve exposure of the bone. The approach simplified fracture reduction and fixation. Normal fracture healing and excellent limb function resulted in each case.  相似文献   
88.
An autogenous free vascular bone transfer using a segment of ulna along with its periosteum and vascular pedicle was developed. The vascular pedicle, based on the common interosseous artery and vein, emerged where muscular branches from the cranial interosseous artery enter the extensor carpi ulnaris and lateral digital extensor muscles. Four autogenous heterotopic (ulna to tibia) vascular transfers by microvascular anastomosis and two avascular transfers were performed to compare the osteogenic potential and viability of free revascularized grafts with avascular bone grafts. Successful microvascular anastomosis was demonstrated in three of the four vascular transfers by early bone scanning using technetium-labeled polyphosphate. Radiographically, there was more periosteal new bone and callus formation in the successfully revascularized bone transfers than in the failed vascular transfer and the avascular controls. Histologically, viable bone with an intact medullary and periosteal vascular supply was recognized in the grafts successfully revascularized by microvascular anastomosis.  相似文献   
89.
Three concentrations of povidone-iodine (0.1% w/v, 0.2% w/v, 0.5% w/v) and one concentration of chlorhexidine (0.5% w/v) were selected as antimicrobial joint lavage solutions. Through-and-through joint lavage was performed with one of these antimicrobial solutions on a tarsocrural joint of 12 horses. The contralateral tarsocrural joints (control limbs) were lavaged with a balanced electrolyte solution (BES). The effect of the lavage solution on the joints was evaluated with respect to lameness, foot flight pattern, soreness to joint palpation, articular and periarticular enlargement, and synovial fluid composition on Day 1,4, and 8 postlavage. On Day 8 postlavage, all horses were euthanized and the tarsocrural joints were examined.
All solutions induced a synovitis. Based on clinical assessment, synovial fluid protein levels, color, clarity, mucin clot forming ability, gross appearance of the joint at necropsy, and synovial membrane histologic evaluation, a similar, mild, transient, synovitis was induced by the BES and 0.1% povidone-iodine (PI) solution. The 0.2% PI solution induced a more prolonged neutrophilic response and poorer mucin clot forming ability in the synovial fluid as compared to the BES.
The 0.5% PI and 0.5% chlorhexidine solutions produced severe lameness, soreness to joint palpation, and limb enlargement. The elevated synovial fluid total protein content persisted significantly longer (p < 0.05) than the corresponding control (BES) solution. Histologic evaluation of the synovial membrane confirmed the presence of a moderate to severe neutrophilic synovitis in these treatment groups.  相似文献   
90.
High-frequency ventilation (HFV) is a form of artificial ventilation that uses higher rates and smaller tidal volumes than those used with conventional mechanical ventilation (intermittent positive pressure ventilation [1PPV]). HFV is divided into three categories based on the rate and type of equipment used: 1) high-frequency positive pressure ventilation administered through a system with low internal compliance having an expiratory valve to maintain positive airway pressure during expiration and rates of 60 to 120/minute; 2) high-frequency jet ventilation delivered through an open system or a system with an expiratory valve at rates of 120 to 400/minute; and 3) high-frequency oscillation using open systems and rates of 400 to 2400/minute. All forms of HFV provide adequate ventilation in normal animals at lower peak and mean airway pressures, resulting in less cardiovascular depression than that associated with 1PPV. HFV provides adequate ventilation with less cardiovascular depression and risk of barotrauma than 1PPV in the presence of pulmonary disease. The exact mechanism of gas exchange during HFV is not clearly understood, but enhanced diffusion as a result of turbulent gas flow appears to be a major factor.  相似文献   
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