Physeal Fractures in the Horse II. Management and Outcome

Seventy physeal fractures in horses were initially managed by euthanasia (18), stall confinement (25), application of a cast (7), or internal fixation (20). Of the 52 physeal fractures initially managed with stall confinement, a cast, or internal fixation, 23 (44%) healed and 13 (25%) of these horses became sound. The number of horses less than 4.5 months of age with pressure physeal fractures that became sound was significantly higher (p < 0.05) than the number of horses greater than 4.5 months of age. The number of horses with functional, pain-free limbs (sound horses) or functional limbs (lame horses) was not significantly different (p > 0.05) for Salter-Harris Type I, II, III, or IV pressure physeal fractures; however, critical examination for growth disturbances was not performed. The number of horses with pressure or traction physeal fractures of less than 5 days duration prior to presentation that healed or became sound was not significantly different (p > 0.05) when compared with those horses with fractures of greater than or equal to 5 days duration.     

Puncture Wounds of the Navicular Bursa in 38 Horses A Retrospective Study

The medical records of 38 horses with puncture wounds of the navicular bursa were reviewed. Only 12 horses had a satisfactory outcome (breeding or riding). Of the remaining 26 horses, 19 were euthanized, five were sold due to persistent severe lameness, one died, and one was lost to long-term follow-up. Different combinations of conservative management prior to surgical debridement and drainage of the navicular bursa were unsuccessful in resolving the condition. Horses that were treated surgically within 1 week of the injury and had a hind leg affected had the best chance of a satisfactory outcome. Additional wound debridement was necessary in 15 horses after initial surgical treatment. The most common complications encountered were navicular bone osteomyelitis and sepsis of the deep digital flexor tendon. Thirteen of 14 horses that had rupture of the deep digital flexor tendon and subluxation of the distal interphalangeal joint had an unsatisfactory outcome. One mare subsequently developed ankylosis of the distal interphalangeal joint and was a useful brood mare. Two horses that had biaxial palmar digital neurectomy because of persistent lameness were later euthanized because of navicular bone fracture and rupture of the deep digital flexor tendon. Results from limited numbers of bacterial cultures and antibiotic sensitivities suggest that penicillin and an aminoglycoside antibiotic should be used as initial antibiotic therapy. Immediate surgical debridement and appropriate antibiotic treatment are recommended as the minimum therapy for penetrating wounds of the navicular bursa in horses.     

Medial Plating for the Repair of Middle and Distal Diaphyseal Fractures of the Humerus in Dogs

Six middle and distal humeral shaft fractures in dogs were repaired by the application of a bone plate along the medial shaft of the humerus. In all animals, clinical and radiographic evidence of normal bone healing was observed. The bone plate and ancillary implants were removed from five dogs by 10 months. In none of the six dogs were any untoward effects of placing the bone plate along the medial shaft of the humerus detected nor were there any difficulties encountered with the medial humeral soft tissues.     

Pharyngeal Mucoceles in Dogs

Eight cases of pharyngeal mucoceles were diagnosed in 49 dogs with salivary mucoceles over a 7 year period. Five of the eight pharyngeal mucoceles were seen in Miniature Poodles. The presenting complaint in all eight dogs was labored breathing, with or without coughing upon excitement or exercise. Diagnosis was made by aspirating a thick mucoid fluid from the pharyngeal swelling. Treatment consisted of resection of the mandibular and sublingual salivary glands on the affected side and aspiration of the mucocele in all eight dogs, and resection of redundant pharyngeal tissue in five dogs. Time to follow-up ranged from 1.5 to 7.5 years. There were no postsurgical complications or recurrences of the mucocele.     

Resurfacing Canine Femoral Trochleoplasties with Free Autogenous Periosteal Grafts

Femoral trochleoplasties resurfaced with autogenous free periosteal grafts in six dogs were compared to femoral trochleoplasties performed without grafts in six dogs. The grafts produced cartilage as early as 4 weeks after surgery; however, it was fibrocartilage rather than normal hyaline articular cartilage. The trochleoplasties not resurfaced with periosteum also healed with fibrocartilage but not until 40 weeks postoperatively. The grafted stifles had less patellar cartilage damage when compared to trochleoplasties left to heal without resurfacing.     

Cryosurgical Epiphysiodesis in the Dog

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.     

In Vitro Comparison of the Three Loop Pulley and Locking Loop Suture Patterns for Repair of Canine Weightbearing Tendons and Collateral Ligaments

Both triceps tendons and the medial collateral ligaments of both stifles of 10 freshly euthanized dogs were sharply transected. One tendon and one ligament of each dog were sutured with a three loop pulley pattern, and the opposite tendons and ligaments were sutured with a locking loop pattern. The tendons and ligaments were harvested with their muscular and bony attachments. The anastomoses were slowly tested in tension until failure occurred. The amount of tensile load required to produce failure of the anastomosis, the amount of distraction of the sutured ends prior to failure, and the modes of failure were recorded. In both tendons and ligaments, the three loop pulley pattern provided significantly greater tensile strength (p < 0.01) and allowed significantly less distraction between the sutured ends (p < 0.01) than the locking loop pattern. In tendons, disruption of the suture material was the most common mode of failure with both patterns. In ligaments, both patterns failed most commonly by pulling free from the tissue.     

Autogenous Cancellous Bone Grafts From the Sternum in Horses Comparison With Other Donor Sites and Results of Use in Orthopedic Surgery

Cancellous bone was collected from the fourth or fifth sternebra of six horses aged 12 to 36 months, and compared quantitatively and qualitatively with cancellous bone collected from the tuber coxa, proximal tibia, and rib at the time of necropsy, 28 to 49 days after surgery. Cancellous bone collected from the sternum was equivalent in amount and in microscopic appearance to that collected from the other three sites.
Cancellous bone also was collected from the sternum for use during clinical orthopedic surgery in 18 horses. Wound dehiscence occurring in two horses healed uneventfully by second intention. In each horse, an adequate amount of cancellous bone was obtained from one sternebra, with the exception of one horse where cancellous bone from two sternebra was used. Major complications with the donor sites were not encountered.     

Partial Hepatectomy with Temporary Hepatic Vascular Occlusion in Dogs with Hepatic Arteriovenous Fistulas

A technique for temporary hepatic vascular occlusion during partial hepatectomy for hepatic arteriovenous (AV) fistulas in the dog is presented in seven dogs, and three additional cases of hepatic AV fistulas are reviewed. Hematologic, serum biochemical, radiologic, and nuclear scintigraphic parameters before and after surgery are discussed; abnormalities included anemia, hypoproteinemia, leukocytosis, increased liver function tests, retrograde filling of the portal vein during celiac angiography, and increased arteriovenous ratios during nuclear scintigraphy. Hemodynamic and pathologic findings are presented, and portal hypertension and secondary multiple portosystemic shunts are described. Clinical improvement was observed in four dogs with follow-up periods ranging from 5 months to 3 years.     

Modified Segmental Spinal Instrumentation in Repair of Spinal Fractures and Luxations in Dogs

A modified segmental spinal stabilization technique was used in four dogs weighing 10 to 56 kg with thoracolumbar and lumbosacral spinal fractures/luxations. A Steinmann pin was bent to encircle the dorsal spinous processes and was wired together with longitudinal pins to the cranial articular facets and dorsal spinous processes in the thoracolumbar application. The central pin was omitted, and the longitudinal pins were bent at a right angle and passed through the ilial wings in the lumbosacral application. Fracture fixation and stabilization were excellent in all dogs. One broken pin was detected in one dog after 18 months. No other complications due to the spinal instrumentation were observed. Neurologic recovery was excellent in two dogs, good in one dog, and fair in one dog.