Osteochondritis Dissecans in the Dog

Osteochondritis dissecans (OeD) is a manifestation of osteochondrosis characterized by a focal thickening of joint cartilage and subsequent dissection of a flap of this thickened cartilage away from the underlying subchondral bone. The etiology of this condition remains somewhat of a mystery; trauma, nutrition, ischemia, and hereditary abnormalities of ossification have all been suggested. The disease is usually seen in the faster growing members of large and giant breed dogs. The first clinical signs of lameness are usually noted when the dog is between 5 and 9 months of age. OCD is most commonly recognized in the proximal humerus, but is also found in the distal humerus, distal femur, and tibial tarsal bone. One case of OeD of the distal radius has been reported. Other manifestations of osteochondrosis include ununited anconeal process, fragmented coronoid process, and retained cartilage of metaphyseal growth plates. Current research suggests there may be some relationship between osteochondrosis and the development of cervical spondylolisthesis, slipped femoral capital epiphysis, and hip dysplasia

Fracture of L7 vertebral articular facets and pedicles following dorsal laminectomy in a dog

abstract: A 6.5-year-old German Shepherd Dog underwent decompressive surgery for cauda equina syndrome. On the basis of intraoperative findings, the dorsal laminectomy was extended from L6 to S2. Partial dorsal annulectomies were also performed on the L6-7 and L7-S1 intervertebral disks. Two weeks following discharge, the dog had an acute onset of signs of pain and worsening of the neurologic status. Radiography and surgical exploration revealed bilateral fractures of the vertebral pedicles and caudal articular facets of L7. Vertebral stabilization was achieved with intramedullary pins and methylmethacrylate. The dog fully recovered. Although the destabilizing effect of various procedures on the vertebral column has been documented in vitro, vertebral fractures associated with instability have not been reported. Our description of a vertebral fracture following a cauda equina decompressive procedure in a dog emphasizes the need for caution when performing multi-level dorsal laminectomy and diskectomy

Journal of the American Animal Hospital Association 22 1 57 64

The type I double connecting bar configuration of external skeletal fixation was used to stabilize clinical long bone fractures in 10 dogs. The technique for applying the device is presented. Fracture healing occurred in eight instances, and good to excellent clinical limb function occurred in seven. The two non-unions and one poor clinical result are discussed to emphasize proper application technique and case selection.

American Journal of Veterinary Research 52 10 1731 1737 UNITED STATES

Seven dogs with torn cruciate ligament were used to evaluate the "over-the-top" repair procedure, using instantaneous center of rotation (ICR). Normal and cruciate-torn stifles of dogs were radiographed before surgery, using an image intensifier videotape system. The injured stifle was reradiographed 6 weeks after surgery. Images of the stifles were photographed from video monitor. Photographs were analyzed by a digitizer hooked to a computer to find the ICR at various angles. Data were analyzed, using multivariate analysis of variance. Relative to those of normal stifles, ICR of the damaged stifles were located significantly (P less than 0.05) proximal and caudal. After surgery, the ICR were still proximal and caudal, but not significantly so. We conclude that the cruciate-torn stifle deviates significantly from normal and that such deviation is restored to normal limits by use of the over-the-top procedure

Effect of volume variations on osteogenic capabilities of autogenous cancellous bone graft in dogs

abstract: OBJECTIVE: To evaluate the osteogenic effect of differing volumes of autogenous cancellous bone graft (ACBG) placed into partial cortical defects of the ulna. ANIMALS: 15 healthy, mature Beagles. PROCEDURE: Weekly radiographic views of defects were obtained over 8 weeks and were analyzed for bone density by use of radiographic optical densitometry. Histologic sections were obtained 8 weeks after surgery and were planimetrically evaluated for area of total, lamellar, and woven bone. RESULTS: Defects receiving 0.3 and 0.75 g of ACBG had rapid initial bone production, and dogs receiving 0.3 g of ACBG had faster bone ingrowth than did those receiving 0.1 g of ACBG or controls. Defects receiving 0.75 g of ACBG had a rate of bony ingrowth equal to 0.3 g of ACBG. There was no difference in the histomorphometric area fractions of total, lamellar, or woven bone between defects treated with 0.1 or 0.75 g of ACBG, and between grafted or control defects, 8 weeks after surgery. CONCLUSIONS: Overfilling a cortical defect with ACBG does not enhance early osteogenesis within the defect, and underfilling will delay the onset of osteogenesis within the defect. CLINICAL RELEVANCE: A volume of ACBG sufficient only to fill a cortical defect is required to obtain a clinical osteogenic effect from the graft

Journal of the American Veterinary Medical Association 187 3 262 267 UNITED STATES

Mechanical attributes and techniques of applying the type I biplanar (quadrilateral) configuration of external skeletal fixation are reported. The apparatus was used clinically on 9 dogs and 1 cat with long bone fractures. Bony union occurred in these animals, but was slightly delayed in one. Return to clinical function of the limb generally was good to excellent. The instances of delayed union and poor clinical results are discussed to emphasize the use of good techniques of application and case selection

Journal of the American Veterinary Medical Association 199 4 479 482 UNITED STATES

A 1-year-old male Cairn Terrier was evaluated for chronic coughing that was aggravated by eating or drinking. Radiography revealed an esophageal diverticulum, regional megaesophagus, and focal interstitial densities in the right caudal and middle lung lobes. Using fluoroscopy and contrast radiography, contrast material was seen to accumulate in the diverticulum and to reflux into the right middle, caudal, and accessory bronchi. Radiographic diagnosis was bronchoesophageal fistula. Via right eighth intercostal space thoracotomy, the abnormal connection between esophagus and caudal lobe of the right lung was identified, the lobe was resected, and the esophagus was closed. Histologic examination of the connecting tissue revealed a lining of stratified epithelium, with the superficial layer being predominantly ciliated columnar epithelium. Several findings led to the conclusion that the fistula was a congenital lesion, arising from aberrant formation of the respiratory tract from the embryologic digestive tract. Histologic examination revealed smooth muscle and lack of inflammation in tissue surrounding the fistula, which are criteria for identifying congenital bronchoesophageal fistula in human patients. The dog was young and did not have a history of esophageal foreign bodies. Postoperative complications were not encountered, and 9 months later, the dog was reported to be eating dry dog food without coughing. Congenital and acquired bronchoesophageal fistulas in dogs are reported infrequently. Furthermore, 2 of 12 previously reported bronchoesophageal fistulas in dogs, one of which was considered congenital, developed in Cairn Terriers