Contact area and static pressure profile at the plate-bone interface in the nonluted and luted bone plate.

Contact area and pressure between 6-hole broad dynamic compression plates and 20 pairs of equine third metatarsal bones were measured using nonluted and luted plating techniques. Pressure-sensitive film (pressure ranges 10 to 50 MPa and 50 to 130 MPa) was used as the static pressure transducer. Nonluted and one of two luting techniques were tested on each pair of bones; each luting technique was tested on 20 bones. Quantitative determinations of contact area and pressure were made using computerized image processing techniques. Mean (+/- SD) total contact area for nonluted plates was 18.49% +/- 3.5% of the potential plate-bone contact area. Luting increased (P < .05) total contact area to 25.56% +/- 4.0% and 31.29% +/- 6.6% for the respective luting techniques. The effects of luting on contact area were dependent on the contact pressure. At contact pressure ranges 10 to 20 and 21 to 35 MPa, luting increased contact area. In contact pressure ranges 36 to 45 and 50 to 65 MPa, plate-bone contact was inherently greatest and plate luting had no significant effect on contact area. In contact pressure ranges 66 to 99 and 100 to 126 MPa, luting decreased contact area. Contact area was increased at lower contact pressures at the expense of higher pressure contact. Contact in the middle third of the plate was 20% to 40% of the contact at either end of the plate. Plate luting increased contact area best where plate-bone contour was most similar.

Septic cholangiohepatitis and cholangiocarcinoma in a horse.

Septic cholangiohepatitis was diagnosed in an 11-year-old Warmblood gelding with a history of intermittent colic and fever. Klebsiella pneumoniae, susceptible to gentamicin, was cultured from the biopsy specimen. However, treatment with gentamicin was unsuccessful, and histologic examination and bacteriologic culture of a biopsy specimen obtained 3 weeks later revealed progression of the hepatic inflammation and yielded growth of gentamicin-resistant K pneumoniae. At this time, several discrete hyperechoic structures, suggestive of biliary calculi, were seen ultrasonographically. A change in antibiotic treatment was associated with gradual resolution of clinical signs. Five months after initial examination, the horse had a sudden onset of severe right forelimb lameness. The horse responded to treatment with antibiotics and phenylbutazone, but lameness and fever that was unresponsive to treatment recurred 7 months later, and the horse was euthanatized. Necropsy revealed nodules throughout the liver and a mass associated with the right metacarpophalangeal joint. Histologic and immunohistochemical examination revealed carcinomatous infiltration of the liver and metacarpophalangeal joint. The tumor was probably of biliary origin. Carcinoma should be considered in cases of septic cholangiohepatitis unresponsive to antibiotic treatment.

Concordance of ultrasonographic and physical findings in cattle with an umbilical mass or suspected to have infection of the umbilical cord remnants: 32 cases (1987-1989).

Medical records of 32 cattle treated for umbilical abnormalities that had undergone ultrasonographic examination of the umbilicus followed by umbilical resection or postmortem examination were reviewed. Thirty of the cattle were between 6 and 240 days old (mean, 73 days); the remaining 2 cattle were a 3-year-old bull and a 5-year-old cow. Thirty (94%) animals had external evidence of infection associated with the umbilicus. Two calves did not have external signs of infection; 1 had an abscess of the urachus and the other was found to be normal. Two-dimensional real-time ultrasonography was used to identify abnormal umbilical cord remnants. Ultrasonographic results were most reliable for the urachus, and the urachus was the most commonly affected internal umbilical cord remnant. Statistical agreement between ultrasonographic and physical (surgical or postmortem) findings was good to excellent for all umbilical structures. Intra-abdominal adhesions were found at surgery in 47% of animals with umbilical abnormalities; however, adhesions were not detected ultrasonographically.

Unusual internal carotid artery branching that prevented arterial occlusion with a balloon-tipped catheter in a horse.

A mare with hemorrhage caused by guttural pouch mycosis was treated by insertion of a balloon-tipped catheter into the left internal carotid artery. During recovery from general anesthesia, the mare had profuse epistaxis, and was anesthetized again to determine the site of hemorrhage. The affected guttural pouch was opened to confirm that hemorrhage was from the left internal carotid artery. The mare was euthanatized, and, at necropsy, the balloon catheter was found in an aberrant branch that arose from the internal carotid artery and joined the basilar artery. The mycotic plaque was on the left internal carotid artery, distal to the origin of the aberrant branch, so that the balloon did not obstruct retrograde flow through the infected segment. Additional dissection of the internal carotid artery before insertion of a balloon catheter is recommended to identify any aberrant branches. Ligation of aberrant branches at their bifurcation with the internal carotid artery is recommended to prevent both inadvertent catheterization and retrograde flow from the cerebral arterial circle.