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in Journal of the American Veterinary Medical Association
in Journal of the American Veterinary Medical Association

Abstract

Objective—To identify risk factors for successful surgical management of dogs with atlantoaxial subluxation (AAS).

Design—Retrospective study.

Animals—46 dogs managed surgically for AAS.

Procedure—Age at onset of clinical abnormalities, duration of clinical abnormalities prior to surgery, radiographic appearance of the dens, type (dorsal or ventral procedure) and number (1 or 2) of surgeries performed, grade of postoperative atlantoaxial joint reduction, and neurologic status prior to surgery (preoperative), when dogs were discharged from the hospital (postoperative), and during a follow-up evaluation (final) were obtained from the dogs' medical records. Risk factors for surgical success and degree of neurologic improvement were identified and analyzed for predictive potential.

Results—Age at onset of clinical abnormalities ≤ 24 months was significantly associated with greater odds of a successful first surgery and final outcome and a lower postoperative neurologic grade. Duration of clinical abnormalities ≤ 10 months was significantly associated with greater odds of a successful final outcome and a lower final neurologic grade. A preoperative neurologic grade of 1 or 2 was significantly associated with a lower final neurologic grade. Potential risk factors that did not affect odds of a successful outcome included type of surgery performed, grade of atlantoaxial joint reduction, radiographic appearance of the dens, or need for a second surgery.

Conclusions and Clinical Relevance—Age at onset of clinical abnormalities, duration of clinical abnormalities prior to surgery, and preoperative neurologic status are risk factors for success of surgical management of AAS in dogs. (J Am Vet Med Assoc 2000; 216:1104–1109)

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in Journal of the American Veterinary Medical Association

Abstract

Objective

To ascertain effects of x-ray beam centering and limb position on apparent congruity of a normal cubital joint (elbow).

Animals

6 skeletally mature male Treeing Walker Coonhounds without physical, radiographic, or gross evidence of elbow abnormalities.

Procedure

Relative movement among humerus, radius, and ulna and measured joint space width on mediolateral and craniocaudal radiographic views was compared, using various x-ray beam centering and limb positions.

Results

Highest agreement and greatest certainty on subjective determination of congruity was for the flexed 90° mediolateral radiographic view with the x-ray beam centered on the elbow. Distortion artifact of the proximal ulnar measurements was significant when the x-ray beam was centered on the midpoint of the radius. On the mediolateral view, the humeroradial joint space became significantly wide when the elbow was flexed. On the craniocaudal view, maximal humeroradial joint space width was obtained when the x-ray beam bisected the angle of the joint or was angled +30° toward the humerus.

Conclusions

Artifact distortion of joint width affected objective and subjective assessment of elbow congruity when the limb was placed in extreme flexion or extension or when the x-ray beam was not centered over the area of interest. Optimal visualization of the humeroradial joint space on the craniocaudal view was achieved when the x-ray beam bisected the angle of the elbow or was slightly angled toward the humerus.

Clinical Relevance

Elbow congruity was best assessed on the flexed 90° lateral radiographic view with the x-ray beam centered on the joint. (Am J Vet Res 1998;59:1351–1357)

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in American Journal of Veterinary Research

Abstract

Objective—To determine whether hyperbaric oxygen treatment (HBOT) would affect incorporation of an autogenous cancellous bone graft in diaphyseal ulnar defects in cats.

Animals—12 mature cats.

Procedure—Bilateral nonunion diaphyseal ulnar defects were created in each cat. An autogenous cancellous bone graft was implanted in 1 ulnar defect in each cat, with the contralateral ulnar defect serving as a nongrafted specimen. Six cats were treated by use of hyperbaric oxygen at 2 atmospheres absolute for 90 minutes once daily for 14 days, and 6 cats were not treated (control group). Bone labeling was performed, using fluorochrome markers. Cats were euthanatized 5 weeks after implanting, and barium sulfate was infused to evaluate vascularization of grafts. Ulnas were evaluated by use of radiography, microangiography, histologic examination, and histomorphometric examination.

Results—Radiographic scores did not differ between treatment groups. Microangiographic appearance of grafted defects was similar between groups, with all having adequate vascularization. Differences were not observed between treated and nontreated groups in the overall histologic appearance of decalcified samples of tissue in grafted defects. Mean distance between fluorescent labels was significantly greater in cats given HBOT than in nontreated cats. Median percentage of bone formation in grafted defects was significantly greater in cats given HBOT.

Conclusions—Hyperbaric oxygen treatment increased the distance between fluorescent labels and percentage of bone formation when incorporating autogenous cancellous bone grafts in induced nonunion diaphyseal ulnar defects in cats, but HBOT did not affect revascularization, radiographic appearance, or qualitative histologic appearance of the grafts. (Am J Vet Res 2000;61:691–698)

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in American Journal of Veterinary Research

Abstract

OBJECTIVE To determine effects of prosthetic laryngoplasty on return to racing, performance index, and career longevity in racing Quarter Horses with recurrent laryngeal neuropathy (RLN) and to evaluate performance variables for horses with RLN undergoing prosthetic laryngoplasty, compared with a control horse population.

DESIGN Multicenter, retrospective cohort study.

ANIMALS 162 racing Quarter Horses with RLN treated with prosthetic laryngoplasty (case horses) and 324 racing Quarter Horse without RLN (control horses).

PROCEDURES Medical and race records of case and control horses examined at 5 referral centers between January 2000 and December 2015 were reviewed retrospectively. Two control horses were matched with each case horse. Return to racing, earnings, number of racing starts, performance index, and career longevity were evaluated.

RESULTS The odds of returning to racing did not differ significantly between case and control horses but decreased with increasing age. Neither racing starts nor career longevity were affected by prosthetic laryngoplasty or by RLN grade. In fact, horses undergoing laryngoplasty for treatment of RLN and horses with the lowest RLN grade before surgery had higher performance indices after the surgery, compared with indices for control horses.

CONCLUSIONS AND CLINICAL RELEVANCE The faster speeds and shorter distances raced with Quarter Horses could alter how RLN impacts respiratory variables and performance in Quarter Horses, compared with other racehorse breeds. Further study is needed to understand the impacts of RLN and surgical treatments for RLN in racing Quarter Horses.

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in Journal of the American Veterinary Medical Association

Objective

To determine the usefulness of 5 radiographic projections of the elbow joint for identification of fragmented coronoid process (FCP) and associated secondary degenerative changes in dogs.

Design

Longitudinal clinical study.

Animals

19 dogs suspected of having FCP (7 dogs, 1 elbow joint; 12 dogs, both elbow joints).

Procedure

5 radiographic projections were obtained before and after surgery for all elbow joints on which exploratory arthrotomy was performed because of suspected FCP. Radiographs obtained before surgery were compared with radiographs obtained after surgery and radiographs taken of the excised fragments. Each projection was evalated for its utitility in definitively identifying FCP and 7 specific degenerative changes. Interevaluator agreement, use of each radiographic projection for definitively identifying a feature, and ability of the 4 evaluators to definitively identify a feature were analyzed.

Results

The craniolateral-caudomedial oblique (Cr15L-CdMO) projection had a significantly higher sensitivity for definitively identifying FCP, compared with the other 4 projections. Interevaluator and kappa agreement for the 5 projections did not differ significantly among the 7 degenerative changes evaluated. The radiographic projection with the highest sensitivity and specificity for detection of a particular degenerative change varied by feature.

Clinical Implications

Of the 5 radiographic projections evaluated, the Cr15L-CdMO projection provided the highest sensitivity and was the best projection to use for definitively identifying FCP. The craniocaudal, Cr15L-CdMO, and mediolateral projections most reliably allowed for identification of secondary degenerative changes. (J Am Vet Med Assoc 1999;214:52–58)

Free access
in Journal of the American Veterinary Medical Association