Search Results

You are looking at 1 - 4 of 4 items for

  • Author or Editor: James B. Robertson x
  • Refine by Access: Content accessible to me x
Clear All Modify Search

Abstract

Objective—To investigate the effect of laser shock peening on the fatigue life and surface characteristics of 3.5-mm-diameter cortical bone screws.

Sample Population—32 stainless steel, 3.5-mm-diameter cortical bone screws.

Procedure—Screws were randomly assigned to an untreated control group or 2 power-density treatment groups, 6 gigawatts (GW)/cm2 and 8.5 GW/cm2, for laser shock peening. Number of cycles to failure and findings on scanning electron microscopy-assisted morphometric evaluation, including the mode of failure, surface debris, surface damage, and thread deformation, were compared between control and treated screws.

Results—The 6 GW/cm2 treated screws had a significant (11%) improvement in fatigue life, compared with untreated control screws. The 8.5 GW/cm2 treated screws had a significant (20%) decrease in fatigue life, compared with control screws. A mild but significant increase in thread deformation was evident in all treated screws, compared with control screws. The 8.5 GW/cm2 treated screws had significantly more surface irregularities (elevations and pits), compared with control or 6 GW/cm2 treated screws.

Conclusions and Clinical Relevance—A modest positive increase in fatigue strength was produced by this design of laser shock peening on the midshaft of cortical bone screws. High laser shock peening power densities were detrimental, decreasing screw fatigue strength probably resulting from structural damage. Greater fatigue life of cortical bone screws can be generated with laser shock peening and could reduce screw breakage as a cause of implant failure; however, future studies will be necessary to address biocompatibility, alternative cleaning techniques, alterations in screw strength and pullout characteristics, and effects on susceptibility to corrosion. ( Am J Vet Res 2004;65:972–976)

Full access
in American Journal of Veterinary Research

Abstract

OBJECTIVE

To describe the clinical features, treatment, and outcomes of wild freshwater turtles with fishing hook injuries.

ANIMALS

126 wild turtles residing in central North Carolina that were presented to a wildlife rescue clinic.

METHODS

Medical records from July 1997 to July 2022 were reviewed, and data were collected and analyzed.

RESULTS

The most common species presenting for a fishhook injury was the yellow-bellied slider (Trachemys scripta scripta) (n = 69/126 [54.8%]; 95% CI, 45.7 to 63.6). The most common location identified was the oral cavity (n = 77/140 [55%]; 95% CI, 46.4 to 63.4) and the most common removal method was retrograde removal after cutting the barb off of the hook (76/120 [63.3%]; 95% CI, 54.1 to 71.9). Fishhooks embedded in the esophagus had a significantly higher chance of complications affecting recovery (OR estimate, 3.49; 95% CI, 1.07 to 11.38). There was no significant increase in mortality associated with the location of the injury; however, there was a significant increase in mortality in patients that experienced complications (P < 0.001). The time in care ranged from 1 to 150 days (median, 16 days). Of the turtles evaluated, 10.8% (n = 12/111; 95% CI, 5.7 to 18.1) were euthanized or died after treatment and 89.2% (99/111; 95% CI, 81.9 to 94.3) were released.

CLINICAL RELEVANCE

These findings describe various successful techniques to remove fishhooks from turtles. While no superior treatment was identified, considerations should be taken to provide patient comfort, decrease injury-associated complications, and shorten recovery time by using minimally invasive techniques. Overall, freshwater turtles with fishhook injuries have a high release rate even when the injuries are severe.

Full access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To determine the items (question topics) for a subjective instrument to assess degenerative joint disease (DJD)–associated chronic pain in cats and determine the instrument design most appropriate for use by cat owners.

Animals—100 randomly selected client-owned cats from 6 months to 20 years old.

Procedures—Cats were evaluated to determine degree of radiographic DJD and signs of pain throughout the skeletal system. Two groups were identified: high DJD pain and low DJD pain. Owner-answered questions about activity and signs of pain were compared between the 2 groups to define items relating to chronic DJD pain. Interviews with 45 cat owners were performed to generate items. Fifty-three cat owners who had not been involved in any other part of the study, 19 veterinarians, and 2 statisticians assessed 6 preliminary instrument designs.

Results—22 cats were selected for each group; 19 important items were identified, resulting in 12 potential items for the instrument; and 3 additional items were identified from owner interviews. Owners and veterinarians selected a 5-point descriptive instrument design over 11-point or visual analogue scale formats.

Conclusions and Clinical Relevance—Behaviors relating to activity were substantially different between healthy cats and cats with signs of DJD-associated pain. Fifteen items were identified as being potentially useful, and the preferred instrument design was identified. This information could be used to construct an owner-based questionnaire to assess feline DJD-associated pain. Once validated, such a questionnaire would assist in evaluating potential analgesic treatments for these patients.

Full access
in American Journal of Veterinary Research

Abstract

OBJECTIVE

To document clinicopathologic findings in domestic rabbits with liver lobe torsion and identify prognostic factors.

ANIMALS

82 rabbits.

PROCEDURE

Medical records of 4 institutions were reviewed to identify rabbits with an antemortem diagnosis of liver lobe torsion that were examined between 2010 and 2020.

RESULTS

The prevalence of liver lobe torsion was 0.7% (82/11,402). In all 82 rabbits, the diagnosis was made by means of abdominal ultrasonography. Fifty (60.1%) rabbits underwent liver lobectomy, 23 (28%) received medical treatment alone, and 9 (10.9%) were euthanized or died on presentation. Overall, 32 (39%) rabbits died within 7 days of initial presentation and 50 (61%) survived. Seven-day survival rate did not differ significantly between medical treatment alone and surgical treatment. However, median survival time following medical treatment (530 days) was shorter than that following surgical treatment (1,452 days). Six of 14 rabbits had evidence of systemic inflammatory disease on necropsy. Rabbits with right liver lobe torsion were less likely to survive for 7 days than were those with caudate torsions (P = 0.046; OR, 3.27; 95% CI, 1.04 to 11.3). Rabbits with moderate to severe anemia were less likely to survive for 7 days than were rabbits that were not anemic or had mild anemia (P = 0.006; OR, 4.41; 95% CI, 1.55 to 12.51). Other factors associated with a decreased 7-day survival rate were high heart rate at admission (P = 0.013) and additional days without defecation after admission (P < 0.001). Use of tramadol was associated with an increased survival rate (P = 0.018).

CLINICAL RELEVANCE

The prognosis for rabbits with liver lobe torsions was more guarded than previously described. Rabbits that underwent liver lobectomy had a longer median survival time than did rabbits that only received medical treatment.

Full access
in Journal of the American Veterinary Medical Association