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- Author or Editor: David E. Anderson x
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Abstract
Objective—To determine in vitro effects of PBSS, milk, and bacteria-contaminated milk (BCM; contaminated by Streptococcus agalactiae) on properties of 3 synthetic absorbable suture materials.
Sample Population—3 types of synthetic absorbable suture materials (poliglecaprone 25, polyglycolic acid, and polydioxanone).
Procedures—Suture materials were tested to determine breaking strength and elasticity before (day 0) and after incubation in 3 media (PBSS, milk, and BCM) for 7, 14, and 21 days. A loop of suture material was elongated at a rate of 60 mm/min until it reached the breaking point. Tensile properties were statistically analyzed among media and incubation times.
Results—Incubation in milk and BCM significantly decreased breaking strength and elasticity of poliglecaprone 25, compared with results for incubation in PBSS. Incubation in BCM significantly decreased tensile properties of polyglycolic acid suture, compared with results for incubation in PBSS and milk. After incubation for 21 days, tensile properties of polydioxanone did not differ significantly among the media but were significantly decreased from values on day 0.
Conclusions and Clinical Relevance—On the basis of this study, poliglecaprone 25 is an inappropriate suture material for use in teat surgery. Polyglycolic acid suture should be avoided in teats of cattle with mastitis. Of the suture materials tested, polydioxanone was best suited for use in teat surgery, as determined on the basis of material testing after incubation in milk, even when the milk was contaminated with bacteria.
Abstract
Objective—To determine features, outcome, and complications of surgical treatment of camelid tooth root abscesses.
Design—Retrospective case series.
Animals—123 camelids with tooth root abscesses.
Procedures—Signalment, history, teeth involved, surgery performed, ancillary diagnostic tests, and short-term complications were recorded from each medical record. An owner questionnaire was used to obtain long-term (> 1 year) follow-up information.
Results—The most common surgical treatments included tooth extraction (n = 106) and apicoectomy (13). Owners provided follow-up information on 84 animals. Postoperative complications were reported in 42 of 84 animals. The most common complications included reinfection (n = 15), chronic draining tract (14), and osteomyelitis (14). Significantly more camelids that were in good or obese body condition at the time of surgery were alive at the time of follow-up, compared with those with thin body condition at the time of surgery. Camelids with 2 teeth extracted had significantly more complications than those with 1 tooth extracted. Thirty-four of 47 owners reported that they were completely satisfied with the outcome.
Conclusions and Clinical Relevance—Owners of camelids in poor body condition should be forewarned that such animals are at greater risk for complications following dental surgery. Clinicians should recognize that the number of teeth affected was not associated with a poorer outcome.
Abstract
Case Description—5 calves were evaluated for abnormal respiratory noise associated with variable degrees of respiratory distress.
Clinical Findings—Tachypnea and inspiratory dyspnea were detected at initial evaluation in all calves. Endoscopic evaluation of the upper respiratory tract revealed enlarged and immobile arytenoids. Radiographic (n = 3) and computed tomographic (1) evaluation of the laryngeal area revealed images that were indicative of a large soft tissue mass at the level of the arytenoids obstructing the rima glottis. A presumptive diagnosis of arytenoid chondritis was made.
Treatment and Outcome—A tracheostomy tube was placed in all calves. Medical treatment (with antimicrobials and anti-inflammatory drugs) was attempted in 4 calves after initial evaluation. Unilateral arytenoidectomy via a laryngotomy was performed under general anesthesia in all calves. Dysphagia and coughing were the most frequent postoperative complications. Three calves survived at least 6 months after the procedure. One calf died of a perforated abomasal ulcer 3 months after the surgery. Another calf died suddenly 1 month after the surgery of an undetermined cause.
Clinical Relevance—Unilateral arytenoidectomy was a viable surgical treatment for arytenoid chondritis in calves. Further research in a larger number of affected cattle is needed to determine the advantages or disadvantages of this procedure over other surgical techniques.
Abstract
Objective—To determine density of corneal endothelial cells, corneal thickness, and corneal diameters in normal eyes of llamas and alpacas.
Animals—36 llamas and 20 alpacas.
Procedure—Both eyes were examined in each camelid. Noncontact specular microscopy was used to determine density of corneal endothelial cells. Corneal thickness was measured, using ultrasonographic pachymetry. Vertical and horizontal corneal diameters were measured, using Jameson calipers.
Results—Values did not differ significantly between the right and left eyes from the same camelid. There was no significant effect of sex on density of corneal endothelial cells or corneal thickness in either species. Mean density of endothelial cells was 2,669 cells/mm2 in llamas and 2,275 cells/mm2 in alpacas. Density of endothelial cells decreased with age in llamas. Polymegathism was observed frequently in both species. Mean corneal thickness was 608 µm for llamas and 595 µm for alpacas. Corneal thickness and density of endothelial cells were negatively correlated in llamas. Older (> 36 months old) llamas had significantly larger horizontal and vertical corneal diameters than younger llamas, and older alpacas had a significantly larger vertical corneal diameter than younger alpacas.
Conclusions and Clinical Relevance—Density of corneal endothelial cells is only slightly lower in camelids than other domestic species. Density of endothelial cells decreases with age in llamas. Age or sex does not significantly affect corneal thickness in normal eyes of llamas and alpacas. Specular microscopy is useful for determining density of corneal endothelial cells in normal eyes of camelids. (Am J Vet Res 2002;63:326–329)
Abstract
OBJECTIVE
To determine the effects of 2 augmentation techniques on the mechanical properties of titanium cannulated bone screws.
SAMPLE
33 titanium cannulated bone screws (outer diameter, 6.5 mm; guide channel diameter, 3.6 mm).
PROCEDURES
11 screws were allocated to each of 3 groups. The guide channel of each screw was filled with polymethyl methacrylate bone cement alone (OCS group) or in combination with a 3.2-mm-diameter orthopedic pin (PCS group) or remained unmodified (control group) before mechanical testing. Each screw underwent a single-cycle 3-point bending test to failure with a monotonic loading rate of 2.5 mm/min. Failure was defined as an acute decrease in resistance to load of ≥ 20% or a bending deformation of 15 mm. Mechanical properties were determined for each screw and compared among the 3 groups.
RESULTS
All screws in the control and OCS groups and 1 screw in the PCS group broke during testing; a 15-mm bending deformation was achieved for the remaining 10 screws in the PCS group. Maximum load and load at failure differed significantly among the 3 groups. Stiffness and load at yield for the PCS group were significantly greater than those for the control and OCS groups but did not differ between the control and OCS groups.
CONCLUSIONS AND CLINICAL RELEVANCE
Use of bone cement and an orthopedic pin to fill the guide channel of cannulated screws significantly increased the strength of the construct, but ex vivo and in vivo studies are necessary before this augmentation technique can be recommended for clinical patients.
Abstract
Objective—To determine the effects of phenylbutazone (PBZ) on bone activity and bone formation in horses.
Animals—12 healthy 1- to 2-year-old horses.
Procedures—Biopsy was performed to obtain unicortical bone specimens from 1 tibia on day 0 and from the contralateral tibia on day 14. Fluorochromic markers were administered IV 2 days prior to and on days 0, 10, 15, and 25 after biopsy was performed. Six horses received PBZ (4.4 mg/kg of body weight, PO, q 12 h) and 6 horses were used as controls. All horses were euthanatized on day 30 and tissues from biopsy sites, with adjacent cortical bone, were collected. Osteonal density and activity, mineral apposition rate (MAR), and percentage of mineralized tissue filling the biopsy-induced defects in cortical bone were assessed. Serum samples from all horses were analyzed for bone-specific alkaline phosphatase activity and concentration of PBZ.
Results—MAR was significantly decreased in horses treated with PBZ. Regional acceleratory phenomenon was observed in cortical bone in both groups but was significantly decreased in horses treated with PBZ. Osteonal activity was similar at all time points in all horses. In control horses, percentage of mineralized tissue filling the cortical defects was significantly greater in defects present for 30 days, compared with defects present for 14 days. Differences in percentage of mineralized tissue were not detected in horses treated with PBZ.
Conclusions and Clinical Relevance—PBZ decreased MAR in cortical bone and appeared to decrease healing rate of cortical defects in horses. (Am J Vet Res 2000;61:537–543)
