Holding Power of Different Pin Designs and Pin Insertion Methods in Avian Cortical Bone     

LAUREL A. DEGERNES DVM  Diplomate ABVP    SIMON C. ROE BVSc  PhD  Diplomate ACVS  C. FRANK ABRAMS Jr.  PhD  PE 《Veterinary surgery : VS》1998,27(4):301-306

Objective —To measure pullout strength of four pin types in avian humeri and tibiotarsi bones and to compare slow-speed power and hand insertion methods.
Study Design —Axial pin extraction was measured in vitro in avian bones.
Animal Population —Four cadaver red-tailed hawks and 12 live red-tailed hawks.
Methods —The pullout strength of four fixator pin designs was measured: smooth, negative profile threaded pins engaging one or two cortices and positive profile threaded pins. Part 1: Pins were placed in humeri and tibiotarsi after soft tissue removal. Part 2: Pins were placed in tibiotarsi in anesthetized hawks using slow-speed power or hand insertion.
Results —All threaded pins, regardless of pin design, had greater pullout strength than smooth pins in all parts of the study ( P < .0001). The cortices of tibiotarsi were thicker than the cortices of humeri ( P < .0001). There were few differences in pin pullout strengths between threaded pin types within or between bone groups. There were no differences between the pullout strength of pins placed by slow-speed power or by hand.
Conclusions —There is little advantage of one threaded pin type over another in avian humeri and tibiotarsi using currently available pin designs. There were few differences in pin pullout strengths between humeri and tibiotarsi bones. It is possible that the ease of hand insertion in thin cortices minimizes the potential for wobbling and therefore minimizes the difference between slow-speed drill and hand insertion methods.
Clinical Relevance —Threaded pins have superior bone holding strength in avian cortices and may be beneficial for use with external fixation devices in birds.  相似文献   

Biomechanical Comparison of the Trocar Tip Point and the Hollow Ground Tip Point for Smooth External Skeletal Fixation Pins     

JUAN M. MARTI LV  Cert SAO  MVM  MRCVS  SIMON C. ROE BVSc  MS  PhD  Diplomate ACVS 《Veterinary surgery : VS》1998,27(5):423-428

Objective —To compare the insertional characteristics of external fixator pins with hollow ground (HG), modified HG, and trocar (T) points.
Study Design —An acute, in vitro biomechanical evaluation.
Sample Population—Thirteen radii from canine cadavers.
Methods —A total of 16 T-tipped and 16 HG-tipped pins were inserted into 8 canine radii. Ten pins of each modification of the HG tip (length of the cutting edge reduced by 0.127 mm and 0.254 mm, respectively) were inserted into another five radii. All pins were inserted with low-speed power drilling and 80 N drilling load. Differences between peak tip temperature, drilling energy, and pullout force were determined for each pin type at both diaphyseal and metaphyseal locations.
Results —HG-tipped pins showed a 40% lower tip temperature in diaphyseal bone, a 25% reduction in drilling energy in diaphyseal bone, and a reduction of pullout force in both diaphyseal (65%) and metaphyseal (50%) bone compared with T-tipped pins. HG 0.254-mm pins generated higher tip temperatures and had greater pullout than HG pins in diaphyseal bone.
Conclusions —The HG tip was a more efficient design; however, the reduction in pullout force suggests that, because a better hole was drilled, radial preload is reduced. Reduction of the cutting edge by 0.254 mm increased the pullout force but also increased the temperatures.
Clinical Relevance —Thermal and microstructural damage are reduced by the HG tip, but pin-bone interface stability is also compromised. The use of a tip with 0.254 mm reduction in the cutting edge may optimize the biological and mechanical factors at the pin-bone interface.  相似文献   

Enteric Function in Cats after Subtotal Colectomy for Treatment of Megacolon     

C. R. GREGORY DVM  DiplomateACVs    W. G. GUILFORD BVSc    C. R. BERRY DVM    N. C. PEDERSON DVM  PhD  J. OLSEN DVM 《Veterinary surgery : VS》1990,19(3):216-220

The enteric function of four cats that had undergone subtotal colectomy for megacolon was compared with that of four normal cats. All cats were fed the same diet before and during the study. History, physical condition, body weight, blood chemistry panel, fasting and postprandial serum bile acids, serum cobalamin concentration, serum folate concentration, fecal weight, fecal water content, fecal fat content, fecal osmolality and electrolyte concentration, quantitative anaerobic fecal bacterial culture, partial thromboplastin time, prothrombin time, breath hydrogen concentration, urinary calcium, phosphorus and electrolyte concentrations, and abdominal radiographic examination with air contrast studies (pneumocolon) were examined. The four cats treated surgically were healthy and thriving and, in general, enteric function was similar to the controls. Bowel movements occurred only slightly more frequently with no significant differences in fecal volume or water content. Serum cobalamin concentrations were significantly higher in cats treated surgically. Fecal sodium concentrations were high and fecal potassium concentrations were low. Results of this study did not show any significant subclinical evidence of abnormal bowel function in cats after subtotal colectomy.  相似文献   

Dysgenesis of the tubal system in an infertile mare karyotype 63,X:64,XY:65,XXY     

C.R.E. Halnan MA  Vet MB  PhD  FRCVS  C.F.P. Irwin BVSc  MACVSc 《Journal of Equine Veterinary Science》1985,5(6):328-329

A Thoroughbred mare, barren during three years at stud, unresponsive to therapy, and not palpably abnormal anatomically was found to have hypoplasia of the uterine tubes after excision at laparotomy. The cause was an unbalanced genotype. The mosaic karyotype, determined on a blood sample, was indispensible in diagnosis and the case extends the potential for cytogenetic prognostic procedures.  相似文献   

REPEATABILITY OF DOPPLER ULTRASONOGRAPHIC MEASUREMENT OF EQUINE DIGITAL BLOOD FLOW     

NICOLA J. MENZIES-GOW  CELIA M. MARR 《Veterinary radiology & ultrasound》2007,48(3):281-285

The repeatability and sensitivity of Doppler ultrasonographic measurement of lateral digital arterial and venous blood flow has not been previously determined. Doppler ultrasonography was used to measure blood flow within the forelimb lateral digital vessels in one normal adult Thoroughbred horse on six occasions and in six normal adult Thoroughbred horses on three occasions, each occasion being at least 1 h apart, to determine the within- and between-horse variation. The values obtained from the right and left lateral digital vessels did not differ significantly. The within-horse coefficients of variation (CV) for arterial and venous measurements were all acceptable (< 11%); the between-horse CV were acceptable (< 7%) for all parameters except TaVa (average velocity of first peak of arterial waveform) and TaVb (average velocity of remainder of arterial waveform). The within-horse intraclass correlation coefficients (ICC) demonstrated excellent repeatability (> or = 0.71) for all parameters except venous diameter; the between-horse ICC demonstrated good to excellent repeatability (> or = 0.67) for all parameters except TaVb. Doppler ultrasonography can detect differences of 0.005 and 0.01 ml/ min in digital arterial and venous flow, respectively, using measurements from six horses on three occasions (80% power; P < 0.05). Thus, the technique is sufficiently repeatable and sensitive to be able to detect changes in flow during different physiological or pathological states or following pharmacologic intervention.  相似文献   

Holding Power of Orthopedic Screws in Equine Third Metacarpal and Metatarsal Bones: Part II. Adult Horse Bone     

JOHN V. YOVICH BSc  BVMS    A. S. TURNER BVSc  MS  DiplomateACVS  F. W. SMITH BSME  MSME  PhD 《Veterinary surgery : VS》1985,14(3):230-234

Comparison was made of the holding power of 5.5 and 4.5 mm cortical orthopedic screws inserted into third metacarpal and metatarsal cadaver bones from 3- and 8-year-old horses. The tensile strength of these screws was tested mechanically. In nine comparative trials of these screws, 5.5 mm screws pulled out of bone in five trials at an average of 116.0 kg tensile force and broke in four trials at an average of 1383.2 kg. A 4.5 mm screw pulled out of bone at 834.5 kg in one trial, and screws broke at an average of 849.2 kg in eight trials. The larger 5.5 mm screw required a significantly greater (p = 0.022) pullout force than the mean force at 4.5 mm screw breakage. Fixation failure was due to screw breakage or bone shear, with 5.5 mm screws occasionally creating bone fragmentation during pullout. The average tensile breaking strengths of the 5.5 mm screws (1391.4 kg) and 4.5 mm screws (832.7 kg) determined mechanically were similar to forces at screw breakage during pullout testing in bone. Since the 5.5 mm screws have greater holding power and tensile strength than 4.5 mm screws, the use of the 5.5 mm screw in fracture repair in adult horses is recommended.  相似文献   

Placement of Multiple Full Pins for External Fixation Technique and Results in Four Dogs     

SIMON C. ROE BVSc  MVSt    ANN L. JOHNSON dvm  MS  DiplomateACVS JOSEPH HARARI DVM  MS 《Veterinary surgery : VS》1985,14(3):247-252

A technique using a third bar and guide clamp was developed to permit reduction and stabilization of distal limb fractures with full pins and two connecting bars, one on each side of the bone. The system uses only single Kirschner clamps. Four distal limb fractures were stabilized using this technique. Closed reduction was used in three dogs to avoid devitalization of fragments and avoid contamination of a closed fracture. The fracture site stability achieved with this configuration allowed early return to weight bearing and rapid bone healing.  相似文献   

Biomechanical Evaluation of a Novel Subcuticular Skin Stapling Device for Use in Equine Abdominal Surgeries          下载免费PDF全文

Adam Biedrzycki BVSc  Diplomate ACVS  Mark D. Markel DVM  PhD  Diplomate ACVS  Sabrina H. Brounts DVM  MS  Diplomate ACVS 《Veterinary surgery : VS》2015,44(2):231-235

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Perception of Teaching and Assessing Technical Proficiency in American College of Veterinary Surgeons Small Animal Surgery Residency Programs          下载免费PDF全文

Stanley E. Kim BVSc  MS  DACVS  J. Brad Case DVM  MS  DACVS  Daniel D. Lewis DVM  DACVS  Gary W. Ellison DVM  MS  DACVS 《Veterinary surgery : VS》2015,44(6):790-797

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Combined Rostrolateral Rhinotomy for Removal of Rostral Nasal Septum Squamous Cell Carcinoma: Long‐Term Outcome in 10 Dogs          下载免费PDF全文

Gert Ter Haar DVM  PhD  Diplomate ECVS  Rachel Hampel BSc  BVSc 《Veterinary surgery : VS》2015,44(7):843-851

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