bluuebunny/crossref_metadata_2025_split huggingface dataset:
Traumatic Coxofemoral Luxation in Dysplastic Dogs Managed with a Triple Pelvic Osteotomy: Results in four Dogs
Authors: Lewis D. D. , Kerwin S. C. , Murphy S. T. 
Published: March 2018

SummaryTriple pelvic osteotomy (TPO) was used in the treatment for traumatic coxofemoral luxations in four adult, large breed dogs with hip dysplasia. Initial closed reductions failed in three and one dog had an initial closed reduction and subsequent open reduction of the coxofemoral luxation that failed. Hip dysplasia was thought to be a prominent factor contributing to the reluxation. TPO successfully maintained reduction of the coxofemoral luxation in all of the dogs. An increase in dorsal acetabular coverage of the femoral head following TPO was demonstrated by an increased Norberg angle. The improved congruency was thought to maintain reduction of the femoral head in the acetabulum and decrease stresses on the joint capsule, allowing healing to occur. Long-term (median: 343, mean ± SD: 406 ± 226 days follow-up) function of the affected limb was comparable to the contralateral limb. Three of the four dogs did not have radiographic progression of coxofemoral degenerative joint disease of the affected joint and differences in the progression of degenerative joint disease were not evident between the affected and the contralateral coxofemoral joint. A decrease in abduction and external rotation and an increase in internal rotation following TPO was noted in the affected coxofemoral joint. Our results establish the utility of this procedure in dysplastic dogs with traumatic coxofemoral luxations.Triple pelvic osteotomy used in the treatment for traumatic coxofemoral luxation in four adult, large breed dogs with hip dysplasia successfully maintained reduction and resulted in satisfactory limb function in all patients.
Heat Conduction of Fixator Pins with Polymethylmethacrylate External Fixation
Authors: Tomlinson J. L. , Hahn A. W. , Constantinescu G. M. , Wagner-Mann Colette , Williams N. 
Published: March 2018

SummaryThe purpose of this study was to determine the degree of thermal conduction along the fixation pins associated with acrylic external fixators and to develop a means of minimizing the potential for thermal injury. The data suggest that the degree of temperature conducted with 1.9 cm diameter acrylic external fixators was of minimal clinical significance if maintained a distance of one centimeter from the patient’s tissues. Larger diameter columns increase the potential for injury, however, this can be minimized with the use of a constant saline drip at the pin-acrylic interface to facilitate heat loss.This article describes the evaluation of thermal properties of polymethylmethacrylate external skeletal fixators. The data demonstrate heat conduction along the fixation pins. Thermal injury is theoretically minimized if columns are maintained a distance of at least one centimeter from the patient’s tissue.Research supported in part by and presented for the University of Missouri Pi Chapter of the Honor Society of Phi Zeta in coordination with SmithKline Beecham Animal Health, April 7, 1994
The Microvascular Carpal Foot Pad Flap: Results in Three Clinical Cases
Authors: Moens Noel M. M. , Fowler J. David 
Published: March 2018

SummaryFour microvascular carpal foot pad transfers were performed on three dogs for reconstruction of weight bearing surfaces. All of the dogs had suffered severe trauma to the major weight bearing foot pads of at least one foot due to: burn injury (one dog), ischaemic injury (one dog) or sharp trauma (one dog). The vascular anatomy of the carpal foot pad flap was consistent in all of the dogs. The arterial pedicle arose from the caudal interosseous artery and the venous effluent drained via the cephalic vein. All of the flaps survived transfer. Post-operative care included heavily padded bandages and daily visual assessment of flap viability. All of the flaps developed partial wound dehiscence along their distal borders, presumably due to incisional stresses from weight bearing. The flaps were surgically repositioned as necessary in order to maintain a central weight bearing position. Ultimately, all of the flaps healed and hypertrophied to accomodate weight bearing stresses. In all dogs functional results were good.Foot pads are highly specialized to withstand the hostile environments into which they are placed. Reconstruction of weight bearing surface following loss of foot pads, therefore, is difficult. Microvascular free transfer of foot pads allows the reconstruction of such deficits with tissue that is, anatomically, most appropriately suited to adopt the function of weight bearing. Microvascular free transfer of the carpal foot pad flap for foot reconstruction is demonstrated in three clinical cases.
Fatigue Study of Six and Eight mm Diameter Interlocking Nails with Screw Holes of Variable Size and Number
Authors: Vanderby R. , McCabe R. P. , Dueland R. T. 
Published: March 2018

SummaryClinical fatigue failure of 6 mm diameter interlocked nails (ILN) with holes accommodating 3.5 mm screws has been reported. This problem was investigated by testing eight different designs of 6 mm and 8 mm diameter ILN with a 2 plus 2 screw hole pattern and a multiple holed pattern. Interlocking nails with holes to accommodate 3.5 and 4.5 mm screws in 8 mm ILN and 2.7 and 3.5 mm screws in 6 mm diameter ILN were used. A rotating beam testing device produced uniform bending moments across a test region of the ILN containing at least two holes. These moments fully reversed with each cycle. Fatigue failure occurred through screw holes. Using statistical modeling, reduction of the 6 mm ILN hole size from accommodating 3.5 screws to 2.7 mm screws increased the estimated fatigue life (EFL) of the latter by 52 times, comparable to the EFL of the 8 mm ILN with 4.5 screw holes. Reducing the 8 mm ILN screw hole size from accommodating 4.5 screws to 3.5 mm screws increased the comparative EFL by eight times. Fatigue testing is a good method to compare fatigue behavior of various implant designs. This gives a surgeon more information when selecting an ILN for fracture fixation.Occasional breakage of interlocking nails (ILN) in clinical cases prompted fatigue testing of original ILN and new designs of ILN. This study documented base line fatigue resistance information of the various ILN designs. Results indicated smaller screw holes markedly increased the fatigue resistance of both 6 mm and 8 mm diameter ILN. This information will aid the surgeon in planning fracture treatment.
Evaluation of Stiffness and Stress of External Fixators with Curved Acrylic Connecting Bars
Authors: Shahar R. 
Published: March 2018

SummaryThe use of acrylic connecting bars in external fixators has become widespread in veterinary orthopaedics. One of the main advantages of an acrylic connecting bar is the ability to contour it into a curved shape. This allows the surgeon to place the transcortical pins according to safety and convenience considerations, without being bound by the requirement of the standard stainless steel connecting bar, that all transcortical pins be in the same plane.The purpose of this study was to evaluate the stiffness of unilateral and bilateral medium-sized external fixator frames with different curvatures of acrylic connecting bars. Finite element analysis was used to model the various frames and obtain their stiffness under four types of load: Axial compression, four-point medio-lateral bending, fourpoint antero-posterior bending and torsion. The analysis also provided the maximal pin stresses occurring in each frame for each loading condition.Based on the results of this study, curvatures of acrylic connecting bars of up to a maximal angular difference between pins of 25° will result in very similar stiffness and maximal pin stresses to those of the equivalent, uniplanar stainless steel system. In both unilateral and bilateral systems the stiffness decreases slightly as angulation increases for axial compression and medio-lateral bending, increases slightly for torsion and increases substantially for antero-posterior bending.External fixator systems with curved acrylic connecting bars are commonly used in veterinary orthopaedics. This paper evaluates the biomechanical performance of such systems by applying the finite element analysis method. It shows that external fixators with curved acrylic connecting bars exhibit stiffness and maximal pin stresses which are similar to those of the standard stainless steel system.
A Comparative Study of the Length Patterns of Anterior Cruciate Ligament Reconstructions in the Dog and Man
Authors: Andrish J. T. , Olmstead M. L. , Kambic Helen , Shah A. , Palmisano M. P. 
Published: March 2018

SummaryTo measure the change of length patterns of nine different simulated anterior cruciate ligament (ACL) reconstructions in the canine and human knee.Six fresh-frozen canine cadaver knees and six fresh-frozen human cadaver knees were used in this study. All of the soft tissues were removed from each cadaver knee, leaving the menisci, collateral ligaments and cruciate ligaments intact. After fixation of the femur to a custom-made frame, the ACL was excised. Three tunnels were made each at the ACL origin and insertion, making possible nine reconstruction combinations. A modified intra-articular technique was used to measure change of length, in mm, of each ACL reconstruction through a range of motion of 0 degrees (full extension) to 135 degrees of flexion. A rankorder list of reconstruction combinations was determined. The most isometric combination was determined for the canine and human knees, and trends in length patterns were also evaluated in both species relative to femoral and tibial position. Statistical significance was determined by ANOVA.A combination joining a point caudal to the ACL origin (over-the-top) and anterior on the tibial insertion was found to be the most isometric combination in both the canine and human. The trends in change of length patterns across all reconstruction combinations were similar in the dog and man. Isometry was improved as the reconstruction was placed further posterior on the femur and anterior on the tibia. Conclusions: The canine knee is an appropriate animal model for the study of isometry of the human ACL and its reconstructions.The length patterns of nine simulated Anterior Cruciate Ligament (ACL) reconstructions were determined in the dog and man. In both species, the most isometric reconstruction was one joining points corresponding to a position at the posterior edge of the intercondylar roof of the femur (over-thetop) with a position anterior on the ACL insertion. For the sake of clarity the term anterior cruciate ligament has been used, throughout, for both species, instead of the cranial cruciate ligament (CCL) in the dog. Also knee has been used in place of stifle for the dog.
Effects of wire tension on the biomechanics of asymmetric four-ring circular external skeletal fixator constructs
Authors: Lewis D. D. , Rigaud S. , Mackinzie G. B. , Rapoff A. J. , Cross A. R. 
Published: March 2018

SummaryThis study evaluated the effects of fixation wire tension (0 kg, 30 kg, 60 kg, and 90 kg) on the biomechanics of a four ring asymmetric circular external fixator construct in four testing modes (axial compression, medio-lateral bending, craniocaudal bending, and torsional loading) using a gap fracture model. Wire tension had a significant direct effect on gap stiffness in all of the testing modes. Axial compression load-deformation curves exhibited non-linearity, characteristic of the self-tensioning effect observed with fine wire fixation. Bending loaddeformation curves had two discrete linear segments, attributable to slipping of the bone models on the fixation wires, once a critical bending moment was exceeded. Torsional loading caused a gradual ‘windup’ of the construct which was followed by a linear load-displacement curve. Increasing wire tension had a small but significant effect on gap stiffness, which generally diminished as higher tensions were applied, thus demonstrating the need for adequate initial construct design to achieve sufficient stability during fracture healing.
Influence of the connecting rod on the biomechanical properties of five external skeletal fixation configurations
Authors: Ross J. D. , Toombs J. P. , Welch R. D. , Bronson D. G. 
Published: March 2018

SummaryA recently developed external skeletal fixation system (SK™, IMEX Veterinary, Inc.) utilizes larger diameter connecting rods, therefore overcoming one of the weaknesses of the original Kirschner-Ehmer (KE) system. The purpose of the current study was to compare five typical external fixator constructs in axial compression, torsion, Cranial-Caudal (C-C) and Medial-Lateral (M-L) bending to determine the effect of the larger connecting rods on frame stiffness. The results demonstrate that the larger connecting rod has a significant effect on overall frame stiffness. The use of two or more full-pins, as in the type II and III techniques nullified the contribution of the connecting rod diameter and frame stiffness was more a factor of pin size, number and orientation.
Microdamage at the pin-bone interface of external skeletal fixation pins after short-term cyclical loading
ex-vivo
Authors: Cohen K. , McCabe R.P. , Kalscheur V.L. , Vanderby R. , Markel M.D. , Muir P. 
Published: March 2018

SummaryThis study determined microdamage associated with external fixation pin insertion and short-term cyclical loading, using an ex vivo ovine tibial model. Orthofix tapered blunt-tipped 3.5/4.5 mm fixation pins and Apex® self-drilling self-tapping fixation pins, 4 mm in diameter, were used. After insertion, the constructs were either loaded in cantilever bending or not loaded. Constructs were then bulk-stained in basic fuchsin, and calcified sections were made. The sections were reviewed qualitatively and the microcrack surface density (Cr.S.Dn, μm/mm2) was quantified at the pin-bone interface. The pattern and quantity of microdamage induced was significantly influenced by fixation pin design and cortical region within the cisor transcortex, but not short-term cyclical loading. Overall, Cr.S.Dn was significantly increased with use of the Orthofix fixation pin (P < 0.01). Cr.S.Dn was also increased in the medial cis-cortex, compared with the lateral transcortex (P < 0.05). Diffuse damage within the medial cis-cortex was higher with the Orthofix pin. In contrast, the Howmedica Apex® fixation pin caused fracture of the periosteal region of the lateral transcortex, but relatively little microdamage within the medial cis-cortex. In this model as a consequence of pin insertion, fixation pin design had significant specific damage effects on both the medial cis-cortex and the lateral trans-cortex
Assessing the efficacy of long-term administration of Tolfenamic acid in dogs undergoing femoral head and neck excision
Authors: Dupuis J. , Moreau M. , Daminet S. , Hébert P. , Grisneaux E. , Charette B. 
Published: March 2018

SummaryFemoral head and neck excision (FHNE) is a salvage procedure routinely performed when severe osteoarthritis is present and clinical signs cannot be managed by conservative treatment, or when total hip replacement is cost prohibitive for the owners. The purpose of the study reported herein was to evaluate the adverse effects and efficacy of long-term administration of Tolfenamic acid in dogs undergoing FHNE. Twenty dogs admitted with clinical signs associated with bilateral hip degenerative joint disease and weighing more than 20 kg were included in the study. Ten dogs received Tolfenamic acid for four months following FHNE and 10 dogs received a placebo. At four months after surgery, the placebo group had a significant decrease, compared with pre-operative values, in peak vertical force (PVF) (60.38% BW vs 64.77% BW, p = 0.046), and a significant decrease in vertical impulse (VI) (8.38% BW x sec. vs 9.64% BW x sec., p = 0.023). There was not any significant difference between pre- and post-operative results in the Tolfenamic acid group regarding PVF (65.13% BW vs 63.31% BW, p = 0.296) and VI (8.24% BW x sec. vs 8.71% BW x sec., p = 0.945). A significant difference was not found between the two groups with regard to endoscopic evaluation of mucosal lesions. Subjectively, the owners of the dogs in the Tolfenamic acid group reported an earlier use of the limb, a more compliant dog during physical therapy and a more rapid return to a ‘normal’ gait. Long-term administration of Tolfenamic acid may therefore be recommended, following FHNE, to improve the results of the operation.
Antebrachiocarpal luxation in a cat
Authors: Geyer H. , Montavon P. M. , Voss K. 
Published: March 2018

SummaryA complete palmar antebrachiocarpal luxation due to rupture of the medial collateral ligament was diagnosed in a cat. Complete antebrachiocarpal luxation in dogs is generally associated with the disruption of multiple carpal ligaments. A comparative anatomical study of cadavers of five cats and five dogs revealed that, unlike in dogs, the medial collateral ligament in cats consists of only one branch, which extends from its dorsoproximal attachment on the radius obliquely to its palmarodistal attachment on the radial carpal bone. The oblique course of the ligament likely opposes palmar dislocation of the radial carpal bone rather than medial opening of the radiocarpal joint.In this present reported case, adequate joint stability was achieved by replacing the medial collateral ligament using two 1.5-mm cortical screws and a3.5 (metric gauge) polypropylene figure-8 suture sling. Minimal signs of osteoarthrosis developed three months after surgery, but functional outcome at six months was very satisfactory.
Quantification of histomorphometric and structural bone changes in a sheep model for fracture treatment in osteoporotic bone
Authors: Winterstein E. , Eckhardt C. , Rahn B. , Goldhahn J. , Schneider E. , Lill C. A. 
Published: March 2018

SummaryThe histomorphometrical cancellous bone parameters of osteoporotic ewes were examined to establish a large animal model for the investigation of fracture treatment and healing in osteoporotic bone. Eighteen animals were divided into 2 groups. Group 1 (n = 8, age 3 to 5 years) served as an untreated control. In Group 2 (n = 10, age 7 to 9 years) osteoporosis was induced by means of ovariectomy, methylprednisolone application (average dose 160 mg/week) and Ca./Vit.D restricted diet during 7 months. Biopsies from iliac crest, femoral head and lumbar spine were harvested. Structural parameters from the biopsies were determined using μCT. In order to investigate static and dynamic parameters of bone remodelling, undecalcified sections were digitized and evaluated by means of image analysing software. Morphologically, bone area and trabecular thickness were reduced in osteoporotic sheep. Bone perimeter (−20%), trabecular number (−16%) and separation (+39%) showed a significant change in the iliac crest. The structure model index indicated a shift from the plate-to the rodmodel. At different skeletal sites of osteoporotic sheep bone resorption was significantly increased (250-675%), and bone formation significantly decreased (77-89%). Osteoid thickness (O.Th) was reduced (28-62%). In osteoporotic sheep the mean length of single labels was significantly shortened (64-73%) and the mineralising surface showed a significant decrease (80-92%). The mineralisation of the osteoid was comparable to the control group. The histomorphometrical changes in this sheep model of osteoporosis are comparable to the human situation of a combined post-menopausal and steroid-induced osteoporosis.
A Scintigraphic Investigation of Magnetic Field Therapy on the Equine Third Metacarpus
Authors: Johnston G. R. , Lauper Linda , Kobluk C. N. 
Published: March 2018

SummaryScintigraphy was performed in the vascular, soft tissue and bone phase to demonstrate increased blood flow resulting from the local application of a permanent magnetic pad on the equine third metacarpus using a crossover trial in eight horses.The results of the vascular phase showed a highly significant (p <0.01) increase in counts associated with magnet application. An increase in counts results from increased blood flow carrying more radionuclide to the area investigated. Fifteen of the sixteen limbs tested showed an increased vascular response. The soft tissue phase had a highly significant response (p = 0.01) with thirteen of the sixteen limbs showing increased activity. The bone phase also had a highly significant response (p <0.01) with fourteen of the sixteen limbs showing increased activity.This study shows that the Equinepad® applied to the third metacarpus of the horse increases the circulation and metabolic activity of the soft tissue and bone. These effects show some variability in degree and occur in the majority of limbs tested.Scintigraphy was performed in the vascular, soft tissue and bone phase using a cross over trial to demonstrate increased blood flow and metabolic activity as a result of the local application of a permanent magnetic pad on the equine metacarpus. A highly significant increase was evident in the three phases.
In Vitro Comparison of the Krackow and Locking Loop Suture Patterns for Tenorrhaphy of Flat Tendons
Authors: Barnes S. L. , Wenzel J. G. W. , Milton J. L. , Terry G. C. , Montgomery R. D. 
Published: March 2018

SummaryTenorrhaphy of 20 pairs of canine patellar tendons, was by a modification of the Krackow suture pattern on one of the pair and a single locking loop suture pattern on the contralateral tendon. The tenorrhaphies were pulled apart at a rate of 127 cm/min. The mode of failure for all tendons was disruption of the tendon and the suture material pulling out of the tendon. The mean maximum load for the locking loop suture pattern was 67.2 N (S.D. 7.8), compared to 61.3 N (S.D. 9.3) for the modified Krackow suture pattern. The mean energy absorbed to maximum load was 0.54 Joules (J) (S.D. 0.168) for the locking loop and 0.37 J (S.D. 0.12) for the modified Krackow. The mean stiffness was 4846 N/m (S.D. 803) for the locking loop and 5573 N/m (S.D. 921) for the modified Krackow.This study indicated the locking loop suture pattern was significantly better than the modified Krackow suture pattern in maximum strength (p = 0.03), total energy absorbed to failure (p = 0.0004) and stiffness (p = 0.004). Both suture patterns are suitable for use in flat tendons or ligaments based on their maximum strength. However, the effect of the modified Krackow suture pattern on vascularity and healing has not been evaluated.The locking loop suture pattern proved to be significantly better than the modified Krackow suture pattern in maximum strength, total energy absorbed to failure and stiffness.