Browsing by Author "Muro, Noelle Marie"

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    Mechanical Comparison of a Type II External Skeletal Fixator and Locking Compression Plate in a Fracture Gap Model
    Muro, Noelle Marie (Virginia Tech, 2017-06-16)
    The purpose of this study was to compare the stiffness of a Type II external skeletal fixator (ESF) to a 3.5 mm locking compression plate (LCP) in axial compression, mediolateral, and craniocaudal bending in a fracture gap model. The hypothesis was that the Type II ESF would demonstrate comparable stiffness to the LCP. A bone simulant consisting of short fiber reinforced epoxy cylinders and a 40 mm fracture gap was used. The LCP construct consisted of a 12 hole 3.5 mm plate with three 3.5 mm bicortical locking screws per fragment. The Type II ESF construct consisted of 3 proximal full fixation pins (Centerface®) per fragment in the mediolateral plane, and 2 carbon fiber connecting rods. Five constructs of each were tested in non-destructive mediolateral and craniocaudal bending, and axial compression. Stiffness was determined from the slope of the elastic portion of force-displacement curves. A one-way ANOVA and a Tukey-Kramer multiple comparisons test were performed, with significance defined as p < 0.05. In mediolateral bending, the stiffness of the Type II ESF (mean ± standard deviation; 1584.2 N/mm ± 202.8 N/mm) was significantly greater than that of the LCP (110.0 N/mm ± 13.4 N/mm). In axial compression, the stiffness of the Type II ESF (679.1 N/mm ± 20.1 N/mm) was significantly greater than that of the LCP (221.2 N/mm ± 19.1 N/mm). There was no significant difference between the constructs in craniocaudal bending. This information can aid in decision-making for fracture fixation, although ideal stiffness for healing remains unknown.
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    Preoperative Tibial Plateau Leveling Osteotomy Planning Using the Conventional and Common Tangent Methods: A Cadaveric Study
    Davis, Anastacia Marie (Virginia Tech, 2020-05-21)
    Objective - To compare preoperative tibial plateau leveling osteotomy planning using the common tangent method to the current conventional method and evaluate the effect on tibial translation and patellar ligament angle following rotation of the tibial plateau. Study Design – Cadaveric study. Seven paired canine pelvic limbs. Methods- Radiographs of the stifle were taken at 135° of extension prior to and following rotation of the tibial plateau under load (0N and 30N). The tibial plateau of each limb was rotated both according to the common tangent and conventional method. Tibial plateau angle (TPA), tibial translation, and the patellar ligament angles (PLA) were measured radiographically following rotation of the tibial plateau. Results- There was no significant difference between planning methods with regards to the amount of rotation of the tibial plateau or position of the tibia relative to the femur following rotation. There was no significant association between the postoperative tibial plateau angle and position of the tibia relative to the femur between groups. There was no significant difference between the patellar ligament angles following rotation based on the common tangent or conventional method preoperative TPLO planning. Conclusion- Both the conventional and common tangent TPLO planning results in adequate proximal tibial rotation to achieve a PLA of approximately 90°, thereby counteracting the compressive shear forces during ambulation. The TPA for both groups following rotation had no significant impact on the amount of cranial or caudal tibial translation relative to the femur.
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    Ruby Joint Stabilization System as a Suitable Method of Extracapsular Repair
    Dominic, Christopher Gerard (Virginia Tech, 2021-06-28)
    Objective: To characterize the effect of the Ruby Joint Stabilization System (Ruby) on the motion of the cranial cruciate ligament (CrCL) deficient stifle. To compare the motion with the Ruby to that of the CrCL-intact and CrCL-deficient stifle. Study Design: Each canine pelvic limb was mounted in a loading jig under 30% body weight. Motion data was collected using an electromagnetic tracking system at stifle angles of 125o, 135o and 145o with the CrCL-intact, CrCL-deficient and the Ruby applied. Results: Total translation of the CrCL-deficient stifle following the Ruby was reduced, but remained greater than the CrCL-intact stifle at angles of 125o, 135o and 145o. Internal rotation of the Ruby groups was greater than the CrCL-intact group at 145o, but not 125o and 135o. Varus motion of the Ruby group was decreased compared to the CrCL-deficient group, but increased compared to the CrCL-intact group at angles of 125o, 135o and 145o. Conclusion: Total translation and internal rotation of the CrCL-deficient stifle following the Ruby differed from that of the CrCL-intact stifle. However, the Ruby reduced total translation and internal rotation of the tibia relative to the femur in the CrCL-deficient stifle to levels that may yield clinically acceptable results.