Engineering Commons^™

Fundamentals Of The Biomechanical Characteristics Related To The Loading Of Reverse Total Shoulder Arthroplasty Implants And The Development Of A Wear Simulation Strategy, G Daniel G. Langohr

Electronic Thesis and Dissertation Repository

A greater understanding of reverse total shoulder arthroplasty (RTSA) in terms of articular contact mechanics and wear is essential for the optimization of current surgical technique and future implant design. Despite the prevalence of RTSA for shoulder reconstruction, there is little information in current literature regarding the effects of changes in implant parameters on articular contact mechanics and wear. The present work describes the use of in-vitro cadaveric studies, a computational model of the articular contact surfaces, and the development and implementation of a wear simulation strategy to assess RTSA contact mechanics and wear.

The articular loading characteristics of RTSA …

Effect Of Hemiarthroplasty Implant Contact Geometry And Material On Early Cartilage Wear, Alana Khayat

Electronic Thesis and Dissertation Repository

Hemiarthroplasty is a minimally invasive, cost-effective alternative to total arthroplasty in joints of the upper limb. Though these procedures reduce patient morbidity while restoring joint kinematics, their longevity is limited by wear of the adjacent cartilage. This work investigates the roles of contact geometry and implant stiffness on cartilage wear with the aim of elucidating the mechanics that contribute to cartilage damage. An in vitro study examined the influence of implant geometry on cartilage wear using a pin-on-plate wear simulator. A significant decrease in volumetric wear was observed as contact area increased, which suggests that maximizing contact area should be …

Design And Development Of A Novel Expanding Pedicle Screw For Use In The Osteoporotic Lumbar Spine, Parham Rasoulinejad

Electronic Thesis and Dissertation Repository

Pedicle screws are commonly utilized in spinal surgery; however, traditional designs often do not provide adequate fixation in osteoporotic spines. The objective of this thesis was to develop a novel expanding screw for use in osteoporotic lumbar pedicles. Helical screws capable of expanding post insertion were built on a rapid prototype machine. A materials testing machine performed axial load to failure tests in both Sawbones and cadaveric specimens comparing the new design to traditional screws (rate = 10mm/min to 20 mm). Output parameters included yield load, ultimate load, stiffness, energy to failure and total energy. The expanding screw showed a …

An Investigation Of Subaxial Cervical Spine Trauma And Surgical Treatment Through Biomechanical Simulation And Kinematic Analysis, Stewart D. Mclachlin

Electronic Thesis and Dissertation Repository

In vitro biomechanical investigations can help to identify changes in subaxial cervical spine (C3-C7) stability following injury, and determine the efficacy of surgical treatments through controlled joint simulation experiments and kinematic analyses. However, with the large spectrum of cervical spine trauma, a large fraction of the potential injuries have not been examined biomechanically. This includes a lack of studies investigating prevalent flexion-distraction injuries. Therefore, the overall objective of this thesis was to investigate the changes in subaxial cervical spine kinematic stability with simulated flexion-distraction injuries and current surgical instrumentation approaches using both established and novel biomechanical techniques.

Three in vitro …

The Contact Mechanics And Kinematics Of Radial Head Implants, Hannah L. Shannon

Electronic Thesis and Dissertation Repository

A number of commercially available radial head (RH) implants are used for the management of RH fractures. The optimal shape of a RH implant to restore joint mechanics to the native state has not been established. This work compares radiocapitellar contact and kinematics for three implant designs as well as the native RH. These implants include an axisymmetric, a quasi-anatomic and a patient-specific design. When compared to the native RH, only the axisymmetric implant was significantly different in contact area (p=0.008). Active and passive forearm supination was assessed for differences in translations of the RH. Significant differences were found in …

Development Of An Active Elbow Motion Simulator And Coordinate Systems To Evaluate Kinematics In Multiple Positions, Louis M. Ferreira

Electronic Thesis and Dissertation Repository

Elbow disorders are common as a consequence of both traumatic and degenerative conditions. Relative to disorders of the lower limb, there is comparatively little evidence to direct the treatment of many elbow disorders. Biomechanical studies are required to develop and validate the optimal treatment of elbow disorders prior to their application in patients. Clinically relevant simulation of elbow motion in the laboratory can be a powerful tool to advance our knowledge of elbow disorders. This work was undertaken with the rationale that simulation and quantification of elbow motion could be improved significantly. This treatise includes the development and evaluation of …