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Doctoral Thesis Proposal
Georgia Institute of Technology, School of Biological Sciences
February 27, 2017, 3:00pm, Room 1253, 555 14th St NW
Joshua R. Jarrell
Title: Quadrupedal locomotion with a unilateral bone-anchored transtibial prosthesis in the cat
Committee Members: Boris I. Prilutsky, Ph.D. (Advisor); T. Richard Nichols, Ph.D.; Johnna S.
Temenoff, Ph.D.; Young-Hui Chang, Ph.D.; and W. Lee Childers, Ph.D.
Abstract
Bone-anchored limb prostheses offer numerous advantages over conventional socket-supported
prostheses. Loads on a bone-anchored prosthetic limb during natural activities are directly
transmitted to the residual bone that prevents damage of skin and other soft tissues in the case of
socket prostheses. Despite this and other documented advantages, however, bone-anchored
prostheses have been limited in their availability in the United States due to an increased risk of
skin and deep tissue infection through the skin-implant interface. A novel porous titanium pylon,
the skin- and bone-integrating pylon (SBIP), has been developed to promote deeper tissue
integration with the percutaneous implant and thereby reduce the risk of infection (Pitkin et al.,
2009; Pitkin and Raykhtsaum, 2012; Farrell et al., 2014). Further research is needed to examine
if the SBIP can be utilized for anchoring limb prosthesis in natural load bearing applications. In
veterinary medicine, gait changes in animals after limb loss and subsequent prosthesis
intervention have not been extensively investigated. In addition, it is not completely understood
how the motor system adapts to a loss of sensory feedback from the distal leg and to a reduced
ability to absorb and generate mechanical energy for locomotion. Currently, detailed
biomechanical analyses of such adaptations are missing. Therefore, the overall goal of the
study is to examine if or how the motor system adapts to a unilateral, transtibial SBIPanchored
prostheses during locomotion in the cat. The general hypothesis to be tested is that
the SBIP will provide secure, infection free anchoring of a transtibial prosthesis and that will
permit the cats to adopt the prosthesis for stable quadrupedal locomotion. In Specific Aim 1 I
will examine the ability of the SBIP to serve as attachment for a unilateral, transtibial boneanchored
prostheses during walking in the cat. In Specific Aim 2 I will determine the amount of
skin and bone ingrowth into the SBIP after the residual tibia has been loaded during natural
motor activities including locomotion. In Specific Aim 3 I will determine margins of static and
dynamic stability during quadrupedal walking with a unilateral bone-anchored passive transtibial
prosthesis. This study will provide important new information about the ability of the novel SBIP
implant to serve for anchoring limb prostheses and about how the motor system of a quadrupedal
animal adapts to a partial loss of afferent sensory feedback and the ability to generate mechanical
energy for locomotion.
