The following work presents the design of a haptic training simulator for pedicle screw insertions in pediatric scoliosis surgery. In particular, the haptic simulator simulates the haptic sensations associated with probe channeling through the pedicle using the free-hand technique. The design includes 1 DOF custom haptic device, haptic model, and controller. The design is tested and evaluated for feasibility through a small pilot studying involving 5 expert surgeons. Significant agreement across expert surgeons was obtained regarding the feasibility and potential for the simulator to be a useful training tool.

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The purpose of this study was to compare the protective characteristics of four different ankle braces and one form of ankle taping. An inversion and plantar flexion platform was used to induce ankle movements. The subjects used in this study consisted of 10 volunteer male students. The subjects had no sprains five months prior to testing. All subjects were tested in the same size 10 shoes, high tops and low tops. A Certified Athletic Trainer applied all ankle braces and ankle tapings. A closed basketweave with heel locks, adherent spray, and pre-wrap was used for all taping conditions.After the application of the ankle braces or taping, each subject performed two tests on the inversion and plantar flexion platform. A random order was used among the subjects. An ankle inversion platform was modified to induce 30 degrees of inversion and 35 degrees of plantar flexion simultaneously. The subjects will be filmed using a Locam 16mm at 200 frame/second. All subjects were filmed from the posterior plane with markings on the posterior aspect of the lower leg to help analyze the movement at the subtalar joint. A Calcomp 9100 series digitizer that was interfaced with a VAX computer was used to analyze the data and calculate the amount of angular displacement at the subtalar joint. An ANOVA with repeated measures was used to determine significant differences between support techniques. University procedures for the protection of human subjects was followed. ANOVA procedures indicated no significant difference in angular displacement between braces. A statistical analysis indicated that low top shoes provided significantly more support than high top shoes in braced ankles. / School of Physical Education

The impact forces at landing are predominately absorbed by the hip, knee and ankle joints. Fatigue has been shown to increase the amount of work performed by the ankle and to reduce the work performed by the knee during landings. The purpose of this study was to assess the kinematic lower extremity motion and kinetic patterns during landings to fatigue, with and without ankle brace usage. Nine recreationally active males (n = 7) and females (n = 2) performed repetitive drop jumps to fatigue for an un-braced and braced condition. Kinematic and kinetic variables were assessed during the first 100 ms after ground impact. Due to the high skill level of the participants, none of the individuals reached a fatigued state. No significant main effect of fatigue was demonstrated on ankle work (p= 0.260). There was no significant main effect due to fatigue on the hip (p= 1.000), knee (p= 1.000) or ankle (p= 0.636) relative work contributions. Fatigue caused a shift toward a more erect landing position at initial ground contact (IGC). No significant main effect of the brace on hip (p= 0.437), knee (p= 0.283) or ankle (p= 0.314) angles was observed at IGC angles. The use of Ankle Stabilizing Orthosis® (ASO) ankle braces caused a shift toward greater knee contribution in a fatigued state. Plantar flexion angles were decreased the most during the braced un-fatigued condition. There was an inverse relationship between knee and hip angles as compared to ankle angles at IGC. When the hip and knee joint displayed less flexion at IGC, the ankle balanced the positions out by landing in more plantar flexion. / School of Physical Education, Sport, and Exercise Science

Cartilage tissue provides compressive resistance in diarthrodial joints, and has been shown to be regulated by mechanical signals, in particular with regard to production of extracellular matrix proteins. However, less is understood about how chondrocytes in regions not solely purposed to provide compressive resistance may also be affected by mechanical forces. The growth plate is a small layer of cartilage that functions to facilitate longitudinal growth of the long bones from in utero through post-adolescent development. The growth plate maintains distinct regions of chondrocytes at carefully regulated stages of endochondral ossification that are in part characterized by their morphology and differential responsiveness to vitamin D metabolites. Understanding if mechanical cues could be harnessed to accelerate or delay the process of endochondral ossification might be beneficial for optimizing tissue engineering of cartilage or osteochondral interfaces. This study focused on three aims to provide a basis for future work in this area: 1) Develop a cell line culture model useful for studying growth plate chondrocytes, 2) Determine the response of primary growth plate chondrocytes and the cell line model to fluid shear stress, and 3) determine if expression of integrin beta 1 is important for the observed responses to shear stress. The findings of this study suggest that inorganic phosphate can promote differentiation in coordination with the 24,25(OH)2D3 metabolite of vitamin D, and that fluid shear stress generally inhibits differentiation and proliferation of growth plate chondrocytes in part through an integrin beta 1 mediated pathway.

Bibliography: leaves 198-219. / xii, 219 leaves : ill. (chiefly col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Examines the effect of implant design on the femoral bone remodelling response in a sheep cemented hip arthroplasty model. The clinical section of the thesis also indicates the importance of biological factors in the femoral bone remodelling response. / Thesis (Ph.D.)--University of Adelaide, Dept. of Orthopaedics and Trauma, 1998

[Truncated abstract] Unicondylar knee arthroplasty (UKA) has re-emerged as a successful treatment option for isolated single compartment tibio-femoral joint osteoarthritis. However despite its increasing use, controversy still remains over fixed or mobile bearing tibial components, as there is a lack to prospective randomised studies reported in the literature. In addition, the theoretical advantages of the mobile bearing for knee kinematics, kinetics and clinical outcome have not been evaluated in vivo. The aim of this research study was to explore the clinical and biomechanical outcomes of the fixed and mobile bearing UKA. . . . When the results for the both studies were combined, utilising the Preservation and MG fixed bearing prostheses, there was a significant relationship between knee adduction moment, and a poor prognosis predicted from RSA. Those patients with translation or rotation of the tibial component in any direction above 1mm and 1.5 degrees respectively were considered to have a poor prognosis for long term fixation. Of the 28 patients, the 8 patients considered to have a poor prognosis, had increased knee adduction moments post-surgery (mean difference = 1.66Nm.kg-1, p = 0.007). There was no difference between the groups for knee flexion moment (mean difference 0.16Nm.kg-1, p = 0.844). Pre-surgery gait was unable to predict the post-surgery outcome, due to the significant changes in gait from pre- to post-surgery. Care must taken when implanting the Preservation mobile bearing prosthesis, as long term outcome is questionable. The mobile bearing prosthesis also produced the worst clinical outcome, however the theoretical advantages of the mobile bearing does not affect gait. Gait analysis is a useful tool to identify patient who are overloading their prosthesis, leading to potential early failure. Identification of these gait patterns can allow for early intervention to reduce joint load, and possible extend the longevity of the prosthesis.

Thesis (Ph.D.)--University of Adelaide, Dept. of Orhtopaedics and Trauma, 1998. / Bibliography: leaves 198-219.

Thesis (Ph.D.) - University of Queensland, 1998. / Includes bibliography.

Thesis (M.A.)--University of North Carolina at Chapel Hill, 2005. / Includes bibliographical references (leaves 109-114). Also available online (PDF file) by a subscription to the set or by purchasing the individual file.