Thesis (M App Sc in Physiotherapy) -- University of South Australia

Thesis (M App Sc in Physiotherapy) -- University of South Australia

Thesis (doctoral)--Lund University, 1995. / Added t.p. with thesis statement inserted.

Thesis (doctoral)--Lund University, 1995. / Added t.p. with thesis statement inserted.

Thesis (MAppSci in Physiotherapy) -- University of South Australia, 1993

Bone disease and metabolic bone disorders are characterized by decrease in bone mineral content (BMC) and the vertebrae are primarily affected in osteoporosis. Thus it is essential to monitor changes in BMC due to disease, growth or therapy. Dual photon absorptiometry (DPA) is as yet the most efficient method for BMC determination in the lumbar vertebrae; most previous investigators have used ¹⁵³Gd which is generally accepted as possessing the ideal dual photon energy combination. Davis and Webber (1978) developed a method for routine production of ¹⁵³Sm which emits photons of nearly the same energy as ¹⁵³Gd and suggested its use in DPA. In the present study using ¹⁵³Sm, measurements with aluminum standards immersed in water resulted in errors of 4% and 4.5% in accuracy and precision respectively for mass of Al in the range 0.4-1.8 g.cm⁻². These results were obtained using different volumes of water, verifying that bone mineral mass determined by this method is independent of soft tissue content. Experiments with bone mineral phantoms gave values which correlated highly (r=0.97) with results obtained on a commercially available clinical densitometer using ¹²⁵I. Considering that these results are comparable with those obtained earlier using ¹⁵³Gd, that ¹⁵³Gd is scarcely available and several hundred times the cost, ¹⁵³Sm promises to be the potential source for routine clinical measurement of osteopenia in the lumbar spine by DPA. However, further invitro and invivo studies are necessary before it can be used regularly in nuclear medicine departments. / Thesis / Master of Engineering (ME)

No description available.

M.Tech.

Lumbar spine fusion (LSF) is a common surgical procedure used in the treatment of lower back pain. Numerous studies have been conducted investigating the effects of LSF. Biomechanical studies have found that mechanical changes at adjacent joints create cumulative stress and pain, while clinical studies suggest that many patients develop symptomatic adjacent segmental disease (ASD) following LSF, which may necessitate additional surgery. Recently, ASD pain following LSF has been attributed to accelerated sacroiliac (SI) joint degeneration. Normal SI joints are mobile segments adjacent to the lumbosacral spine articulation and it has been hypothesized that altered biomechanics at the SI joints due to LSF could accelerate degeneration of the joints. The purpose of this study was to obtain a better understanding of the biomechanics at the SI joints and to determine whether LSF causes biomechanical changes at the SI joints. Six cadaver pelves were tested in flexion/extension, torsion, double leg compression and single leg compression, under four conditions: 1) intact, 2) after a 360 degree instrumented fusion at L4-5, 3) after a 360 degree instrumented lumbosacral fusion at L4-S1 and 4) after a unilateral SI joint fusion. Anterior and posterior SI joint movements were recorded during the study, along with load/displacement data. This study proved that motion does exist at the SI joints, although it is quite variable between specimens and between right and left SI joints within an individual specimen. It was also determined that changes in biomechanics do occur at the SI joints following fusion (L4-5, L4-S1 and unilateral SI joint fusion). Anteriorly, an overall increase in motion was detected at the SI joints during axial compression as fusions were performed. The posterior SI joints also demonstrated increased motion, however, this increase was detected in all of the parameters tested (flexion/extension, torsion and axial compression). However, due to the small number and variability of specimens tested, significance could not be established. The results of this study may help surgeons make more informed decisions, by being made aware of SI joint degeneration as a possible side effect of fusion surgeries, and taking that into consideration when determining a treatment plan.

Traumatic lumbar punctures (TLPs) in children with acute lymphoblastic leukemia are associated with a poorer prognosis. The objective of this study was to determine risk factors for TLPs using a retrospective cohort. We compared and contrasted three different regression methods for the analysis of repeated-measures data. In the multivariable model using generalized estimating equations, variables significantly associated with TLPs were age < l year or ≥ 10 years; body mass index percentile ≥ 95; platelet counts < 100 x 103/µL; fewer days since previous LP, and a preceding TLP. The same variables, with similar estimates and confidence-intervals, were identified by the random-effects model. In a fixed-effects model where each patient was used as their own control, days since prior LP and the effect of using image-guidance were significant. Random-effects and GEE lead to similar conclusions, whereas fixed-effects discards between-subject comparisons and leads to different estimates and interpretation of results.