Computer assisted mosaic arthroplasty (CAMA) is a surgical technique that transplants cylindrical osteochondral grafts to repair damaged cartilage. An earlier in vivo study on sheep showed that short-term clinical outcomes are improved with the use of computer assistance, as compared to the conventional technique. This thesis reports on a study comparing three mosaic arthroplasty techniques -- one conventional and two computer assisted -- on human anatomy. This in vitro study used solid foam femur models modified to incorporate simulated cartilage defects. There were five participating surgeons ranging from a third year resident to a senior orthopedic surgeon. Each of the five participating surgeons performed a total of nine trials. There were three distinct sets of identical solid foam femur models with simulated cartilage defects. Three surgical techniques (conventional, opto-electronic, and patient-specific template) were performed on each. Several measures were made to compare surgical techniques: operative time; surface congruency; defect coverage; graft surface area either too high or too low; air volume below the grafts; and distance and angle of the grafts from the surgical plan. The patient-specific template and opto-electronic techniques resulted in improved surface congruency, defect surface coverage, graft surface within 0.50mm recessed and 0.25mm proud of the original surface, and below-graft air gap volume in comparison to the conventional technique. However, the conventional technique had a shorter operative time. The patient-specific template technique had less variance in surface congruency and shorter operative time than did the opto-electronic technique. / Thesis (Master, Computing) -- Queen's University, 2013-11-28 17:06:06.961

Brachytherapy is an important method of breast cancer treatment; however, improvements in both treatment planning and delivery are needed. The procedure involves insertion of catheters in the tumor site, which, in current practice, is prone to clinically significant error. In order to improve on contemporary catheter placement accuracy, integration of pre-operative imaging, supplemented by computerized surgical planning and mathematical optimization were used to develop and test an intra-operative immobilization and catheter guidance system. A custom-template specific to each patient with optimally-placed guide-holes for catheter insertion was designed and fabricated for use on phantom studies. Template creation is based on a virtual reality reconstruction of the patient's anatomy from computed tomography imaging. The template fits on the patient's breast, immobilizing the soft tissue, to provide pre-planned catheter insertion holes for guidance to the tumor site. Agar-based phantom and target models were used for quantitative validation of the template using computed tomography imaging for template planning and validation. Planned catheter tracks were compared to post-insertion image data and distance measurements from target location were used to create an error measure. Using the latest template design spanning multiple experiments resulted in a mean of 2.6 mm, 95%, CI =3.1-2.2, which is within the clinically acceptable range of 3 mm, as validated with our clinical collaborators. Validation of the brachytherapy template on phantom tissue produced clinically acceptable results. Use of a patient-specific template for breast brachytherapy is feasible and may improve the procedure accuracy and outcome. This work has been a proof-of-concept, providing evidence to support moving forward with the next phase of patient-specific breast template trials for use in brachytherapy. / Thesis (Master, Computing) -- Queen's University, 2011-10-03 15:17:07.933