Purpose There remains controversy as to whether computernavigated total knee replacement (TKR) improves the overall prosthesis alignment and patient function. The aim of this study was to determine whether computer-assisted total knee arthroplasty provides superior prosthesis positioning when compared to a conventional jig-assisted total knee replacement and whether this affected the functional outcome. Methods This prospective, randomised controlled study compared computer navigated and conventional jig-assisted total knee replacement in 37 patients who underwent bilateral TKR. A quantitative assessment of the spatial positioning of the implant in the 74 total knee replacements was determined using a low-dose dual-beam CT scanning technique. This resulted in six parameters of alignment that were compared. Functional outcomes using the high activity arthroplasty score and Knee Society score were assessed pre-operatively, postoperatively, at three years and at five years. Patients also indicated which knee they felt was subjectively the best. Results There was no statistically significant difference in the prosthesis alignment between both groups and the number of outliers was not decreased with navigation. All function scores improved from pre-operative to postoperative but there was no statistically significant difference between the groups at five years. At five years, 40.6 % of patients thought their jigassisted knee was the better knee compared with 21.9 % their computer assisted knee and 37.5 % of patients who felt they were the same. Conclusion Computer-assisted implantation of total knee replacements does not offer a significant advantage in prosthesis alignment. There was no difference in functional outcome or subjective "best knee" between the computer-assisted or jig-assisted knee.

At our institution the median time for completion of surveillance to repair was 6 months. An AAA with a diameter of 55 mm has an expected risk of rupture of 5%, with mortality approaching 90%. In our series, mortality was 4.9% (two patients died while awaiting repair), consistent with expected figures. Factors contributing to this delay of 6 months to repair were identified. Modifications to this journey are suggested to improve the time interval and therefore hopefully reduce the aneurysm-related mortality in this group.