Background: A tourniquet is often used to create a bloodless surgical field during total knee arthroplasty (TKA). It is still debated whether tourniquet use improves durability of cemented implant... Show moreBackground: A tourniquet is often used to create a bloodless surgical field during total knee arthroplasty (TKA). It is still debated whether tourniquet use improves durability of cemented implant fixation and thereby prosthesis survival. Some studies showed tourniquet application has a negative impact on post-operative wound healing, pain and function, whilst other publications contradict this. However, no previous studies evaluated the effect of tourniquet use on prosthesis survival and mid-term functional outcome specifically. Methods: In this longitudinal observational cohort study 115 patients (116 knees) undergoing TKA without tourniquet use were compared with 374 patients (395 knees) with a tourniquet. Prosthesis survival, revision risks and complications were analysed through chart review after a mean follow-up period of 5.3 years. Additionally, patient reported outcome measures regarding knee functionality and health status (PROMs; KOOS, OKS, EQ-5D, SF-12) were collected prospectively. Results: Both groups had an equal overall re-operation rate of 4.3% and showed similar revision rates for aseptic loosening as well as for other causes. In the tourniquet group a higher complication rate (14.7% vs 10.3%) was observed. The majority was urinary retention requiring bladder catheterization. Both groups showed comparable, improved post-operative functional results compared to the pre-operative state for all PROMs at all time points. Conclusions: In this study TKA without tourniquet use yielded similar mid-term results as TKA with tourniquet use with regard to prosthesis survival, reoperations, complications, knee functionality and health status.(c) 2022 Elsevier B.V. All rights reserved. Show less
The primary aim of this work was to develop novel model-based mJSW measurement methods using a 3D reconstruction and compare the accuracy and precision of these methods to conventional mJSW... Show moreThe primary aim of this work was to develop novel model-based mJSW measurement methods using a 3D reconstruction and compare the accuracy and precision of these methods to conventional mJSW measurement. This thesis contributed to the development, validation and clinical application of model-based mJSW measurements for the natural knee and for total knee prostheses. The majority of this work focusses on measuring linear wear of the total knee protheses by estimating the remaining insert thickness with the mJSW. Both in vivo and in vitro research shows that the application of model-based techniques can give a large improvement in measurement accuracy and precision. This applies for measurements based on both Röntgen Stereogrammetric Analysis (RSA) and standard radiographs. Secondary, this work investigated volumetric wear measurement and the effect of patient positioning on the measurement outcome. In conclusion, this work presents convincing evidence that the mJSW measurement accuracy and precision is improved using model-based measurement techniques in RSA images as well as in standard AP radiographs. The next steps towards clinical application are to improve the measurement software and to conduct further research on the influence of knee flexion and implant design on the reliability of mJSW as surrogate for the insert thickness. Show less
