Comparative analysis of radiation exposure in robot-assisted total knee arthroplasty using popular robotic systems

Robotic-assisted TKA (RATKA) is a rapidly emerging technique that has been shown to improve precision and accuracy in implant alignment in TKA. Robotic-assisted TKA (RATKA) uses computer software to create a three-dimensional model of the patient's knee. Different types of preoperative imaging, including radiographs and CT scans, are used to create these models, each with varying levels of radiation exposure. This study aims to determine the radiation dose associated with each type of imaging used in RATKA, to inform patients of the potential risks. A retrospective search of our clinical radiology and arthroplasty database was conducted to identify 140 knees. The patients were divided into three groups based on the type of preoperative imaging they received: (1) CT image-based MAKO Protocol, (2) Antero-posterior long leg alignment films (LLAF), (3) standard AP, lateral, and skyline knee radiographs. The dose of CT imaging technique for each knee was measured using the dose-length product (DLP) with units of mGycm², whereas the measurement for XRAY images was with the dose area product (DAP) with units of Gycm². The mean radiation dose for patients in the CT (MAKO protocol) image-based group was 1135 mGy.cm2. The mean radiation dose for patients in the LLAF group was 3081 Gycm2. The mean radiation dose for patients undergoing knee AP/lateral and skyline radiographs was the lowest of the groups, averaging 4.43 Gycm2. Through an ANOVA and post hoc analysis, the results between groups was statistically significant. In this study, we found a significant difference in radiation exposure between standard knee radiographs, LLAF and CT imaging. Nonetheless, the radiation dose for all groups is still within acceptable safety limits.