Preoperative Mapping in Unicompartmental Knee Arthroplasty Using Computed Tomography Scans Is Associated with Radiation Exposure and Carries High Cost.

Robotic-assisted knee arthroplasty with some systems requires the use of computed tomography (CT) scans. The associated radiation dose has not been studied. The effective dose (ED, mSv) of radiation was calculated for 236 preoperative CT scans used for planning of robotic assisted surgery. The mean ED was 4.8±3.0 mSv. There was a 3-fold difference in ED between institutions. One or more additional CT scans were obtained in 25% of patients, amounting to a cumulative ED per patient up to 103 mSv. Preoperative CT is a disadvantage of some robotic-assisted knee arthroplasty systems due to additional cost and radiation exposure. Newer image-free robotic technologies are an alternative to CT-dependent surgery if accuracy and safety are not compromised.