The volume of resection is highlighted as a color-coded distance map according to the preoperative collision detection and ROM analysis. The burr is tracked in real time and color changes on the map indicate the proximity of the depth of resection to the pre-planned goal. Reprinted from The Journal of Arthroplasty, 27(2), Ecker TM, Puls M, Steppacher SD, Bastian JD, Keel MJB, Siebenrock KA, Tannast M, Computer Assisted Femoral Head-Neck Osteochondroplasty Using a Surgical Milling Device, 122-131, 2012, with permission from Elvesier.