Pre-operative AR-ultrasound application for determination of individual hip posture

The application developed is using Augmented Reality technique for pre-determine a patients individual pelvic posture. The Measurements were done under use of a hip model and a tracked ultrasound probe which was first covered with a 2D trackable marker and then coated with a water transfer printing technique. Three landmarks were needed for calculation of the pelvic posture. Preoperative examination of pelvic rotation could allow individualized placement of the acetabular cup for each hip patient, thereby reducing dislocation rates and impingement on the implant. Through interactive AR visualization the user could point the depth profile of the ultrasound image with a virtual pointer. For both trackable targets the pelvic posture was measured with a webcam and a smartphone camera. The trials were evaluated among themselves and on the basis of their repeatability and accuracy.