Abstract
Purpose
To validate a small, easy to use and cost-effective augmented marker-based hybrid navigation system for peri-acetabular osteotomy [PAO] surgery.
Methods
A cadaver study including 3 pelvises (6 hip joints) undergoing navigated PAO was performed. Inclination and anteversion of two navigation systems for PAO were compared during acetabular reorientation. The hybrid system consists of a tracking unit which is placed on the patient's pelvis and an augmented marker which is attached to the patient's acetabular fragment. The tracking unit sends a video stream of the augmented marker to the host computer. Simultaneously, the augmented marker sends orientation output from an integrated inertial measurement unit (IMU) to the host computer. The host computer then computes the pose of the augmented marker and uses it (if visible) to compute acetabular orientation. If the marker is not visible, the output from the IMU is used to update the orientation. The second system served as ground truth and is a previously developed and validated optical tracking-based navigation system.
Results
Mean absolute difference for inclination and anteversion (N = 360) was 1.34 degrees and 1.21 degrees, respectively. The measurements from our system show a very strong correlation to the ground-truth optical tracking-based navigation system for both inclination and anteversion (0.9809 / 0.9711).
Conclusion
In this work, we successfully demonstrated the feasibility of our system to measure inclination and anteversion during acetabular reorientation.
