Efficient contact-based registration for minimally invasive anterior hip arthroplasty

Abstract

This paper introduces an efficient contact-based registration method for minimally invasive anterior hip arthroplasty. Unlike existing methods that involve radiation exposure, implanted screws, or tedious point collection, our method requires only one contact within the acetabulum and two contacts on the landmarks. Inspired by the probe’s ball tip, we define a unique position, named stable point, to decouple translation from the overall transformation. The stable point in patient space is easily acquired by our tool, simplifying translation estimation to compute the stable point in image space. We present a fast computation method based on dichotomic search. After aligning the stable points, we introduce two bone landmarks for rotation estimation in a center-aware manner. Additionally, a deltille grid position-sensing (DGPS) marker is used to improve instrument tracking robustness. Experiments were conducted to evaluate the performance of our methods, demonstrating an average accuracy of $0.16\pm 0.03\mathrm{mm}$ for instrument tracking and $1.41\pm 0.16\mathrm{mm}$ for registration. Moreover, the entire process takes less than 1 minute. Results suggest that our method has significant potential for clinical application.