Trackerless ultrasound-integrated bone cement detection using a modular minirobot in revision total hip replacement

Area of Science:

• Medical robotics
• Surgical navigation
• Ultrasound imaging

Background:

• Freehand manipulation is less accurate than robotic systems for precise surgical interventions.
• Revision total hip replacement requires accurate detection and removal of bone cement.

Purpose of the Study:

• To present a novel modular minirobot for automated ultrasound-based bone cement detection and milling.
• To evaluate the impact of integrated ultrasound modules and varying degrees of freedom (DOFs) on scanning accuracy.

Main Methods:

• Development of a modular minirobot with an integrated ultrasound module, eliminating external tracking.
• Investigation of 2, 3, and 4 DOFs scanning strategies for transducer alignment.
• Comparison of model-based and statistical approaches for automated scanning path calculation using a cadaver study.

Main Results:

• The integrated ultrasound module provides direct contour data within the robot's coordinate system.
• Model-based approaches outperformed statistical methods in cement cavity geometry estimation.
• 3DOFs and 4DOFs scanning strategies significantly improved accuracy over 2DOFs, with 3DOFs offering a balance between complexity and accuracy.

Conclusions:

• The modular minirobot concept is adaptable for various surgical applications.
• Optimized transducer alignment and higher DOFs enhance bone cement detection accuracy in revision hip surgery.
• The developed system offers a precise, efficient solution for complex orthopedic procedures.