Development of an end-effector device for loose body removal in hip arthroscopy

This article describes a novel hand-operated end-effector device developed for loose body removal in hip arthroscopy. This sterilizable and reusable device incorporates a wire-ball joint mechanism that provides motion with 5 degrees of freedom. The design accounted for the following: (1) the diameter of the femoral head, (2) range of motion of the wrist joint of the operator, (3) ease of assembly of modular parts, and (4) material stiffness and durability. The developed device is composed of three parts: a pistol-shaped hand-held unit, forceps module, and end-effector module, all of which were constructed using polyamide-imide. Experiments were conducted to characterize the range of motion, pushing force, and lateral stiffness of the end-effector. Seven consulting surgeons evaluated the performance of the device in arthroscopic hip model and cadaveric studies in comparison with that of a conventional linear grasper. The experimental results show that the developed device can perform tasks that conventional linear graspers cannot. A specialized end-effector device was developed for hip arthroscopy where a high degree of stiffness is required. The end-effector module is interchangeable based on the required outer diameter, and it is also reusable after sterilization at high temperature.