Physical simulation environment for arthroscopic joint irrigation

Good arthroscopic view is important to perform arthroscopic operations (minimally invasive surgery in joints) safely and fast. To obtain this, the joint is irrigated. However, optimal irrigation settings are not described. To study the complex clinical practice of irrigation, a physical simulation environment was developed that incorporates the main characteristics for performing arthroscopy. Its irrigation capacities were validated with patient data. The physical simulation environment consists of a specially designed knee phantom, all normally used arthroscopic equipment, and registration devices for two video streams, pressures, and flows. The physical embodiment of the knee phantom matches that of human knee joints during arthroscopic operations by the presence of important anatomic structures in sizes comparable to human knee joints, the presence of access portals, and the ability to stress the joint. The hydrostatic and hydrodynamic behavior of the knee phantom was validated with pressure and flow measurements documented during arthroscopic knee operations. Surgeons confirmed that the knee phantom imitated human knee joints sufficiently. The hydrostatic parameters of the knee phantom could be tuned within the range of the human knee joints (restriction: 0.0266-29.3 N s ²/m⁸ versus 0.0143-1.22 x 10¹⁸ N s ²/m⁸ and capacitance: 6.89 m⁵/N versus 7.50 x 10^-9 m⁵/N). The hydrodynamic properties of the knee phantom were acceptably comparable to those of the human knee joints. The physical simulation environment enables realistic and conditioned experimental studies to optimize joint irrigation. The foundation has been laid for evaluation of other surgical instruments and of training of surgical skills.