Table 1.

Types and characteristics of computer navigation[4,5,6,7,13,52,56]

Type	Advantages	Shortcomings	Applications
CT-based navigation	High resolution; preoperative planning and simulation	No real-time imaging; expensive	Spinal pedicle screw implantation; hip and knee replacement
2D-fluoroscopic navigation	Latest image obtained at any time; low cost	Image distortion	Fracture reduction and internal fixation
3D-fluoroscopic navigation	High-resolution three-dimensional image data; real-time high-definition visualization of trajectory	Easy to be occluded by objects during operation; more X-ray needed	Reduction and internal fixation of complex fracture
Imageless navigation	No requirement for image registration	Anatomic markers to be exposed; limited reconstruction of bone structure	Hip and knee surgery
Electromagnetic navigation	High resolution for soft tissue; no need for a direct line of sight	A stable magnetic field needed	Orthopedic tumor; orthopedic minimally invasive treatment
Ultrasound-based navigation	No radiation	Immature technology	Further improvement needed

CT: Computed tomography; 2D: 2-dimensional; 3D: 3-dimensional.