Navigation systems assist users in locating objects. Navigation systems may employ light signals, sound waves, magnetic fields, radio frequency signals, etc. in order to track the position and/or orientation of objects. A localizer cooperates with tracking elements on tracking devices to ultimately determine a position and orientation of the objects. Navigation systems are often used in industrial, aerospace, defense, and medical applications. In the medical field, navigation systems assist surgeons in placing surgical instruments relative to a patient's anatomy. Exemplary surgeries in which navigation systems are used include neurosurgery and orthopedic surgery.
Often the surgical navigation system includes attaching the tracking device to an anatomic object, typically bony anatomy, with a bone screw or other suitable fastener. Once secured to the bony anatomy, and particularly after the tracking device is registered with the localizer, it is essential that the tracking device does not move relative to the anatomy. Misalignment due to movement of the tracking device relative to the anatomy can require recalibration or re-registration of the tracking device, or if unnoticed, can result in serious consequences during the surgical procedure, including inadvertent collision with critical anatomic structures, suboptimally located surgical hardware, and the like.
A bone plate is often secured to the bony anatomy through overlying soft tissue such as skin, fat, muscle, and vascular structures, after which the tracking device is coupled to the bone plate. The soft tissues between the bone plate and the bony anatomy can endure appreciable compressive forces, resulting in possible surgical complication and/or delayed recovery.
Therefore, a need exists in the art for a tracking device designed to overcome one or more of the aforementioned disadvantages.