A novel surgical navigation technology for placement of implants in slipped capital femoral epiphysis.

BACKGROUND: Fixation with a single screw is the recommended treatment for slipped capital femoral epiphysis (SCFE). Achieving optimal implant positioning can be difficult owing to the complex geometry of the proximal femur in SCFE. We assessed a novel navigation technology incorporating an inertial measurement unit to facilitate implant placement in an SCFE model. METHODS: Guidewires were placed into 30 SCFE models, using a navigation system that displayed the surgeon's projected implant trajectory simultaneously in multiple planes. The accuracy and the precision of the system were assessed as was the time to perform the procedure. RESULTS: Implants were placed an average of 5.3 mm from the femoral head center, with a system precision of 0.94 mm. The actual trajectory of the implant deviated from the planned trajectory by an average of 4.9° ± 2.2°. The total average procedure time was 97 seconds. CONCLUSION: The use of computer-based navigation in a SCFE model demonstrated good accuracy and precision in terms of both implant trajectory and placement in the center of the femoral head.

Improved screw placement for slipped capital femoral epiphysis (SCFE) using robotically-assisted drill guidance.

Slipped Capital Femoral Epiphysis (SCFE) is a common hip displacement condition in adolescents. In the standard treatment, the surgeon uses intra-operative fluoroscopic imaging to plan the screw placement and the drill trajectory. The accuracy, duration, and efficacy of this procedure are highly dependent on surgeon skill. Longer procedure times result in higher radiation dose, to both patient and surgeon. A robotic system to guide the drill trajectory might help to reduce screw placement errors and procedure time by reducing the number of passes and confirmatory fluoroscopic images needed to verify accurate positioning of the drill guide along a planned trajectory. Therefore, with the long-term goals of improving screw placement accuracy, reducing procedure time and intra-operative radiation dose, our group is developing an image-guided robotic surgical system to assist a surgeon with pre-operative path planning and intra-operative drill guide placement.