Femoral neck fracture is common. Traditionally, we use a freehand method for screw placement. Now we apply the robot-assisted orthopedic surgery system in surgical manipulation, which has satisfactory results.
The robot assess system could provide more accurate screw placement, a more efficient suture precise, reduced intraoperative radiation exposure, and achieve a better outcome. This system can be used in minimal invasive orthopedic surgery, particular in the procedure recurrent process screw placement, such as pelvic or acetabular fracture and the spine injury. Demonstrating the procedure, we have Yongchao Duan, an intraoperative imaging technologist, and Hai Huang, a surgeon from my department.
To begin, identify the patient with a femoral neck fracture with tenderness or percussed pain around the hip joint. Fix the limb to the traction bed for continuous traction during the operation. Before starting the operation, connect the components of the robot-assisted orthopedic surgery system and unfold the robot arm.
Log into the system and record the patient's medical records. After routine surgical disinfection, place a Schanz pin on the ipsilateral iliac wing, and fix the patient's tracer on the pin. Put sterile protective sleeves on the robotic arm and on the C-arm.
Assemble the positioning ruler with the 10 identification points for the robot positioning system with the robotic arm. Position the C-arm x-ray machine centrally to the femoral neck, and put the robotic arm with the positioning ruler between the C-arm and the patient. Collect anteroposterior and lateral view X-ray images containing the 10 identification points of the positioning ruler.
Import the anteroposterior and lateral view images containing 10 identification points, and the entire proximal femur into the workstation. Locate the screw channel in the center of the femoral neck with the neck shaft angle of 130 degrees, and parallel to the long axis of the femoral neck on the anteroposterior and lateral views. Locate the tip of the screw five millimeters under the cartilage of the femoral head.
Replace the positioning ruler with the sleeve on the robotic arm. Run the robotic arm to the position of the entry point according to the planned path. Then make a three centimeter incision on the skin along the long axis of the femur with a knife.
Blunt separate the subcutaneous tissue, and insert the sleeve to contact the bone cortex. Confirm the entry point and direction of the sleeve in accordance with the planned path. Drill the guide wire into the bone through the sleeve until it is five millimeters from the subchondral bone.
Remove the robotic arm and check the position of the guide wire by x-ray. Ream the hole along the guidewire using a hollow drill bit, and insert the bolt and plate into the femoral head. Then place the anti-rotation screw and locking screw.
After applying dynamic compression, verify the FNS placement with the bolt in the center of the femoral neck, both on the anterior, posterior and lateral views, and five millimeters from the subchondral bone and with the plate fitting the bone. Following the operation, suggest assisted passive hip flexion activities, and active exercise of the knee and ankle joints. The pre-operation x-ray images of the femoral neck fracture in anteroposterior and lateral view are shown here.
The fracture was reduced by closed reduction to a proper position. The collected x-ray images using the patient tracer and the positioning ruler with the positioning ruler between the C-arm and the patient are demonstrated along with the fluoroscopy images containing the positioning ruler. Surgical path planning was performed on the software, and the screw channel was virtually displayed.
The structure of the FNS process, the reaming process, the placement of the bolt and plate, the anti-rotation screw, and the locking screw are shown. X-ray images confirmed dynamic compression in anteroposterior and lateral view. This robot-assisted orthopedic surgery system simulates the screw plates virtually, assisting the screw placement precisely and reduce the risk of surgical procedure.
