Robot-assisted Temporary Hemiepiphysiodesis With Eight-plates for Lower Extremity Deformities in Children

Purpose: This study was performed to compare the radiographic results of robot-assisted and traditional methods of treating lower extremity deformities (LEDs). Methods: From January 2019 to February 2022, 55 patients with LEDs were treated by temporary hemiepiphysiodesis with eight-plates. They were divided into a robot group and a freehand group. The fluoroscopy time and operation time were recorded. The accuracy of screw placement was measured after the operation using the following parameters: coronal entering point (CEP), sagittal entering point (SEP), and angle between the screw and epiphyseal plate (ASEP). The limb length discrepancy (LLD) and femorotibial angle (FTA) were measured before the operation, after the operation, and at the last follow-up. Patients were followed up for 12 to 24 months, and the radiographic results of the 2 groups were compared. Results: Among the 55 patients with LEDs, 36 had LLD and 19 had angular deformities. Seventy-six screws were placed in the robot group and 85 in the freehand group. There was no difference in the CEP between the 2 groups ( P >0.05). The robot group had a better SEP (2.96±1.60 vs. 6.47±2.80 mm) and ASEP (3.46°±1.58° vs. 6.92°±3.92°) than the freehand group ( P <0.001). At the last follow-up, there was no difference in the LLD or FTA improvement between the two groups ( P >0.05). The incidence of complications was significantly lower in the robot group than in the freehand group (0/27 vs. 5/28, P <0.05). Conclusion: Robot-assisted temporary hemiepiphysiodesis with eight-plates is a safe and effective method for treating LEDs in children. Robotic placement of screws is superior to freehand placement with respect to the entering position and direction. Although the correction effect for LLD and angular deformity is similar, screw dislocation is less common when using robot assistance. Levels of Evidence: Level—III. Retrospective comparative study.