Robot‐assisted Percutaneous Cannulated Screw Fixation of Femoral Neck Fractures: Preliminary Clinical Results

Abstract

Objective To assess the clinical efficacy of TiRobot‐assisted percutaneous cannulated screw fixation in the treatment of femoral neck fractures. Methods From September 2015 to July 2017, 26 patients with unilateral femoral neck fractures were treated with TiRobot‐assisted percutaneous cannulated screw fixation. The femoral necks were fixed using three cannulated screws with robot assistance applying the following procedure: image acquisition, path planning, and needle and screw placement. The results of the treatment, including operation duration, frequency of fluoroscopy use, implant placement accuracy, intraoperative bleeding, total drilling, surgical complications, fracture healing time, fracture healing rate, and Harris scores at the last follow‐up, were recorded and compared with 23 similar patients who underwent conventional manual positioning surgery. Results A total of 147 cannulated screws were placed in all patients. The TiRobot group had shorter operation duration (62.6 ± 8.7 min vs 72.4 ± 10.3 min) and fracture healing time (5.1 ± 2.4 months vs 5.9 ± 2.8 months) than the conventional group ( P > 0.05). The robot group had significantly less use of fluoroscopy (26.5 ± 7.4 times vs 51.3 ± 9.4 times), intraoperative bleeding (8.2 ± 5.3 mL vs 36.4 ± 12.5 mL), and total drilling (9.4 ± 4.2 times vs 18.3 ± 9.1 times) than the conventional group (all P < 0.05). The screw parallelism was significantly improved (24.0 ± 0.6 points vs 21.5 ± 1.2 points) and the neck‐width coverage (72.0 ± 6.7 mm 2 vs 53.8 ± 10.4 mm 2 ) was significantly enlarged compared to the conventional group ( P < 0.05). Only three guiding needles were used to penetrate the femoral head during manual insertion in the TiRobot group, which was significantly lower than that in the conventional group (3/78, 3.8% vs 9/69, 13.0%; P < 0.05). Other complications such as wound infection, vascular or nerve injury, screw loosening, and secondary screw displacement, did not occur in the two groups. There was no significant difference between the two groups in fracture healing rate (88.4% vs 82.6%) and Harris scores at the last follow up (88.2 ± 3.6 points vs 87.3 ± 4.7 points; P > 0.05). Conclusion TiRobot‐assisted percutaneous cannulated screw fixation of femoral neck fractures is advantageous over conventional surgery with manual positioning due to easier manipulation, more accurate screw insertion, less invasion, and less radiation exposure, suggesting that it is a better method to stabilize femoral neck fra...

TiRobot‐Assisted Percutaneous Cannulated Screw Fixation in the Treatment of Femoral Neck Fractures: A Minimum 2‐Year Follow‐up of 50 Patients

“…The screw parallelism was significantly improved and the neck‐width coverage was significantly enlarged compared to the conventional surgery group. However, there was no significant difference between the two groups in terms of the fracture healing rate and Harris scores at the last follow‐up 10 .…”

The Oval‐like Cross‐section of Femoral Neck Isthmus in Three‐dimensional Morphological Analysis

“…Due to variation in the anatomical shape of the femoral neck, the cannulated screw configuration and steel plate size should be individually selected according to the shape of the femoral neck on the healthy side before surgery. Precise preoperative planning aided by computer stimulation or 3D‐print may be a trend in the treatment of femoral neck fractures in the future 12,33 .…”

“…One of the important factors that affect the implant selection and mechanical properties of femoral neck internal fixation is the spatial shape of the femoral neck canal, especially the morphological characteristics of the cross‐section of the femoral neck isthmus, which directly affects both the spatial configuration and type of the cannulated screws 7 . Previous studies have shown that the cross‐section of the femoral neck gradually changed from a circle to an oval shape from the proximal to distal ends 11,12 . Du et al .…”

“…Currently, the diverse configuration of implants is controversial among surgeons and causes subjective deviations and mismatching of implants 11,12,15 . The ideal insertion of screws should provide enough support in multiple directions and minimize the iatrogenic injuries in the femoral neck.…”

“…compared the single‐cylinder method with the two‐angled cylinder method and found that the continuous ellipse method using the 3D reconstruction was more accurate in identifying the morphology of the femoral neck. Moreover, the regression analysis showed that the continuous cross‐section ellipse model might be a better way to describe the structure of the femoral neck 11,12 .…”