2023, Vol. 27 ›› Issue (27): 4324-4331

Preoperative planning-based navigation system-assisted total hip arthroplasty: a randomized controlled clinical study

Guo Feng1, Zhang Zhifeng2, Sun Zhiwen1, Lyu Xin1, Piao Junjie1, Wang Di1, Niu Shuang1, Chen Xiaowei1, Zhang Yibo1   

Abstract: BACKGROUND: Total hip arthroplasty is an effective treatment for advanced osteoarthritis of the hip, rheumatoid arthritis, ischemic necrosis of the femoral head, ankylosing spondylitis of the hip, pain, ankylosis and functional deficits due to fractures of the femoral neck in advanced age. The longevity of the acetabular prosthesis after total hip arthroplasty depends primarily on the accurate placement of the acetabular cup. A preoperatively planned navigation system was applied to assist total hip arthroplasty.  
OBJECTIVE: To evaluate the effectiveness of a preoperative planning-based navigation system for achieving optimal mounting accuracy of implanted acetabulars in total hip arthroplasty and to elucidate the clinical utility of this navigation system.
METHODS: A centralized randomization system was used to assign subjects to the group to reduce selection bias. Subjects were randomized in a 1:1 ratio to the navigation group (20 cases) and the conventional technique group (23 cases), with one patient lost to follow-up in the navigation group. Total hip arthroplasty was performed in the lateral decubitus position with a posterolateral approach. The navigational group used a preoperative planning-based navigation system to assist in the implantation of the acetabular cup, and the conventional technique group used conventional surgical instruments to guide the implantation of the acetabular cup. The acetabular position was determined by CT at 1 month (±7 days) postoperatively and the abduction and anteversion angles were measured and recorded; the Harris score, WOMAC score and SF-36 score were performed.  
RESULTS AND CONCLUSION: (1) The mean abduction angle of the acetabular prosthesis placed using preoperative planning-based navigation system was (41.82±5.26)˚ and the mean abduction angle of the acetabular prosthesis placed using conventional surgical techniques was (43.69±5.83)˚, with no significant difference (P=0.29). The mean anteversion angle of the acetabular prosthesis placed using preoperative planning-based navigation system was (18.95±5.24)˚ and the angle was (21.73±6.50)˚ for acetabular prostheses placed with conventional surgical techniques, with no significant difference (P=0.14). (2) 94.7% of acetabular prostheses placed with the aid of preoperative planning-based navigation system were placed within the Lewinnek safety zone, and 60.9% of acetabular prostheses placed in the conventional technique group were placed within the Lewinnek safety zone (χ²=4.844, P=0.028); 73.7% of acetabular prostheses placed with the aid of preoperative planning-based navigation system were placed within the Callanan safety zone, while 34.8% of acetabular prostheses placed in the conventional technique group were placed within the Callanan safety zone (χ²=6.313, P=0.012), and the accuracy of the navigation group was significantly better than that of the conventional technique group. (3) The intraoperative bleeding of total hip arthroplasty was not significant in the two groups, and the operating time was significantly longer in the navigation group. The Harris score, WOMAC score and SF-36 score improved significantly in both groups after arthroplasty compared with those before arthroplasty (P < 0.05). (4) These results concluded that both preoperative planning-based navigation system-assisted total hip arthroplasty and conventional total hip arthroplasty significantly improved patients' functional scores, and the preoperative planning-based navigation system improved the positioning accuracy of the acetabular arthroplasty in a safe area, but the navigation group took longer to operate.

Key words: hip joint, joint arthroplasty, navigation, acetabular, anteversion angle, abduction angle