Robot-assisted core decompression combined with bone grafting can improve the early clinical results in femoral head necrosis: a prospective cohort study
Authors: Tian Run , Luo Sen , Wang Chunsheng , Wang Kunzheng , Yang Pei 
Published: November 2021

Abstract
Background: To explore the clinical effect of robot-assisted core decompression combined with bone grafting in the treatment of femoral head necrosis involved in early stage.Methods: This study is a prospective cohort study. The study included 49 patients (78 hips) who attended the Department of Orthopedics and Joint Surgery of the Second Affiliated Hospital of Xi'an Jiaotong University from August 2019 to February 2021. All the patients suffering Association Research Circulation Osseous (ARCO) II stage of femoral head necrosis underwent core decompression and bone grafting. Among the patients undergoing surgery, 30 patients (54 hips) were treated with traditional surgical methods, and 19 patients (24 hips) were assisted by the made-in-China orthopedic robot system. All operations were performed by the same operator. The baseline data of the two groups of patients, the time of unilateral operation, the number of unilateral X-ray fluoroscopy, the Harris hip score (HHS) at the last follow-up after surgery, the visual analog score (VAS), and the collapse rate at the last follow-up were collected and compared. Results: A total of 41 patients (70 hips) were followed up, including 24 cases (42 hips) in the traditional surgery group and 17 cases in the robot-assisted group (28 hips). The average follow-up time of all cases was (13.9±3.4) months (range: 8-18 months). At the last follow-up, a total of 13 patients (13 hips) suffered femoral head surface collapse, including 11 patients in the traditional surgery group (11 hips) and 2 patients in the robot-assisted group (2 hips). The rate of femoral head collapse between the two groups had statistical difference. The average operation time of unilateral hip in the traditional operation group was (22.5±5.5) min, and (18.2±4.0) min in the robot-assisted group, with significant difference. The number of X-ray fluoroscopy of unilateral hip in the traditional operation group was (14.7±3.1) times, and (10.1±3.1) times in the robot-assisted group, with significant difference. The HHS before surgery in the traditional surgery group was (63.8±3.2) points, and (84.6±3.4) points at the last follow-up,while the preoperative HHS of the robot-assisted surgery group was (65.5±3.5) points, and (85.9±3.1) points at the last follow-up. The HHS at the last follow-up of the two groups were significantly different from those before the operation, but there was no difference between the two groups. The preoperative VAS of the traditional surgery group was (4.8±0.8) points, and (1.7±1.2) points at the last follow-up. The preoperative VAS of the robot-assisted surgery group was (5.0±0.7) points, and (0.9±0.7) points at the last follow-up. At the last follow-up of the two groups, there were significant differences in VAS, and significant difference between the two groups was also detected.Conclusion: Core decompression combined with bone grafting have a definite effect in the treatment of femoral head necrosis at early stage. Compared with traditional surgery, robot-assisted surgery can achieve better short-term results and head preservation rate. Trial registration: the research has been registered in China National Medical Research Registration and Filing System