Correlation between hand feeling and torque of screw insertion in lumbar pedicle system
Jiang Guozheng1, Feng Ningning1, Yu Xing2, Zhao He2, Yang Yongdong2, Qu Yi2, Wang Fengxian2
1Beijing University of Traditional Chinese Medicine, Beijing 100029, China; 2Dongzhimen Hospital Affiliated to Beijing University of Traditional Chinese Medicine, Beijing 100700, China
Abstract: BACKGROUND: Screw loosening is a common complication of lumbar transpedicle screw fixation in patients with osteoporosis. It is a difficult problem for clinicians to accurately choose the right time to strengthen pedicle screw fixation.
OBJECTIVE: To investigate the correlation between hand feel and screw torque in the process of lumbar pedicle screw insertion, and initially screen the visual simulation score of hand feeling and the range of torque for bone cement reinforcement.
METHODS: A total of 34 patients with degenerative diseases of lumbar spine who underwent lumbar internal fixation fusion in Dongzhimen Hospital Affiliated to Beijing University of Traditional Chinese Medicine from January to December 2020 were included. During the operation, the operator’s hand feeling, visual simulation score of hand feeling and the maximum screw torque value were recorded, and the screw loosening was evaluated periodically after the operation. All 188 screws were divided into groups with small, average, large and laborious hand resistance according to hand feeling. Hand score and torque value among the four groups were compared, and the correlation between torque value and hand feeling was analyzed.
RESULTS AND CONCLUSION: (1) The hand feeling resistance group of screw insertion was reinforced with bone cement. The feeling score and torque value of this group were significantly lower than those in the other three groups (P ≤ 0.001, P ≤ 0.05), and the torque value was strongly positively correlated with the feeling of screw insertion. (2) The results showed that hand feeling score and torque value of pedicle screw could assist the surgeon to judge the stability of screw. When hand feeling score ≤ 3 and torque value ≤ 1.3 N·m, the possibility of screw loosening after operation was greater, and bone cement fixation was recommended.
Key words: pedicle screw, lumbar degenerative lesion, hand feeling of screw insertion, torque, screw looseing, bone mineral density, osteoporosis