Feng Qiu1, Xilin Xu1, Xiangyang Ma2, Weicheng Jiang1, Gengchao Liu1, Zhouqun Fang1, Zejiang Lin1. 1. Department of Orthopaedics, Puning Overseas Chinese Hospital, Puning Guangdong, 515300, P.R.China. 2. Department of Spinal Surgery, Orthopaedics Hospital, General Hospital of Southern Theatre Command, Guangzhou Guangdong, 510010, P.R.China.
Abstract
OBJECTIVE: To evaluate the stability of the fixation technique for the crossed rods consisting of occipital plate and C 2 bilateral lamina screws by biomechanical test. METHODS: Six fresh cervical specimens were harvested and established an atlantoaxial instability model. The models were fixed with parallel rods and crossed rods after occipital plate and C 2 bilateral laminae screws were implanted. The specimens were tested in the following sequence: atlantoaxial instability model (unstable model group), under parallel rods fixation (parallel fixation group), and under crossed rods fixation (cross fixation group). The range of motion (ROM) of the C 0-2 segments were measured in flexion-extension, left/right lateral bending, and left/right axial rotation. After the test, X-ray film was taken to observe the internal fixator position. RESULTS: The biomechanical test results showed that the ROMs in flexion-extension, left/right lateral bending, and left/right axial rotation were significantly lower in the cross fixation group and the parallel fixation group than in the unstable model group ( P<0.05). There was no significant difference between the cross fixation group and the parallel fixation group in flexion-extension and left/right lateral bending ( P>0.05). In the left/right axial rotation, the ROMs of the cross fixation group were significantly lower than those of the parallel fixation group ( P<0.05). After the test, the X-ray film showed the good internal fixator position. CONCLUSION: The axial rotational stability of occipitocervical fusion can be further improved by crossed rods fixation when the occipital plate and C 2 bilateral lamina screws are used.
OBJECTIVE: To evaluate the stability of the fixation technique for the crossed rods consisting of occipital plate and C 2 bilateral lamina screws by biomechanical test. METHODS: Six fresh cervical specimens were harvested and established an atlantoaxial instability model. The models were fixed with parallel rods and crossed rods after occipital plate and C 2 bilateral laminae screws were implanted. The specimens were tested in the following sequence: atlantoaxial instability model (unstable model group), under parallel rods fixation (parallel fixation group), and under crossed rods fixation (cross fixation group). The range of motion (ROM) of the C 0-2 segments were measured in flexion-extension, left/right lateral bending, and left/right axial rotation. After the test, X-ray film was taken to observe the internal fixator position. RESULTS: The biomechanical test results showed that the ROMs in flexion-extension, left/right lateral bending, and left/right axial rotation were significantly lower in the cross fixation group and the parallel fixation group than in the unstable model group ( P<0.05). There was no significant difference between the cross fixation group and the parallel fixation group in flexion-extension and left/right lateral bending ( P>0.05). In the left/right axial rotation, the ROMs of the cross fixation group were significantly lower than those of the parallel fixation group ( P<0.05). After the test, the X-ray film showed the good internal fixator position. CONCLUSION: The axial rotational stability of occipitocervical fusion can be further improved by crossed rods fixation when the occipital plate and C 2 bilateral lamina screws are used.
Authors: Andrew T Hale; Irene Say; Smit Shah; Michael C Dewan; Richard C E Anderson; Luke D Tomycz Journal: Pediatr Neurosurg Date: 2019-03-07 Impact factor: 1.162
Authors: Erik J Timmermans; Emiel O Hoogendijk; Marjolein I Broese van Groenou; Hannie C Comijs; Natasja M van Schoor; Fleur C F Thomése; Marjolein Visser; Dorly J H Deeg; Martijn Huisman Journal: Eur J Public Health Date: 2019-12-01 Impact factor: 3.367