Lifeng Li1, Na Li1, Jiahui Zhou2, Handong Li1, Xianping Du3, Haibo He1, Pengfei Rong1, Wei Wang1, Yin Liu1. 1. Department of Radiology, The Third Xiangya Hospital, Central South University, Changsha, China. 2. Department of Orthopedics, The Third Xiangya Hospital, Central South University, Changsha, China. 3. School of Marine Engineering and Technology, Sun Yat-sen University, Zhuhai, China.
Abstract
Background: Adjacent segment pathology (ASP) is one of the primary complications affecting the long-term efficacy of anterior cervical fusion (ACF). At present, the cause and mechanism of adjacent segmental lesions are still controversial. Methods: We performed a retrospective analysis on 88 patients with cervical spondylotic myelopathy (CSM) who had been followed up for at least 1 year after ACF. The patients were divided into radiological adjacent segment pathology (RASP) and non-RASP groups according to the presence of postoperative RASP. On the lateral radiographs of the cervical spine of all patients taken before and after surgery at the short-term and final follow-ups, the following parameters were measured: C2-7 Cobb angle of the cervical vertebrae; Cobb angle of the operated segments; and the anterior and posterior height of the fused segments [i.e., the anterior fusion segment height (AFH) and the posterior fusion segment height (PFH)]. The intra- and inter-group differences of the patients before and after surgery were calculated, as well as correlation of ACF with the occurrence of RASP. Results: There were 42 cases in the RASP group and 46 cases in the non-RASP group. In the RASP group, the C2-7 Cobb angle was significantly reduced in the short term after surgery (20.42±9.92° vs. 13.81±8.52°, P<0.01), while in non-RASP group the C2-7 Cobb angle was significantly increased in the short term after surgery (12.65±11.91° vs. 15.35±10.05°, P<0.05). The heights of both the anterior and posterior fused segments in the 2 groups were significantly higher after surgery, and they were significantly lower at the final follow-up than at the short-term follow-up. Post-operative AFH change was significantly correlated with C2-7 Cobb angle (r=0.274, P=0.010) and fused segment Cobb angle change (r=0.333, P=0.002). However, Cox regression analysis showed that only the postoperative C2-7 Cobb angle change was associated with RASP, with a hazard ratio of 0.336. Conclusions: Decreased cervical lordosis after ACF may be related to postoperative RASP. Maintaining good cervical curvature after surgery may reduce the incidence of RASP after ACF. 2022 Quantitative Imaging in Medicine and Surgery. All rights reserved.
Background: Adjacent segment pathology (ASP) is one of the primary complications affecting the long-term efficacy of anterior cervical fusion (ACF). At present, the cause and mechanism of adjacent segmental lesions are still controversial. Methods: We performed a retrospective analysis on 88 patients with cervical spondylotic myelopathy (CSM) who had been followed up for at least 1 year after ACF. The patients were divided into radiological adjacent segment pathology (RASP) and non-RASP groups according to the presence of postoperative RASP. On the lateral radiographs of the cervical spine of all patients taken before and after surgery at the short-term and final follow-ups, the following parameters were measured: C2-7 Cobb angle of the cervical vertebrae; Cobb angle of the operated segments; and the anterior and posterior height of the fused segments [i.e., the anterior fusion segment height (AFH) and the posterior fusion segment height (PFH)]. The intra- and inter-group differences of the patients before and after surgery were calculated, as well as correlation of ACF with the occurrence of RASP. Results: There were 42 cases in the RASP group and 46 cases in the non-RASP group. In the RASP group, the C2-7 Cobb angle was significantly reduced in the short term after surgery (20.42±9.92° vs. 13.81±8.52°, P<0.01), while in non-RASP group the C2-7 Cobb angle was significantly increased in the short term after surgery (12.65±11.91° vs. 15.35±10.05°, P<0.05). The heights of both the anterior and posterior fused segments in the 2 groups were significantly higher after surgery, and they were significantly lower at the final follow-up than at the short-term follow-up. Post-operative AFH change was significantly correlated with C2-7 Cobb angle (r=0.274, P=0.010) and fused segment Cobb angle change (r=0.333, P=0.002). However, Cox regression analysis showed that only the postoperative C2-7 Cobb angle change was associated with RASP, with a hazard ratio of 0.336. Conclusions: Decreased cervical lordosis after ACF may be related to postoperative RASP. Maintaining good cervical curvature after surgery may reduce the incidence of RASP after ACF. 2022 Quantitative Imaging in Medicine and Surgery. All rights reserved.