Lai-Qing Sun1, Ming Li2, Yong-Min Li1. 1. Orthopedic Department of Changhai Hospital, Second Military Medical University, No. 168, Changhai Rd., Shanghai 200433, People's Republic of China; Department of Spine Surgery, The Second Hospital of Tangshan, Tangshan, Hebei 063000, People's Republic of China. 2. Orthopedic Department of Changhai Hospital, Second Military Medical University, No. 168, Changhai Rd., Shanghai 200433, People's Republic of China. Electronic address: spine_liming@163.com.
Abstract
OBJECTIVES: The original K-line was developed on plain radiograph to predict incomplete indirect decompression for the patients with ossification of the posterior longitudinal ligament. The current study modified the K-line on magnetic resonance imaging (MRI) to determine risk factors for incomplete decompression after laminoplasty and to provide a guide for predicting incomplete decompression after laminoplasty and making decisions regarding the surgical approach in patients with cervical spondylotic myelopathy (CSM). PATIENTS AND METHODS: A retrospective review of 47 patients with CSM after laminoplasty was conducted. The modified K-line was defined as a line connecting both anterior points of the spinal cord at the level of the inferior vertebrae endplates of C2 and C7 on sagittal T1-weighted MR image. Quantitative analysis of the interval between the maximal anterior compression factor and the modified K-line (IAK) was performed to investigate the efficiency and practicality of this modified K-line. Data analysis involved logistic regression and Spearman rank correlation coefficient. RESULTS: Thirteen patients (27.7%) had postoperative residual anterior compression of the spinal cord (ACS). Univariate logistic regression with backward stepwise procedure showed that only IAK (odds ratio: 0.301; 95% confidence interval: 0.134-0.673, P=0.003) was a significant risk factor for the occurrence of postoperative ACS. Incidence of ACS was 80% in patients with an IAK of less than 1.5mm and 96.2% in those whose IAK is 0mm. CONCLUSION: The modified k-line can provide a guide for predicting poor clinical outcome after laminoplasty and making decisions regarding the surgical approach in patients with CSM.
OBJECTIVES: The original K-line was developed on plain radiograph to predict incomplete indirect decompression for the patients with ossification of the posterior longitudinal ligament. The current study modified the K-line on magnetic resonance imaging (MRI) to determine risk factors for incomplete decompression after laminoplasty and to provide a guide for predicting incomplete decompression after laminoplasty and making decisions regarding the surgical approach in patients with cervical spondylotic myelopathy (CSM). PATIENTS AND METHODS: A retrospective review of 47 patients with CSM after laminoplasty was conducted. The modified K-line was defined as a line connecting both anterior points of the spinal cord at the level of the inferior vertebrae endplates of C2 and C7 on sagittal T1-weighted MR image. Quantitative analysis of the interval between the maximal anterior compression factor and the modified K-line (IAK) was performed to investigate the efficiency and practicality of this modified K-line. Data analysis involved logistic regression and Spearman rank correlation coefficient. RESULTS: Thirteen patients (27.7%) had postoperative residual anterior compression of the spinal cord (ACS). Univariate logistic regression with backward stepwise procedure showed that only IAK (odds ratio: 0.301; 95% confidence interval: 0.134-0.673, P=0.003) was a significant risk factor for the occurrence of postoperative ACS. Incidence of ACS was 80% in patients with an IAK of less than 1.5mm and 96.2% in those whose IAK is 0mm. CONCLUSION: The modified k-line can provide a guide for predicting poor clinical outcome after laminoplasty and making decisions regarding the surgical approach in patients with CSM.
Authors: Jun Li; Yan Zhang; Ning Zhang; Zheng-Kuan Xv; Hao Li; Gang Chen; Fang-Cai Li; Qi-Xin Chen Journal: Medicine (Baltimore) Date: 2017-06 Impact factor: 1.889