Byung-Jou Lee1, Jin Hoon Park2,3, Sang-Ryong Jeon1, Seung-Chul Rhim1, Sung Woo Roh4,5. 1. Department of Neurosurgery, Asan Medical Center, University of Ulsan College of Medicine, 88 Olympic-ro43-gil, Songpa-gu, Seoul, 05505, South Korea. 2. Department of Neurosurgery, Asan Medical Center, University of Ulsan College of Medicine, 88 Olympic-ro43-gil, Songpa-gu, Seoul, 05505, South Korea. grandblue@gnah.co.kr. 3. Department of Neurological Surgery, Asan Medical Center, University of Ulsan College of Medicine, 88 Olympic-ro 43 gil, Songpa-gu, Seoul, 05505, Korea. grandblue@gnah.co.kr. 4. Department of Neurosurgery, Asan Medical Center, University of Ulsan College of Medicine, 88 Olympic-ro43-gil, Songpa-gu, Seoul, 05505, South Korea. swroh@amc.seoul.kr. 5. Department of Neurological Surgery, Asan Medical Center, University of Ulsan College of Medicine, 88 Olympic-ro 43 gil, Songpa-gu, Seoul, 05505, Korea. swroh@amc.seoul.kr.
Abstract
PURPOSE: To investigate radiographic parameters to improve the accuracy of radiologic diagnosis for ossification of ligamentum flavum (OLF)-induced thoracic myelopathy and thereby establish a useful diagnostic method for identifying the responsible segment. METHODS: We classified 101 patients who underwent surgical treatment for OLF-induced thoracic myelopathy as the myelopathy group and 102 patients who had incidental OLF and were hospitalized with compression fracture as the non-myelopathy group between January 2009 and December 2016. We measured the thickness of OLF (TOLF), cross-sectional area of OLF (AOLF), anteroposterior canal diameter, and the ratio of each of these parameters. RESULTS: Most OLF cases with lateral-type axial morphology were in the non-myelopathy group and most with fused and tuberous type in the myelopathy group. Most grade-I and grade-II cases were also in the non-myelopathy group, whereas grade-IV cases were mostly observed in the myelopathy group. The AOLF ratio was found to be the best radiologic parameter. The optimal cutoff point of the AOLF ratio was 33.00%, with 87.1% sensitivity and 87.3% specificity. The AOLF ratio was significantly correlated with preoperative neurological status. CONCLUSIONS: An AOLF ratio greater than 33% is the most accurate diagnostic indicator of OLF-induced thoracic myelopathy. In cases of multiple-segment OLF, confirmation of cord signal change on MRI and an AOLF measurement will help determine the responsible segment. AOLF measurement will also improve the accuracy of diagnosis of OLF-induced thoracic myelopathy in cases of grade III or extended-type axial morphology. These slides can be retrieved under Electronic Supplementary Material.
PURPOSE: To investigate radiographic parameters to improve the accuracy of radiologic diagnosis for ossification of ligamentum flavum (OLF)-induced thoracic myelopathy and thereby establish a useful diagnostic method for identifying the responsible segment. METHODS: We classified 101 patients who underwent surgical treatment for OLF-induced thoracic myelopathy as the myelopathy group and 102 patients who had incidental OLF and were hospitalized with compression fracture as the non-myelopathy group between January 2009 and December 2016. We measured the thickness of OLF (TOLF), cross-sectional area of OLF (AOLF), anteroposterior canal diameter, and the ratio of each of these parameters. RESULTS: Most OLF cases with lateral-type axial morphology were in the non-myelopathy group and most with fused and tuberous type in the myelopathy group. Most grade-I and grade-II cases were also in the non-myelopathy group, whereas grade-IV cases were mostly observed in the myelopathy group. The AOLF ratio was found to be the best radiologic parameter. The optimal cutoff point of the AOLF ratio was 33.00%, with 87.1% sensitivity and 87.3% specificity. The AOLF ratio was significantly correlated with preoperative neurological status. CONCLUSIONS: An AOLF ratio greater than 33% is the most accurate diagnostic indicator of OLF-induced thoracic myelopathy. In cases of multiple-segment OLF, confirmation of cord signal change on MRI and an AOLF measurement will help determine the responsible segment. AOLF measurement will also improve the accuracy of diagnosis of OLF-induced thoracic myelopathy in cases of grade III or extended-type axial morphology. These slides can be retrieved under Electronic Supplementary Material.
Entities:
Keywords:
Area of ligamentum flavum; Optimal cutoff point; Ossification of ligamentum flavum; Thickness of ligamentum flavum; Thoracic myelopathy
Authors: H Sugimura; Y Kakitsubata; Y Suzuki; S Kakitsubata; S Tamura; O Uwada; T Kodama; T Yano; K Watanabe Journal: J Comput Assist Tomogr Date: 1992 Jan-Feb Impact factor: 1.826
Authors: Ning Lang; Hui Shu Yuan; Hong Lei Wang; Jing Liao; Man Li; Fu Xin Guo; Shan Shi; Zhong Qiang Chen Journal: Eur Spine J Date: 2012-09-15 Impact factor: 3.134
Authors: Guillermo Alejandro Ricciardi; Ignacio Gabriel Garfinkel; Gabriel Genaro Carrioli; Daniel Oscar Ricciardi Journal: Spinal Cord Ser Cases Date: 2021-07-09