Diagnostic value of the fat deposition between the base of spinous process and dura mater for occult pars interarticularis defect
10.3760/cma.j.cn121113-20220509-00259
- VernacularTitle:棘突基底部与硬膜之间脂肪沉积对隐匿性腰椎峡部裂的诊断价值
- Author:
Na ZHAO
1
;
Zhi HUANG
;
Xing ZHAO
;
Shunwu FAN
Author Information
1. 浙江大学医学院附属邵逸夫医院骨科，杭州 310016
- Keywords:
Lumbar vertebrae;
Dura mater;
Magnetic resonance imaging
- From:
Chinese Journal of Orthopaedics
2022;42(18):1230-1235
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To observe the diagnostic value of the fat deposition between the base of spinous process and dura mater in the mid-sagittal T1WI image of lumbar spine MRI for occult pars interarticularis defect, and to discuss the its mechanism.Methods:From January 2015 to December 2019, 32 cases with low back and leg pain were confirmed by MR scanning that the fat deposition between the dura mater and the base of spinous process with or without fat deposition in the rest of the spinal canal, including 20 males and 12 females were included. The age was 28.5±6.2 years (range, 18-57 years). Spiral CT scanning and multiplanar reconstruction were used to judge the integrity of the isthmus, levels of defect, and unilateral or bilateral defect. The observation of the above imaging data were independently completed by two orthopaedic doctors.Results:In 32 patients with epidural fat deposition, there were 24 patients with occult isthmus and 8 patients with simple epidural lipomatosis, confirmed by spiral CT multiplanar reconstruction. In 24 cases of isthmus, there were 18 males and 6 females. The age was 27.3±5.3 years (range, 18-45 years). There were 2 cases between the base of L 4 spinous process and dura mater, and 22 cases between the base of L 5 spinous process and dura mater, without fat deposition in the rest of the spinal canal. All 24 cases were bilateral isthmus, and the anterior and lateral X-ray could not be diagnosed. All patients complained of different degrees of mechanical low back pain. 6 cases with disc herniation, and no case with intermittent claudication. In 8 patients with simple epidural lipomatosis, there were 2 males and 6 females. The age ranged from 32 to 55 years, with an average of 38.4±6.7 years. There were 4 cases between the base of L 3 spinous process and dura mater, 3 cases between the base of L 4 spinous process and dura mater, and 1 case between the base of L 5 spinous process and dura mater. All 8 patients had fat deposition between the lamina and dura mater in the upper and/or the same level, and the dura mater was compressed by the fat. 8 patients complained of different degrees of low back pain without tenderness. 2 cases with disc herniation, and one case with intermittent claudication. Conclusion:The fat deposition sign between the base of spinous process and dura mater has certain specificity for occult lumbar spondylolysis. As an effective supplement to the discontinuous bone signal of spondylolysis, it is helpful to the early diagnosis of spondylolysis.
