Answer to Quiz No. 23/2015 dated 02 August 2015
Ossification of the posterior longitudinal ligament
Findings
CT - Long segment posterior longitudinal ligament thickening and ossification from lower C2 to upper T1 level causing canal compromise
MRI - There is thick bar like ossification of the PLL extending from the C2-7 level with resulting spinal canal compromise and mild indentation of the cord from C3 to C6 level
Mild multilevel degenerative changes in the spine with disc desiccations and disc osteophyte complexes
Discussion
Ossification of the posterior longitudinal ligament is a condition of abnormal calcification of the posterior longitudinal ligament. The most common location is at the cervical spine region. The spinal cord can be compressed by this lesion, which can cause neurological deficits.There are many diseases associated with OPLL, such as diffuse idiopathic skeletal hyperostosis, ankylosing spondylitis, and other spondyloarthropathies.Clinical presentation depends on the size of the OPLL, spinal canal diameter, and range of motion of the spine.May present with neurological deficits such as radiculopathy, myelopathy, and in severe cases, bowel and bladder symptoms. Based on lateral plain radiography, cervical OPLL can be classified into 4 types : continuous, segmental, mixed, or circumscribed type. The most reliable diagnostic sign on radiography and CT is the characteristic dense, linear radiopaque strip of 1-5 mm thickness, paralleling the posterior vertebral body margins. Commonly, a radiolucent zone is interspaced between the ossified ligament and vertebral body, corresponding to the unossified deeper ligamentous layers. Axial CT shows characteristic mushroom or hill shape MRI may show OPLL as a high signal intensity (fatty marrow) or hypointense band (fibrous replacement of fatty marrow). The length of this ossification may be only one vertebral body width or traverse a number of contiguous segments
References
1. Hida K, Iwasaki Y, Koyanagi I, Abe H: Bone window computed tomography for detection of dural defect associated with cervical ossified posterior longitudinal ligament. Neurol Med Chir (Tokyo) 37:173–176, 1997
2. Saetia K, Cho D, Lee S et-al. Ossification of the posterior longitudinal ligament: a review. Neurosurg Focus. 2011;30 (3): E1
3. Essentials of skeletal radiology. Yochum and Rowe. 3rd edition
Contributed By:
Dr. Susanna K Jose, Dr. Shyjumon George, Dr. Deepa Korula, Dr. Jacob Therakathu, Dr. Koyeli M
Christian Medical College, Vellore
Findings
CT - Long segment posterior longitudinal ligament thickening and ossification from lower C2 to upper T1 level causing canal compromise
MRI - There is thick bar like ossification of the PLL extending from the C2-7 level with resulting spinal canal compromise and mild indentation of the cord from C3 to C6 level
Mild multilevel degenerative changes in the spine with disc desiccations and disc osteophyte complexes
Discussion
Ossification of the posterior longitudinal ligament is a condition of abnormal calcification of the posterior longitudinal ligament. The most common location is at the cervical spine region. The spinal cord can be compressed by this lesion, which can cause neurological deficits.There are many diseases associated with OPLL, such as diffuse idiopathic skeletal hyperostosis, ankylosing spondylitis, and other spondyloarthropathies.Clinical presentation depends on the size of the OPLL, spinal canal diameter, and range of motion of the spine.May present with neurological deficits such as radiculopathy, myelopathy, and in severe cases, bowel and bladder symptoms. Based on lateral plain radiography, cervical OPLL can be classified into 4 types : continuous, segmental, mixed, or circumscribed type. The most reliable diagnostic sign on radiography and CT is the characteristic dense, linear radiopaque strip of 1-5 mm thickness, paralleling the posterior vertebral body margins. Commonly, a radiolucent zone is interspaced between the ossified ligament and vertebral body, corresponding to the unossified deeper ligamentous layers. Axial CT shows characteristic mushroom or hill shape MRI may show OPLL as a high signal intensity (fatty marrow) or hypointense band (fibrous replacement of fatty marrow). The length of this ossification may be only one vertebral body width or traverse a number of contiguous segments
References
1. Hida K, Iwasaki Y, Koyanagi I, Abe H: Bone window computed tomography for detection of dural defect associated with cervical ossified posterior longitudinal ligament. Neurol Med Chir (Tokyo) 37:173–176, 1997
2. Saetia K, Cho D, Lee S et-al. Ossification of the posterior longitudinal ligament: a review. Neurosurg Focus. 2011;30 (3): E1
3. Essentials of skeletal radiology. Yochum and Rowe. 3rd edition
Contributed By:
Dr. Susanna K Jose, Dr. Shyjumon George, Dr. Deepa Korula, Dr. Jacob Therakathu, Dr. Koyeli M
Christian Medical College, Vellore
