PMC9699864_01
CT images demonstrating C6 fracture with ossification of the posterior longitudinal ligament in addition to diffuse idiopathic skeletal hyperostosis with anterior osteophytosis. There is calcification of the longitudinal ligament from C2/3 down to T3. (a) Sagittal, (b) axial at C3 with island of ossification of posterior longitudinal ligament, and (c) CT scan axial at various levels from C2/3 till C6 #: CT scan axial at various levels from C2/3 till C6.
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F1
There was also suggestion of fracture of the ossified PLL at C3 level [Figures 1a-c].
MRI scan images showing that there is marked spinal canal stenosis from C2 down to C4 due to ossified posterior longitudinal ligament with intrinsic signal changes in the cord. (a) Sagittal scan of cervicothoracic spine, (b) images showing severe cord compression at C3/4 levels, and (c) at C2/3 level. The blue bar in figures 2b and 2c indicates the axial level. 2b axial at C3/4 disc level and 2c axial at C3 vertebral body level. This also corresponds to the area of maximal stenosis and cord compression.
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F2
There was also edema of posterior elements and muscles s/o recent fall and injury with evidence of C6 vertebral body fractures [Figures 2a-c].
(a and b) Standing X-ray 10 days after admission showing progressive kyphosis of 32  at C5/6 level. The yellow line in the figure indicates the lower end plate of superior and upper end plate of inferior vertebral bodies to measure Cobb's Angle.
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F3
However, subsequent standing AP and lateral X-rays showed 32  of local kyphosis without brace with reduction in the width of C6 body through the fracture line [Figures 3a and b].
Augmented motor-evoked potentials from the right (yellow) cross-over noted to the left (white).
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F4
APB, right ADM, and right abductor hallucis [Figure 4] in association with an augmented body jerk from the patient. An alert was given to the surgeon and the patient retested four min later.
Motor-evoked potential (MEP) abolished below C4, MEPs remained present bilaterally from trapezius, right (yellow), left (white) and abolished below from deltoid, extensor digitorumcommunis, abductor pollicis brevis, adductor digiti minimi, and abductor hallucis. Prone baseline MEPs are displayed in green.
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F5
On retest, MEPs were abolished below spinal level C4 [Figure 5] with preservation of trapezius MEPs.
Intraoperative CT scan images showing satisfactory wide decompression of cord at various levels.
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F6
To assess for any ongoing compression and hardware malposition, we performed an intraoperative CT which showed that the decompression was satisfactory and no evidence of spinal subluxation or screw misplacement [Figure 6].
Immediate postoperative MRI was done to rule out any compressive pathology. (a) MRI showed T2 intramedullary hyperintensity of the cord at C3 level which appeared expanded with a central syrinx. (b) Cord edema was noted at the C3 level. No evidence of epidural hematoma or other compressive lesion at the operative site indicating reperfusion injury. The blue bar in the figure indicates the axial images with maximal intramedullary hyperintensity of the cord and the reperfusion injury which corresponds to C3 level. (c) Axial at C3 and C3/4 Levels showing whitening of the cord (White Cord Syndrome).
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F7
No evidence of epidural hematoma or other compressive lesion was noticeable at the operative site [Figures 7a-c] and the diagnosis of WCS/RPI was established based on postoperative MRI findings as there were no other discernible causes of Quadriplegia.