PMC5646301_01
Reconstructed computed tomography (CT) and magnetic resonance images of sacrum at first hospital presentation. (a) Sagittal reconstructed CT image. (b) Axial CT image at S2-3 level. (c) Sagittal plane on a T2-weighted image. (d) Axial plane on a T2-weighted image. Fractures in the sacral vertebral body (white arrow) and lamina (white arrowhead) can be observed (a). Radiological findings were consistent with a Roy-Camille classification type I fracture. Sacral canal was narrowed by the protruding sacral vertebral body (black arrow) (b). This radiological finding was diagnosed as a Denis Zone III sacral fracture. Sagittal and axial plane on T2-weighted images showed that sacral nerves were compressed by the vertebral body (white arrow) (c, d).
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fig1
Sagittal reconstructed computed tomography (CT) revealed that both sacral lamina and vertebral body were fractured and displaced into the sacral canal at the S2-3 level (Figure 1(a)). Axial reconstructed CT revealed that sacral canal was narrowed by the protruding sacral vertebral body (Figure 1(b)). Sagittal and axial plane magnetic resonance imaging (MRI) revealed that sacral nerves were compressed by the angulated sacral vertebral body and lamina on T2-weighted images (Figures 1(c) and 1(d)).
Schemata of sacral kyphotic angle. We defined the sacral kyphotic angle as the angle between the line from the sacral promontorium to the anterior edge of the proximal fracture fragment and the line from the anterior edge of the distal fracture fragment to the caudal edge of the fourth sacral body in a midline sagittal reconstructed computed tomography image.
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The sacral kyphotic angle was 107 degrees (Figure 2). The sacral kyphotic angle was 105 degrees and the sacral kyphotic deformity did not deteriorate (Figure 2).
Postoperative three-dimensional computed tomography (CT) and schemata. (a) Three-dimensional CT. (b) Operation schema. Three-dimensional CT showing S2-3 laminectomy and S2AI screws and rods (red color) (a). Surgical method (b): we performed S2-3 laminectomy and then passed ultrahigh molecular weight polyethylene (UHMWPE) cables from the central laminectomy area to the third posterior sacral foramina. We inserted S2AI screws and connected the rods, after which the UHMWPE cables were tightened to the rods.
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Finally, we tightened the UHMWPE cables to the rods (Figures 3(a) and 3(b)).
Follow-up sagittal reconstructed computed tomography (CT) images of the sacrum. (a) One-month sagittal reconstructed CT image. (b) Three-month sagittal reconstructed CT image. (c) One-year sagittal reconstructed CT image. The second-third sacral vertebral body exhibited a high-density area (a). The high-density area in the second-third sacral vertebral body increased (b). The second-third sacral vertebral body had united without any displacement (c).
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One- and 3-month postoperative follow-up sagittal reconstructed CT revealed high-density areas in the second and third sacral vertebral bodies (Figures 4(a) and 4(b)). One-year postoperative follow-up sagittal reconstructed CT revealed that the sacral vertebral bodies had united without any displacement (Figure 4(c)).
PMC5646301_02
Schemata of sacral kyphotic angle. We defined the sacral kyphotic angle as the angle between the line from the sacral promontorium to the anterior edge of the proximal fracture fragment and the line from the anterior edge of the distal fracture fragment to the caudal edge of the fourth sacral body in a midline sagittal reconstructed computed tomography image.
CRIOR2017-7396564.002.jpg
PMC5646301_02_CRIOR2017-7396564.002.jpg
fig2
The sacral kyphotic angle was 107 degrees (Figure 2). The sacral kyphotic angle was 105 degrees and the sacral kyphotic deformity did not deteriorate (Figure 2).
Reconstructed computed tomography (CT) and magnetic resonance image of sacrum at first hospital presentation. (a) Sagittal reconstructed CT image. (b) Axial CT image at S2 level. (c) Sagittal plane on a T2-weighted image. (d) Axial plane on a T2-weighted image. Displaced fractures in the second sacral vertebral body (white arrow) can be observed (a). This radiological finding was consistent with a Roy-Camille classification type II fracture. Sacral canal was narrowed by the protruding sacral vertebral body (black arrow) (b). This radiological finding was diagnosed as a Denis Zone III sacral fracture. Sagittal and axial planes on T2-weighted images showed that sacral nerves were compressed by the vertebral body (white arrow) (c, d).
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fig5
Sagittal reconstructed CT revealed that the second sacral vertebral body was fractured and displaced into the sacral canal (Figure 5(a)). Axial reconstructed CT confirmed that sacral canal was narrowed by the protruding sacral vertebral body (Figure 5(b)). Sagittal and axial plane MRI revealed that sacral nerves were compressed by the angulated sacral vertebral body and lamina on T2-weighted images (Figures 5(c) and 5(d)).
Postoperative three-dimensional computed tomography (CT) and schema. (a) Three-dimensional CT. (b) Operation schema. Three-dimensional CT showing S1-3 laminectomy, S1 pedicular screws, S2AI screws, and rods (red color) (a). Operation method (b): we performed S1-3 laminectomy. We then passed ultrahigh molecular weight polyethylene (UHMWPE) cables from the central laminectomy area to the third and fourth posterior sacral foramina. We inserted S1 pedicular screws and S2AI screws and connected the rods, following which the UHMWPE cables were tightened to the rods.
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fig6
Finally, we tightened the UHMWPE cables to the rods (Figures 6(a) and 6(b)).
Follow-up sagittal reconstructed computed tomography (CT) images of the sacrum. (a) One-month sagittal reconstructed CT image. (b) Three-month sagittal reconstructed CT image. (c) One-year sagittal reconstructed CT image. The second sacral vertebral body was not displaced (a). The second sacral vertebral body contained a high-density area (b). The second sacral vertebral body had united without any displacement (c).
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fig7
One- and three-month postoperative follow-up sagittal reconstructed CT revealed a high-density area in the second sacral vertebral body (Figures 7(a) and 7(b)). One-year postoperative follow-up sagittal reconstructed CT revealed that the second sacral vertebral body had united without any displacement (Figure 7(c)).