PMC6287336_01
(a) Lateral radiograph showing moderately displaced odontoid fracture. (b and c) T2-weighted sagittal and axial MRI scans with no evidence of TAL injury
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F1
X-rays revealed a moderately displaced Anderson & D' Alonzo type-3 odontoid fracture; however, the atlanto-dens interval (ADI) was maintained (e.g., excluding sagittal atlantoaxial instability) [Figure 1a]. Magnetic resonance imaging (MRI) ruled out a ligamentous injury [Figure 1b and c].
Preoperative CT scan showing fracture pattern
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F2
On computed tomography (CT), the ADI was less than 3 mm, and the fracture line was oriented from the posterosuperior margin of the odontoid base to the anteroinferior of the body of the axis [Figure 2].
(a) Acceptable fracture reduction achieved after closed reduction in halo vest. (b) 4 weeks follow-up with well-aligned fracture
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F3
The fracture was managed with closed reduction and halo vest immobilization [Figure 3].
(a) Follow-up at 10 weeks. (b) Follow-up at 13 weeks
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F4
Thirteen weeks later, the fracture was fused on radiographs, and the halo vest was removed [Figure 4a and b].
(a) At 17 weeks, slightly increased ADI (3.18 mm) with C2-C6 cervical kyphosis of 33 . (b) At 5 months, large ADI of 9.18 mm showing frank instability
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F5
ADI (3.18 mm) [Figure 5a]. At 5 months, the patient developed frank atlantoaxial instability [e.g., widened ADI (9.18 mm) with cervical kyphosis (C2-C6 kyphosis = 33 ] [Figure 5b]. A posterior atlantoaxial C1-C2 fusion was performed utilizing sublaminar wires and iliac crest bone graft [Figure 6a].
(a) Postoperative AP and lateral radiographs after posterior fusion with sublaminar wiring and iliac crest bone graft. (b) 6 months follow-up AP and lateral radiographs showing fusion and C2-C6 cervical kyphosis of 41 . (c) 2 years follow-up showing resolution of some of kyphosis
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F6
At 5 months, the patient developed frank atlantoaxial instability [e.g., widened ADI (9.18 mm) with cervical kyphosis (C2-C6 kyphosis = 33 ] [Figure 5b]. A posterior atlantoaxial C1-C2 fusion was performed utilizing sublaminar wires and iliac crest bone graft [Figure 6a]. Solid fusion was achieved at 6 postoperative months [Figure 6b], and the 2-year follow-up showed some improvement in kyphosis (41  - 12  =33 ) [Figure 6c].