PMC10353903_01
Computerized tomographic image of the cervical spine on the midsagittal plane. Note the dorsally displaced axis and the sclerotic end plates at the C5-C6 interface.
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fig1
The adjacent endplates were sclerotic and mildly irregular (Figure 1).
Immediate postoperative CT of the cervical spine on the sagittal plane.
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A postoperative CT confirmed appropriate reduction of the atlantoaxial joint and placement of screws with PMMA (Figure 2).
Recheck CT six months postoperatively. (a) Note the ventral displacement of the cranial-most screw on the left aspect of the body of C1. (b) Note the progressive collapse of the C5-6 disc space.
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C5-6 disc space and ventral displacement of the cranial end plate and dorsal lamina of C6 relative to C5 (Figure 3). Clinically, the dog was neurologically improved with only mild tetraparesis and ataxia noted at that time.
Digital radiographs of the cervical spine in lateral (a) and dorsal (b) views. Note the caudoventrally displaced implant.
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Cervical radiographs revealed caudoventral migration of the implant and regional left-sided soft tissue swelling (Figure 4).
Open draining tract on the left lateral aspect of the neck.
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Two weeks later, the dog was reexamined for the development of a draining tract associated with the cervical mass and dysphagia (Figure 5).
CT of the cervical spine, dorsal view. Note the draining tract on the left lateral aspect of the implant.
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The neurologic examination was normal, and the dog was transferred to the neurology service for a cervical CT scan which confirmed that the PMMA and screws had migrated ventrally and were no longer in contact with C1-C3 (Figure 6).
(a) Upon clearing the surrounding fibrous capsule, the implant was identified. (b) Removal of the explant. (c) Pin demonstrating the communication between the external wound and draining tract to the region of the implant.
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Gelpi retractors were placed at the cranial and caudal aspects of the implant (Figure 7).
Lateral cervical radiograph immediately postoperative explant. Note the normal alignment between C1-C2 is maintained.
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fig8
Postoperative radiographs were performed, and there was no evidence of malalignment (Figure 8).