PMC7210916_01
(a) Lateral radiograph of cervical spine with anterior translation of C1 over C2 and fractured and anteriorly displaced dens.(b) Sagittal view computed tomography (CT) showing Type 2 odontoid fracture with anterior displacement and angulation. (c and d) Sagittal cuts through the facet joints showing locked right and left facet joints. (e) CT angiogram done to see anomalous vertebral artery anatomy showing exposed superior articular facets of C2.
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F1
Onradiological evaluation, the patient was diagnosed to have anteriorly displaced Type 2 odontoid fracture with complete dislocation of atlas over axis such that bilateral atlas inferior facets were locked anterior of axis superior facets (Fig. 1).
Post-operative lateral radiographs of cervical spine showing complete reduction of atlas over axis following posterior instrumentation and joint remodeling.
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F2
C1 lateral mass screws were placed bilaterally by carefully retracting C2 ganglion and nerve root caudally (Fig. 2 and 3). C2 pars screw were placed, and high-speed burr was used to burr out overriding superior facets of axis after retracting the nerve root cephalad.
(a-c) Post-operative computed tomography scans sagittal views through facet joints and dens showing completely reduced inferior facets of C1 over superior facets of C2 vertebra and dens reduced over C2 body. (d and e) Axial cuts through C1 and C2 showing screw placement through C1 lateral mass and C2 pars.
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F3
C1 lateral mass screws were placed bilaterally by carefully retracting C2 ganglion and nerve root caudally (Fig. 2 and 3). C2 pars screw were placed, and high-speed burr was used to burr out overriding superior facets of axis after retracting the nerve root cephalad.
Schematic diagram showing facet joint remodeling and manipulation helping in subsequent reduction through posterior approach. (a)Locked facets of C1 over C2 (spondyloptosis) and (b) C1 lateral mass and C2 pars screws in place. (c) Shaded part of C2 superior facet is the overhanging part preventing reduction by routine maneuvers needing burring or osteotomizing composing the step of "joint remodeling." (d) Application of forces in the direction of arrowheads obtained, namely intraoperative cervical traction and gradual neck extension to bring about reduction. (e) Application of compressive forces along the cervical rods to bring about fusion.
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F4
Intraoperatively axial traction and careful neck extension manoeuvre was done to achieve reduction, and rods were connected (Fig. 4).