A single-stage posterior approach with open reduction and pedicle screw fixation in subaxial cervical facet dislocations

Abstract

<jats:sec> <jats:title>OBJECT</jats:title> <jats:p>The optimal treatment for cervical facet dislocations is controversial, but the generally accepted process recommends an initial closed reduction with the next step determined according to the success of the closed reduction and the presence of traumatic disc herniation. This study aimed to show the efficacy of a posterior approach performed with an open reduction and pedicle screw fixation with removal of disc particles, if required, in the management of subaxial cervical dislocations.</jats:p></jats:sec> <jats:sec> <jats:title>METHODS</jats:title> <jats:p>Between March 2012 and September 2013, 21 consecutive patients with cervical facet dislocations were enrolled. The affected levels were as follows: 4 at C3–4; 2 at C4–5; 5 at C5–6; and 10 at the C6–7 level. Seven patients had traumatic disc herniations. Closed reduction was not attempted; a prompt posterior cervical surgery was performed instead. After open reduction, pedicle screw fixation was performed. In cases with traumatic disc herniation, herniated disc fragments were excised via a posterolateral approach and successful decompressions were determined by postoperative MRI studies. Clinical outcomes were assessed using the American Spinal Injury Association (ASIA) grading system. Radiological outcomes were assessed by comparing the degree of subluxation and the angle of segmental lordosis between pre- and postoperative CT scans.</jats:p></jats:sec> <jats:sec> <jats:title>RESULTS</jats:title> <jats:p>All patients improved neurologically. The mean segmental angles improved from 7.3° ± 8.68° to −5.9° ± 4.85°. The mean subluxation improved from 23.4% ± 16.52% to 2.6% ± 7.19%. Disc fragments were successfully removed from the 7 patients with herniated discs, as shown on MRI.</jats:p></jats:sec> <jats:sec> <jats:title>CONCLUSIONS</jats:title> <jats:p>Open reduction followed by pedicle screw fixation or posterolateral removal of herniated disc fragments is a good treatment option for cervical facet dislocations.</jats:p></jats:sec>

An Assessment of the Medial Angle of Inserted Subaxial Cervical Pedicle Screw during Surgery: Practical Use of Preoperative CT Scanning and Intraoperative X-rays

“…The accuracy rate was 94.6% (368/389) and the results were similar to those we reported previously. 8,9) …”

“…1–6) According to previous reports, most pedicle perforations occur in the lateral direction, which might cause injury to the vertebral artery (VA). 7–9) These observations indicate that the most important factor for CPS is creating a sufficient medial angle. To identify a sufficient medial angle for a CPS, we have focused previously on the interpretation of intraoperative anterior–posterior (AP) radiographical images after screw insertion.…”

“…A more detailed technical description including our abnormal ball tip palpation technique was described in the previous article. 8,9) …”

“…In the axial plane, lateral wall perforation was defined according to the following definition: Grade 1, perforation into the VA foramen with the external edge of the screw deviated out of the lateral pedicle, but not violating the largest diameter of the VA foramen; Grade 2, the screw laterally deviated into the largest diameter of the VA foramen, but not completely occluding it; or Grade 3, complete occlusion of VA foramen. 8,9) …”

“…Because we usually used 28–30 mm length screws in the majority of patients in previous series, the above recommendation was useful. 8,9) However, when smaller length screws below 28 mm were used, due to the CPS with the maximally permissible small medial angle, the presence of a previous anterior instrument, an anterior column unstable fracture, the lack of enough longer screw preparation, or small-sized vertebra, we couldn’t apply the above suggestion. In addition, not every surgeon uses a 28–30 mm length screw like ours.…”