MRI-Based Surgical Planning for Irreducible Subaxial Cervical Fracture-Dislocation With Bilateral Locked Facet Joints: A Retrospective Cohort Study.

OBJECTIVE

Subaxial cervical fracture-dislocation with bilateral locked facet joints represents a critical spinal injury. The management of this condition remains a subject of debate, particularly regarding the optimal surgical approach. This study aims to introduce a quantified indicator to guide surgical decision-making and to assess its safety in clinical practice.

METHODS

We retrospectively compared 62 patients treated according to the Spinal Cord Buffer Space (SCBS) criteria with 63 patients treated before SCBS was introduced. Briefly, SCBS was measured on preoperative MRI to quantitatively assess whether sufficient buffer space exists for the spinal cord, ensuring that a posterior reduction can be performed without causing iatrogenic spinal cord injury. The neural status was assessed with the American Spinal Injury Association (ASIA) impairment scale. Local sagittal alignment was evaluated at the dislocation level. Fisher's exact test and independent t-test were used to compare the parameters between the two groups.

RESULTS

Surgical planning according to SCBS is relatively safe, with no patient experiencing neurologic deterioration after operation (p = 0.014). Forty-two patients with preoperative grade E on ASIA had no postoperative changes. Thirteen patients with preoperative grade D recovered to grade E after surgery, while 7 patients remained grade D but reported improved limb function. In comparison, 63 patients were treated before SCBS was introduced. Among 47 patients with preoperative grade E, 43 patients remained grade E while 4 patients were downgraded to grade D. For 16 patients with preoperative grade D, there were 2 patients with postoperative grade C, 6 patients with postoperative grade D, and 8 patients with postoperative grade E. No loosening, displacement, or breakage of the implants was observed in both groups during the follow-up.

CONCLUSIONS

SCBS is a reliable and quantified indicator for surgical planning, and can significantly reduce the incidence rate of iatrogenic neurologic deterioration. For patients with a positive SCBS, posterior reduction can be safely performed. In contrast, for patients with a negative SCBS, anterior decompression should be prioritized.