後頚椎脱臼における回旋性後弯牽引整復法（EKD-RT）による固定関節整復術

To evaluate the effectiveness of the single-stage anterior eccentric kyphotic distraction reduction technique (EKD-RT) for treating lower cervical dislocation with locked facet joints, assessing its reduction success rate, neurological improvement, and safety.

A retrospective analysis was conducted on 67 patients with lower cervical dislocation and locked facet joints (21 unilateral, 46 bilateral) treated between January 2015 and January 2024. There were 39 males and 28 females, with an average age of 49.5 years (range, 22-75 years). The injured segments included C _{3, 4} in 4 cases, C _{4, 5} in 13 cases, C _{5, 6} in 22 cases, and C _{6, 7} in 28 cases. The interval between injury and admission ranged from 2 hours to 2 days (mean, 5.6 hours). Preoperative Frankel grading included grade A in 9 cases, grade B in 28 cases, grade C in 17 cases, grade D in 11 cases, and grade E in 2 cases. Japanese Orthopaedic Association (JOA) score was 7.0±1.4. All patients underwent single-stage anterior cervical discectomy and fusion. Following discectomy at the dislocated level, the EKD-RT was applied to unlock and reduce the locked facet joints, followed by internal fixation. Operation time, blood loss, reduction success rate, and complications were recorded. Interbody fusion status was evaluated using Bridwell criteria. Neurological status was assessed pre- and post-operatively using Frankel grading. Spinal cord function was scored using the 17-point JOA score, and the improvement rate was calculated.

Successful reduction of the locked facet joints achieved in all cases. The operation time was 41-85 minutes (range, 63.3 minutes), and intraoperative blood loss was 50-360 mL (range, 125.0 mL). Complications included cerebrospinal fluid leakage in 2 cases; no severe complications such as major vascular injury or recurrent laryngeal nerve injury occurred. All patients were followed up 12-24 months (mean, 17.9 months). At last follow-up, radiological examination confirmed interbody fusion in all patients, with no implant failure or migration. The Frankel grading included grade A in 3 cases, grade B in 9 cases, grade C in 13 cases, grade D in 16 cases, and grade E in 26 cases; the JOA score reached 13.7±2.3; all of which significantly improved compared to preoperative levels ( P<0.05). The improvement rate of JOA score was 66.1%±24.7%.

The EKD-RT is an effective surgical approach for lower cervical dislocation with locked facet joints. It enables safe and efficient reduction of the locked facet joints via a single incision, resulting in significant neurological improvement with a low complication rate.