Stage I anterior cervical reduction, decompression, interbody fusion and internal fixation of single-segment lower cervical injury of AO type C subtype F4 / 中华创伤杂志

ABSTRACT

Objective:To investigate the efficacy of stage I anterior cervical reduction, decompression, interbody fusion and internal fixation of single-segment lower cervical injury of AO type C subtype F4.Methods:A retrospective case series study was made on 45 patients with single-segment lower cervical injury of AO C type F4 subtype admitted to Zhengzhou Orthopedic Hospital from January 2012 to December 2019. The study included 31 males and 14 females with the age of (48.5±3.7)years (range, 23-78 years). Segment of injury was located at C 4/5 in 11 patients, at C 5/6 in 19, and at C 6/7 in 15. Under general anesthesia, all patients (16 unilateral injury and 29 bilateral injury) underwent stage I anterior cervical reduction, decompression, interbody fusion and internal fixation within 24 hours after injury. The interbody fusion methods included autogenous iliac bone in 28 patients and cervical fusion cage in 17. The operation time, blood loss, reduction time and correction rate of zygapophysial joints, postoperative complications and incision healing were analyzed. The height of cervical intervertebral space and Cobb angle were measured through X-ray of lateral cervical vertebrae before operation and3 months after operation to assess the cervical physiological curvature. The type of injury was clarified according to Lenke classification through coronal and sagittal CT scanning to determine the intervertebral bone graft fusion rate. The intraspinal spinal cord decompression was observed through MRI. The nerve function was assessed before operation and 3 months after operation using American Spinal Injury Association (ASIA) scale and Japanese Orthopedic Association (JOA) score, and the improvement rate was measured. Results:All the patients were followed up for (6.1±3.6)months (range, 3-9 months). The operation time was (55.1±8.2)minutes (range, 40-75 minutes), and intraoperative blood loss was (45.2±5.3)ml (range, 40-80 ml). The Zygapophysial joint reduction took (2.1±0.5)minutes (range, 1.5-3.0 minutes), with a success rate of 100%. Surgical procedures were performed with no postoperative complications such as aggravated spinal cord injury, large vascular injury or esophageal lesion. All the patients obtained Class I incision healing at first stage. The height of cervical intervertebral space was improved from preoperative (3.3±0.6)mm to (4.9±0.8)mm at postoperative 3 months ( P<0.05). The Cobb angle was increased from preoperative (-4.6±3.6)° to (6.5±2.1)° at postoperative 3 months ( P<0.01). According to Lenke classification, the intervertebral body fusion was good at postoperative 3 months, including Grade A in 41 patients and Grade B in 4. The rest of the patients showed varying degrees of neurological recovery according to ASIA scale, except for 6 patients with ASIA Grade A. The JOA score was improved from preoperative (7.4±2.3)points to (15.0±3.2)points at postoperative 3 months ( P<0.05), with the improvement rate of (73.3±17.6)%. Conclusion:For stage I anterior cervical reduction, decompression, interbody fusion and internal fixation of single-segment lower cervical injury of AO type C subtype F4, early surgical decompression is needed so as to reduce the perched facet or dislocated zygapophyseal joints and effectively improve the cervical spinal cord function.