Application of cortical bone trajectory screw in the revision of lumbar disease

Objective To evaluate and discuss the clinical outcomes and advantages of midline lumbar fusion (MIDLF) with cortical bone trajectory (CBT) screw in the reoperation of lumbar disease. Methods From June 2014 to August 2015, a total of 12 patients, 5 male and 7 female with an average age of 68.5±5.6 years old (ranged from 56-76 years). The indications of reoperation including: 5 cases of adjacent segment disease, 2 cases of discogenic back pain after lumbar dynamic stabilization, 5 cases of recurrent disc herniation. The interval time from primary surgery to second surgery was 3-9.5 years (average 6.0±2.0 years). Disease level: L2/3 1 case, L3/4 2 cases, L4/5 7 cases, L5/S1 2 cases. All cases were got the X-ray, CT scan and MRI examination before surgery. The operative duration, blood loss, complications were all evaluated. Back and leg pain were recorded by visual analogue scale (VAS) scores. Functional recovery was evaluated by Oswestry disability index (ODI). Results Operative time was 110-210 min, and mean duration was (158.3±36.4) min. Blood loss was 150-310 ml, and mean loss was (231.7±51.0) ml. There was 1 case of cerebrospinal fluid leakage which treated with pillow supine for 1 week after surgery, and strengthened the prevention of antibiotics, incision healing, with no headache and other low intracranial pressure of dizziness, the remaining patients had no intraoperative and postoperative complications. The time of follow-up was 12-25 months, with an average of (17.9±4.6) months. The back pain of VAS score of preoperative was 3.9±1.4, and the last follow-up was 1.9±0.5, the difference was statistically significant (t=4.506, P=0.001). The VAS score of preoperative leg pain (4.9±1.4) was significant higher than the last follow-up (1.2±0.6, t=9.134, P=0.000). The preoperative ODI was 32.9±3.4, and last follow-up was 13.3±3.2, and the difference was statistically significant (t=15.002, P=0.000). Conclusion MIDLF was applicable with good clinical outcome and technical advantages in current cases, and it might be a choice of reoperation for lumbar disease. Key words: Spinal fusion; Internal fixators; Reoperation