Clinical application of cortical bone screw technique in elderly patients with lumbar degenerative diseases

Abstract

Objective To investigate the clinical outcome of application of transpedicular cortical bone trajectory (CBT) screw fixation in lumbar degenerative diseases. Methods A retrospective research based on the collection of 53 lumbar degenerative disease cases, who underwent posterior spinal canal decompression and interbody fusion since August 2016 to May 2018, in 920 hospital of the PLA Joint Logistic Unit. 23 cases were treated with CBT screw technique and 30 cases were treated with traditional pedicle screw technique. The operation time, intraoperative blood loss, VAS score, JOA score and improvement rate and postoperative functional restoration, clinical complications has been observed in the two groups for comprehensive evaluation of clinical efficacy. Results All patients received an average of (12±4) months (3-18 months) follows up. During the screw placement process, no insufficient holding of screws, isthmus or pedicle cleft palate occurred, blood vessel and nerve damage caused by the screw placement process as well. The symptoms of the two groups showed various degree of improvement. Postoperative JOA scores (CBT group: 23.7±2.3, pedicle screw group: 23.9±2.0) and VAS scores (CBT group: 1.2±0.7, pedicle screw group: 1.3±0.8) were improved compared with preoperative (CBT group: 5.3±1.2, pedicle screw group: 5.4±1.2). The operation time was compared between the two groups (CBT group: single segment was 2.0±0.3 h, double segment was 2.8±0.4 h. pedicle screw group: single segment 2.1±0.3 h, double segment 3.0±0.2 h), postoperative VAS score (CBT group: 1.2±0.7, pedicle screw group: 1.3±0.8) and JOA scores (CBT group: 23.7±2.3 points, pedicle screw group: 23.9±2.0 points) had no statistically significant difference, but the intraoperative blood loss of the CBT screw group (single segment: 297±48 ml, double segment: 367±41 ml) was less than the pedicle screw group (single segment: 347±44 ml, double segment: 427±46 ml)(t=-3.209, t=-2.692, P<0.05). No postoperative adverse events such as loose screws, tail screw detachment, broken screws loss of intervertebral space, and intervertebral cage displacement have been observed. Conclusion CBT screw for the treatment of lumbar degenerative disease is a less trauma, faster postoperative recovery, safe and reliable screw placement method. Key words: Pedicle screws; Spine; Lumbar Vertebrae