Application of cortical bone trajectory screw and sacral alar screw internal fixation for surgical treatment of lumbar adjacent segment degeneration

Abstract

Objective: To explore the application of cortical bone trajectory screw (CBTS) and sacral alar screw (SAS) internal fixation in the treatment of lumbar adjacent segment degeneration (ASD) and evaluate its clinical effect. Methods: Data of 24 patients who were diagnosed with ASD and treated by CBTS or SAS in Beijing Chaoyang Hospital were retrospectively reviewed. There were 14 males and 10 females with a mean age of (67.9±8.2) years. The patients were followed-up for (2.6±0.4) years. Perioperative parameters including operation time, intraoperative blood loss and postoperative time on the ground were counted. All patients were followed-up for at least 2 years. Visual analogue scale (VAS) and the Oswestry disability index (ODI) were compared between pre-operation and at the last follow-up. The internal fixation-related complications, pseudarthrosis and adjacent re-degeneration were evaluated in the follow-up. Results: There were 14 proximal ASD patients, 8 distal ASD patients, 1 both ends ASD patient and 1 ASD patient in between the fusion surgeries. Bone mineral density (BMD) T score of the adjacent vertebrae was -1.98±0.91 on average. The ASD patients were re-operated with CBTS and SAS internal fixation technique. A small incision was made in the revision surgery and the original fixation was not completely cut open and removed. The mean operation time was (125±36) min, mean blood loss was (85±33) ml. The postoperative ambulation time was (3.1±1.9) days, and the hospitalization time was (9.0±2.6) days. Before the operation, the average VAS (back pain) score was 5.2±1.0, the average of VAS (leg pain) score was 6.8±1.9 and ODI was 56.6%±12.8%. VAS score was reduced to 1.4±0.6 (waist pain) and 0.9±0.4 (leg pain). ODI was improved to 13.8%±6.3%. All the difference between preoperative and the last follow-up was statically significant (all P<0.01). No internal fixation failure, pseudarthrosis and adjacent re-degeneration were observed in the final follow-up. Conclusion: The application of CBTS and SAS internal fixation techniques in the surgical treatment of lumbar ASD has the advantages of less trauma, faster postoperative recovery, reliable internal fixation, and fewer complications, especially in patients with low bone mineral density.