Efficacy of posterior decompression and dynamic neutralization system for treatment of lumbar degenerative disease

Abstract

Objective To analyze the clinical efficacy of posterior decompression and dynamic neutralization system (Dynesys) for treatment of lumbar degenerative disease. Methods A total of 97 patients with lumbar degenerative diseases, who underwent posterior spinal decompression and Dynesys fixation of vertebral pedicle between May 2011 and September 2013 were included in the study, including 54 males and 43 females (aged 29 to 56 years old, median age 38 years old; 63 cases of single segment, 34 cases of double segments, Using Oswestry disability index (ODI) , visual analogue scale (VAS) and Japan Orthopaedic Society (JOA) scoring to evaluate the clinical efficacy. According to the imaging data of the preoperative and the last follow-up, the changes of the intervertebral height of surgical segments, vertebral range of motion (ROM) of surgical and adjacent segments, and intervertebral disc degeneration were determined. The intervertebral angles of anterior-posterior lateral and dynamic lumbar X-ray were measured, and the ROM of the intervertebral angles was calculated. The average calibrated disc signal (CDS) of surgical segments was calculated by lumbar magnetic resonance imaging (MRI). The repaired condition of intervertebral disc was evaluated. Results The length of follow-up was 24 to 52 months, and the median length of follow -up was (31.21 ± 7.63) months. There were no serious complications and recurrence of repaired cases. Low back pain was aggravated in 3 patients at 3 months after the operation, and was relieved after conservative treatment. The VAS score and ODI of the last follow -up after the operation were significantly reduced than those before the operation (P 0.05). Fifty-three patients received lumbar MRI reexamination at the last preoperative follow-up [mean age (37.83±11.56) years old, a total of 66 segments], and the average CDS of surgical segments was improved from 39.51%±10.76% to 47.35%±13.61% (P<0.01). Conclusion The length of follow-up was 24 to 52 months, and the median length of follow-up was (31.21±7.63) months. There were no serious complications and recurrence of repaired cases. Low back pain was aggravated in 3 patients at 3 months after the operation, and was relieved after conservative treatment. The VAS score and ODI of the last follow-up after the operation were significantly reduced than those before the operation (P 0.05). Fifty-three patients received lumbar MRI reexamination at the last preoperative follow-up [mean age (37.83±11.56) years old, a total of 66 segments] , and the average CDS of surgical segments was improved from 39.51%±10.76% to 47.35%±13.61% (P<0.01). Key words: Lumbar vertebrae; Intervertebral disc; Treatment outcome; Dynamic neutralization system