Application of Dynesys dynamic fixation with small incision intramuscular approach in the treatment of lumbar disc herniation

English Keywords:Lumbar disc herniation  Dynamic internal fixation  Dynesys system  Intermuscular approach

English Abstract:

  【Abstract】 Objectives: To observe the feasibility and clinical efficacy of posterior small incision in the treatment of lumbar disc herniation with bilateral intermuscular approach Dynesys implantation and discectomy. Methods: Retrospective analysis of clinical and imaging data of 25 patients with lumbar disc herniation treated with Dynesys implantation and discectomy through bilateral intermuscular approach from April 2014 to April 2016. Another 25 patients with lumbar disc herniation treated with conventional exposure were selected for comparison. Incision length, operative time, intraoperative blood loss, and complications were recorded. The VAS score of low back and leg pain, ODI score preoperatively, 3 days and 3 months postoperatively, and at final follow-up were collected. Perioperative serum C-reactive protein was measured. The motion of surgical segment and proximal adjacent segment, and the disc height of surgical segment were measured at follow-up. The residual rate of multifidus muscle was measured. Results: Complete follow-up was achieved for patients in both groups, and the follow-up period was 30-54 months. The average follow-up time was 35.5±7.3 months in the small incision group, and 34.8±5.1 months in the control group. There was no significant difference in the preoperative VAS score and ODI score between the two groups. At final follow-up, both were significantly improved(P<0.05) without significant difference between the two groups(P<0.05). In the operation time, intraoperative blood loss, incision length, and postoperative drainage volume, the small incision group were better than those of the conventional exposed group(P<0.05). The postoperative low back pain VAS, leg pain VAS, and ODI of the two groups were significantly alleviated than preoperation(P<0.05). Three days after surgery, the VAS score of low back pain in small incision group was better than that of the conventional exposed group(P<0.05). The CRP levels of patients in the small incision group at 3 and 5 days after surgery were lower than those in the conventional exposure group(P<0.05). There was still some motion on surgical segment at final follow-up without cases of screw broken or loose. The residual rate of multifidus muscle in the decompression side of the small incision group was higher than that of the conventional exposed group(P<0.05). The height of the intervertebral space increased at 3 months after the operation, but returned to the preoperative level at final follow-up(P<0.05). There were 2 cases of delayed healing in the small incision group and 1 in the control group. Conclusions: Dynesys implantation and discectomy to treat lumbar disc herniation with posterior small incision bilateral intermuscular approach has shorter operation time, less intraoperative blood loss, less drainage volume and less length of the incision, less tissue damage than conventional exposure. It is one of the options for surgical treatment of lumbar disc herniation.