[Comparative study of two elastic fixation systems in single-segment lumbar disc herniation surgery for nucleus pulposus extraction].

Objective: To investigate the clinical application of two elastic pedicle internal fixation systems in single-segment lumbar disc herniation fenestration.

Methods: A retrospective analysis of 64 patients with lumbar intervertebral disc herniation treated by surgery from June 2019 to March 2021. According to the different elastic fixation systems placed during the operation, the patients were divided into ordinary pedicle screw elastic rod link group (elastic rod group) and a special elastic pedicle screw rigid rod fixed connection group (elastic screw group). There were 33 cases in the elastic rod group, including 18 males and 15 females, aged from 30 to 69 years old with an average of(49.18±10.23) years old;and 31 cases in the elastic screw group, including 16 males and 15 females, aged from 32 to 68 with an average of (49.81±9.24) years old. The operation time, intraoperative blood loss, postoperative wound drainage, and postoperative landing time of the two groups were recorded separately. The visual analogue scale (VAS), Japanese Orthopaedic Association (JOA) score, and Oswestry Disability Index (ODI) were compared before and 3, 12 months after operation. The height of the adjacent vertebral space on the lateral DR film before and 12 months after the operation was measured. The clinical efficacy was evaluated by Macnab standard.

Results: All the patients successfully completed the operation, and were followed up. The operation time, intraoperative blood loss, postoperative wound drainage and postoperative landing time in the elastic rod group were(63.73±12.01) min, (89.55±16.07) ml, (81.67±16.00) ml, (3.45±0.75) d , while in the elastic nail group was (62.96±11.54) min, (88.35±17.14) ml, (82.29±15.40) ml, (3.29±0.78) d, the difference was not statistically significant. The symptoms of low back pain and lower extremity numbness were significantly improved in all patients after operation. There was no significant difference in VAS, JOA score and ODI between the two groups before and after surgery (>0.05). At 12 months after operation, there was no significant difference in the height of the adjacent vertebral space between the upper adjacent vertebral body and the same segment before operation(>0.05), and there was no significant difference between the groups before and after the operation. According to Macnab criteria, the elastic rod group was excellent in 30 cases, good in 2 cases, fair in 1 case, while the elastic nail group was excellent in 29 cases, good in 2 cases, fair in 0 cases, and there was no significant difference(=-0.42, =0.68).

Conclusion: In fenestrated nucleus pulposus extraction for lumbar disc herniation, the two elastic pedicle internal fixation systems are equally effective and can be used. The elastic screw internal fixation system has certain advantages when the distance between the two vertebral bodies is short, and the elastic rod cannot be placed or is difficult to be placed, and it is more widely used.