ABSTRACT
Objective:To investigate the characteristics and causes of endplate injury in the oblique lateral interbody fusion for the treatment of lumbar diseases, and summarize the precaution of endplate injury.Methods:Thirty-five cases of endplate injury were observed, which were originally treated with oblique lateral interbody fusion with or without pedicle screw fixation from October 2014 to December 2017. There were 7 males and 28 females, and the age ranged from 51 to 78 years old (averagely 62.8±8.13 years). There were 2 cases of lumbar disc degeneration, 10 cases of lumbar canal stenosis, 17 cases of lumbar degenerative spondylolisthesis, 2 cases of lumbar spondylolysis with or without spondylolisthesis, and 4 cases of lumbar degenerative scoliosis. Lesion sites contained L 3,4 in 2 cases, L 4,5 in 21 cases, L 2-4 in 3 cases, L 3-5 in 4 cases, L 2-5 in 3 cases and L 1-5 in 2 cases. Preoperative bone mineral density examination revealed there were 7 cases of T>-1 SD, 24 cases of -2.5 SD<T<-1 SD and 4 cases of T<-2.5 SD. There were 5 cases of high iliac crest. There were 25 cases of single segment, 5 cases of double segment, 3 cases of three segments, and 2 cases of four segments. Endplate injury occurred in all cases, and a total of 40 endplates occurred in 39 intervertebral spaces, of which the upper and lower endplates of 1 intervertebral space were injured, and the rest were single endplate injuries. There were 35 cases of upper endplate injury, 5 cases of lower endplate injury and 3 cases combined with vertebral fracture. The cage location where the endplate injury occurred: 3 cases in zone Ⅰ-Ⅱ, 31 cases in zone Ⅱ-Ⅲ and 5 cases in zone Ⅲ-Ⅳ. The main observation indicators were Visual Analog Scale (VAS) for low back pain, Oswestry disability index (ODI), intervertebral space height, and position of cage. Results:The reasons for endplate injury were: osteopenia or osteoporosis 28 cases, improper surgical steps 9 cases, high iliac crest 5 cases, endplate anatomical morphology variation 5 cases, obvious stenosis of the intervertebral space 4 cases, large cage 3 cases and mixed factors 12 cases. The follow-up time was 18.5±8.1 months. There was no pedicle screw loosen during the follow-up. There were 3 cases of lateral displacement of cage, including 1 case of Stand-alone OLIF, 2 cases of OLIF combined with pedicle screw fixation. In all cases, different degrees of cage subsidence occurred. Among them, 7 cases of Stand-alone OLIF were supplemented with posterior pedicle screw fixation. The intervertebral height of diseased segment was well restored postoperatively, which was statistically significant compared with preoperative. But there was significant loss during the follow-up, and the difference was statistically significant at the last follow-up. The low back pain VAS score was from 6.6±2.2 preoperative to 1.3±0.74 at the last follow-up, which was statistically different. The ODI was from 36.3%±7.4% preoperative to 9.6%±3.5% at the last follow-up, which was statistically different. Except 3 cases, the remaining had well interbody fusion, with the fusion rate of 91.4%.Conclusion:The incidence of endplate injury during oblique lateral interbody fusion is high. The reasons of endplate injury include both the patient's factors and the surgical factors. Endplate injury is closely related to the decreased intervertebral space height during the follow-up period, as well as the settlement or displacement of cage. Some cases may require reoperation. The prevention of endplate injury should be strengthened. Once it occurs, timely and effective treatment should be taken, and follow-up should be done closely.
ABSTRACT
Objective:To compare the clinical outcomes and complications of oblique lateral interbody fusion combined with bilateral pedicle screw fixation through intermuscular approach and posterior interbody fusion combined with bilateral pedicle screw fixation through intermuscular approach by channel for lumbar spinal stenosis.Methods:A retrospective study was conducted on 73 patients who underwent surgical treatment for lumbar spinal stenosis from Jun 2015 to Jun 2017, including 33 males and 40 females. The average age was 66.8±7.94 years (from 39-85 years). These diseases occured at L 3/4 in 5 patients and L 4/5 in 68 patients. Random according to the time of admission, 38 cases were treated with oblique lateral interbody fusion combined with bilateral pedicle screw fixation through intermuscular approach (oblique lateral fusion group), and 35 cases with posterior interbody fusion combined with bilateral pedicle screw fixation through intermuscular approach by channel (posterior fusion group). The clinical results, image data and complications were compared between the two groups. Results:All patients in both groups had operation performed smoothly. The operation time was 99±8.96 min in the oblique lateral fusion group and 96.8±9.57 min in the posterior fusion group, and there was no significant difference between the two groups. The intraoperative bleeding in the oblique lateral fusion group 80±24.72 ml was significantly less than that in the posterior fusion group 261±52.87 ml ( t=9.621, P<0.05). No incision infection occurred after surgery. The VAS score of lumbar incision 72h after operation in the oblique lateral fusion group 1.21±0.55 was significantly less than that in the posterior fusion group 1.70±0.86 ( t=3.723, P=0.028). The follow-up period lasted for 12-24 months, averagely 17.5±2.58 months. There was statistically significant difference between preoperative and postoperative in the two groups, whether it was the area of the foraminal canal or the area of the spinal canal. There wboth the foraminal area and the spinal canal area were enlarged. The intervertebral space height in the two groups recovered significantly after surgery, the difference was statistically significant. But the intervertebral space height were partly lost at the last follow-up, and there was significant difference compared with postoperative. During the follow-up, no pedicle screw loosening, displacement, rupture, or anterior and lateral displacement of cage occurred. The fusion rate was 97.1% in the posterior fusion group and 100% in the oblique lateral fusion group. There was no statistical difference between the two groups.In terms of ODI index: the posterior fusion group recovered from 48.6±6.1 preoperative to 10.2±2.2 at the last follow-up, and the oblique lateral fusion group recovered from 49.0±5.7 preoperative to 9.3±1.8 at the last follow-up. There was statistically difference between last follow-up and preoperative in the two groups. The incidence of complications in the posterior fusion group was 22.86%, and the incidence in the oblique lateral fusion group was 23.68%. There was no significant difference between the two groups. Conclusion:Both the two decompression and fusion methods have achieved good clinical results in the treatment of lumbar spinal stenosis, with the advantages of less trauma, good stability, fast recovery, and high fusion rate. Compared with posterior decompression and fusion methods, the advantages of OLIF are more obvious, such as less bleeding,lower risk of nerve injury and good indirect decompression of spinal canal. Therefore, the OLIF technique can be a better choice for surgical treatment of lumbar spinal stenosis.