Risk Factors For Endplate Collapse And Clinical Efficacy Of Oblique Lumbar Interbody Fusion

Part Ⅰ: Clinical efficacy study of oblique lateral interbody fusion with different internal fixation modalitiesBackground and purpose: Oblique lateral approach lumbar fusion(OLIF)can be combined with different internal fixation methods,and the three most common methods used in clinical practice are Stand-Alone technique with simple interbody fusion,combined with lateral plate internal fixation,and combined with pedicle screw internal fixation.Stronger internal fixation often means more trauma,higher cost,and longer operative time,while insufficient internal fixation can lead to stability-related complications such as endplate collapse.In this study,clinical and follow-up data of patients treated with different internal fixation modalities were collected to compare the clinical efficacy and surgical indexes of OLIF combined with different internal fixation modalities.The aim was to guide the clinical selection of a more precise,safe and effective procedure.Methods: A total of 106 patients who underwent OLIF in our hospital between February2021 and February 2022 were divided into three groups according to the combination of different internal fixation methods: the Stand-Alone group,the lateral plate internal fixation group and the pedicle screw internal fixation group.The complication rate,operative time,bleeding volume,number of fluoroscopy,and visual analog(VAS)score of low back and leg pain at 1 week,3 months,and 12 months postoperatively,Oswestry dysfunction index(ODI)were compared between the two groups and statistically analyzed.Results: A total of 106 patients were included in the study,including 50 patients in the Stand-Alone group,19 patients in the lateral plate internal fixation group,and 38 patients in the pedicle screw internal fixation group.there was no significant difference between the Stand-Alone group and the lateral plate internal fixation group in terms of operative time and bleeding(P>0.05),and the number of intraoperative fluoroscopic views was significantly less in the Stand-Alone group(16.28 times vs 19.74 times,P<0.01),and the two groups did not show significant differences in VAS scores and ODI for low back and leg pain at 1 week,3 months and 12 months after surgery.The pedicle screw fixation group showed significantly higher operative time,bleeding,and intraoperative fluoroscopy than the Stand-Alone group(203.03 min,95.53 ml,27.95 vs.85.60 min,38.30 ml,16.28,P<0.01),and the VAS score of low back pain was significantly higher in the pedicle screw group than in the Stand-Alone group at 1 week postoperatively.-Alone group(5.03 vs.4.02,<0.01).Conclusion: The lateral plate placement is convenient and quick,without changing position and additional tissue stripping and exposure,so there is no significant difference in operative time and bleeding with the Stand-Alone technique,and only the number of fluoroscopic views is slightly higher;the heel screw placement requires intraoperative position change,which causes additional trauma to the posterior muscles of the lumbar spine and requires repeated fluoroscopic views to determine the screw placement position,so the operative time,intraoperative bleeding and intraoperative fluoroscopic views are significantly higher.The intraoperative bleeding and the number of intraoperative fluoroscopic views were significantly higher than those of the other two groups.The three groups did not show significant differences in long-term clinical outcomes,but the VAS score for low back pain was significantly higher in the pedicle screw group at 1 week postoperatively,and perioperative comfort was lower than in the other two groups.Part Ⅱ: Risk factors for endplate collapse in oblique lateral interbody fusionBackground and Objectives: Oblique lateral interbody fusion(OLIF)restores intervertebral height and indirect decompression by placing a large intervertebral cage.The support provided by the large intervertebral cage allows the OLIF technique to be performed without posterior pedicle screw fixation,resulting in the Stand-Alone technique and lateral plate fixation.However,this technique cannot provide adequate support stability for all patients and have a high rate of endplate collapse,which can lead to fusion failure.This study investigated the risk factors for endplate collapse after OLIF by analyzing the clinical data and intraoperative decision-making differences among patients undergoing lumbar fusion with the OLIF,aiming to guide the clinical selection of a more precise,safe,and effective surgical procedure.Methodology: The samples of this study are 64 patients who underwent OLIF and OLIF combined with lateral plate fixation in the Affiliated Hospital of Qingdao University between February 2021 and February 2022,with a total of 80 surgical segments.They were divided into collapsed and non-collapsed groups according to the presence or absence of collapsed CT endplates at 6 months postoperatively.The general data(gender,age,BMI);imaging data(whether combined with Spondylolisthesis,dynamic stability of the vertebral body,mean CT values of the vertebral body above and below the responsible segment,and the number of fused segments);surgical decision and differences brought about by intraoperative operations(change in vertebral space height,whether combined with lateral plate fixation,and whether combined with intraoperative endplate injury)were compared between the two groups.Potential risk factors with P<0.05 in the univariate analysis were included in the Logistic regression for multivariate analysis and plotted on a line graph.Results: Out of 80 operated segments,endplate collapse occurred in 24 cases(30%).Risk factor analysis showed that dynamic instability of the vertebral body,low CT values of the vertebral body,and intraoperative endplate injury were independent risk factors for postoperative endplate collapse.There was no statistical significance between patient gender,age,BMI,number of fused segments,vertebral body spreading height,and combined lateral plate fixation and the occurrence of endplate collapse.Conclusion: Dynamic instability of vertebral body,low CT value of vertebral body and intraoperative endplate injury are independent risk factors for postoperative endplate collapse.Combined with lateral steel plate fixation has no significant protective effect on postoperative endplate collapse.Stronger internal fixation should be applied for these patients.