Clinical Outcomes Of Unilateral Biportal Endoscopic Lumbar Interbody Fusion (ULIF) Compared With Posterior Lumbar Interbody Fusion (PLIF) In The Treatment Of Lumbar Instability

Background: For patients with lumbar degenerative disease with severe symptoms and ineffective conservative treatment,open surgery was often used to treat lumbar degenerative diseases.However,open surgery has great trauma to muscles,ligaments and other tissues.The spinal endoscopic surgery has the advantages of less tissue damage,less trauma,and less bleeding.It is a new method to treat lumbar degenerative diseases.However,compared with the traditional open lumbar surgery,the spinal endoscopic surgery also has some disadvantages: narrow operating space,small surgical field of vision,longer learning curve,etc.For fusion surgery,because the interbody fusion cage needs to pass through the working sleeve,the size of the interbody fusion cage is limited.In contrast,UBE has a clear field of vision and flexible instrument operation during the operation,which can complete the decompression thoroughly and meticulously.UBE technology has small pipeline restrictions,and the operation channel can use the surgical instruments of traditional open surgery.Moreover,intervertebral fusion cage can be placed under direct vision,and the operation is safer.However,the evidence about the advantages of ULIF is still weak.It is necessary to conduct a controlled trial to understand the advantages and disadvantages of ULIF and provide guidance for clinical practice.Objective: This study aims to compare the clinical effects of ULIF with those of conventional open posterior lumbar interbody fusion(PLIF)in the treatment of lumbar instability,and to provide guidance for clinical practice.Methods: Adult patients who underwent L3–S1 single level lumbar interbody fusion were included in the study.They were divided into a PLIF group and a ULIF group according to the type of surgery.119 patients were included in this study: 48 in the ULIF group and 71 in the PLIF group.The preoperative baseline(sex,age,body mass index,course of disease,proportion of main diagnosis,proportion of surgical section),surgical technique-related outcomes(mean length of hospital stay,mean operation time,blood loss during operation,postoperative drainage,and postoperative hospital stay),clinical efficacy indicators before and after surgery and during follow-up,and the clinical laboratory indexes were compared between the two groups,as well as the incidence of complications,such as dural tear,nerve root injury,infection,and postoperative non-fusion.Results: There was no significant difference in preoperative baseline between the two groups.The ULIF group experienced less blood loss,postoperative drainage and a shorter postoperative hospital stay than the PLIF group;however,the ULIF group required a longer operation time than the PLIF group(P < 0.05).CRP,ESR,CPK,IL-6,and TNF-α levels of the PLIF group were all significantly higher than those of the ULIF group after operation(P < 0.05).At the fifth day after operation,the VAS and JOA of leg pain in the ULIF group were significantly better than those in the PLIF group(P < 0.05).At the last follow-up,there was no statistical difference in the clinical efficacy index and fusion rate between the two groups(P > 0.05).Conclusion: This study showed that ULIF and PLIF were both effective surgical techniques for lumbar interbody fusion.However,ULIF caused less bleeding,reduced inflammatory reaction,less tissue damage and faster postoperative recovery compared with PLIF.