scholarly journals Biomechanical Evaluation of Oblique Lateral Locking Plate System for Oblique Lumbar Interbody Fusion: A Finite Element Analysis

2021 ◽  
Author(s):  
Yinge Wang ◽  
Jiajia Wang ◽  
Sha Tu ◽  
Shuang Li ◽  
Jiangpu Yi ◽  
...  
Keyword(s):  
Finite Element ◽  
Interbody Fusion ◽  
Locking Plate ◽  
Lumbar Interbody Fusion ◽  
Lateral Plate ◽  
Flexion Extension ◽  
Cage Subsidence ◽  
Oblique Lumbar Interbody Fusion ◽  
Locking Plate System ◽  
Plate System

Abstract Objective: Oblique lateral locking plate system (OLLPS) with the locking and reverse pedicle track screw configuration is a novel internal fixation designed for oblique lumbar interbody fusion(OLIF). It is placed in a single-position through the oblique lateral surgical corridor to reduce operative time and subsequent complications of prolonged anesthesia and prone positioning. The purpose of this study was to verify the biomechanical effect of OLLPS.Methods: The intact finite element model of L1–S1（Intact） was established based on CT images of a healthy male volunteer. The L4-L5 intervertebral space was selected as the surgical segment. The surgical models were established separately according to the OLIF surgical procedures and the different internal fixations: (1) stand-alone OLIF (SA); (2) OLIF with 2-screw lateral plate (LP-2); (3) OLIF with 4-screw lateral plate (LP-4); (4) OLIF with OLLPS (OLLPS); and (5) OLIF with bilateral pedicle screw fixation (BPS). After validating the intact model, the physiological loading was applied to the superior surface of L1 to simulate flexion, extension, left bending, right bending, left rotation, and right rotation motions. The evaluation indexes included the L4/5 range of motion (ROM), the L4 maximum displacement, and the maximum stress of the superior and inferior endplate, cage, and supplemental fixation.Results: In OLIF surgery, OLLPS provided multiplanar stability which was similar to that of BPS. Compared with LP-2 and LP-4, OLLPS had the better biomechanical properties in enhancing the instant stability of the surgical segment, reducing the stress of the superior and inferior endplates of the surgical segment, and reducing the risk of cage subsidence.Conclsions: With the minimally invasive background, OLLPS can be an alternative to BPS in OLIF and has a better prospect of clinical promotion and application.

scholarly journals Biomechanical Evaluation of Anterolateral Screw Fixation for Oblique Lumbar Interbody Fusion Surgery – A Finite Element Analysis

2020 ◽  
Author(s):  
gufang Fang ◽  
SG Chen ◽  
wda zhuang ◽  
WH Huang ◽  
Hongxun Sang
Keyword(s):  
Finite Element ◽  
Interbody Fusion ◽  
Screw Fixation ◽  
Upper Body ◽  
Lumbar Interbody Fusion ◽  
Element Analysis ◽  
Flexion Extension ◽  
Cage Subsidence ◽  
Oblique Lumbar Interbody Fusion ◽  
Maximum Stresses

Abstract Background: The most common complication of oblique lumbar interbody fusion (OLIF) is cage subsidence. OLIF combined with internal fixation could help decrease the cage subsidence and increase the fusion rate. The aim of this study was to evaluate the biomechanical feasibility and safety in the patients undergoing OLIF surgery with anterolateral screw fixation (ASF). Methods: Based on our previous validated model , L4-L5 functional surgical models corresponding to the ASF and Bilateral pedicle screw fixation(BPSF) methods were created. A 500 N compression force was applied to the superior surface of the model to represent the upper body weight, and a 7.5 Nm moment was applied to simulate the six movement directions of the lumbar spinal model: flexion/extension, right/left lateral bending and right/left axial rotation. Finite element (FE) models were developed to compare the biomechanics of the ASF and BPSF groups. Results: Compared to the range of motion (ROM) of the intact lumbar model, that of the ASF model was decreased by 82.0% in flexion, 60.0% in extension, and the BPSF model was decreased by 86.7% in flexion, 77.3% in extension. Compared to the BPSF model, the maximum stresses of the L4 inferior endplate (IEP) and L5 superior endplate (SEP) were greatly increased in the ASF model; The contact surface between vertebrae and screw (CSVS) in the ASF model produced nearly100% more stresses than the BPSF model in all moment .Conclusions: OLIF surgery with ASF could not reduce the maximum stresses on the endplate and CSVS, which may be a potential risk factor for cage subsidence and screw loosening.

scholarly journals Biomechanical effect of cage position combined with bilateral pedicle screw fixation in the osteoporotic lumbar spine of oblique lumbar interbody fusion: a finite element analysis

2021 ◽  
Author(s):  
Yichuan Qin ◽  
Bin Zhao ◽  
Jie Yuan ◽  
Chaojian Xu ◽  
Junqiang Su ◽  
...  
Keyword(s):  
Finite Element ◽  
Lumbar Spine ◽  
Pedicle Screw ◽  
Interbody Fusion ◽  
Screw Fixation ◽  
Pedicle Screw Fixation ◽  
Lumbar Interbody Fusion ◽  
Cage Subsidence ◽  
Oblique Lumbar Interbody Fusion ◽  
Bilateral Pedicle Screw

Abstract Background: The influence of cage position on postoperative cage subsidence has been paid increasing attention. The best cage position in oblique lumbar interbody fusion (OLIF) is still unclear. This study aimed to evaluate the biomechanical effects of different cage positions with stand-alone (SA) methods and bilateral pedicle screw fixation (BPSF) in the osteoporotic lumbar spine after OLIF.Methods: A finite element (FE) model of an intact L3-L5 lumbar spine was constructed. After validation, an osteoporosis model (OP) was constructed by assigning osteoporotic material properties. SA models (SA1, SA2, SA3) and BPSF models (BPSF1, BPSF2, BPSF3) in which a cage was placed in the anterior, middle and posterior third of the L5 superior endplate (SEP) were constructed at the L4-L5 segment of the OP. The L4-L5 range of motion (ROM), the stress of the L5 SEP, the stress of the cage and the stress of fixation were compared among the different models.Results: According to the degree of ROM of L4-L5, the stress of the L5 SEP and the stress of the cage for most physiological motions, the SA and BPSF models were ranked as follows: SA2＜SA1＜SA3, BPSF2＜BPSF1＜BPSF3. In BPSF2, the stress of fixation was minimal in most motions. At the same cage position, the ROM of L4-L5, the stress of the L5 SEP and the stress of the cage in the BPSF models were significantly reduced compared with those in SA models; compared with SA2, BPSF2 had a maximum reduction of 83.24%, 70.71% and 73.52% in these parameters, respectively.Conclusions: Placing the cage in the middle third of the L5 SEP for OLIF could reduce the maximum stresses of the L5 SEP, the cage and the fixation, which may reduce the risk of postoperative cage subsidence, endplate collapse and fixation fracture in the osteoporotic lumbar spine. Compared with SA OLIF, BPSF could provide sufficient stability for the surgical segment and may reduce the incidence of the aforementioned complications.

scholarly journals Additional lateral plate fixation has no effect to prevent cage subsidence in oblique lumbar interbody fusion

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Tenghui Ge ◽  
Jintao Ao ◽  
Guanqing Li ◽  
Zhao Lang ◽  
Yuqing Sun
Keyword(s):  
Interbody Fusion ◽  
Plate Fixation ◽  
Lumbar Interbody Fusion ◽  
Degenerative Diseases ◽  
Lateral Plate ◽  
Subsidence Rate ◽  
Cage Subsidence ◽  
Indirect Decompression ◽  
Oblique Lumbar Interbody Fusion ◽  
Lumbar Degenerative Diseases

Abstract Background For lumbar degenerative diseases, cage subsidence is a serious complication and can result in the failure of indirect decompression in the oblique lumbar interbody fusion (OLIF) procedure. Whether additional lateral plate fixation was effective to improve clinical outcomes and prevent cage subsidence was still unknown. This study aimed to compare the incidence and degree of cage subsidence between stand-alone oblique lumbar interbody fusion (SA-OLIF) and OLIF combined with lateral plate fixation (OLIF + LP) for the treatment of lumbar degenerative diseases and to evaluate the effect of the lateral plate fixation. Methods This was a retrospective comparative study. 20 patients with 21 levels underwent SA-OLIF and 21 patients with 26 levels underwent OLIF + LP. We compared clinical and radiographic outcomes between two groups. Clinical evaluation included Visual Analog Scale (VAS) for back pain and leg pain, Japanese Orthopaedic Association (JOA) scores and Oswestry Disability Index (ODI). Radiographical evaluation included disc height (DH), segmental lordosis angle (SL), and subsidence rate on standing lateral radiographs. Cage subsidence was classified using Marchi’s criteria. Results The mean follow-up duration was 6.3 ± 2.4 months. There were no significant differences among perioperative data (operation time, estimated intraoperative blood loss, and complication), clinical outcome (VAS, ODI, and JOA) and radiological outcome (SH and SL). The subsidence rate was 19.0% (4/21) in SA-OLIF group and 19.2% (5/26) in OLIF + LP group. 81.0% in SA-OLIF group and 80.8% in OLIF + LP group had Grade 0 subsidence, 14.3% in SA-OLIF group and 15.4% in OLIF + LP group had Grade I subsidence, and 4.8% in SA-OLIF group and 3.8% in OLIF + LP group had Grade II subsidence (P = 0.984). One patient with severe cage subsidence and lateral plate migration underwent revision surgery. Conclusions The additional lateral plate fixation does not appear to be more effective to prevent cage subsidence in the oblique lumbar interbody fusion, compared with stand-alone technique. If severe cage subsidence occurs, it may result in lateral plate migration in OLIF combined with lateral plate fixation.

scholarly journals Prevalence and location of endplate fracture and subsidence after oblique lumbar interbody fusion for adult spinal deformity

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Gen Inoue ◽  
Wataru Saito ◽  
Masayuki Miyagi ◽  
Takayuki Imura ◽  
Eiki Shirasawa ◽  
...  
Keyword(s):  
Spinal Deformity ◽  
Interbody Fusion ◽  
Sagittal Plane ◽  
Adult Spinal Deformity ◽  
Major Complication ◽  
Global Alignment ◽  
Lumbar Interbody Fusion ◽  
Significant Difference ◽  
Cage Subsidence ◽  
Oblique Lumbar Interbody Fusion

Abstract Background Recently, Oblique lumbar interbody fusion (OLIF) is commonly indicated to correct the sagittal and coronal alignment in adult spinal deformity (ASD). Endplate fracture during surgery is a major complication of OLIF, but the detailed location of fracture in vertebral endplate in ASD has not yet been determined. We sought to determine the incidence and location of endplate fracture and subsidence of the OLIF cage in ASD surgery, and its association with fusion status and alignment. Methods We analyzed 75 levels in 27 patients were analyzed using multiplanar CT to detect the endplate fracture immediately after surgery and subsidence at 1 year postoperatively. The prevalence was compared between anterior and posterior, approach and non-approach sides, and concave and convex side. Their association with fusion status, local and global alignment, and complication was also investigated. Results Endplate fracture was observed in 64 levels (85.3%) in all 27 patients, and the incidence was significantly higher in the posterior area compared with the anterior area (85.3 vs. 68.0%, p=0.02) of affected vertebra in the sagittal plane. In the coronal plane, there was no significant difference in incidence between left (approach) and right (non-approach) sides (77.3 and 81.3%, respectively), or concave and convex sides (69.4 and 79.6%) of wedged vertebra. By contrast, cage subsidence at 1 year postoperatively was noted in 14/75 levels (18.7%), but was not associated with endplate fracture. Fusion status, local and global alignment, and complications were not associated with endplate fracture or subsidence. Conclusion Endplate fracture during OLIF procedure in ASD cases is barely avoidable, possibly induced by the corrective maneuver with ideal rod counter and cantilever force, but is less associated with subsequent cage subsidence, fusion status, and sustainment of corrected alignment in long fusion surgery performed even for elderly patients.

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