Cadaveric biomechanical analysis of multilevel lateral lumbar interbody fusion with and without supplemental instrumentation

Abstract

Background This study was to evaluate and compare the biomechanical features of multilevel lateral lumbar interbody fusion (LLIF) with or without supplemental instrumentations. Methods Six human lumbar specimens were tested under multidirectional nondestructive moments (7.5 N·m), with a 6 degree-of-freedom spine simulator. The overall and intervertebral range of motion (ROM) were measured optoelectronically. Each specimen was tested under the following conditions at L2–5 levels: intact; stand-alone; cage supplemented with lateral plate (LP); cage supplemented with unilateral or bilateral pedicle screw/rod (UPS or BPS). Results Compared with intact condition, the overall and intersegmental ROM were significantly reduced after multilevel stand-alone LLIF. The ROM was further reduced after using LP instrumentation. In flexion-extension (FE) and axial rotation (AR), pedicle screw/rod demonstrated greater overall ROM reduction compared to LP (P < 0.01), and bilateral greater than unilateral (P < 0.01). In lateral bending (LB), BPS demonstrated greater overall ROM reduction compared to UPS and LP (P < 0.01), however, UPS and LP showed similar reduction (P = 0.245). Intervertebral ROM reductions showed similar trend as the overall ones after using different types of instrumentation. However, at L2/3 (P = 0.57) and L3/4 (P = 0.097) levels, the intervertebral ROM reductions in AR were similar between UPS and LP. Conclusions The overall and intervertebral stability increased significantly after multilevel LLIF with or without supplemental instrumentation. BPS provided the greatest stability, followed by UPS and LP. However, in clinical practice, less invasive adjunctive fixation methods including UPS and LP may provide sufficient biomechanical stability for multilevel LLIF.

Biomechanical study of oblique lumbar interbody fusion (OLIF) augmented by different instrumentations: a finite element analysis

“…Our study showed that OLIF reduces the ROM of the L4-L5 surgical segment and thus provides a high degree of stability at this segment. In all postures, the ROM of the surgical segment in the ve OLIF surgery models decreased by > 80% (86.26-98.97%) compared with the intact model, consistent with the trend reported in previous studies [32][33][40][41][42]. Lu et al [32] conducted a FE analysis to explore the biomechanical performances of four types of LIF surgery (PLIF, TLIF, XLIF, and OLIF); the ROM of the surgical segment was reduced by 75.3-92.6% when surgery was combined with bilateral pedicle screw xation.…”

“…In addition, in terms of restricting segment motion and preventing instrumentation failure, the OLIF + BPSF and OLIF + TFJF + UPSF models had smaller ROM and ESPFI values, indicative of greater stability. The reason for the relationship between ESPC and the stability in the OLIF models was suggested in previous in vitro and FE studies, which demonstrated the greater stability of the surgical segment conferred by bilateral pedicle screws [33,[41][42]44]. In our study, the OLIF + BPSF model had the smallest ESPC; it can thus be expected to provide the strongest resistance to cage subsidence and to maintain disc height.…”

“…Since the stability of the spine as a whole hinders excessive deviation of each spinal motion segment, the middle area between the vertebrae is kept within the physiological limit. The results of our FE study together with those of in vitro cadaver experiments [32][33][40][41][42] indicate that bilateral pedicle screw xation for OLIF provides greater stability than that obtained with other xation instruments.…”

Oblique Lateral Interbody Fusion Combined With Lateral Plate Fixation for the Treatment of Lumbar Degenerative Diseases: a Preliminary Clinical Study

“…In a three dimensional nite element study, Liu et al suggested the lateral plate and screws can not provide the favorable biomechanical stability for the multilevel lateral interbody fusion [26]. However, In an cadaveric biomechanical study, Lai et al suggested that less invasive adjunctive xation methods such as unilateral pedicle screw and lateral plate may provide su cient biomechanical stability for multilevel LLIF [27]. In present study, we apply the lateral plate xation system only to the one-segmental lumbar degenerative disease patients, and the grade II or more serious lumbar spondylisthesis patients were excluded.…”

Comparison of Hybrid Posterior Fixation and Conventional Open Posterior Fixation Combined with Multilevel Lateral Lumbar Interbody Fusion for Adult Spinal Deformity

“…There are multiple reports about its effectiveness [5,6]. Lai et al reported that overall and intervertebral stability significantly increased after multilevel LLIF and that bilateral pedicle screws provided the greatest stability, followed by a unilateral pedicle screw and lateral plate, in the cadaveric biomechanical analysis [7]. In addition, minimally invasive posterior surgery with the use of percutaneous pedicle screws (PPSs) was used to prevent damage to the paraspinal muscles, which was a serious problem with the conventional approach [8].…”