Biomechanical analysis of a novel posterior construct in a transforaminal lumbar interbody fusion model an in vitro study

Sethi, Anil; Muzumdar, Aditya; Ingalhalikar, Aditya; Vaidya, Rahul

doi:10.1016/j.spinee.2011.06.015

Cited by 33 publications

(32 citation statements)

References 25 publications

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“…21 The vertebral bodies were centered and aligned using a series of leveling tools and customized potting frames to ensure proper force transmission to the functional spinal units while testing. Dissection and testing of each specimen were performed at room temperature (21 ± 2°C) for no longer than 48 hours.…”

Section: Specimen Preparationmentioning

confidence: 99%

Biomechanical analysis of an interspinous fusion device as a stand-alone and as supplemental fixation to posterior expandable interbody cages in the lumbar spine

Gonzalez-Blohm

Doulgeris

Aghayev

et al. 2014

SPI

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Object In this paper the authors evaluate through in vitro biomechanical testing the performance of an interspinous fusion device as a stand-alone device, after lumbar decompression surgery, and as supplemental fixation to expandable cages in a posterior lumbar interbody fusion (PLIF) construct. Methods Nine L3–4 human cadaveric spines were biomechanically tested under the following conditions: 1) intact/control; 2) L3–4 left hemilaminotomy with partial discectomy (injury); 3) interspinous spacer (ISS); 4) bilateral pedicle screw system (BPSS); 5) bilateral hemilaminectomy, discectomy, and expandable posterior interbody cages with ISS (PLIF-ISS); and 6) PLIF-BPSS. Each test consisted of 100 N of axial preload with ± 7.5 Nm of torque in flexion-extension, right/left lateral bending, and right/left axial rotation. Significant changes in range of motion (ROM), neutral zone stiffness (NZS), elastic zone stiffness (EZS), and energy loss (EL) were explored among conditions using nonparametric Friedman test and Wilcoxon signed-rank comparisons (p ≤ 0.05). Results The injury increased ROM in flexion (p = 0.01), left bending (p = 0.03), and right/left rotation (p < 0.01) and also decreased NZS in flexion (p = 0.01) and extension (p < 0.01). Both the ISS and BPSS reduced flexion-extension ROM and increased flexion-extension stiffness (NZS and EZS) with respect to the injury and intact conditions (p < 0.05), but the ISS condition provided greater resistance than BPSS in extension for ROM, NZS, and EZS (p < 0.01). The BPSS increased the rigidity (ROM, NZS, and EZS) of the intact model in lateral bending and axial rotation (p ≤ 0.01), except in EZS for left rotation (p = 0.23, Friedman test). The incorporation of posterior cages marginally increased (p = 0.05) the EZS of the BPSS construct in flexion but these interbody devices provided significant stability to the ISS construct in lateral bending and axial rotation for ROM (p = 0.02), in lateral bending for NZS (p = 0.02), and in flexion/axial rotation for EZS (p ≤ 0.03); however, both PLIF constructs demonstrated equivalent ROM and stiffness (p ≥ 0.16), except in lateral bending where the PLIF-BPSS was more stable (p = 0.02). In terms of EL, the injury increased EL in flexion-extension (p = 0.02), the ISS increased EL for lateral bending and axial rotation (p ≤ 0.03), and the BPSS decreased EL in lateral bending (p = 0.02), with respect to the intact condition. The PLIF-ISS decreased lateral bending EL with respect to the ISS condition (p = 0.02), but not enough to be smaller or, at least, equivalent, to that of the PLIF-BPSS construct (p = 0.02). Conclusions The ISS may be a suitable device to provide immediate flexion-extension balance after a unilateral laminotomy, but the BPSS provides greater immediate stability in lateral bending and axial rotation motions. Both PLIF constructs performed equivalently in flexion-extension and axial rotation, but the PLIF-BPSS construct is more resistant to lateral bending motions. Further biomechanical and clinical evidence is required to strongly support the recommendation of a stand-alone interspinous fusion device or as supplemental fixation to expandable posterior interbody cages.

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Section: Specimen Preparationmentioning

confidence: 99%

Biomechanical analysis of an interspinous fusion device as a stand-alone and as supplemental fixation to posterior expandable interbody cages in the lumbar spine

Gonzalez-Blohm

Doulgeris

Aghayev

et al. 2014

SPI

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show abstract

“…They found that no measurable differences in terms of the stiffness or ROM between BPSs and UPSFSs were observed during flexion-extension, lateral bending, and axial rotation after transforaminal lumbar interbody fusion. In another biomechanical study, Sethi et al 24 tested 7 fresh human lumbar spines (L2-5) by applying pure moments of ± 8 Nm, with no compressive preload, and found that UPSFS fixation was able to achieve more reduction in ROM compared with UPS fixation and was comparable to BPS fixation in flexion-extension, lateral bending, and axial torsion. However, both of these studies only focused on single-level lumbar spinal fusion (L3-4), and whether UPSFS fixation could be extended to 2-level or even multilevel conditions remains unclear.…”

Section: Discussionmentioning

confidence: 99%

“…Three instrumentation systems yielded 6 kinds of testing orders. To minimize the variance of biomechanical performance induced by different testing orders, as previous studies did, 24,25 the following testing order of each instrumentation system (UPS, UPS-FS, and BPS; Fig. 2) was generated by a series of random numbers (Table 1).…”

Section: Testing Protocolmentioning

confidence: 99%

“…The ROM was defined as the angular excursion in all directions at maximum load; the NZ was defined as the difference at zero load between the angular positions in all directions of the loading and unloading phases. 19,24 Statistical analysis was performed using SPSS (version 19.0 for Windows, SPSS Inc.). For the ROM and NZ data, single-factor ANOVA with repeated measures was per- formed.…”

Section: Data Collection and Analysismentioning

confidence: 99%

“…15,23 To the best of our knowledge, several studies have evaluated the biomechanical performance of this hybrid instrumentation technique. 15,[23][24][25] However, most researchers only focused on single-level conditions, and the biomechanics of this hybrid technique at 2 levels have not been well characterized.…”

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A biomechanical comparison of 3 different posterior fixation techniques for 2-level lumbar spinal disorders

Liu

Zhu

Liu

et al. 2016

SPI

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OBJECT This study sought to make a biomechanical comparison of 3 different posterior fixation techniques for 2-level lumbar spinal disorders. METHODS Eight fresh-frozen human cadaver lumbar spines (4 from L-1 to L-5, 4 from L-1 to S-1) were tested by applying pure moments of ± 8 Nm. Each specimen was first tested intact, and then the left facetectomies of L3–4 and L4–5 were performed to establish an unstable condition without removal of discs. Three instrumentation systems were then tested randomly: unilateral pedicle screw (UPS), UPS with contralateral translaminar facet screw (UPSFS), and bilateral pedicle screw (BPS). The range of motion (ROM) and the neutral zone (NZ) of L3–5 were measured. RESULTS All fixation types could reduce the ROM of L3–5 significantly in flexion, extension, and lateral bending, compared with the intact state. In axial torsion, only BPS reduced the ROM significantly, compared with the intact state. The UPSFS technique provided intermediate stability, which was superior to the UPS in flexion-extension and lateral bending, and inferior to the BPS in lateral bending. Compared with the intact state, the NZs decreased significantly for UPS, UPSFS, and BPS in flexion-extension, while not significantly in lateral bending and axial torsion. CONCLUSIONS In this study, among the 3 fixation techniques, BPS offered the highest stability, UPSFS provided intermediate stability, and UPS was the least stable for 2-level lumbar spinal disorders. UPSFS appeared to be able to offer a less invasive choice than BPS in well-selected patients with 2-level lumbar spinal disorders.

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New Techniques and MIS: The Interfacet Fixation with Facet Wedge Device

Hartensuer

Spruit

2017

Modern Thoraco-Lumbar Implants for Spinal Fusion

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Biomechanical analysis of a novel posterior construct in a transforaminal lumbar interbody fusion model an in vitro study

Cited by 33 publications

References 25 publications

Biomechanical analysis of an interspinous fusion device as a stand-alone and as supplemental fixation to posterior expandable interbody cages in the lumbar spine

Biomechanical analysis of an interspinous fusion device as a stand-alone and as supplemental fixation to posterior expandable interbody cages in the lumbar spine

A biomechanical comparison of 3 different posterior fixation techniques for 2-level lumbar spinal disorders

New Techniques and MIS: The Interfacet Fixation with Facet Wedge Device

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