scholarly journals Biomechanical study on the effect of five different lumbar reconstruction techniques on adjacent-level intradiscal pressure and lamina strain

2006 ◽  
Vol 5 (2) ◽  
pp. 150-155 ◽  
Author(s):  
Hideki Sudo ◽  
Itaru Oda ◽  
Kuniyoshi Abumi ◽  
Manabu Ito ◽  
Yoshihisa Kotani ◽  
...  
Keyword(s):  
Interbody Fusion ◽  
Sagittal Alignment ◽  
Biomechanical Study ◽  
Intradiscal Pressure ◽  
Adjacent Segment ◽  
Initial Stiffness ◽  
Flexion Extension ◽  
Fusion Methods ◽  
Local Kyphosis ◽  
The One

Object The objectives of this study were to compare the biomechanical effects of five lumbar reconstruction models on the adjacent segment and to analyze the effects of three factors: construct stiffness, sagittal alignment, and the number of fused segments. Methods Nondestructive flexion–extension tests were performed by applying pure moments to 10 calf spinal (L3–S1) specimens. One-segment (L5–6) or two-segment (L5–S1) posterior fusion methods were simulated: 1) one-segment posterolateral fusion (PLF); 2) one-segment PLF with interbody fusion cages (one-segment PLIF/PLF); 3) two-segment PLF; 4) two-segment PLIF/PLF; and 5) two-segment PLF in kyphosis (two-segment kyphotic PLF). The range of motion (ROM) of the reconstructed segments, intradiscal pressure (IDP), and lamina strain in the upper (L4–5) adjacent segment were analyzed. The ROM was significantly decreased in the PLIF/PLF models compared with that in the PLF alone models after both the one- and two-segment fusions. If the number of fused segments was increased, the pressure and strains were also increased in specimens subjected to the PLIF/PLF procedure, more so than the PLF-alone procedure. In the one-segment PLIF/PLF model the authors observed a reduced IDP and lamina strain compared with those in the kyphotic two-segment PLF model despite the latter’s higher levels of initial stiffness. Conclusions If the number of fused levels can be reduced by using PLIF to correct local kyphosis, then this procedure may be valuable for reducing adjacent-segment degenerative changes.

Outcomes of 2-level posterior lumbar interbody fusion for 2-level degenerative lumbar spondylolisthesis

2013 ◽  
Vol 19 (1) ◽  
pp. 90-94 ◽  
Author(s):  
Hironobu Sakaura ◽  
Tomoya Yamashita ◽  
Toshitada Miwa ◽  
Kenji Ohzono ◽  
Tetsuo Ohwada
Keyword(s):  
Lumbar Spine ◽  
Clinical Outcome ◽  
Interbody Fusion ◽  
Sagittal Alignment ◽  
Posterior Lumbar Interbody Fusion ◽  
Adjacent Segment ◽  
Lumbar Interbody Fusion ◽  
Single Level ◽  
The Mean

Object A systematic review concerning surgical management of lumbar degenerative spondylolisthesis (DS) showed that a satisfactory clinical outcome was significantly more likely with adjunctive spinal fusion than with decompression alone. However, the role of adjunctive fusion and the optimal type of fusion remain controversial. Therefore, operative management for multilevel DS raises more complicated issues. The purpose of this retrospective study was to elucidate clinical and radiological outcomes after 2-level PLIF for 2-level DS with the least bias in determination of operative procedure. Methods Since 2005, all patients surgically treated for lumbar DS at the authors' hospital have been treated using posterior lumbar interbody fusion (PLIF) with pedicle screws, irrespective of severity of slippage, patient age, or bone quality. The authors conducted a retrospective review of 20 consecutive cases involving patients who underwent 2-level PLIF for 2-level DS and had been followed up for 2 years or longer (2-level PLIF group). They also analyzed data from 92 consecutive cases involving patients who underwent single-level PLIF for single-level DS during the same time period and had been followed for at least 2 years (1-level PLIF group). This second group served as a control. Clinical status was assessed using the Japanese Orthopaedic Association (JOA) score. Fusion status and sagittal alignment of the lumbar spine were assessed by comparing serial plain radiographs. Surgery-related complications and the need for additional surgery were evaluated. Results The mean JOA score improved significantly from 12.8 points before surgery to 20.4 points at the latest follow-up in the 2-level PLIF group (mean recovery rate 51.8%), and from 14.2 points preoperatively to 22.5 points at the latest follow-up in the single-level PLIF group (mean recovery rate 55.3%). At the final follow-up, 95.0% of patients in the 2-level PLIF group and 96.7% of those in the 1-level PLIF group had achieved solid spinal fusion, and the mean sagittal alignment of the lumbar spine was more lordotic than before surgery in both groups. Early surgery-related complications, including transient neurological complications, occurred in 6 patients in the 2-level PLIF group (30.0%) and 11 patients in the 1-level PLIF group (12.0%). Symptomatic adjacent-segment disease was found in 4 patients in the 2-level PLIF group (20.0%) and 10 patients in the 1-level PLIF group (10.9%). Conclusions The clinical outcome of 2-level PLIF for 2-level lumbar DS was satisfactory, although surgery-related complications including symptomatic adjacent-segment disease were not negligible.

Adjacent-segment effects of lumbar cortical screw–rod fixation versus pedicle screw–rod fixation with and without interbody support

2021 ◽  
pp. 1-7
Author(s):  
Piyanat Wangsawatwong ◽  
Anna G. U. Sawa ◽  
Bernardo de Andrada Pereira ◽  
Jennifer N. Lehrman ◽  
Luke K. O’Neill ◽  
...  
Keyword(s):  
Pedicle Screw ◽  
Interbody Fusion ◽  
Lumbar Fusion ◽  
Statistical Significance ◽  
Adjacent Segment ◽  
Lumbar Interbody Fusion ◽  
Lateral Bending ◽  
Single Level ◽  
Cortical Screw ◽  
Flexion Extension

OBJECTIVE Cortical screw–rod (CSR) fixation has emerged as an alternative to the traditional pedicle screw–rod (PSR) fixation for posterior lumbar fixation. Previous studies have concluded that CSR provides the same stability in cadaveric specimens as PSR and is comparable in clinical outcomes. However, recent clinical studies reported a lower incidence of radiographic and symptomatic adjacent-segment degeneration with CSR. No biomechanical study to date has focused on how the adjacent-segment mobility of these two constructs compares. This study aimed to investigate adjacent-segment mobility of CSR and PSR fixation, with and without interbody support (lateral lumbar interbody fusion [LLIF] or transforaminal lumbar interbody fusion [TLIF]). METHODS A retroactive analysis was done using normalized range of motion (ROM) data at levels adjacent to single-level (L3–4) bilateral screw–rod fixation using pedicle or cortical screws, with and without LLIF or TLIF. Intact and instrumented specimens (n = 28, all L2–5) were tested using pure moment loads (7.5 Nm) in flexion, extension, lateral bending, and axial rotation. Adjacent-segment ROM data were normalized to intact ROM data. Statistical comparisons of adjacent-segment normalized ROM between two of the groups (PSR followed by PSR+TLIF [n = 7] and CSR followed by CSR+TLIF [n = 7]) were performed using 2-way ANOVA with replication. Statistical comparisons among four of the groups (PSR+TLIF [n = 7], PSR+LLIF [n = 7], CSR+TLIF [n = 7], and CSR+LLIF [n = 7]) were made using 2-way ANOVA without replication. Statistical significance was set at p < 0.05. RESULTS Proximal adjacent-segment normalized ROM was significantly larger with PSR than CSR during flexion-extension regardless of TLIF (p = 0.02), or with either TLIF or LLIF (p = 0.04). During lateral bending with TLIF, the distal adjacent-segment normalized ROM was significantly larger with PSR than CSR (p < 0.001). Moreover, regardless of the types of screw-rod fixations (CSR or PSR), TLIF had a significantly larger normalized ROM than LLIF in all directions at both proximal and distal adjacent segments (p ≤ 0.04). CONCLUSIONS The use of PSR versus CSR during single-level lumbar fusion can significantly affect mobility at the adjacent segment, regardless of the presence of TLIF or with either TLIF or LLIF. Moreover, the type of interbody support also had a significant effect on adjacent-segment mobility.

Immediate Stiffness of the C5–C6 Segment after Discectomy with the Cloward Technique: An in Vitro Biomechanical Study on a Human Cadaveric Model

Neurosurgery ◽  
2001 ◽  
Vol 49 (6) ◽  
pp. 1399-1408 ◽  
Author(s):  
Andrzej Maciejczak ◽  
Michał Ciach ◽  
Maciej Radek ◽  
Andrzej Radek ◽  
Jan Awrejcewicz
Keyword(s):  
Interbody Fusion ◽  
Spinal Instrumentation ◽  
Axial Rotation ◽  
Postoperative Management ◽  
Biomechanical Study ◽  
Lateral Bending ◽  
Cervical Discectomy ◽  
Cloward Procedure ◽  
Flexion Extension

ABSTRACT OBJECTIVE To determine whether the Cloward technique of cervical discectomy and fusion increases immediate postoperative stiffness of single cervical motion segment after application of interbody dowel bone graft. METHODS We measured and compared the stiffness of single-motion segments in cadaveric cervical spines before and immediately after interbody fusion with the Cloward technique. Changes in range of motion and stiffness of the C5–C6 segment were measured in a bending flexibility test (flexion, extension, lateral bending and axial rotation) before and after a Cloward procedure in 11 fresh-frozen human cadaveric specimens from the 4th through the 7th vertebrae. RESULTS The Cloward procedure produced a statistically significant increase in stiffness of the operated segment in flexion and lateral bending when compared with the intact spine. The less stiff the segment before the operation, the greater the increase in its postoperative flexural stiffness (statistically significant). The Cloward procedure produced nonuniform changes in rotational and extensional stiffness that increased in some specimens and decreased in others. CONCLUSION Our data demonstrate that Cloward interbody fusion increases immediate postoperative stiffness of an operated segment only in flexion and lateral bending in cadaveric specimens in an in vitro environment. Thus, Cloward fusion seems a relatively ineffective method for increasing the stiffness of a construct. This may add to discussion on the use of spinal instrumentation and postoperative management of patients after cervical discectomy, which varies from bracing in hard collars through immobilization in soft collars to no external orthosis.

scholarly journals Biomechanical Evaluation of strategies for Adjacent Segment Disease after Lateral lumbar interbody fusion: is extension of pedicle screw necessary?

2019 ◽  
Author(s):  
Ziyang Liang ◽  
Jianchao Cui ◽  
Jiarui Zhang ◽  
Jiahui He ◽  
Jingjing Tang ◽  
...  
Keyword(s):  
Pedicle Screw ◽  
Interbody Fusion ◽  
Adjacent Segment Disease ◽  
Adjacent Segment ◽  
Fe Model ◽  
Rigid Fixation ◽  
Lateral Bending ◽  
Maximum Displacement ◽  
Flexion Extension ◽  
Posterior Extension

Abstract Background: Adjacent segment disease (ASD) is a well-known complication after interbody fusion. Pedicle screw-rod revision possessed sufficient strength and rigidity. However, is a surgical segment with rigid fixation necessary for ASD reoperation? This study aimed to investigate the biomechanical effect on LLIF with different instrumentation for ASD treatment.Methods: A validated L2~5 finite element (FE) model was modified to simulate. ASD was considered the level cranial to the upper-instrumented segment(L3/4). Bonegraft fusion in LLIF with bilateral pedicle screw fixation (BPS) has occurred at the L4/5. The ASD segment for each group was underwent a) LLIF + posterior extension of BPS, b) PLIF + posterior extension of BPS, c) LLIF + lateral screw, d) Stand-alone LLIF. L3/4 Range of motion (ROM), interbody cage stress and strain, screw-boneinterface stress, cage-endplate interface stress, and L2/3 nucleus pulposus of intradiscal pressure (NP-IDP) analysis were calculated for the comparisons among fourmodels.Results: All reconstructive models displayed decreased motion at L3/4. In each loading condition, difference was not significant between model a and b, which providedthe maximum ROM reduction (73.8% to 97.7%, 68.3% to 98.4%, respectively). Model c also provided a significant ROM reduction (64.9% to 77.5%). Model d provided a minimal restriction of ROM (18.3% to 90.1%), which exceeded that of model a by 13.1 times in flexion-extension, 10.3 times in lateral bending and 4.8 times in rotation. Model b generated greater cage stress than other models, particularly in flexion. The maximum displacement of the cage and the peak stress of cage-endplate interface were found to be the highest in the model d in all loading conditions. For the screw bone interface, the stress was significantly greater in lateral instrumentation than that of posterior instrumentation.Conclusions: Stand-alone LLIF is likely to have limited stability, particularly in lateral bending and axial rotation. Posterior extension of BPS can provide the reliablystability and excellently protective effect on instrumentation and endplate. However, LLIF with in situ screw may be an alternative for ASD reoperation.

scholarly journals Biomechanical Study of Cervical Disc Arthroplasty Devices Using Finite Element Modeling

2021 ◽  
Vol 4 (2) ◽  
Author(s):  
Narayan Yoganandan ◽  
Yuvaraj Purushothaman ◽  
Hoon Choi ◽  
Jamie Baisden ◽  
Deepak Rajasekaran ◽  
...  
Keyword(s):  
Finite Element ◽  
Intradiscal Pressure ◽  
Cervical Disc ◽  
Cervical Disc Arthroplasty ◽  
Adjacent Segment ◽  
Lateral Bending ◽  
Disc Arthroplasty ◽  
Bryan Disc ◽  
Flexion Extension ◽  
Index Level

Abstract Many artificial discs for have been introduced to overcome the disadvantages of conventional anterior discectomy and fusion. The purpose of this study was to evaluate the performance of different U.S. Food and Drug Administration (FDA)-approved cervical disc arthroplasty (CDA) on the range of motion (ROM), intradiscal pressure, and facet force variables under physiological loading. A validated three-dimensional finite element model of the human intact cervical spine (C2-T1) was used. The intact spine was modified to simulate CDAs at C5-C6. Hybrid loading with a follower load of 75 N and moments under flexion, extension, and lateral bending of 2 N·m each were applied to intact and CDA spines. From this work, it was found that at the index level, all CDAs except the Bryan disc increased ROM, and at the adjacent levels, motion decreased in all modes. The largest increase occurred under the lateral bending mode. The Bryan disc had compensatory motion increases at the adjacent levels. Intradiscal pressure reduced at the adjacent levels with Mobi-C and Secure-C. Facet force increased at the index level in all CDAs, with the highest force with the Mobi-C. The force generally decreased at the adjacent levels, except for the Bryan disc and Prestige LP in lateral bending. This study demonstrates the influence of different CDA designs on the anterior and posterior loading patterns at the index and adjacent levels with head supported mass type loadings. The study validates key clinical observations: CDA procedure is contraindicated in cases of facet arthroplasty and may be protective against adjacent segment degeneration.

scholarly journals Reduction in adjacent-segment degeneration after multilevel posterior lumbar interbody fusion with proximal DIAM implantation

2015 ◽  
Vol 23 (2) ◽  
pp. 190-196 ◽  
Author(s):  
Kang Lu ◽  
Po-Chou Liliang ◽  
Hao-Kuang Wang ◽  
Cheng-Loong Liang ◽  
Jui-Sheng Chen ◽  
...  
Keyword(s):  
Interbody Fusion ◽  
Posterior Lumbar Interbody Fusion ◽  
Adjacent Segment Degeneration ◽  
Adjacent Segment ◽  
Lumbar Interbody Fusion ◽  
Flexion Extension ◽  
Second Surgery ◽  
Group A ◽  
Group B ◽  
Interspinous Process Device

OBJECTMultilevel long-segment lumbar fusion poses a high risk for future development of adjacent-segment degeneration (ASD). Creating a dynamic transition zone with an interspinous process device (IPD) proximal to the fusion has recently been applied as a method to reduce the occurrence of ASD. The authors report their experience with the Device for Intervertebral Assisted Motion (DIAM) implanted proximal to multilevel posterior lumbar interbody fusion (PLIF) in reducing the development of proximal ASD.METHODSThis retrospective study reviewed 91 cases involving patients who underwent 2-level (L4–S1), 3-level (L3–S1), or 4-level (L2–S1) PLIF. In Group A (42 cases), the patients received PLIF only, while in Group B (49 cases), an interspinous process device, a DIAM implant, was put at the adjacent level proximal to the PLIF construct. Bone resection at the uppermost segment of the PLIF was equally limited in the 2 groups, with preservation of the upper portion of the spinous process/lamina and the attached supraspinous ligament. Outcome measures included a visual analog scale (VAS) for low-back pain and leg pain and the Oswestry Disability Index (ODI) for functional impairment. Anteroposterior and lateral flexion/extension radiographs were used to evaluate the fusion status, presence and patterns of ASD, and mobility of the DIAM-implanted segment.RESULTSSolid interbody fusion without implant failure was observed in all cases. Radiographic ASD occurred in 20 (48%) of Group A cases and 3 (6%) of Group B cases (p < 0.001). Among the patients in whom ASD was identified, 9 in Group A and 3 in Group B were symptomatic; of these patients, 3 in Group A and 1 in Group B underwent a second surgery for severe symptomatic ASD. At 24 months after surgery, Group A patients fared worse than Group B, showing higher mean VAS and ODI scores due to symptoms related to ASD. At the final follow-up evaluations, as reoperations had been performed to treat symptomatic ASD in some patients, significant differences no longer existed between the 2 groups. In Group B, flexion/extension mobility at the DIAM-implanted segment was maintained in 35 patients and restricted or lost in 14 patients, 5 of whom had already lost segmental flexion/extension mobility before surgery. No patient in Group B developed ASD at the segment proximal to the DIAM implant.CONCLUSIONSProviding a dynamic transition zone with a DIAM implant placed immediately proximal to a multilevel PLIF construct was associated with a significant reduction in the occurrence of radiographic ASD, compared with PLIF alone. Given the relatively old age and more advanced degeneration in patients undergoing multilevel PLIF, this strategy appears to be effective in lowering the risk of clinical ASD and a second surgery subsequent to PLIF.

scholarly journals In vitro biomechanical effects of reconstruction on adjacent motion segment: comparison of aligned/kyphotic posterolateral fusion with aligned posterior lumbar interbody fusion/posterolateral fusion

2003 ◽  
Vol 99 (2) ◽  
pp. 221-228 ◽  
Author(s):  
Hideki Sudo ◽  
Itaru Oda ◽  
Kuniyoshi Abumi ◽  
Manabu Ito ◽  
Yoshihisa Kotani ◽  
...  
Keyword(s):  
Interbody Fusion ◽  
Posterior Lumbar Interbody Fusion ◽  
Posterolateral Fusion ◽  
Adjacent Segment ◽  
Lumbar Interbody Fusion ◽  
Content Type ◽  
Motion Segment ◽  
Flexion Extension ◽  
Fine Print

Object. Posterior lumbar interbody fusion (PLIF) was developed to overcome the limitations of posterolateral fusion in correcting spinal deformity and maintaining lumbar lordosis. In this study the authors compare the biomechanical effects of three different posterior reconstructions on the adjacent motion segment. Methods. Ten calf spinal (L2—S1) specimens underwent nondestructive flexion—extension testing (± 6 Nm). The specimens were destabilized at the L5—S1 levels after intact testing. This was followed by pedicle screw fixation with and without interbody cages as follows: 1) with straight rods (“aligned” posterolateral fusion); 2) with kyphotically prebent rods (“kyphotic” posterolateral fusion); and 3) with interbody cages combined with straight rods (“aligned” PLIF/posterolateral fusion). The range of motion (ROM) of the operative segments, the intradiscal pressure (IDP), and longitudinal lamina strain in the superior adjacent segment (L4–5) were analyzed. The ROM associated with aligned PLIF/posterolateral fusion-treated specimens was significantly less than both the aligned and kyphotic posterolateral fusion-treated procedures in both flexion and extension loading (p < 0.05). The aligned PLIF/posterolateral fusion was associated with greater IDP and the lamina strain compared with the aligned and kyphotic posterolateral fusion groups in flexion loading. Under extension loading, greater IDP and lamina strain were present in the kyphotic posterolateral fusion group than in the aligned posterolateral fusion group. The highest IDP and lamina strain were shown in the aligned PLIF/posterolateral fusion group. Conclusions. Compared with kyphotic posterolateral fusion, PLIF may lead to even higher load at the superior adjacent level because of the increased stiffness of the fixed segments even if local kyphosis is corrected by PLIF.

Bioabsorbable anterior lumbar plate fixation in conjunction with cage-assisted anterior interbody fusion

2002 ◽  
Vol 97 (4) ◽  
pp. 447-455 ◽  
Author(s):  
Denis J. DiAngelo ◽  
Jeffrey L. Scifert ◽  
Scott Kitchel ◽  
G. Bryan Cornwall ◽  
Bobby J. McVay
Keyword(s):  
Interbody Fusion ◽  
Plate Fixation ◽  
Axial Rotation ◽  
Biomechanical Study ◽  
Local Motion ◽  
Content Type ◽  
Flexion Extension ◽  
Spine Model ◽  
Fine Print

Object. An in vitro biomechanical study was conducted to determine the effects of anterior stabilization on cage-assisted lumbar interbody fusion biomechanics in a multilevel human cadaveric lumbar spine model. Methods. Three spine conditions were compared: harvested, bilateral multilevel cages (CAGES), and CAGES with bioabsorbable anterior plates (CBAP), tested under flexion—extension, lateral bending, and axial rotation. Measurements included vertebral motion, applied load, and bending/rotational moments. Application of anterior fixation decreased local motion and increased stiffness of the instrumented levels. Clinically, this spinal stability may serve to promote fusion. Conclusions. Coupled with the bioabsorbability of the plating material, the bioabsorbable anterior lumbar plating system is considered biomechanically advantageous.

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