In vitro biomechanical investigation of the stability and stress-shielding effect of lumbar interbody fusion devices

2000 ◽  
Vol 93 (2) ◽  
pp. 259-265 ◽  
Author(s):  
Masahiro Kanayama ◽  
Bryan W. Cunningham ◽  
Charles J. Haggerty ◽  
Kuniyoshi Abumi ◽  
Kiyoshi Kaneda ◽  
...  
Keyword(s):  
Interbody Fusion ◽  
Stress Shielding ◽  
Shielding Effect ◽  
Lumbar Interbody Fusion ◽  
Content Type ◽  
Different Types ◽  
Spine Model ◽  
Structural Allografts ◽  
Fine Print

Object. Interbody fusion devices are rapidly gaining acceptance as a method of ensuring lumbar interbody arthrodesis. Although different types of devices have been developed, the comparative reconstruction stability remains controversial. It also remains unclear how different stress-shielded environments are created within the devices. Using a calf spine model, this study was designed to compare the construct stiffness afforded by 11 differently designed lumbar interbody fusion devices and to quantify their stress-shielding effects by measuring pressure within the devices. Methods. Sixty-six lumbar specimens obtained from calves were subjected to anterior interbody reconstruction at L4–5 by using one of the following interbody fusion devices: four different threaded fusion cages (BAK device, BAK Proximity, Ray TFC, and Danek TIBFD), five different nonthreaded fusion devices (oval and circular Harms cages, Brantigan PLIF and ALIF cages, and InFix device); two different types of allograft (femoral ring and bone dowel) were used. Construct stiffness was evaluated in axial compression, torsion, flexion, and lateral bending. Prior to testing, a silicon elastomer was injected into the cages and intracage pressures were measured using pressure needle transducers. Conclusions. No statistical differences were observed in construct stiffness among the threaded cages and nonthreaded devices in most of the testing modalities. Threaded fusion cages demonstrated significantly lower intracage pressures compared with nonthreaded cages and structural allografts. Compared with nonthreaded cages and structural allografts, threaded fusion cages afforded equivalent reconstruction stiffness but provided more stress-shielded environment within the devices.

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.

Retroperitoneal lateral lumbar interbody fusion with titanium threaded fusion cages

2002 ◽  
Vol 96 (1) ◽  
pp. 50-55 ◽  
Author(s):  
Christopher E. Wolfla ◽  
Dennis J. Maiman ◽  
Frank J. Coufal ◽  
James R. Wallace
Keyword(s):  
Interbody Fusion ◽  
Lumbar Fusion ◽  
Fusion Rate ◽  
Lumbar Interbody Fusion ◽  
Anterior Longitudinal Ligament ◽  
Content Type ◽  
Single Cage ◽  
Novel Technique ◽  
Methodological Problems ◽  
Fine Print

Object. Intertransverse arthrodesis in which instrumentation is placed is associated with an excellent fusion rate; however, treatment of patients with symptomatic nonunion presents a number of difficulties. Revision posterior and traditional anterior procedures are associated with methodological problems. For example, in the latter, manipulation of the major vessels from L-2 to L-4 may be undesirable. The authors describe a method for performing retroperitoneal lumbar interbody fusion (LIF) in which a threaded cage is placed from L-2 through L-5 via a lateral trajectory, and they also detail a novel technique for implanting a cage from L-5 to S-1 via an oblique trajectory. Although they present data obtained over a 2-year period in the study of 15 patients, the focus of this report is primarily on describing the surgical procedure. Methods. The lateral lumbar spine was exposed via a standard retroperitoneal approach. Using the anterior longitudinal ligament as a landmark, the L2–3 through L4–5 levels were fitted with instrumentation via a true lateral trajectory; the L5—S1 level was fitted with instrumentation via an oblique trajectory. A single cage was placed at each instrumented level. Fifteen symptomatic patients in whom previous lumbar fusion had failed underwent retroperitoneal LIF. Thirty-eight levels were fitted with instrumentation. There have been no instrumentation-related failures, and fusion has occurred at 37 levels during the 2-year postoperative period. Conclusions. The use of retroperitoneal LIF in which threaded fusion cages are used avoids the technical difficulties associated with repeated posterior procedures. In addition, it allows L2—S1 instrumentation to be placed anteriorly via a single surgical approach. This construct has been shown to be biomechanically sound in animal models, and it appears to be a useful alternative for the management of failed multilevel intertransverse arthrodesis.

Beta—tricalcium phosphate as a substitute for autograft in interbody fusion cages in the canine lumbar spine

2002 ◽  
Vol 97 (3) ◽  
pp. 350-354 ◽  
Author(s):  
Takashiro Ohyama ◽  
Yoshichika Kubo ◽  
Hiroo Iwata ◽  
Waro Taki
Keyword(s):  
Lumbar Spine ◽  
Tricalcium Phosphate ◽  
Interbody Fusion ◽  
Donor Site ◽  
Posterolateral Approach ◽  
Content Type ◽  
Spine Model ◽  
Group A ◽  
Group B ◽  
Fine Print

Object. An interbody fusion cage has been introduced for cervical anterior interbody fusion. Autogenetic bone is packed into the cage to increase the rate of union between adjacent vertebral bodies. Thus, donor site—related complications can still occur. In this study a synthetic ceramic, β—tricalcium phosphate (TCP), was examined as a substitute for autograft bone in a canine lumbar spine model. Methods. In 12 dogs L-1 to L-4 vertebrae were exposed via a posterolateral approach, and discectomy and placement of interbody fusion cages were performed at two intervertebral disc spaces. One cage was filled with autograft (Group A) and the other with TCP (Group B). The lumbar spine was excised at 16 weeks postsurgery, and biomechanical, microradiographic, and histological examinations were performed. Both the microradiographic and histological examinations revealed that fusion occurred in five (41.7%) of 12 operations performed in Group A and in six (50%) of 12 operations performed in Group B. The mean percentage of trabecular bone area in the cages was 54.6% in Group A and 53.8% in Group B. There were no significant intergroup differences in functional unit stiffness. Conclusions. Good histological and biomechanical results were obtained for TCP-filled interbody fusion cages. The results were comparable with those obtained using autograft-filled cages, suggesting that there is no need to harvest iliac bone or to use allo- or xenografts to increase the interlocking strength between the cage and vertebral bone to achieve anterior cervical interbody fusion.

Resorbable polymer implants in unilateral transforaminal lumbar interbody fusion

2002 ◽  
Vol 97 (4) ◽  
pp. 464-467 ◽  
Author(s):  
Thomas G. Lowe ◽  
Jeffrey D. Coe
Keyword(s):  
Adverse Events ◽  
Biodegradable Polymers ◽  
Clinical Studies ◽  
Interbody Fusion ◽  
Transforaminal Lumbar Interbody Fusion ◽  
Degenerative Disease ◽  
Lumbar Interbody Fusion ◽  
Content Type ◽  
Fine Print

Object. Sixty patients underwent instrumentation-assisted posterior transforaminal lumbar interbody fusion (TLIF) with resorbable polymer cages and autograft bone for degenerative disease. This article discusses the technique of TLIF and its early outcomes. Methods. Although the follow-up period is short and results are preliminary, no adverse events or complications were attributed to the resorbable polymer. Conclusions. Further multicenter clinical studies are underway with a minimum 2-year follow-up period chosen as an endpoint to provide insight as to the future of biodegradable polymers as spinal interbody devices.

Posterior lumbar interbody fusion with cages: an independent review of 71 cases

1999 ◽  
Vol 91 (2) ◽  
pp. 186-192 ◽  
Author(s):  
Siviero Agazzi ◽  
Alain Reverdin ◽  
Daniel May
Keyword(s):  
Retrospective Study ◽  
Clinical Outcome ◽  
Interbody Fusion ◽  
Posterior Lumbar Interbody Fusion ◽  
Fusion Rate ◽  
Lumbar Interbody Fusion ◽  
Content Type ◽  
Fixation Techniques ◽  
Independent Review ◽  
Fine Print

Object. The authors conducted a retrospective study to provide an independent evaluation of posterior lumbar interbody fusion (PLIF) in which impacted carbon cages were used. Interbody cages have been developed to replace tricortical interbody grafts in anterior and PLIF procedures. Superior fusion rates and clinical outcomes have been claimed by the developers. Methods. In a retrospective study, the authors evaluated 71 consecutive patients in whom surgery was performed between 1995 and 1997. The median follow-up period was 28 months. Clinical outcome was assessed using the Prolo scale. Fusion results were interpreted by an independent radiologist. The fusion rate was 90%. Overall, 67% of the patients were satisfied with their outcome and would undergo the same operation again. Based on the results of the Prolo scale, however, in only 39% of the patients were excellent or good results achieved. Forty-six percent of the work-eligible patients resumed their working activity. Clinical outcome and return-to-work status were significantly associated with socioeconomic factors such as preoperative employment (p = 0.03), compensation issues (p = 0.001), and length of preoperative sick leave (p = 0.01). Radiographically demonstrated fusion was not statistically related to clinical outcome (p = 0.2). Conclusions. This is one of the largest independent series in which PLIF with cages has been evaluated. The results show that the procedure is safe and effective with a 90% fusion rate and a 66% overall satisfaction rate, which compare favorably with those of traditional fixation techniques but fail to match the higher results claimed by the innovators of the cage techniques. The authors' experience confirms the reports of others that many patients continue to experience incapacitating back pain despite successful fusion and neurological recovery.

Stabilizing effect of posterior lumbar interbody fusion cages before and after cyclic loading

2000 ◽  
Vol 92 (1) ◽  
pp. 87-92 ◽  
Author(s):  
Annette Kettler ◽  
Hans-Joachim Wilke ◽  
Rupert Dietl ◽  
Matthias Krammer ◽  
Christianto Lumenta ◽  
...  
Keyword(s):  
Cyclic Loading ◽  
Interbody Fusion ◽  
Posterior Lumbar Interbody Fusion ◽  
Axial Rotation ◽  
Lumbar Interbody Fusion ◽  
Lateral Bending ◽  
Content Type ◽  
Flexion Extension ◽  
Stabilizing Effect ◽  
Fine Print

Object. The function of interbody fusion cages is to stabilize spinal segments primarily by distracting them as well as by allowing bone ingrowth and fusion. An important condition for efficient formation of bone tissue is achieving adequate spinal stability. However, the initial stability may be reduced due to repeated movements of the spine during everyday activity. Therefore, in addition to immediate stability, stability after cyclic loading is of remarkable relevance; however, this has not yet been investigated. The object of this study was to investigate the immediate stabilizing effect of three different posterior lumbar interbody fusion cages and to clarify the effect of cyclic loading on the stabilization. Methods. Before and directly after implantation of a Zientek, Stryker, or Ray posterior lumbar interbody fusion cage, 24 lumbar spine segment specimens were each evaluated in a spine tester. Pure lateral bending, flexion—extension, and axial rotation moments (± 7.5 Nm) were applied continuously. The motion in each specimen was measured simultaneously. The specimens were then loaded cyclically (40,000 cycles, 5 Hz) with an axial compression force ranging from 200 to 1000 N. Finally, they were tested once again in the spine tester. Conclusions. In general, a decrease of movement in all loading directions was noted after insertion of the Zientek and Ray cages and an increase of movement after implantation of a Stryker cage. In all three cage groups greater stability was demonstrated in lateral bending and flexion than in extension and axial rotation. Reduced stability during cyclic loading was observed in all three cage groups; however, loss of stability was most pronounced when the Ray cage was used.

Clinical outcomes and complications associated with pedicle screw fixation—augmented lumbar interbody fusion

2004 ◽  
Vol 1 (3) ◽  
pp. 261-266 ◽  
Author(s):  
Dennis J. Rivet ◽  
David Jeck ◽  
James Brennan ◽  
Adrian Epstein ◽  
Carl Lauryssen
Keyword(s):  
Carbon Fiber ◽  
Pedicle Screw ◽  
Interbody Fusion ◽  
Screw Fixation ◽  
Pedicle Screw Fixation ◽  
Lumbar Interbody Fusion ◽  
Content Type ◽  
Repeated Surgery ◽  
Fine Print

Object. The authors conducted a prospective study to evaluate the clinical and radiological outcomes and complications associated with uni- and bilateral transforaminal lumbar interbody fusion (TLIF) performed using carbon fiber Brantigan I/F Cages and pedicle screw fixation. Methods. Forty-two consecutive patients who had undergone uni- or bilateral TLIF between February 1999 and July 2000 were prospectively evaluated. Clinical outcome was graded using a modified Prolo Scale, the McGill Pain Index Scale, a follow-up questionnaire, and charts. An independent radiologist assessed radiological outcomes. All patients were followed for at least 1 year. Based on Prolo Scale scores, an excellent or good 1-year outcome was achieved in 73% of patients; 90% of patients responded that they would undergo the procedure again. At 1 year, radiographic fusion was demonstrated in 74% and was statistically related to clinical outcome (p < 0.05). There were no deaths or major hardware failures. Complications requiring repeated surgery included one case of cerebrospinal fluid (CSF) leakage and one case in which the hemovac drain was retained. There were four cases involving minor wound infections, eight involving CSF leaks, and none requiring repeated surgery. On routine follow-up radiography one pedicle screw was found to be broken; the patient remained asymptomatic and fusion occurred. Conclusions. Unilateral and bilateral TLIF involving placement of carbon fiber cages and pedicle screw fixation are effective treatment options in patients with indications for lumbar arthrodesis. The procedures result in acceptable rates of fusion and clinical success, and a minimal incidence of morbidity when performed by an experienced surgeon.

Guide device for percutaneous placement of translaminar facet screws after anterior lumbar interbody fusion

2003 ◽  
Vol 98 (1) ◽  
pp. 100-103 ◽  
Author(s):  
Jee Soo Jang ◽  
Sang Ho Lee ◽  
Sang Rak Lim
Keyword(s):  
Interbody Fusion ◽  
Screw Fixation ◽  
Anterior Lumbar Interbody Fusion ◽  
Posterior Fixation ◽  
Foraminal Stenosis ◽  
Lumbar Interbody Fusion ◽  
Content Type ◽  
Guide Device ◽  
Fine Print

Because the degree of immediate stabilization provided by cage-assisted anterior lumbar interbody fusion (ALIF) has been shown by several studies to be inadequate, supplementary posterior fixation, such as that created by translaminar or transpedicle screw fixation, is necessary. In this study, the authors studied the ALIF-augmentation procedure in which a special guide device is used to place percutaneously translaminar facet screws in 18 patients with degenerative lumbar disease. The minimum follow-up period was 1 month (mean 6 months, range 1–13 months). Degenerative spondylolisthesis with foraminal stenosis was diagnosed in nine patients, associated degenerative disc disease alone or combined with foraminal stenosis in eight, and recurrent disc herniation in one. Following screw placement, computerized tomography scanning was conducted to evaluate the accuracy of the facet screw positioning. All screws were properly placed. No screw penetrated the spinal canal or injured the neural structures. Excellent or good clinical outcomes were demonstrated in all patients at the last follow up. The use of this guide device for post—ALIF percutaneous translaminar facet screw fixation represents a safe, accurate, and minimally invasive modality with which to achieve immediate solid fixation in the lumbar spine.

Minimally invasive transforaminal lumbar interbody fusion with ipsilateral pedicle screw and contralateral facet screw fixation

2005 ◽  
Vol 3 (3) ◽  
pp. 218-223 ◽  
Author(s):  
Jee-Soo Jang ◽  
Sang-Ho Lee
Keyword(s):  
Minimally Invasive ◽  
Pedicle Screw ◽  
Interbody Fusion ◽  
Transforaminal Lumbar Interbody Fusion ◽  
Lumbar Interbody Fusion ◽  
Content Type ◽  
The Mean ◽  
Level Fusion ◽  
Fine Print

Object. The purpose of this study was to introduce a minimally invasive transforaminal lumbar interbody fusion (TLIF) technique that involves ipsilateral pedicle screw (PS) and contralateral facet screw (FS) fixation. Methods. Eight men and 15 women (mean age 59.5 years, range 48–68) underwent the aforementioned TLIF procedure for degenerative spondylolisthesis and uni- or bilateral radiculopathy. Twenty-two patients underwent one-level fusion and one patient two-level fusion (L4—S1). In all cases the various procedures were undertaken via one small incision. There were no intraoperative complications. The mean estimated blood loss (EBL) was 310 ml, and the mean operative time was 150 minutes in cases of one-level fusion. The follow-up period ranged from 13 to 28 months (mean 19 months). The mean Numeric Rating Scale score reflected improvement-reductions from 7.5 (back pain) and 7.4 (leg pain) to 2.3 and 0.7, respectively (p < 0.0001). The mean Oswestry Disability Index (ODI) scores also reflected improved status (ODI of 33.1 before the surgery to 7.6 after the surgery; p < 0.0001). Examination indicated that 22 of 24 fusion sites exhibited osseous union. At the last follow-up examination, satisfactory outcomes were observed in 21 out of 23 patients. Conclusions. The TLIF with ipsilateral PS and contralateral FS fixation has the advantages over the conventional TLIF of reduced EBL and diminished soft-tissue injury.

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