scholarly journals A Technical Nuance to Avoid Lumbar Five Radiculopathy with Anterior Lumbar Fusion and Posterior Instrumentation

2021 ◽  
Vol 2021 ◽  
pp. 1-4
Author(s):  
Matthew T. Neal ◽  
Maziyar A. Kalani ◽  
Mark K. Lyons

The anterior lumbar interbody fusion (ALIF) is a well-established procedure used to treat a multitude of spinal pathologies. When performed at the L5-S1 level, the ALIF is often supplemented with posterior pedicle screw and rod fixation. Because the interbody device can restore disk and foraminal height, one benefit of the ALIF procedure is indirect neural decompression in the spinal canal and neural foramina. If the contour of the posterior rod is not matched to the exact position of the tulip heads on the pedicle screws, spondylolisthesis can be introduced, leading to foraminal stenosis and nerve compression. This concern is particularly germane when the posterior instrumentation is placed percutaneously without any direct foraminal decompression. In this report, we describe a patient who had an L4-S1 ALIF, resulting in new L5-S1 retrolisthesis and worsening L5 radiculopathy. Technical nuances and avoidance strategies are discussed.

2010 ◽  
Vol 12 (4) ◽  
pp. 372-380 ◽  
Author(s):  
Dean G. Karahalios ◽  
Taro Kaibara ◽  
Randall W. Porter ◽  
Udaya K. Kakarla ◽  
Phillip M. Reyes ◽  
...  

Object An interspinous anchor (ISA) provides fixation to the lumbar spine to facilitate fusion. The biomechanical stability provided by the Aspen ISA was studied in applications utilizing an anterior lumbar interbody fusion (ALIF) construct. Methods Seven human cadaveric L3–S1 specimens were tested in the following states: 1) intact; 2) after placing an ISA at L4–5; 3) after ALIF with an ISA; 4) after ALIF with an ISA and anterior screw/plate fixation system; 5) after removing the ISA (ALIF with plate only); 6) after removing the plate (ALIF only); and 7) after applying bilateral pedicle screws and rods. Pure moments (7.5 Nm maximum) were applied in flexion and extension, lateral bending, and axial rotation while recording angular motion optoelectronically. Changes in angulation as well as foraminal height were also measured. Results All instrumentation variances except ALIF alone reduced angular range of motion (ROM) significantly from normal in all directions of loading. The ISA was most effective in limiting flexion and extension (25% of normal) and less effective in reducing lateral bending (71% of normal) and axial rotation (71% of normal). Overall, ALIF with an ISA provided stability that was statistically equivalent to ALIF with bilateral pedicle screws and rods. An ISA-augmented ALIF allowed less ROM than plate-augmented ALIF during flexion, extension, and lateral bending. Use of the ISA resulted in flexion at the index level, with a resultant increase in foraminal height. Compensatory extension at the adjacent levels prevented any significant change in overall sagittal balance. Conclusions When used with ALIF at L4–5, the ISA provides immediate rigid immobilization of the lumbar spine, allowing equivalent ROM to that of a pedicle screw/rod system, and smaller ROM than an anterior plate. When used with ALIF, the ISA may offer an alternative to anterior plate fixation or bilateral pedicle screw/rod constructs.


2021 ◽  
pp. 1-9

OBJECTIVE Excessive stress and motion at the L5–S1 level can lead to degenerative changes, especially in patients with posterior instrumentation suprajacent to L5. Attention has turned to utilization of L5–S1 anterior lumbar interbody fusion (ALIF) to stabilize the lumbosacral junction. However, questions remain regarding the effectiveness of stand-alone ALIF in the setting of prior posterior instrumented fusions terminating at L5. The purpose of this study was to assess the biomechanical stability of an L5–S1 ALIF with increasing lengths of posterior thoracolumbar constructs. METHODS Seven human cadaveric spines (T9–sacrum) were instrumented with pedicle screws from T10 to L5 and mounted to a 6 degrees-of-freedom robot. Posterior fusion construct lengths (T10–L5, T12–L5, L2–5, and L4–5) were instrumented to each specimen, and torque-fusion level relationships were determined for each construct in flexion-extension, axial rotation, and lateral bending. A stand-alone L5–S1 ALIF was then instrumented, and L5–S1 motion was measured as increasing pure moments (2 to 12 Nm) were applied. Motion reduction was calculated by comparing L5–S1 motion across the ALIF and non-ALIF states. RESULTS The average motion at L5–S1 in axial rotation, flexion-extension, and lateral bending was assessed for each fusion construct with and without ALIF. After adding ALIF to a posterior fusion, L5–S1 motion was significantly reduced relative to the non-ALIF state in all but one fused surgical condition (p < 0.05). Longer fusions with ALIF produced larger L5–S1 motions, and in some cases resulted in motions higher than native state motion. CONCLUSIONS Posterior fusion constructs up to L4–5 could be appropriately stabilized by a stand-alone L5–S1 ALIF when using a nominal threshold of 80% reduction in native motion as a potential positive indicator of fusion. The results of this study allow conclusions to be drawn from a biomechanical standpoint; however, the clinical implications of these data are not well defined. These findings, when taken in appropriate clinical context, can be used to better guide clinicians seeking to treat L5–S1 pathology in patients with prior posterior thoracolumbar constructs.


Neurosurgery ◽  
2019 ◽  
Vol 66 (Supplement_1) ◽  
Author(s):  
George V Huffmon

Abstract INTRODUCTION Lateral position interbody lumbar fusion surgery has become popular as an excellent modality for obtaining lumbar fusion and achieving sagital balance. Posterior instrumentation with pedicle screw fixation adds structural integrity to the construct. Maintaining the patient in the lateral position for pedicle screw placement decreases the time that the patient is under general anesthesia. Since August 2017 we have successfully performed 32 single position pedicle screw fixations utilizing robotic guidance. METHODS The lateral position was utilized for interbody fusion using a variety of techniques; oblique lumbar interbody fusion, extreme lateral lumbar interbody fusion, and lateral anterior lumbar interbody fusion. The Mazor X robot (Medtronic) was utilized for guidewire placement maintaining the patient in the lateral position. Pedicle screws of various manufacturers were placed over the guide wires and connecting rods were placed in the lateral position. RESULTS Since August 2017 we have successfully placed pedicle screws in 1 and 2 level single position lateral lumbar fusions in 32 of 39 cases attempted. There were no nerve root injuries nor any complications related to pedicle screw placement. CONCLUSION Single position lateral lumbar fusion cases utilizing robotic guidance for pedicle screw placement is a viable surgical procedure. Placement of the pedicle screws in the lateral position can reduce intraoperative anesthetic time by eliminating the placement of the patient into the prone position. Utilization of robotic guidance can decrease intraoperative fluoroscopy exposure.


2003 ◽  
Vol 98 (1) ◽  
pp. 100-103 ◽  
Author(s):  
Jee Soo Jang ◽  
Sang Ho Lee ◽  
Sang Rak Lim

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.


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