Degenerative Scoliosis with Left L3 Radiculopathy
Patient Presents with Mechanical Low Back Pain and Neurogenic Claudication
The patient is a high-functioning 80-year-old female who presents with mechanical low back pain, left L3 radiculopathy, and neurogenic claudication. Her past medical history is benign.
The physical exam reveals that she is neurovascularly intact.
Her VAS Back score is 70; VAS Leg is 90.
She scores 28 on ODI.
Previously, the patient has tried basic non-operative treatments (mainly physical therapy), but she has not found relief.
Figure 1: AP x-ray showing mild lumbar degenerative scoliosis
Figure 2: Lateral x-ray showing multi-level degenerative disc disease and a grade 2 degenerative spondylolisthesis at L4-L5
Figures 3A and 3B: Flexion-extension x-rays show vacuum disc at L2-L3 and minimal translation at L4-L5
Figures 4A and 4B: T1-weighted MRI (left) and T2-weighted MRI confirm plain film findings
Figure 5: Axial MRI of L3-L4 shows large extruded disc fragment (at blue arrow)
The patient was diagnosed with degenerative lumbar scoliosis with spinal stenosis.
Suggest TreatmentIndicate how you would treat this patient by completing the following brief survey. Your response will be added to our survey results below.
I did a staged anterior/posterior indirect decompression and posterior instrumentation. Lateral transpsoas procedures at L1-L4 were done, followed by posterior MIS TLIFs at L4-L5 and L5-S1. There was percutaneous instrumentation at T12-S1.
Figure 6: Fluoroscopic image during lateral transpsoas procedures
Figure 7: Lateral fluoroscopic image during stage one
Figure 8: AP x-ray post-second stage of the surgery: posterior spinal instrumentation T12-sacrum
Figure 9: Lateral x-ray post-second stage
The patient is now 6 months post-op. Her VAS Back dropped from 70 to 30; VAS Leg dropped from 90 to 0. Her ODI remained the same (28).
Dr. Knight presents an excellent case of a patient with degenerative scoliosis whom he treated surgically in a minimally invasive fashion. These types of cases are obviously quite challenging from clinical and surgical perspectives. The advent of minimally invasive techniques and technologies have opened new opportunities to treat these patients in a manner that is both safe and effective.
Based on the intra-operative fluoroscopic images of the first stage lateral transpsoas procedure, it appears that the surgical goals of sagittal/coronal balance correction and intervertebral height restoration have been accomplished. Although the decision to perform two level TLIFs at L4-L5 and L5-S1 as second stage procedures is a valid one, I am assuming that the L4-L5 disc space may have not have been accessible via the lateral approach either due to the prominence of iliac crest and/or presence of the lumbar plexus at this level. Anatomic studies have now shown that the lumbar plexus may be present in up to 20% of cases approached at L4-L5.
This patient also presented with clinically significant leg pain and symptoms consistent with neurogenic claudication. Based on the results of her post-operative VAS leg pain score (0), it appears that the stenosis caused by the sizable left sided disc extrusion at L3-L4 was adequately addressed with an indirect decompression technique via disc height restoration and ligomentotaxis from the placement of PEEK interbody cages.This is somewhat surprising. Although it was not mentioned whether or not a direct decompression was performed, consideration of a left sided L3-L4 microdiscectomy could also have been entertained as an adjuct to the second staged procedure.
I am unsure why the construct was extended up to the T12-L1 level. The T2 weighted sagittal image appears to show a disc that is relatively well hydrated and intact. Although starting/stopping a long construct at the thoracolumbar junction may be somewhat controversial, I tend to preserve as many levels as possible in order to preserve as many motion segments as possible. Therefore, I probably would have elected to limit the percutaneous instrumentation from L1-S1. There was also no mention of a posterolateral facet fusion at the T12-L1 level which brings up the controversial issue of uninstrumented fusions.
Nevertheless, there is no question that the surgical goals of deformity correction and stabilization were performed quite admirably. More importantly, the clinical goal of symptomatic relief from back and leg pain were properly addressed with this innovative, minimally invasive approach. For that, Dr. Knight should be commended for his excellent work.
Comments from Dr. Roh raise several points often encountered during discussion regarding the management of degenerative deformity: What is the primary source of the patient’s complaint and how is that best managed? As with many conditions related to the spine, treatment options are often predicated on the surgeon’s experience, interpretation of the patient’s presenting complaints, physical findings, and imaging studies. Patients with degenerative deformity most commonly present with a complex of issues as seen in this case: radiculopathy, claudication, segmental instability and mechanical low back pain. While all of the treatment options outlined above could address individual components of this patient’s complaints, in my opinion, the staged stabilization with indirect decompression offered the most effective option.
Indirect decompression has become a frequently used component of my practice. The large disc herniation shown on axial MRI was mostly likely the major contributing factor to the patient’s radicular pain. Via the direct lateral approach, preparation of the L3-L4 disc space allows excellent evacuation of disc material. Based on the lack of post-operative symptoms, no formal direct decompression was deemed necessary, and the continued reduction in leg symptoms precluded the need for additional post-operative imaging of the lumbar canal.
As Dr. Roh suggested in his commentary, I would typically address the L4-L5 level via direct lateral approach during the primary stage. For anatomic reasons, proximity of the iliac crest, and degree of spondylolisthesis, the L4-L5 disc space was not safely approachable via the transpsoas technique. In this case, I chose to extend the fusion to T12 in conjunction with posterior facet fusion at T12-L1. While the MIS posterior instrumentation preserves midline ligamentous structures, I remain reluctant to stop fusion and instrumentation at L1. In the majority of cases, I typically extend a construct to T10 or below the beginning of thoracic kyphosis as a means of improving stability. In situations where the disc space at L1-L2 is not integral to the deformity and well hydrated my construct would stop at L2.
Thus far the patient has done very well. There have been no complaints of thigh pain, paraesthesia, or leg weakness. As with many elderly patients, her ODI has not dramatically changed. This is frequently seen in outcome assessment and is probably a testament to the stoic nature of many elderly patients. Some might argue that her age is a contraindication for extensive spinal fusion and that simple decompression was the only procedure required. To the contrary, in my opinion, elderly patients with complex degenerative deformity frequently require a more extensive approach. Procedures with the potential to further destabilize lateral listhesis or spondylolisthesis in an active elderly patient make the revision surgery more difficult on patient and surgeon.