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Lumbar foraminal stenosis, the hidden stenosis including at L5/S1

Authors:
Sumihisa Orita at Chiba University
Sumihisa Orita
Kazuhide Inage at Chiba University
Kazuhide Inage
Yawara Eguchi at Chiba University
Yawara Eguchi
Go Kubota at Numazu City Hospital
Go Kubota
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Abstract and Figures

In patients with lower back and leg pain, lumbar foraminal stenosis (LFS) is one of the most important pathologies, especially for predominant radicular symptoms. LFS pathology can develop as a result of progressing spinal degeneration and is characterized by exacerbation with foraminal narrowing caused by lumbar extension (Kemp's sign). However, there is a lack of critical clinical findings for LFS pathology. Therefore, patients with robust and persistent leg pain, which is exacerbated by lumbar extension, should be suspected of LFS. Radiological diagnosis is performed using multiple radiological modalities, such as magnetic resonance imaging, including plain examination and novel protocols such as diffusion tensor imaging, as well as dynamic X-ray, and computed tomography. Electrophysiological testing can also aid diagnosis. Treatment options include both conservative and surgical approaches. Conservative treatment includes medication, rehabilitation, and spinal nerve block. Surgery should be considered when the pathology is refractory to conservative treatment and requires direct decompression of the exiting nerve root, including the dorsal root ganglia. In cases with decreased intervertebral height and/or instability, fusion surgery should also be considered. Recent advancements in minimally invasive lumbar lateral interbody fusion procedures enable effective and less invasive foraminal enlargement compared with traditional fusion surgeries such as transforaminal lumbar interbody fusion. The lumbosacral junction can cause L5 radiculopathy with greater incidence than other lumbar levels as a result of anatomical and epidemiological factors, which should be better addressed when treating clinical lower back pain.
Diagram of the anatomy of the lumbar spine, depicting regions of the lateral nerve root canal and a definition of foraminal stenosis. The lateral canal is segmented into the lateral recess, vertical interpedicular (foraminal), and extraforaminal zone. The foraminal zone is also appropriately referred to as the “hidden zone”
Diagram of the anatomy of the lumbar spine, depicting regions of the lateral nerve root canal and a definition of foraminal stenosis. The lateral canal is segmented into the lateral recess, vertical interpedicular (foraminal), and extraforaminal zone. The foraminal zone is also appropriately referred to as the “hidden zone”
… 
Anatomy of foramen in a sagittal section. a The anatomical boundaries for foramen is composed of multiple anatomical components: the adjacent superior–inferior vertebral pedicles, the posteroinferior margin of the superior vertebral body, the intervertebral disc (IVD), and the posterosuperior margin of the inferior vertebral body as the anterior boundaries, and the ligamentum flavum and superior and inferior articular facets as the posterior boundaries. b Representative magnetic resonance image in a sagittal section. IVD intervertebral disc, LF ligamentum flavum, AP articular process
Anatomy of foramen in a sagittal section. a The anatomical boundaries for foramen is composed of multiple anatomical components: the adjacent superior–inferior vertebral pedicles, the posteroinferior margin of the superior vertebral body, the intervertebral disc (IVD), and the posterosuperior margin of the inferior vertebral body as the anterior boundaries, and the ligamentum flavum and superior and inferior articular facets as the posterior boundaries. b Representative magnetic resonance image in a sagittal section. IVD intervertebral disc, LF ligamentum flavum, AP articular process
… 
Locational classification of dorsal root ganglia (DRG). a Spinal canal type: The proximal end of the DRG is located at the medial edge of pedicle. b Intraforaminal type: The proximal end of the DRG is located between the centre and medial edge of the pedicle. c Extraforaminal type: The proximal end of the DRG is located lateral to the centre of the pedicle
Locational classification of dorsal root ganglia (DRG). a Spinal canal type: The proximal end of the DRG is located at the medial edge of pedicle. b Intraforaminal type: The proximal end of the DRG is located between the centre and medial edge of the pedicle. c Extraforaminal type: The proximal end of the DRG is located lateral to the centre of the pedicle
… 
Scheme for typical foraminal stenosis in accordance with progressing lumbar spondylosis. (i) The root is compressed vertically by the decreased height of the foramen with bony spurs and deformity induced by the degenerated IVD. (ii) The root is compressed transversely by the hypertrophic/buckled ligamentum flavum with progressing subluxations of the superior facet. b–d Representative images of foraminal stenosis. The dotted circle indicates the normal anatomy, while solid circles indicate MRI findings in LFS. b Vertical stenosis, c transverse stenosis, and d circumferential (vertical and transverse) stenosis
Scheme for typical foraminal stenosis in accordance with progressing lumbar spondylosis. (i) The root is compressed vertically by the decreased height of the foramen with bony spurs and deformity induced by the degenerated IVD. (ii) The root is compressed transversely by the hypertrophic/buckled ligamentum flavum with progressing subluxations of the superior facet. b–d Representative images of foraminal stenosis. The dotted circle indicates the normal anatomy, while solid circles indicate MRI findings in LFS. b Vertical stenosis, c transverse stenosis, and d circumferential (vertical and transverse) stenosis
… 
Fusion image made up of the diffusion tensor tractography of the lumbar spinal nerve root and spinal nerves (L4, L5, and S1) and T2-weighted imaging (adopted from Eguchi et al. [25]) using magnetic resonance imaging. Note the interrupted tractography of the L5 spinal nerve at the L5-S1 foramen (white arrow)
+2
Fusion image made up of the diffusion tensor tractography of the lumbar spinal nerve root and spinal nerves (L4, L5, and S1) and T2-weighted imaging (adopted from Eguchi et al. [25]) using magnetic resonance imaging. Note the interrupted tractography of the L5 spinal nerve at the L5-S1 foramen (white arrow)
… 
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EXPERT’S OPINION •SPINE - LUMBAR
Lumbar foraminal stenosis, the hidden stenosis including at L5/S1
Sumihisa Orita
1
•Kazuhide Inage
1
•Yawara Eguchi
2
•Go Kubota
3
•
Yasuchika Aoki
3
•Junichi Nakamura
1
•Yusuke Matsuura
1
•Takeo Furuya
1
•
Masao Koda
1
•Seiji Ohtori
1
Received: 31 May 2016 / Accepted: 10 June 2016 / Published online: 18 June 2016
Springer-Verlag France 2016
Abstract In patients with lower back and leg pain, lumbar
foraminal stenosis (LFS) is one of the most important
pathologies, especially for predominant radicular symp-
toms. LFS pathology can develop as a result of progressing
spinal degeneration and is characterized by exacerbation
with foraminal narrowing caused by lumbar extension
(Kemp’s sign). However, there is a lack of critical clinical
findings for LFS pathology. Therefore, patients with robust
and persistent leg pain, which is exacerbated by lumbar
extension, should be suspected of LFS. Radiological
diagnosis is performed using multiple radiological modal-
ities, such as magnetic resonance imaging, including plain
examination and novel protocols such as diffusion tensor
imaging, as well as dynamic X-ray, and computed
tomography. Electrophysiological testing can also aid
diagnosis. Treatment options include both conservative and
surgical approaches. Conservative treatment includes
medication, rehabilitation, and spinal nerve block. Surgery
should be considered when the pathology is refractory to
conservative treatment and requires direct decompression
of the exiting nerve root, including the dorsal root ganglia.
In cases with decreased intervertebral height and/or insta-
bility, fusion surgery should also be considered. Recent
advancements in minimally invasive lumbar lateral
interbody fusion procedures enable effective and less
invasive foraminal enlargement compared with traditional
fusion surgeries such as transforaminal lumbar interbody
fusion. The lumbosacral junction can cause L5 radicu-
lopathy with greater incidence than other lumbar levels as a
result of anatomical and epidemiological factors, which
should be better addressed when treating clinical lower
back pain.
Keywords Foramen Lumbar spine Radiculopathy
Fusion Diffusion tensor imaging (DTI) Oblique lateral
interbody fusion (OLIF)
What is ‘‘lumbar foraminal stenosis’’? Conceptual
and epidemiological facts
The lumbar intervertebral foramen is a space that contains
the spinal nerve and dorsal root ganglia (DRG), which are
composed of sensory neurons. Lee et al. subdivided the
lateral intervertebral region into the lateral recess (en-
trance) zone, foraminal zone (vertical interpedicular
[foramen]) zone, and extraforaminal zone [1,2]. The
foraminal zone lies beneath the lamina and facet joints and
is also appropriately referred to as the ‘‘hidden zone’’ [3]
(Fig. 1). The pathology of lumbar foraminal stenosis (LFS)
was first reported in 1927 [4,5] as one of possible origins
of sciatica caused by a transitional sacrum. After the sys-
tematic integration of the concept of lumbar spinal stenosis
[6], the concept of LFS was defined as one of the lateral
spinal stenoses [7]. The prevalence of LFS has been
reported to be 8–11 % [8,9], and a previous cadaveric
study identified LFS in 21 of the 100 lumbar foramina
examined [10]. Clinical LFS is often unrecognized and
accounts for approximately 60 % of failed back surgery
&Sumihisa Orita
sorita@chiba-u.jp
1
Department of Orthopaedic Surgery, Graduate School of
Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku,
Chiba 260-8670, Japan
2
Department of Orthopaedic Surgery, National Hospital
Organization, Shimoshizu Hospital, Yotsukaido, Japan
3
Department of Orthopaedic Surgery, Eastern Chiba Medical
Center, Togane, Japan
123
Eur J Orthop Surg Traumatol (2016) 26:685–693
DOI 10.1007/s00590-016-1806-7
Content courtesy of Springer Nature, terms of use apply. Rights reserved.
... Lumbar foraminal stenosis is defined as the narrowing of the lateral canal (foramen) through which the nerve root exits the spinal canal in the lumbar spine. 1 It can be caused by congenital, developmental, acquired, and inflammatory etiologies. 2 The most common is due to a degenerative process where there is a loss of intervertebral disc height causing anterior and posterior subluxation of the superior articular process of the inferior vertebra, occurring in 8-11% of patients over 40 years. 1,2,3 Among the degenerative causes are disc herniations, osteoarthritis, spondylolisthesis, scoliosis, and facet joint osteoarthritis, among others. 2 Clinically, pain may manifest while at rest, such as when sitting, lying supine, or lying laterally, as well as during prolonged standing and/or walking. ...
... 4 Some patients may exhibit reduced strength, altered sensitivity, and/or changes in myotendinous reflexes. 2,3 The average duration of symptoms is usually 43.7 ± 14.6 months for mechanical lumbar pain and 15.3 ± 12.9 months for radicular pain. 5 As diagnostic tools, lateral and dynamic flexionextension lumbar radiographs are used, as well as computed tomography and magnetic resonance imaging. ...
... 5 As diagnostic tools, lateral and dynamic flexionextension lumbar radiographs are used, as well as computed tomography and magnetic resonance imaging. 3,6,7 There are various classifications for lumbar stenosis, primarily descriptive and lacking specific guidance on management. For central lumbar canal stenosis, the Schizas classification is used, which assesses compression in axial T2 images. ...
View
... The diagnosis of lumbar foraminal stenosis requires a multifaceted approach involving the patient's history, physical exam, and imaging studies [7,9,10,14,15]. Magnetic resonance imaging (MRI) and computed tomography (CT) scans are used to assess and measure neural compression; however, they can present conflicting results for the diagnosis of foraminal stenosis and radiculopathy [9]. Foraminal stenosis on imaging does not guarantee the presence of pain, but rather indicates presence of the degenerative process, and increased risk of developing radiculopathy [7]. ...
... Despite this data from an interventional procedure, there is currently no definitive clinical finding for lumbar foraminal stenosis [14]. Instead, physicians consider the entire spectrum of a patient's symptoms, physical exam findings, and imaging when formulating a diagnosis. ...
View
... Foraminal and central stenoses are among the most prevalent diseases of the lumbar spine, spanning all levels from T12-L1 to L5-S1 [1,2]. Additionally, symptoms of lower back pain and leg pain/irradiation are often intense, preventing patients from performing daily activities [3,4]. ...
... However, despite advancements in both technology and surgery, the anatomical intricacies of L5-S1 still pose challenges to endoscopic transforaminal approaches. The uniqueness of the L5-S1 segment is evident in both its interlaminar and articular anatomy, featuring the largest interlaminar window, greater distance from the spinous process concerning articulation, and highly coronalized facets of the S1 segment [2,13]. Moreover, studies have demonstrated that more caudal, mainly L5-S1, levels present a wider window but a smaller foramen and direct interference from the iliac crest in the transforaminal corridor. ...
New ipsilateral full endoscopic interlaminar approach for L5-S1 foraminal and extraforaminal decompression: technique description and initial case series
Article
Full-text available
  • Aug 2024
  • NEUROSURG REV
Background The L5-S1 interlaminar access described in 2006 by Ruetten et al. represented a paradigm shift and a new perspective on endoscopic spinal approaches. Since then, the spinal community has shown that both the traditional ipsilateral and novel contralateral interlaminar approaches to the L5-S1 foramen are good alternatives to transforaminal access. This study aimed to provide a technical description and brief case series analysis of a new endoscopic foraminal and extraforaminal approach for pathologies at the lumbar L5-S1 level using a new ipsilateral interlaminar approach. Methods Thirty patients with degenerative stenotic conditions at the L5-S1 disc level underwent the modified interlaminar approach. The surgical time, blood loss, occurrence of complications, and clinical outcomes were recorded. The data were compiled in Excel and analyzed using R software version 4.2. All continuous variables are presented as the mean, median, minimum, and maximal ranges. For categorical variables, data are described as counts and percentages. Results Thirty patients were included in the study. The cohort showed significant improvements in all quality-of-life scores (ODI, visual analog scale of back pain, and visual analog scale of leg pain). Five cases of postoperative numbness and three cases of postoperative dysesthesia have been reported. No case of durotomy or leg weakness has been reported. Conclusions The fundamental change proposed by this procedure, the new ipsilateral approach, presents potential advantages to surgeons by overcoming anatomical challenges at the L5-S1 level and by providing surgeon-friendly visualization and access. This approach allows for extensive foraminal and extraforaminal decompression, including the removal of hernias and osteophytosis, without causing neural retraction of the L5-S1 roots while maintaining the stability of the operated level.
View
... Positioned beneath the lamina and facet joints, it is aptly labeled the "hidden zone." 4 The normal foraminal area ranges from 40 to 160 mm 2 . The dorsal root ganglia and spinal nerves, surrounded by radicular vessels and adipose tissue, are located in the anterior and superior region of the foramen. ...
... Moreover, a higher incidence of disc degeneration at the L4-L5 and L5-S1 levels leads to foraminal narrowing, increasing susceptibility to compression of the L4 and L5 nerve roots and the effects of pedicular kinking and foraminal stenosis. 4 Most patients in our study experienced articular process hyperplasia with degenerative scoliosis (preoperative CCA: 14.56 AE 4.79 ). Degenerative spinal scoliosis leads to abnormal stress on the spine, resulting in a decrease in intervertebral space height and subsequently reducing the foramen area. ...
Uniportal Full‐endoscopic Foraminotomy for Lumbar Foraminal Stenosis: Clinical Characteristics and Functional Outcomes
Article
Full-text available
  • Jun 2024
Objective Uniportal full‐endoscopic foraminotomy offers a promising alternative to conventional surgical methods for individuals afflicted by lumbar foraminal stenosis. This study aims to evaluate the efficacy and clinical outcomes of uniportal full‐endoscopic foraminotomy in patients diagnosed with lumbar foraminal stenosis. Methods A comprehensive retrospective analysis was conducted on individuals who underwent full‐endoscopic foraminotomy in our medical center, between January 2018 and December 2019. The investigation encompassed the demographic data of patients and key clinical metrics such as the visual analogue scale of leg (VAS‐L) and back pain (VAS‐B), Oswestry disability index (ODI) scores, the Short Form‐36 Health Survey physical component summary (SF‐36 PCS) and the mental component summary (SF‐36 MCS), as well as modified MacNab grades, were systematically assessed and compared. Furthermore, radiological parameters: Coronal Cobb angle (CCA), Intervertebral angle changes (IAC), Disc height index (DHI), the foraminal cross‐sectional area (FCSA) and the FCSA enlargement ratio were also compared. A variety of statistical analyses including Student t‐test, chi‐square tests, Fisher's exact tests, Pearson's and Spearman's correlation analyses, and Interclass Correlation Coefficients (ICCs) were employed. Results 64 patients, including 34 males and 30 females were enrolled. The mean follow‐up period extended to 22.66 ± 7.05 months. Distribution by affected segments revealed 26.6% at L4‐5, 67.1% at L5‐S1 level, and 6.25% at both L4‐L5 and L5‐S1 levels. At the final follow‐up, VAS‐L decreased from 7.26 ± 1.19 to 1.37 ± 1.25, while VAS‐B decreased from 6.95 ± 0.54 to 1.62 ± 1.13 (p < 0.001). ODI score also demonstrated a substantial decrease from 74.73 ± 8.68 to 23.27 ± 8.71 (p < 0.001). Both SF‐36 PCS and SF‐36 MCS scores improved significantly (p < 0.001). Modified MacNab criteria revealed 58 excellent‐good patients (90.7%), and 6 fair‐poor patients (9.3%). No significant differences were founded in the CCA (p = 0.1065), IAC (p = 0.5544), and DHI (p = 0.1348) between pre‐operation and the final follow‐up. However, the FCSA significantly increased from 73.41 ± 11.75 to 173.40 ± 18.62 mm² (p < 0.001), and the enlargement ratio was 142.9% ± 49.58%. Notably, the final follow‐up FCSA and the FCSA enlargement ratio were found to be larger in the excellent and good group compared to the fair and poor group, according to the modified MacNab criteria. Conclusion The utilization of uniportal full‐endoscopic foraminotomy has demonstrated its safety and efficacy in addressing lumbar foraminal stenosis. The clinical success of this procedure appears to be closely associated with the radiological decompression of the intervertebral foramen area. Importantly, the application of this technology does not seem to compromise the overall stability of the lumbar region.
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... Causes of LFS include, but are not limited to, facet joint hypertrophy, vertebral endplate spurs, synovial cysts, decreased disc height or herniation, cephalic subluxation of the superior articular process of the lower vertebra, and hypertrophy of the ligamentum flavum [1,2]. The prevalence of LFS is 8-11%, and it is believed that 60% of cases of post-laminectomy syndrome are due to the misdiagnosis of lumbar foraminal stenosis prior to surgery [3]. ...
Percutaneous Foraminal Neuroplasty Using Reference Spinal Needles: Technical Description
Article
Full-text available
  • May 2024
Lumbar foraminal stenosis is a common cause of chronic lower back pain and radiculopathy often treated by epidural steroid injections. In the absence of imaging findings with a positive physical exam demonstrating symptoms, percutaneous neuroplasty (PNP) may be an alternative to transforaminal epidural steroid injections that have otherwise failed. We present two cases (55-year-old man and 65-year-old woman) with chronic low back pain and radiculopathy with otherwise normal imaging demonstrating no lumbar foraminal stenosis refractory to transforaminal epidural steroid injections. PNP was performed using reference spinal needles with both patients achieving sustained > 50–75% pain relief. PNP offers interventional chronic pain physicians and patients with refractory chronic low back pain with lumbar radiculopathy due to fibrosis an alternative, safe treatment that offers sustained results. Furthermore, this is the first of its kind to offer a step-by-step procedural step of PNP using a reference spinal needle.
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Degenerative Conditions of the Spine
Chapter
  • Nov 2024
Treatment paradigms for the aging spine are continuously changing as new diagnostic tools and surgical techniques become available. The Spine surgeon has to have great understanding of the pathology at hand and recognize the nuances in diagnosis and treating painful spine disorders as well as those causing neurological deficits.
View
Evaluation of the reliability of measuring lower back muscles cross-sectional area based on manual segmentation within multi-level MRI images
Article
  • Oct 2024
Introduction Manual segmentation of paraspinal muscle cross-sectional area (CSA) is widely used to assess related health disorders. This study aimed to evaluate the reliability of this segmentation process for each paraspinal region of interest across the three intervertebral levels commonly used for segmentation (L3/4, L4/5, and L5/S1). Methods Axial-T2-weighted MRI images for 238 patients were divided among five raters (47 ± 1 cases each). To conduct the intra-rater reliability study, the CSA of each paraspinal lumber muscle (psoas major (PM), multifidus (MF), and erector spinae (ES)) and the intervertebral disc (ID) were manually segmented twice on all targeted levels before being assessed for each region per rater. The Inter-rater reliability was determined by comparing the results of different readers who segmented the same dataset. The Intraclass Correlation (ICC) and Coefficient-of-Variation percentage (CV%) were reported for each analysis. Results Low intra- and inter-rater variability (CV%<11) was found for each reader in each region and intervertebral level. The inter-rater reliability was excellent (ICC>0.9) for the PM, ID, and ES at L3/4. However, it was very good for MF at all levels and ES at L4/5, L5/S1 (ICC range: 0.82–0.88) affected by the fat-infiltration nature of the ES and MF muscles, their proximity to each other, and their smaller size (correlation between muscle size and ICC = 0.6, P < 0.01). The ID segmentation has the lowest CV (<3 %) and excellent ICC (>0.93). Conclusion Manual paraspinal muscle segmentation using axial-T2-weighted MRI is reliable at all commonly segmented intervertebral levels. However, the reliability level can be degraded by the presence of high-fat infiltrate, unclear muscle boundaries, and muscle size. Implications for practice Following consistent guidelines can help improve segmentation results. The IDs can be used as reliable internal references.
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Correction of L5 Tilt in 2-Row Vertebral Body Tethering Versus Posterior Spinal Fusion for Adolescent Idiopathic Scoliosis
Article
  • Oct 2024
Study Design Single-center retrospective cohort study. Objective To compare the correction of fractional curve and L5 tilt in 2RVBT versus PSF with LIV in the lumbar spine. Summary of Background Data Vertebral body tethering, an AIS fusion-alternative, avoids rigid constructs, allowing for lower instrumented vertebra (LIV) selection. Single-tether constructs break, but mini-open thoracoscopic assistant double-row vertebral body tethering (2RVBT) reduces this. Limited comparative studies exist with posterior spinal fusion (PSF). Methods Retrospective analysis of AIS correction surgeries with lumbar LIV using preoperative and minimum 2-year postoperative imaging. Patients were divided into 2RVBT or PSF groups. Data included age, Riser, UIV, LIV, instrumented levels, and revision rates. Radiographic analyses included preoperative and postoperative main curve Cobb (MCC), secondary curve Cobb (SCC), fractional curve Cobb (FCC), and L5 tilt. Results Ninety-nine patients participated (49 in 2RVBT, 50 in PSF). Preoperatively, secondary CC differed significantly (2RVBT: 44.6±10.4 degrees vs. PSF: 39.5±11.8 degrees, P =0.026), but not L5 tilt, MCC, or FCC. Postoperatively, MCC (2RVBT: 25.7±12.3 degrees vs. PSF: 19.5±7.4 degrees, P =0.003) and SCC (2RVBT: 18.0±8.4 degrees vs. PSF: 14.5±6.6 degrees, P =0.012) varied. Preoperative to postoperative changes in MCC (2RVBT: −32.0±11.3 degrees vs. PSF: −37.2±13.3 degrees, P =0.044) and L5 tilt (−13.8±9.0 degrees vs. PSF: −8.1±6.8 degrees, P =0.001) differed. Revision rates were similar (2RVBT: 2.0%, PSF: 4.0%, P =0.57). In 2RVBT, 3 tethers broke, 1 revision occurred for a broken tether, and 1 pleural effusion needed thoracocentesis. In PSF, 1 superficial infection needed surgery, and 1 revision was for add-on phenomenon. After PSM for Lenke classification, 54 patients remained (27 in each group). At 2 years, 2RVBT showed less MCC correction (−30.8±11.8 degrees vs. −38.9±11.9 degrees, P =0.017), but greater L5 tilt correction (−14.6±10.0 degrees vs. −7.5±6.0 degrees, P =0.003). Conclusions This study with a minimum 2-year radiographic follow-up demonstrates that 2RVBT results in greater L5 tilt correction when compared with posterior spinal fusion after PSM for Lenke classification and similar rates of revision surgery. Level of Evidence Level III.
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New ipsilateral full endoscopic interlaminar Approach for L5-S1 foraminal and extraforaminal decompression: technique description and initial case series.
Preprint
Full-text available
  • Jun 2024
Background The L5-S1 interlaminar access described in 2006 by Ruetten et al. represented a paradigm shift and a new perspective on endoscopic spinal approaches. Since then, the spinal community has shown that both the traditional ipsilateral and novel contralateral interlaminar approaches to the L5-S1 foramen are good alternatives to transforaminal access. This study aimed to provide a technical description and brief case series analysis of a new endoscopic foraminal and extraforaminal approach for pathologies at the lumbar L5-S1 level using a new ipsilateral interlaminar approach. Methods Thirty patients with degenerative stenotic conditions at the L5-S1 disc level underwent the modified interlaminar approach. The surgical time, blood loss, occurrence of complications, and clinical outcomes were recorded. The data were compiled in Excel and analyzed using R software version 4.2. All continuous variables are presented as the mean, median, minimum, and maximal ranges. For categorical variables, data are described as counts and percentages. Results Thirty patients were included in the study. The cohort showed significant improvements in all quality-of-life scores (ODI, visual analog scale of back pain, and visual analog scale of leg pain). Five cases of postoperative numbness and three cases of postoperative dysesthesia have been reported. No case of durotomy or leg weakness has been reported. Conclusions The fundamental change proposed by this procedure, the new ipsilateral approach, presents potential advantages to surgeons by overcoming anatomical challenges at the L5-S1 level and by providing surgeon-friendly visualization and access. This approach allows for extensive foraminal and extraforaminal decompression, including the removal of hernias and osteophytosis, without causing neural retraction of the L5-S1 roots while maintaining the stability of the operated level.
View
Grading lumbar foraminal stenosis – Interrater agreement of radiologists and radiology trainees before and after education of a standardised grading scale
Article
  • May 2024
Introduction Lumbar foraminal stenosis is a key contributor to low back pain. Imaging, particularly MRI, is commonly used in the assessment of foraminal stenosis, contributing to treatment planning. The adoption of a standardised grading system to try and improve inter‐rater agreement is thought to be of importance. Our study aims to assess the variability of grading lumbar foraminal stenosis amongst reporting doctors, determine whether education about a validated grading scale increases agreement, and determine if these changes persist over time. Methods A single‐site study involving MRI reporting registrars/radiologists was performed. Participants were shown select MRI images and asked to grade the degree of stenosis in each on a 4‐point scale. Subsequently, they were educated about Lee et al's grading system and asked to re‐grade the cases 1 and 6 weeks later. The level of agreement was calculated using Gwet's AC1 coefficient and Krippendorff's Alpha. Results The baseline level of agreement was substantial (AC1 = 0.71). This decreased to a moderate level of agreement post‐intervention (AC1 = 0.575 at 1‐week, P ‐value 0.033 and AC1 = 0.598 at 6 weeks, P‐ value 0.012). A grading of severe stenosis was 21% more likely 6 weeks post‐education. Conclusion The baseline agreement at our institution was substantial, thought to be due to the single‐centre nature of the study. Moderate agreement was achieved after education regarding the Lee et al.'s scale, in‐line with other studies, with changes maintained at 6 weeks, showing retention of the scale parameters. Grading of severe stenosis was more common post intervention.
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Diagnosis of Lumbar Foraminal Stenosis using Diffusion Tensor Imaging
Article
Full-text available
  • Feb 2016
Diagnosis of lumbar foraminal stenosis remains difficult. Here, we report on a case in which bilateral lumbar foraminal stenosis was difficult to diagnose, and in which diffusion tensor imaging (DTI) was useful. The patient was a 52-year-old woman with low back pain and pain in both legs that was dominant on the right. Right lumbosacral nerve compression due to a massive uterine myoma was apparent, but the leg pain continued after a myomectomy was performed. No abnormalities were observed during nerve conduction studies. Computed tomography and magnetic resonance imaging indicated bilateral L5 lumbar foraminal stenosis. DTI imaging was done. The extraforaminal values were decreased and tractography was interrupted in the foraminal region. Bilateral L5 vertebral foraminal stenosis was treated by transforaminal lumbar interbody fusion and the pain in both legs disappeared. The case indicates the value of DTI for diagnosing vertebral foraminal stenosis.
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Radiographic evaluation of indirect decompression of mini-open anterior retroperitoneal lumbar interbody fusion: oblique lateral interbody fusion for degenerated lumbar spondylolisthesis
Article
Full-text available
  • Aug 2015
  • EUR SPINE J
Extreme lateral interbody fusion provides minimally invasive treatment of spinal deformity, but complications including nerve and psoas muscle injury have been noted. To avoid nerve injury, mini-open anterior retroperitoneal lumbar interbody fusion methods using an approach between the aorta and psoas, such as oblique lumbar interbody fusion (OLIF) have been applied. OLIF with percutaneous pedicle screws without posterior decompression can indirectly decompress the spinal canal in lumbar degenerated spondylolisthesis. In the current study, we examined the radiographic and clinical efficacy of OLIF for lumbar degenerated spondylolisthesis. We assessed 20 patients with lumbar degenerated spondylolisthesis who underwent OLIF and percutaneous pedicle screw fixation without posterior laminectomy. MR and CT images and clinical symptoms were evaluated before and 6 months after surgery. Cross sections of the spinal canal were evaluated with MRI, and disk height, cross-sectional areas of intervertebral foramina, and degree of upper vertebral slip were evaluated with CT. Clinical symptoms including low back pain, leg pain, and lower extremity numbness were evaluated using a visual analog scale and the Oswestry Disability Index before and 6 months after surgery. After surgery, significant increases in axial and sagittal spinal canal diameter (12 and 32 %), spinal canal area (19 %), disk height (61 %), and intervertebral foramen areas (21 % on the right side, 39 % on the left), and significant decrease of upper vertebral slip (-9 %) were found (P < 0.05). Low back pain, leg pain, and lower extremity numbness were significantly reduced compared with before surgery (P < 0.05). Significant improvements in disk height and spinal canal area were found after surgery. Bulging of disks was reduced through correction, and stretching the yellow ligament may have decompressed the spinal canal. Lumbar anterolateral fusion without laminectomy may be useful for lumbar spondylolisthesis with back and leg symptoms.
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Less invasive corrective surgery using oblique lateral interbody fusion (OLIF) including L5-S1 fusion for severe lumbar kyphoscoliosis due to L4 compression fracture in a patient with Parkinson's disease: A case report Case Reports
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Full-text available
  • Dec 2015
  • BMC Res Notes
Corrective surgery for kyphoscoliosis patients tend to be highly invasive due to osteotomy. The present case introduce less invasive corrective surgery using anterior oblique lateral interbody fusion (OLIF) technique. Case presentation An 80-year-old Japanese man with a history of Parkinson’s disease presented to our hospital because of severe kyphoscoliosis and gait disturbance. Considering the postsurgical complications due to osteotomy, we performed an anterior-posterior combined corrective fusion surgery: OLIF of Lumbar (L) 2-3, L3-4, and L4-5 (Medtronic Sofamor Danek, Memphis, TN, USA) followed by L5-Sacral (S) 1 anterior lumbar fusion via the OLIF approach using an anterior intervertebral cage, and posterior L3-4 and L4-5 facetectomy and posterior fusion using percutaneous pedicle screws from Thoracic (T) 10 to S1 with a T-9 hook system. The surgery was performed in a less invasive manner with no osteotomy, and it improved the sagittal alignments with moderate restoration, which improved the patient’s posture and gait disturbance. The patient showed transient muscle weakness of proximal lower extremity contralateral side to the surgical site, which fully recovered by physical rehabilitation 3 months after the surgery. The surgical corrective procedure using the minimally invasive OLIF method including L5-S1 fusion showed a great advantage in treating degenerative kyphoscoliosis in a Parkinson’s disease patient in its less-invasive approac.
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A RADICULAR SYNDROME FROM DEVELOPMENTAL NARROWING OF THE LUMBAR VERTEBRAL CANAL
Article
  • May 1954
1. A clinical condition is described in which there are symptoms of compression of the caudal nerve roots on standing or walking, but not at rest. Seven cases are reported. 2. Myelography showed a block in the lumbar region in every case. 3. At operation narrowing of the spinal canal in part of its lumbar course was found. 4. The nature of the abnormality is discussed. It is suggested that the narrowing is due to encroachment on the spinal canal by the articular processes.
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Perioperative Complications in 155 Patients Who Underwent Oblique Lateral Interbody Fusion Surgery: Perspectives and Indications From a Retrospective, Multicenter Survey
Article
  • Apr 2016
Study design: A retrospective multicenter survey. Objective: To investigate the perioperative complications of oblique lateral interbody fusion (OLIF) surgery. Summary of background data: OLIF has been widely performed to achieve minimally invasive, rigid lumbar lateral interbody fusion. The associated perioperative complications are not yet well described. Methods: The participants were patients who underwent OLIF surgery under the diagnosis of degenerative lumbar diseases between April 2013 and May 2015 at 11 affiliated medical institutions. The collected data were classified into intraoperative and early-stage postoperative (≤1 month) complications. The intraoperative complications were then subcategorized into organ damage (neural, vertebral, vascular, and others) and other complications, mainly related to instrumental failure. The collected data were also divided and analyzed based on (i) whether the surgeon was certified to perform the surgery and (ii) the incidence of complications in the early (April 2013-March 2014) and late stages (April 2014-May 2015) of OLIF introduction. Results: In the 155 included patients, 75 complications were reported (incidence rate, 48.3%). The most common complication was endplate fracture/subsidence (18.7%), followed by transient psoas weakness and thigh numbness (13.5%) and segmental artery injury (2.6%). Almost all these complications were transient, except for 3 patients who had permanent damage: 1 had ureteral injury and 2 had neurological injury. Postoperative complications included surgical site infection (1.9%) and reoperation (1.9%). Whether the primary operator was experienced did not affect the incidence of complications. Regarding the introductory stage, the incidence of complications was 50% in the early stage and 38% in the late stage. Conclusion: The overall incidence of perioperative complications of OLIF surgery reached 48.3%, of which only 1.9% resulted in permanent damage. Our analysis based on surgeon experience indicated that the OLIF procedure could be performed without increasing incidence of complications, under the guidance of experienced supervisors. Level of evidence: 3.
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One-Year Prospective Evaluation of the Technique of Percutaneous Cortical Bone Trajectory Spondylodesis in Comparison with Percutaneous Pedicle Screw Fixation: A Preliminary Report with Technical Note
Article
  • Mar 2016
Background and Objective Cortical bone trajectory (CBT) spondylodesis is a novel screw fixation method in which screws are inserted through the pedicle in a caudal-medial to cephalad-lateral direction, providing a similar or more rigid spinal fixation compared with traditional pedicle screws. However, the traditional CBT technique requires invasive detaching and opening of the paraspinal muscle. In a small clinical prospective study we introduced a percutaneous CBT fixation technique by modifying the percutaneous pedicle screw (PPS) technique and evaluated the short-term outcome. Materials and Methods We enrolled 40 patients with lower back pain (LBP) and limb r;adicular pain with a diagnosis of spondylolisthesis who underwent transforaminal lumbar interbody fusion surgery. The patients were divided into two groups according to screw trajectory: the percutaneous CBT (pCBT) and the traditional PPS arms (20 patients in each). A consecutive group of 20 patients underwent traditional PPS, and the other underwent pCBT; dorsal spondylodesis was combined with transforaminal lumbar interbody fusion (TLIF) in both groups. Perioperative data such as operative time, blood loss, duration of fluoroscopy, and total incision length were investigated. Postoperative outcomes were evaluated using the visual analog scale (VAS) for LBP and leg pain at baseline, 1, 6, and 12 months. A p value < 0.05 was considered statistically significant. Results We observed no significant disadvantages in pCBT patients in perioperative and postoperative data compared with the PPS group. There were no complications. The pCBT patients showed a significantly shorter total incision length (p < 0.01) with a significantly shorter duration of fluoroscopy (p < 0.05). The postoperative VAS score was significantly improved in the pCBT group, especially 6 months after the surgery (p < 0.05). Conclusion The pCBT spondylodesis provided an outcome comparable with PPS fixation with a tendency for improvement 1 year postsurgery. This technique can be used in appropriate cases, combined with lumbar interbody fusion.
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Prevalence and Location of Neuropathic Pain in Lumbar Spinal Disorders
Article
  • Mar 2016
Study Design A cross-sectional study of 1804 consecutive patients. Objective The aim of this study was to investigate the prevalence of pathological pain and its distribution features in patients with chronic lumbar spinal disorders. Summary of Background Data Clinical spinal disorders can involve pathological neuropathic pain (NeP) as well as physiological nociceptive pain (NocP), as they have varied pathology, including spinal cord injury, stenosis, and compression. A study conducted by the Japanese Society for Spine Surgery and Related Research (JSSR) has determined a prevalence of 29.4% for NeP in patients with lumbar spinal disorder. However, the data did not include information on pain location. Methods Patients aged 20 to 79 years with chronic lower back pain (≥3 months, visual analog scale score ≥30) were recruited from 137 JSSR-related institutions. Patient data included an NeP screening questionnaire score and pain location (lower back, buttock, and legs). The association between the pain pathology and its location was analyzed statistically using the unpaired t test and Chi-square test followed by Fisher test. P < 0.05 was considered significant. Results Low back pain subjects showed 31.9% of NeP prevalence, and the pain distribution showed [NocP(%)/NeP(%)] low back pain only cases: 44/22, while low back pain with leg pain cases showed a prevalence of 56/78. This indicates that low back pain alone can significantly induce NocP rather than NeP ( P < 0.01). Buttock pain was revealed to significantly induce both lower back pain and leg pain with NeP properties ( P < 0.01). Leg pain was revealed to be predominantly neuropathic, especially when it included peripheral pain ( P < 0.01). Conclusion Low back pain with no buttock pain induces NocP rather than NeP. Buttock pain is significantly associated with NeP prevalence whether or not leg pain exists. Leg pain can increase the prevalence of NeP, especially when it contains a peripheral element. Level of Evidence: 3
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The diagnosis of double-crush lesion in the L5 lumbar nerve using diffusion tensor imaging
Article
  • Nov 2015
Background context: Double-crush lesions are a condition in which the lumbar nerve is compressed both medially and laterally in the spinal canal, where diagnosis can be very difficult, and are a factor leading to poor surgical success rates. Purpose: Diffusion Tensor Imaging (DTI) was used to determine DTI parameter fractional anisotropy (FA) values and apparent diffusion coefficient (ADC) in both intraspinal column lesions alone and double-crush lesions. Study design: Prospective study PATIENT SAMPLE.: Of the 56 cases (mean age: 72.2 years) that underwent laminectomy for lumbar spinal stenosis at our clinic between April 2013 to March, 2015, 10 cases with L5 radiculopathy due to L4/5 stenosis (Intraspinal stenosis group (Group I); mean age: 74.7 years), and 5 cases with persistent symptoms due to L5 foraminal stenosis despite L4/5 decompression surgery (Double crush Group (Group D); mean age: 77.6 years) were targeted. One patient in Group D was diagnosed through microendoscopic intrapedicular partial pediculotomy, and the remaining 4 cases by nerve root infiltration. Five healthy cases (mean age: 54 years) were studied as controls. Outcome measures: Intraspinal zone (Iz), nerve root (N), and extraforaminal zone (Ez) were established as the ROI, and the L5 nerve FA and ADC values were determined on the affected side. Methods: DTI was performed prospectively by 1.5T MRI before surgery and DTI parameters of L5 nerve were evaluated in all patients and healthy volunteers. Student's t-test was used for group comparisons, and a p<0.05 was considered statistically significant. Results: FA values (Iz, N, Ez) were 0.415, 0.448, and 0.517, increasing as sites became more distal. Group I values were 0.335, 0.393, and 0.484, and Group D values were 0.296, 0.367, and 0.360. Compared to the healthy volunteers, Group D had significantly lower Iz (p<0.05) and Ez (p<0.001) values, while Group I had significantly lower Iz (p<0.05) values. In Group D, Ez FA values were significantly lower (p<0.001) than in Group I. ADC values (Iz, N, Ez) in the healthy control group were 1.270 mm(2)/s, 1.151 mm(2)/s, and 0.937 mm(2)/s with values decreasing as sites grew distal. In Group I, the ADC values were 1.406 mm(2)/s, 1.184 mm(2)/s, and 1.001 mm(2)/s, while in Group D they were 1.551 mm(2)/s, 1.412 mm(2)/s, and 1.329 mm(2)/s. Iz (p<0.05) and Ez (p<0.05) values were significantly higher in Group D compared to the healthy volunteers. N (P<0.01) and Ez (p<0.001) ADC values were significantly higher in Group D than in Group I. Conclusions: Depending on where the nerve was compressed, changes in DTI parameters revealed nerve damage (low FA values, and increased ADC) in the intraspinal canal in the Intraspinal Group, and over a widespread area in the Double-crush Group spanning the medial to lateral spinal canal. Our research suggests that in cases where double-crush is suspected before surgery, failed back surgery syndrome may be prevented by evaluating DTI images.
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Lumbar Intervertebral Foramens
Article
  • May 1991
The lumbar intervertebral foramens of 20 isolated cadaveric spines were investigated by the use of a molding technique to assess their dimensions accurately and how intervertebral disc pathology altered their configuration. Oval foramens predominated over auricularly shaped foramens when the disc was normal, but when the disc was abnormal, the converse was true. Foraminal size varied from 40 to 160 mm2 but showed great variation even at individual levels; these were not accurately reflected by simple radiologic measurements.
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Report of the 1985 ISSLS Traveling Fellowship: Mechanisms of Spinal Pain
Article
  • Dec 1986
The dorsal root ganglion as a mediator for low-back pain an animal model was investigated. Low-frequency vibration, a known mechanical cause of low-back pain, was investigated. Quantitative results suggest a significant reduction effect on substance P, one of several neurotransmitters located in the dorsal root ganglion. The functional results of these changes are currently under investigation.
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