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

Longitudinal DTI analysis of microstructural changes in lumbar nerve roots following Interspinous process device placement

Diffusion tensor imaging (DTI) and its parameters such as fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), radial diffusivity (RD) are increasingly being used to assess peripheral nerve integrity alongside nerve conduction studies. This pilot study aims to compare DTI values of lumbar spinal nerve roots before (T0) and after (T1) treatment with an interspinous process device (IPD). Seven patients (5 females, 2 males; mean age: 68) suffering from neurogenic claudication and lumbar spinal canal and foraminal stenosis were evaluated. Visual Analog Scale (VAS) for perceived pain, Oswestry Disability Index (ODI), and DTI parameters were assessed between T0 and T1. No significant difference in FA was found in treated roots, while MD (p = 0.0015), RD (p = 0.0032), and AD (p = 0.0221) were significantly altered. At untreated levels, all DTI parameters showed highly significant differences (p < 0.0001) between T0 and T1. In treated roots, FA values significantly increased in the intraforaminal segment(p = 0.0229), while MD(p = 0.0124), AD(p = 0.0128), and RD (p = 0.0143) values decreased in the pre-foraminal segment. In untreated roots, FA significantly increased in pre(p = 0.0039)and intraforaminal(p = 0.0003) segments, and MD, AD, and RD decreased in all segments (p < 0.0001). VAS (p < 0.0001) also decreased between T0 and T1. This pilot study aims to clarify the biomechanical impact of interspinous spacers through microstructural analysis of both treated and adjacent untreated nerve roots. To our knowledge, no studies have examined the short- to medium-term changes in DTI values of lumbar nerve roots before and after IPD placement, or compared changes between treated and untreated roots.

Evaluation of the Concentration of Selected Elements in the Serum of Patients with Degenerative Stenosis of the Lumbosacral Spine

In humans, 23 elements have been shown to have biological activity. The purpose of this study was to evaluate the concentrations of iron (Fe), zinc (Zn), sodium (Na), potassium (K), magnesium (Mg), phosphorus (P), and calcium (Ca) in the serum of patients diagnosed with lumbar degenerative stenosis when compared to the concentrations of those elements in the serum of healthy volunteers. The study group consisted of 60 patients who were diagnosed with degenerative stenosis of the lumbosacral spine and who qualified for hemilaminectomy. The control group included 60 healthy volunteers without degenerative spinal stenosis. The clinical specimens studied had sera collected from both groups. The quantitative analysis of the selected elements revealed statistically significant (p < 0.05) lower concentrations of Zn (740 ± 110 µg/L vs. 880 ± 160 µg/L) and Mg (22,091 ± 4256 µg/L vs. 24,100 ± 4210 µg/L) in the serum of the patients from the study group when compared to the controls. By contrast, K (16,230 µg/L ± 1210 µg/L vs. 13,210 µg/L ± 1060 µg/L) and Fe (141.87 µg/L ± 11.22 µg/L vs. 109.1 µg/L ± 26.43 µg/L) levels were significantly higher in the study group compared to the controls (p < 0.05). No statistically significant changes were detected in the concentrations of the assessed micronutrients and macronutrients in both sexes in either the study group, the control group, or those based on body mass index (p > 0.05). In the serum samples from the study group, the strongest correlations were noted between the concentrations. In the study group, we showed a significant relationship between the levels of Fe/Zn (r = 0.41), Fe/Na (r = 0.41), Fe/P (r = 0.55), Zn/P (r = 0.68), Zn/K (r = 0.48), Zn/Ca (r = 0.94), Mg/Ca (r = 0.79), and Na/K (r = 0.67). We showed that only Mg concentration varied statistically significantly with the severity of pain (p < 0.05). These findings suggest that the assessment of Fe, Zn, Mg, and K concentrations can be helpful in predicting the onset of degenerative changes in the spine.

Evaluation of the reliability of measuring lower back muscles cross-sectional area based on manual segmentation within multi-level MRI images

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.

New ipsilateral full endoscopic interlaminar approach for L5-S1 foraminal and extraforaminal decompression: technique description and initial case series

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.

Uniportal Full-endoscopic Foraminotomy for Lumbar Foraminal Stenosis: Clinical Characteristics and Functional Outcomes

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.

Percutaneous Foraminal Neuroplasty Using Reference Spinal Needles: Technical Description

BACKGROUND

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.

CASE PRESENTATION

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.

CONCLUSION

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.

Grading lumbar foraminal stenosis - Interrater agreement of radiologists and radiology trainees before and after education of a standardised grading scale

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.

Exploring the impact of mild-to-moderate foraminal stenosis at L5-S1 on clinical outcomes following L4-5 posterior lumbar interbody fusion

BACKGROUND CONTEXT

Patients scheduled for L4-5 PLIF often have FS at L5-S1. However, data on the clinical and radiographic outcomes of cases with mild-to-moderate L5-S1 FS are lacking, which may affect clinical outcomes or require additional surgery after L4-5 fusion.

PURPOSE

To evaluate the clinical and radiographic outcomes of L4-5 PLIF in patients with and without mild-to-moderate L5-S1 FS, with a primary focus on the association between L5-S1 FS and postoperative clinical outcomes including back pain, leg pain, and scores on the oswestry disability index (ODI) and EuroQol 5-dimension (EQ-5D).

STUDY DESIGN

Retrospective comparative study.

PATIENT SAMPLE

A retrospective review of patients who underwent L4-5 PLIF from 2014 to 2018. The patients were divided according to the presence of mild-to-moderate FS at L5-S1.

OUTCOME MEASURES

Clinical assessment included the pain visual analog scale (VAS), ODI, and EQ-5D score. Radiographic assessments included spinopelvic parameters and grades for central and foraminal stenosis.

METHODS

Clinical outcomes were assessed using validated outcome measures at preoperative, 6-month, 12-month, and 36-month follow-up visits. Radiographic evaluations were performed using preoperative and postoperative radiographs. Foraminal stenosis was assessed qualitatively using MRI with a grading system from none to severe and quantitatively by measuring changes in the foraminal area on CT.

RESULTS

Among 186 patients, 55 were categorized as the FS group and 131 as the non-FS group. The FS group was older (p=0.039) and had more severe central stenosis at L5-S1 (p=0.007) as well as more severe FS at both L4-5 and L5-S1 (both p<0.001). Preoperative disc height (p<0.001), C7-S1 sagittal vertical axis (p=0.003), lumbar lordosis (p=0.005), and pelvic incidence-lumbar lordosis mismatch (p=0.026) were more aggravated in the FS group. The FS group showed inferior clinical outcomes at the final follow-up in terms of back pain (p=.010) and ODI score (p=.003).

CONCLUSION

The presence of mild-to-moderate FS at L5-S1 was associated with more aggravated sagittal balance in terms of smaller preoperative disc height, larger sagittal vertical axis, smaller lumbar lordosis, and larger pelvic incidence-lumbar lordosis mismatch. Patients with L5-S1 FS also had poorer clinical outcomes including back pain and ODI score after L4-5 PLIF. Patients with L5-S1 FS need to be carefully examined before L4-5 fusion considering their adverse outcomes due to underlying degenerative changes.

Degenerative lumbar spondylolisthesis: review of current classifications and proposal of a novel classification system

PURPOSE

To review existing classification systems for degenerative spondylolisthesis (DS), propose a novel classification designed to better address clinically relevant radiographic and clinical features of disease, and determine the inter- and intraobserver reliability of this new system for classifying DS.

METHODS

The proposed classification system includes four components: 1) segmental dynamic instability, 2) location of spinal stenosis, 3) sagittal alignment, and 4) primary clinical presentation. To establish the reliability of this system, 12 observers graded 10 premarked test cases twice each. Kappa values were calculated to assess the inter- and intraobserver reliability for each of the four components separately.

RESULTS

Interobserver reliability for dynamic instability, location of stenosis, sagittal alignment, and clinical presentation was 0.94, 0.80, 0.87, and 1.00, respectively. Intraobserver reliability for dynamic instability, location of stenosis, sagittal alignment, and clinical presentation were 0.91, 0.88, 0.87, and 0.97, respectively.

CONCLUSION

The UCSF DS classification system provides a novel framework for assessing DS based on radiographic and clinical parameters with established implications for surgical treatment. The almost perfect interobserver and intraobserver reliability observed for all components of this system demonstrates that it is simple and easy to use. In clinical practice, this classification may allow subclassification of similar patients into groups that may benefit from distinct treatment strategies, leading to the development of algorithms to help guide selection of an optimal surgical approach. Future work will focus on the clinical validation of this system, with the goal of providing for more evidence-based, standardized approaches to treatment and improved outcomes for patients with DS.

Clinical efficacy and imaging analysis of oblique lateral lumbar interbody fusion in the treatment of different types of lumbar intervertebral foramen stenosis

PURPOSE

To analyze and study the clinical efficacy and imaging indexes of oblique lateral lumbar interbody fusion (OLIF) in the treatment of lumbar intervertebral foramen stenosis(LFS) caused by different causes.

METHOD

33 patients with LFS treated with OLIF from January 2018 to May 2022 were reviewed. Oswestry Dysfunction Index (ODI) and visual analogue scale (VAS) were calculated before and after operation. Segmental lordotic angle (SLA), lumbar lordotic angle (LLA) and segmental scoliosis angle (SSA), disc height (DH), posterior disc height (PDH), lateral disc height (LDH), foraminal height (FH), foramen width (FW) and foraminal cross-sectional area (FSCA) were measured before and after operation.

RESULT

The VAS and ODI after operation were significantly improved as compared with those before operation. Compared with pre-operation, the DH, PHD increased by 67.6%, 94.6%, LDH increased by 107.4% (left), 101.7% (right), and FH increased by 30.2% (left), 34.5% (right). The FSCA increased by 93.1% (left), 89.0% (right), and the FW increased by 137.0% (left), 149.6% (right). The postoperative SSA was corrected by 74.5%, the postoperative SLA, LLA were corrected by 70.2%, 38.1%, respectively. All the imaging indexes were significantly improved (p < 0.01).

CONCLUSION

The clinical efficacy and imaging data of OLIF in the treatment of LFS caused by low and moderate lumbar spondylolisthesis, intervertebral disc bulge and reduced intervertebral space height, degenerative lumbar scoliosis, articular process hyperplasia or dislocation have been well improved. OLIF may be one of the better surgical treatments for LFS caused by the above conditions.

Outcomes of FETD versus UBE in the treatment of L5S1 foraminal stenosis: A comparative study

Background

The L5S1 level exhibits unique anatomical features compared with other levels. This makes minimally invasive surgery for L5S1 foraminal stenosis (FS) challenging. This study compared the surgical outcomes of full endoscopic transforaminal decompression (FETD) and unilateral biportal endoscopy with the far-lateral approach (UBEFLA) in patients with L5S1FS.

Methods

In this retrospective study, 49 patients with L5S1FS were divided into two groups. Of these, 24 patients underwent FETD, 25 patients underwent UBEFLA. The study assessed demographic data, leg pain visual analog scale (VAS) score, back pain VAS score, Oswestry Disability Index (ODI), modified MacNab outcome scale, and radiographic parameters including postoperative lateral facet preservation (POLFP).

Results

The Mann-Whitney U test revealed that the UBEFLA group exhibited a higher VAS score for back pain at one week after the operation, whereas the FETD group exhibited a higher leg pain VAS score 6 weeks after the operation. All four undesired MacNab outcomes in the FETD group were attributed to residual leg pain, whereas all five undesired MacNab outcomes in the UBEFLA group were due to recurrent symptoms. Radiographically, the FETD group exhibited greater POLFP.

Conclusions

When L5S1FS is performed, there may be challenges in adequately clearing the foraminal space in FETD. On the other hand, UBEFLA allowed for a more comprehensive clearance. However, this advantage of UBEFLA was associated with spinal instability as a future outcome.

Clinical Outcomes of Percutaneous Endoscopic Interlaminar Discectomy Using a Laminotomy Technique With Modified Stepwise Local Anesthesia

BACKGROUND

Percutaneous endoscopic interlaminar discectomy (PEID) has been widely used in minimally invasive treatment of lumbar disc herniation (LDH) but is difficult to perform because of the narrow interlaminar window and painful for the patient. Therefore, further research is needed to find a safe and effective method to facilitate the development of PEID.

METHODS

Seventy-one consecutive patients with LDH who underwent PEID using a laminotomy technique with modified stepwise local anesthesia between July 2017 and June 2020. All patients were followed up for at least 6 months. Preoperative patient demographics, perioperative outcomes, and clinical outcomes were recorded. Visual Analog Scale (VAS) scores, Oswestry Disability Index (ODI) scores, and Macnab criteria were used to assess clinical results.

RESULTS

All patients underwent successful surgery under local anesthesia with no conversions to open surgery. The mean operation time was 79.56 ± 32.78 minutes and the average hospital stay was 6.44 ± 2.98 nights. Before surgery, the mean VAS score was 5.66 ± 1.206 and the mean ODI score was 68.41 ± 6.634; the respective scores were decreased to 0.65 ± 0.635 and 7.06 ± 1.594 after 4 weeks of follow-up (P < 0.001) and to 0.56 ± 0.691 and 7.11 ± 0.176 after 6 months (P < 0.001). According to the MacNab criteria, the outcome was excellent in 60 cases and good in the remaining 11 cases.

CONCLUSIONS

PEID via a laminotomy technique with stepwise local anesthesia is safe and effective for L4-5 and L5-S1 LDH.

A correlation study of preoperative lumbar paraspinal muscle quality and L5-S1 lumbar foraminal stenosis degeneration after L4-5 TLIF

STUDY DESIGN

This was a retrospective study.

OBJECTIVES

Adjacent segment degeneration (ASD) is a major complication associated with spinal fusion. The lumbar paraspinal muscle is an essential factor influencing the occurrence of ASD. This study aimed to investigate the effect of preoperative lumbar paraspinal muscle quality on L5-S1 adjacent lumbar foraminal stenosis degeneration (ASLFSD) after L4-5 transforaminal lumbar interbody fusion (TLIF).

METHODS

A total of 113 patients diagnosed with lumbar spinal stenosis at L4-5 were treated with TLIF. Lumbar paraspinal muscle measurements were obtained preoperatively and bilaterally from axial T2-weighted MR images. The measurements included the total cross-sectional area of psoas (PS-tCSA), of erector spinae (ES-tCSA), and of multifidus (MF-tCSA); and fatty infiltration of psoas (PS-FI), of erector spinae (ES-FI), and of multifidus (MF-FI). Foraminal measurements, including posterior disc height (PDH), disc-to-facet distance (D-F), foraminal height (FH), and foraminal area (FA), were obtained bilaterally using a computed tomography system. The association between lumbar paraspinal muscle quality and changes in foraminal measurements was also studied.

RESULTS

We observed that the FH and FA significantly reduced at 1 year postoperatively at the mean follow-up period of 41.56 ± 8.38 months (range, 43-50 months), and PDH, D-F, FH, and FA all significantly reduced at final follow-up. These changes in foraminal measurements were significantly and negatively correlated with PS-FI, ES-FI, and MF-FI.

CONCLUSION

During the clinical follow-up, we found that patients with a higher degree of paraspinal muscle FI were more likely to develop L5-S1 ASLFSD after L4-5 TLIF.

Revisional Endoscopic Foraminal Decompression via Modified Interlaminar Approach at L5-S1 after Failed Posterior Instrumented Lumbar Fusion in Elderly Patients

Elderly people usually have poorer surgical tolerance and a higher incidence of complications when undergoing revision surgery after posterior instrumented lumbar fusion (PILF). Full-endoscopic transforaminal surgery is a safe and effective option, but sometimes, it is difficult to revise L5-S1 foraminal stenosis (FS) after PILF. Therefore, we developed full-endoscopic lumbar decompression (FELD) at the arthrodesis level via a modified interlaminar approach under local anesthesia. This study aimed to describe the technical note and clinical efficacy of the technique. Eleven patients with unilateral lower limb radiculopathy after PILF underwent selective nerve root block and then underwent FELD. Magnetic resonance imaging (MRI) and computer tomography (CT) were performed on the second postoperative day. Their clinical outcomes were evaluated with a Visual analog scale (VAS) of low back pain and sciatica pain, Oswestry disability index (ODI), and the MacNab score. Complete decompression was achieved in every case with FELD without serious complications. Postoperative VAS of sciatica pain and ODI at each time point and VAS of low back pain and ODI after three months postoperatively were significantly improved compared with those preoperative (p < 0.05). According to the MacNab criteria, seven patients (63.6%) had excellent results at the two-year follow-up, and four patients (36.4%) had good results. No patients required further revision surgery. FELD, via a modified interlaminar approach, is effective for treating unilateral L5-S1 FS after PILF in elderly people.

Is the presence of foraminal stenosis associated with outcome in lumbar spinal stenosis patients treated with posterior microsurgical decompression

BACKGROUND

We aim to investigate associations between preoperative radiological findings of lumbar foraminal stenosis with clinical outcomes after posterior microsurgical decompression in patients with predominantly central lumbar spinal stenosis (LSS).

METHODS

The study was an additional analysis in the NORDSTEN Spinal Stenosis Trial. In total, 230 men and 207 women (mean age 66.8 (SD 8.3)) were included. All patients underwent an MRI including T1- and T2-weighted sequences. Grade of foraminal stenosis was dichotomized into none to moderate (0-1) and severe (2-3) category using Lee's classification system. The Oswestry Disability Index (ODI), Zurich Claudication Questionnaire (ZCQ), and numeric rating scale (NRS) for back and leg pain were collected at baseline and at 2-year follow-up. Primary outcome was a reduction of 30% or more on the ODI score. Secondary outcomes included the mean improvement on the ODI, ZCQ, and NRS scores. We performed multivariable regression analyses with the radiological variates foraminal stenosis, Pfirrmann grade, Schizas score, dural sac cross-sectional area, and the possible plausible confounders: patients' gender, age, smoking status, and BMI.

RESULTS

The cohort of 437 patients presented a high degree of degenerative changes at baseline. Of 414 patients with adequate imaging of potential foraminal stenosis, 402 were labeled in the none to moderate category and 12 in the severe category. Of the patients with none to moderate foraminal stenosis, 71% achieved at least 30% improvement in ODI. Among the patients with severe foraminal stenosis, 36% achieved at least 30% improvement in ODI. A significant association between severe foraminal stenosis and less chance of reaching the target of 30% improvement in the ODI score after surgery was detected: OR 0.22 (95% CI 0.06, 0.83), p=0.03. When investigating outcome as continuous variables, a similar association between severe foraminal stenosis and less improved ODI with a mean difference of 9.28 points (95%CI 0.47, 18.09; p=0.04) was found. Significant association between severe foraminal stenosis and less improved NRS pain in the lumbar region was also detected with a mean difference of 1.89 (95% CI 0.30, 3.49; p=0.02). No significant association was suggested between severe foraminal stenosis and ZCQ or NRS leg pain.

CONCLUSION

In patients operated with posterior microsurgical decompression for LSS, a preoperative severe lumbar foraminal stenosis was associated with higher proportion of patients with less than 30% improvement in ODI.

TRIAL REGISTRATION

The study is registered at ClinicalTrials.gov (22.11.2013) under the identifier NCT02007083.

Hybrid surgery of percutaneous transforaminal endoscopic surgery (PTES) combined with OLIF and anterolateral screws rod fixation for treatment of multi-level lumbar degenerative diseases with intervertebral instability

BACKGROUND

Oblique lumbar interbody fusion (OLIF) has been used to treat lumbar intervertebral instability, which has some advantages including less trauma, less blood loss, faster recovery and bigger cage. However, it usually needs posterior screws fixation for biomechanical stability, and possible direct decompression for relieving neurologic symptoms. In this study, OLIF and anterolateral screws rod fixation through mini-incision were combined with percutaneous transforaminal endoscopic surgery (PTES) for the treatment of multi-level lumbar degenerative diseases (LDDs) with intervertebral instability. The purpose of study is to evaluate the feasibility, efficacy and safety of this hybrid surgery.

METHODS

From July 2017 to May 2018, 38 cases of multi-level LDDs of disc herniation, foramen stenosis, lateral recess stenosis or central canal stenosis with intervertebral instability and neurologic symptoms undergoing one-stage PTES combined with OLIF and anterolateral screws rod fixation through mini-incision were recruited in this retrospective study. The culprit segment was predicted according to the position of patient's leg pain and PTES under local anesthesia was performed for the culprit segment in the prone position to enlarge the foramen, remove the flavum ligamentum and herniated disc for the lateral recess decompression and expose bilateral traversing nerve roots for the central spinal canal decompression through an unilateral incision. During the operation, communicate with the patients to confirm the efficacy using VAS. And then mini-incision OLIF using allograft, autograft bone harvested in PTES and anterolateral screws rod fixation were performed in the right lateral decubitus position under general anesthesia. Back and leg pain were preoperatively and postoperatively evaluated using VAS. And the clinical outcomes were evaluated with ODI at the 2-year follow-up. The fusion status was assessed according to Bridwell's fusion grades.

RESULTS

There were 27 cases of 2-level, 9 cases of 3-level and 2 cases of 4-level LDDs with single-level instability on the X-ray, CT and MRI. Five cases of L3/4 instability and 33 cases of L4/5 instability were included. PTES was performed for 1 segment of 31 cases (25 cases of instability segment, 6 cases of no instability segment) and 2 segments including instability segment of 7 cases. Then, all instability segments were treated using mini-incision OLIF and anterolateral screws rod fixation. The average operation duration was 48.9 ± 7.3 min per level for PTES and 69.2 ± 11.6 min for OLIF and anterolateral screws rod fixation. The mean frequency of intraoperative fluoroscopy was 6 (5-9) times per level for PTES and 7 (5-10) times for OLIF. There was a mean blood loss of 30 (15-60) ml, and the incision length was 8.1 ± 1.1 mm for PTES and 40.0 ± 3.2 mm for OLIF. The mean hospital stay was 4 (3-6) days. The average follow-up duration was 31.1 ± 4.0 months. For the clinical evaluation, the VAS pain index and the ODI showed excellent outcomes. Fusion grades based on the Bridwell grading system at 2-year follow-up were grade I in 29 segments (76.3%) and grade II in 9 segments (23.7%). One patient encountered nerve root sleeves rupture during PTES and did not confront cerebrospinal fluid leakage or other abnormal clinical symptoms. There were two cases of hip flexion pain and weakness, which was relieved during 1 week after surgery. No patients had any form of permanent iatrogenic nerve damage and a major complication. No failure of instruments was observed.

CONCLUSIONS

The hybrid surgery of PTES combined with OLIF and anterolateral screws rod fixation is a good choice of minimally invasive surgery for multi-level LDDs with intervertebral instability, which can get direct neurologic decompression, easy reduction, rigid fixation and solid fusion, and hardly destroy the paraspinal muscles and bone structures.

Conservative Treatments for Lumbar Disc Herniation at L3-4 or L4-5 Were More Likely to Fail When Ipsilateral Foraminal Stenosis Was Present at the Caudally Adjacent Segment

BACKGROUND

Conservative treatments are important in lumbar disc herniation (LDH), but predictors for poor outcomes are unclear.

METHODS

Consecutive patients with unilateral single-level LDH at L3-4 or L4-5 were enrolled. Baseline clinical data were collected, and lumbar spine magnetic resonance imaging was evaluated. Foraminal stenosis was evaluated using Lee's approach and further categorized as absence (grade 0 and 1) or presence (grade 2 or 3). Each patient underwent conservative treatments (oral meloxicam and dexamethasone, corset, back extension exercise, physiotherapy, and manual therapy) for 6 weeks. Conservative treatments were defined as failed if a patient underwent surgery within 6 weeks or reported poor recovery at 6-week follow-up. Multivariate logistic regressions were used to examine the associations of failed conservative treatments with baseline characteristics and magnetic resonance imaging findings.

RESULTS

The study included 222 patients (mean age 45.5 ± 9.8 years). Of patients, 48 (21.6%) had concurrent ipsilateral foraminal stenosis at the caudal segment, and conservative treatments failed in 39 (17.6%). At baseline, patients with LDH and caudal foraminal stenosis were older (50.79 ± 6.14 years vs. 44.10 ± 10.13 years, P < 0.001), had greater leg pain (7.06 ± 1.17 vs. 6.39 ± 1.40, P = 0.003), and had a higher rate of positive straight leg raising test (54.2% vs. 33.3%, P = 0.008) than patients without caudal foraminal stenosis. In multivariate regression, failure of conservative treatments was associated with positive straight leg raising test (odds ratio 2.26, P = 0.046), and caudal foraminal stenosis (odds ratio 3.20, P = 0.007).

CONCLUSIONS

In the presence of caudal foraminal stenosis and positive SLR test, conservative treatments were more likely to fail in patients with LDH.

Changes in the lumbar intervertebral foramen between supine and standing posture in patients with adult spinal deformity: a study with upright computed tomography

OBJECTIVE

To quantitatively assess the impact of supine and standing positions on the morphological changes in the lumbar intervertebral foramen (LIF) in patients with adult spinal deformity (ASD) using upright CT and conventional supine CT.

MATERIALS AND METHODS

Thirty patients with ASD were prospectively enrolled in this study. All subjects underwent standing whole spine posterior/anterior radiographs, lateral radiographs, and whole spine CT, both in the supine and upright standing positions. Two orthopedic surgeons independently measured nine radiographic parameters in the radiograph and the lumbar foraminal area (FA) and height (FH) in supine and upright CT. Statistical analyses were performed to evaluate the risk of LIF decrease when standing upright compared to the supine position. The chi-squared, t test, Pearson's coefficients, intra- and inter-rater reliabilities, and ROC curves were calculated. The level of significance was set at p < 0.05.

RESULTS

Among the 300 LIFs, both the lumbar FA and FH were either increased or decreased by > 5% in approximately 30% of LIFs each. The FA decreased in the lower lumbar spine. The concave side had a significantly higher rate of decreased FA and FH than the convex side (p < 0.05 and < 0.05, respectively). ROC analysis showed that narrowing of the intervertebral disc (cutoff > 0.05°) is a risk factor for decreased FA and FH.

CONCLUSIONS

This study describes the details of the changes in the neuroforamen using a novel upright CT. In patients with ASD, approximately 30% of LIFs either increased or decreased in size by > 5% when standing. The risk factors for LIF decrease are the lower lumbar spine, concave side, and narrow side of the disc wedge.

Correlation of Foraminal Parameters with Patient-Reported Outcomes in Patient with Degenerative Lumbar Foraminal Stenosis

The relationship between quantitative anatomic parameters in MRI and patient-reported outcomes (PROs) before and after surgery in degenerative lumbar foraminal stenosis remains unknown. We included 58 patients who underwent transforaminal lumbar interbody fusion (TLIF) for single-level degenerative disc disease with foraminal stenosis between February 2013 and June 2020. PROs were evaluated using the visual analog scale (VAS) for back and leg pain, Oswestry Disability Index (ODI), and EuroQol-5D (EQ-5D). The foraminal parameters assessed using preoperative MRI included foraminal height, posterior intervertebral disc height, superior and inferior foraminal width, and foraminal area. The correlation between foraminal parameters and PROs before operation, at 1 year follow-up, and change from baseline were assessed. The associations between the aforementioned parameters were examined using linear regression analysis. The analysis revealed that among these parameters, superior foraminal width was found to be significantly correlated with ODI and EQ-5D at the 1 year follow-up and with change in ODI and EQ-5D from baseline. The associations remained significant after adjustment for confounding factors including age, sex, body mass index, and duration of hospital stay. The results indicated that in degenerative lumbar foraminal stenosis, decreased superior foraminal width was associated with better improvement in disability and quality of life after TLIF.

Percutaneous Intervertebral-Vacuum Polymethylmethacrylate Injection for Foraminal Stenosis with Degenerative Lumbar Scoliosis

BACKGROUND

Percutaneous intervertebral-vacuum polymethylmethacrylate injection (PIPI) is a minimally invasive procedure for low back pain in elderly patients with degenerative lumbar scoliosis (DLS). Patients with DLS often have radiculopathy as a result of foraminal stenosis in addition to low back pain. The purpose of this study was to evaluate the clinical and radiologic results of PIPI for foraminal stenosis with radiculopathy in elderly patients with DLS.

METHODS

We included patients with de novo DLS aged 65 years or older who underwent PIPI. The presence of an intervertebral vacuum on computed tomography and bone marrow edema on magnetic resonance imaging was required for inclusion. The intersegmental radiologic parameters on plain radiographs and computed tomography and the extent of bone marrow edema on magnetic resonance imaging were measured. The clinical outcomes were evaluated using the visual analog scale (VAS) and Oswestry Disability Index (ODI).

RESULTS

We enrolled 40 patients with DLS who underwent PIPI. There were 16 men and 24 women, and the mean age was 79.0 ± 6.3 years. The mean foraminal height and extent of bone marrow edema showed a significant increase and reduction, respectively, after PIPI (P < 0.05). VAS score for radiculopathy and ODI significantly improved after PIPI (P < 0.01). The minimum clinically important differences in VAS score for radiculopathy and ODI at the final follow-up were 73.9% and 63.6%, respectively.

CONCLUSIONS

PIPI is a minimally invasive procedure not only for low back pain but also for radiculopathy in elderly patients with DLS. It leads to intervertebral stabilization and indirect decompression of the foramen.

Comparison of Outcomes of Lumbar Interbody Fusion and Full-endoscopic Laminectomy for L5 Radiculopathy Caused by Lumbar Foraminal Stenosis

This study compared the outcomes of microendoscopy-assisted lumbar interbody fusion (ME-LIF) and uniportal full-endoscopic laminectomy (FEL) for L5 radiculopathy caused by lumbar foraminal stenosis (LFS). ME-LIF was performed using an 18- to 20-mm tubular retractor and endoscope, and FEL via the translaminar approach (TLA) was performed at the dorsal part of the foramen using a 4.1-mm working channel endoscope. Patients with LFS treated using ME-LIF (n = 39) or FEL-TLA (n = 30) were retrospectively evaluated. Patients' background and operative data were collected. The 36-item Short Form Survey (SF-36), Oswestry Disability Index (ODI), and European Quality of Life-5 Dimension (EQ-5D) scores were recorded preoperatively and 2 years postoperatively. The background data of the two groups (ME-LIF and FEL-TLA) were similar. The mean operation times for ME-LIF and FEL-TLA were 110.7 and 65.2 min, respectively, and the mean length of hospital stay were 10.3 and 1.5 days, respectively. Reoperation was required for surgical site infection, and percutaneous pedicle screw malposition in three patients was treated using ME-LIF. During follow-up, second FEL-TLA and LIF were performed for recurrent L5 radiculopathy in one and three patients in the FEL-TLA group, respectively. Although the SF-36, ODI, and EQ-5D scores 2 years postoperatively improved in both groups, improvement in ODI scores was lower following FEL-TLA than following ME-LIF. FEL-TLA can be performed to treat patients with L5 radiculopathy caused by LFS. Although the ODI score improvement following FEL-TLA was unremarkable, FEL-TLA might be considered because of its better safety profile and minimal invasiveness than ME-LIF.

Pre-existing adjacent level foraminal stenosis does not affect the outcome of a single level lumbar interbody fusion

BACKGROUND

The aim of this study was to investigate whether or not pre-existing asymptomatic neuroforaminal stenosis adjacent to the fusion level develops adjacent segment disease (ASD) after single-level lumbar interbody fusion.

SUMMARY AND BACKGROUND DATA

Risk factors of ASD after spinal fusion have been well investigated, but there have been few studies focused on the relationship between ASD and pre-existing asymptomatic neuroforaminal stenosis.

METHODS

A total of 302 patients who had undergone a single-level lumbar interbody fusion were reviewed at a minimum of 2 year follow-up. They were 109 men and 193 women with a mean age of 68.8 years. Follow-up periods was averaged 53.5 months. ASD was defined as neurological deterioration related to adjacent segment pathologies which required an additional surgery. Based on the pathologies, patients were divided into three categories: ASD due to foraminal stenosis (ASD-FS), ASD due to central stenosis (ASD-CS), and ASD due to herniated disc (ASD-HD). Measured variables were age, gender, diagnosis, BMI, decompression procedures at adjacent segments, preoperative anterior/posterior slip, asymptomatic neuroforaminal stenosis, facet tropism, and postoperative spinopelvic parameters.

RESULTS

Thirty-eight patients (12.6%) developed ASD. There were 15 patients with ASD-FS, 18 patients with ASD-CS, and five patients with ASD-HD. Lumbar lordosis (LL) and sacral slope (SS) were significantly smaller and pelvic tilt (PT) was significantly larger in ASD-FS. Asymptomatic neuroforaminal stenosis was detected preoperatively in 33.3% of the ASD-FS group, and 18.6% of non-ASD group; the incidence was not significantly different.

CONCLUSIONS

Adjacent-level neuroforaminal stenosis was not a significant risk of ASD after single-level lumbar interbody fusion, and might not need to be fused if asymptomatic.

Axial Loading during MRI Induces Lumbar Foraminal Area Changes and Has the Potential to Improve Diagnostics of Nerve Root Compromise

Lumbar foraminal stenosis is a common cause of lumbar radiculopathy and conventionally assessed with magnetic resonance imaging (MRI) in supine-positioned patients. An MRI acquired during spine loading may unmask pathology not otherwise revealed in a relaxed position. Therefore, we investigated how spine loading during MRI affects lumbar foramina. In 89 low-back pain patients’ lumbar, MRIs were performed in a relaxed supine position and during axial loading using a Dynawell^® compression device. The smallest area of all intervertebral foramina at levels L3/L4–L5/S1 (534 foramina) was determined using a freehand polygonal tool in parasagittal T2-weighted sequences. The grading system described by Lee et al. was also used to qualitatively assess foraminal stenosis. Overall, a mean reduction of 2.2% (mean −0.89 cm² and −0.87 cm², respectively) was observed (p = 0.002), however for individual foramina large variations, with up to about 50% increase or decrease, were seen. Stratified for lumbar level, an area reduction was found for L3/L4 and L4/L5 foramina (mean change −0.03 cm²; p = 0.036; and −0.03 cm²; p = 0.004, respectively) but not for L5/S1. When comparing the measured area changes to qualitative foraminal grading, 22% of the foramina with a measured area decrease were evaluated with a higher grading. Thus, detailed information on foraminal appearance and nerve root affection can be obtained using this method.

High-Resolution 3D versus Standard-Resolution 2D T2-Weighted Turbo Spin Echo MRI for the Assessment of Lumbar Nerve Root Compromise

Radiculopathy can be caused by nerve root irritation and nerve root compression at the level of the lateral recess or at the level of the intervertebral foramen. T2-weighted (T2w) MRI is considered essential to evaluate the nerve root and its course, starting at the lateral recess through the intervertebral foramen to the extraforaminal space. With the introduction of novel MRI acceleration techniques such as compressed SENSE, standard-resolution 2D T2w turbo spin echo (TSE) sequences with a slice-thickness of 3–4 mm can be replaced with high-resolution isotropic 3D T2w TSE sequences with sub-millimeter resolution without prolonging scan time. With high-resolution 3D MRI, the course of the nerve root can be visualized more precisely due to a detailed depiction of the anatomical situation and less partial volume effects, potentially allowing for a better detection of nerve root compromise. In this intra-individual comparison study, 55 patients with symptomatic unilateral singular nerve root radiculopathy underwent MRI with both 2D standard- and 3D high-resolution T2w TSE MRI sequences. Two readers graded the degree of lumbar lateral recess stenosis and lumbar foraminal stenosis twice on both image sets using previously validated grading systems in an effort to quantify the inter-readout and inter-sequence agreement of scores. Inter-readout agreement was high for both grading systems and for 2D and 3D imaging (Kappa = 0.823–0.945). Inter-sequence agreement was moderate for both lumbar lateral recess stenosis (Kappa = 0.55–0.577) and lumbar foraminal stenosis (Kappa = 0.543–0.572). The percentage of high degree stenosis with nerve root deformity increased from 16.4%/9.8% to 41.8–43.6%/34.1% from 2D to 3D images for lateral recess stenosis/foraminal stenosis, respectively. Therefore, we show that while inter-readout agreement of grading systems is high for both standard- and high-resolution imaging, the latter outperforms standard-resolution imaging for the visualization of lumbar nerve root compromise.

Relationship Between the Foraminal Area and Demographic and Clinical Characteristics of Patients with Low Back Pain

OBJECTIVE

Our study aims to contribute to existing knowledge by evaluating patients with low back pain to provide a more accurate relationship between the diameter of the intervertebral foramen and the clinical, demographic, and lumbar spine anatomical factors such as age, sex, BMI, the Zurich Claudication Questionnaire (ZCQ) , facet joint, intervertebral disc, ligamentum flavum, and spinal canal.

METHODS

We studied 90 consecutive patients who had undergone evaluation for low back pain. We used magnetic resonance imaging to assess the cross-sectional areas of the intervertebral foramina at each level of the lumbar spine together with the ligamentum flavum area and the dural sac cross sectional area measurements. The presence of disc and facet joint degeneration was evaluated and data on symptoms was obtained.

RESULTS

Age (p<0.0001), lumbar disc degeneration (LDD) grade (p=0.016), and dural sac cross sectional area (DSCSA, p<0.0001) were found to statistically significantly influence the foraminal area (FA). The mean FA at all lumbar levels increased with increasing DSCSA. The mean FA decreased with age at all levels except of L5/S1. LDD grade 1-3 increased the mean FA at L5/S1, but not at other levels. No statistically significant effects of the side of the measurement, sex, BMI, ZCQ score, ligamentum flavum area, nor facet joint degeneration were found.

CONCLUSIONS

The results of the present study allow us to quantify the effect of age, dural sac cross-sectional area, and lumbar disc degeneration grade on the foraminal area.

Full-endoscopic spine surgery treatment of lumbar foraminal stenosis after osteoporotic vertebral compression fractures: A case report

BACKGROUND

Few reports have described lumbar foraminal stenosis-induced radiculopathy after treatment by full-endoscopic spine surgery (FESS) combined with percutaneous vertebroplasty (PVP) in patients with vertebral compression fractures. We herein report such a case, including the patient’s treatment process and doctor’s surgical experience.

CASE SUMMARY

A 79-year-old man presented with symptoms of radiculopathy after sustaining L4 vertebral compression fractures. Imaging and physical examination revealed L4 vertebral compression fractures combined with L3/4 Lumbar foraminal stenosis (LFS). The patient’s symptoms were low back pain with pain in the lateral left leg. Although many reports have described radiculopathy induced by osteoporotic vertebral compression fractures, the use of FESS combined with PVP has rarely been reported. This case report indicates that the combination of FESS and PVP is a safe and effective approach for the treatment of LFS-induced radiculopathy after vertebral compression fractures. This minimally invasive technique has great potential to replace traditional lumbar fixation and decompression surgery. Thus, we suggest the continued accumulation of similar cases to discuss the wider application of FESS.

CONCLUSION

For patients with osteoporotic vertebral compression fracture (OVCF) and LFS, PVP and FESS can be used to restore the vertebral height and reduce the pressure around the intervertebral foramen. Additionally, the combination of FESS and PVP can treat the pain or numbness of the low back and lower limbs and allow for recovery in a short time with excellent postoperative effects. In general, FESS is a good treatment for radiculopathy caused by foraminal stenosis after OVCF.

Clinical and radiological outcomes of endoscopic foraminoplasty and decompression assisted with preoperative planning software for lumbar foraminal stenosis

PURPOSE

To assess the clinical and radiological outcomes of using endoscopic foraminoplasty and decompression assisted with a preoperative planning software in the treatment of lumbar foraminal stenosis.

METHODS

This retrospective study included 43 patients with lumbar foraminal stenosis (Jan 2018 and June 2019). These patients were divided into two groups. Patients in the conventional group (group A) underwent endoscopic lumbar foraminoplasty and decompression. Patients in the experimental group (group B) underwent the same surgery assisted with a preoperative software. The total operation time, puncture-channel establishment time, and the number of intraoperative fluoroscopic images taken were recorded. The Visual Analog Scale (VAS) and Oswestry Disability Index (ODI) were administered preoperatively and postoperatively (at 1-month, 3-month, and 12-month follow-up). The modified MacNab criteria were used to assess the global outcome at 12-month follow-up.

RESULTS

Patients in group B had shorter operation time, puncture-channel establishment time, and less number of intraoperative fluoroscopic images taken, as compared with group A. The VAS and ODI scores were significantly lower than pre-operation for both groups at all follow-ups. No significant difference was observed between these two groups. Based on the modified MacNab criteria, the excellent-to-good rate was 86.4% in group A and 90.5% in group B, respectively. After the operation, no patients had residual osteophytes in group B, while two patients still had residual osteophytes and foraminal stenosis in group A.

CONCLUSION

For endoscopic surgery treating lumbar foraminal stenosis, using preoperative planning software could reduce the puncture-channel establishment time, operation time, and the number of intraoperative fluoroscopic images taken without affecting the clinical outcomes.

Ameliorated Full-Endoscopic Transforaminal Decompression for L5-S1 Foraminal and Extraforaminal Stenosis

STUDY DESIGN

This is a retrospective review.

OBJECTIVE

To describe a modified surgical technique, full-endoscopic transforaminal decompression (FETD) in patients with L5-S1 foraminal stenosis or extraforaminal stenosis (EFS) and to detail the short-term results.

SUMMARY OF BACKGROUND DATA

Performing FETD surgery for L5-S1 FS and EFS is challenging because of high iliac crests in most cases and the difficulty in accurately differentiating between FS and EFS by images preoperatively.

MATERIAL AND METHODS

Patients who had solitary unilateral L5-S1 FS or EFS and had undergone FETD between October 2014 and December 2017 were included. In total, 22 patients underwent FETD for L5 root compressions at the L5-S1 levels. All patients were followed up for more than 1 year.

RESULTS

The mean visual analog scale score for back and leg pain, assessed preoperatively and at 12 months postoperatively, improved from 6.3±1.7 to 1.59±1.30 and from 7.29±0.78 to 1.41±1.20, respectively. The mean Oswestry Disability Index improved from 61.53% preoperatively to 15.8% at 12 months postoperatively. Neurovascular injury-related complications were absent in all these cases.

CONCLUSION

Successful short-term clinical outcome is achievable using the ameliorated FETD technique for treating L5-S1 FS and EFS.

Introduction and reproducibility of an updated practical grading system for lumbar foraminal stenosis based on high-resolution MR imaging

In this paper we sought to develop and assess the reproducibility of an updated 6-point grading system for lumbar foraminal stenosis based on the widely used Lee classification that more accurately describes lumbar foraminal stenosis as seen on high-resolution MRI. Grade A indicates absence of foraminal stenosis. Grades B, C, D and E indicate presence of foraminal stenosis with contact of the nerve root with surrounding anatomical structures (on one, two, three or four sides for B, C, D and E respectively) yet without morphological change of the nerve root. To each grade, a number code indicating the location of contact between the nerve root and surrounding anatomical structure(s) is appended. 1, 2, 3 and 4 indicate contact of the nerve root at superior, posterior, inferior and anterior position of the borders of the lumbar foramen. Grade F indicates presence of foraminal stenosis with morphological change of the nerve root. Three readers graded the lumbar foramina of 101 consecutive patients using high-resolution T2w (and T1w) MR images with a spatial resolution of beyond 0.5 mm³. Interreader agreement was excellent (Cohen’s Kappa = 0.866–1). Importantly, 30.6%/31.6%/32.2% (reader 1/reader 2/ reader 3) of foramina were assigned grades that did not appear in the original Lee grading system (grades B and D). The readers found no foramen that could not be described accurately with the updated grading system. Thus, an updated 6-point grading system for lumbar foraminal stenosis is reproducible and comprehensively describes lumbar foraminal stenosis as seen on high-resolution MRI.

Caudal Lumbar Disc Herniations Are More Likely to Require Surgery for Symptom Resolution

STUDY DESIGN

Retrospective study.

OBJECTIVES

We examined the impact that location of a lumbar disc herniation has on the likelihood that a patient will require surgery after at least 6 weeks of nonoperative management.

METHODS

Using ICD-10 codes M51.26 and M51.27, we identified patients at a single academic institution from 2015 to 2016 who received a diagnosis of primary lumbar radicular pain, had magnetic resonance imaging confirming a lumbar disc herniation, and underwent at least 6 weeks of nonoperative management. Patients experiencing symptoms suggesting cauda equina syndrome or progressive motor deficits were excluded.

RESULTS

Five hundred patients met inclusion/exclusion criteria. Twenty-nine (5.8%) had L3-L4 herniations, 245 (49.0%) had L4-L5 herniations, and 226 (45.2%) had L5-S1 herniations. Overall, 451 (90.2%) patients did not undergo surgery within 1 year of diagnosis. Nonsurgical patients had an average herniation size occupying 31.2% of the canal, compared with 31.5% in patients who underwent surgery. While herniation size, age, sex, and race failed to demonstrate a statistical association with the likelihood for surgery, location of disc herniation demonstrated a strong association. L3-L4 and L4-L5 herniations had odds ratios of 0.19 and 0.45, respectively, relative to L5-S1 herniations (P = .0047). Patients were more than twice as likely to require a surgery on an L5-S1 herniation in comparison with an L4-L5 herniation (P < .05). L3-L4 herniations rarely required surgery.

CONCLUSIONS

Patients with caudal lumbar disc herniations were more likely to require surgery after at least 6 weeks of conservative management than those with disc herniations in the mid-lumbar spine.

Does "Coronal Root Angle" Serve as a Parameter in the Removal of Ventral Factors for Foraminal Stenosis at L5-S1 In Stand-alone Microendoscopic Decompression?

STUDY DESIGN

Prospective single-center cohort study.

OBJECTIVE

The present study aims to investigate the causes of failure of L5/S1 foraminal stenosis, and it is hypothesized that the newly defined "L5 coronal root angle (CRA)" may be a parameter in the removal of ventral pathologies.

SUMMARY OF BACKGROUND DATA

Lumbar foraminal stenosis is an important cause of recurrent leg pain after central spinal stenosis surgery. Although it can be seen at all levels, L5/S1 is the level at which it is most frequently seen due to its specific characteristics, with success rate is lower than other levels after foraminal decompression.

METHODS

L5/S1 microendoscopic foraminal decompression was performed to 51 patients. According to Japanese Orthopedic Association (JOA) improvement at 12-month follow-up, those with improvement >20% were classified as Group 1 and <20% were classified as Group 2. The patients who underwent discectomy in addition to foraminotomy formed Group 3. Lumbar lordosis angle, segmental lordosis angle, anterior disc height, pelvic tilt, pelvic incidence, sacral slope, relative disc height ratio, pedicle height/vertebral body height ratio, L5 depth, L5 CRA, and anterior disc height/ posterior disc height ratio parameters were measured with lumbar radiographic views, computed tomography (CT), and magnetic resonance imaging (MRI).

RESULTS

Among the parameters compared between groups, L5 CRA, posterior disc height, anterior disc height/posterior disc height, relative disc height ratio, and lumbar lordosis angle during extension were seen to be statistically significantly related with low success rate.

CONCLUSION

Failure to remove the ventral pathologies when the L5 CRA is <112. 1º may lead to failed results. Besides, in cases wherein the posterior disc height is <2.85 mm or the anterior/posterior disc height ratio is >3.98, approaches to restoring disc height rather than stand-alone posterior decompression may reduce the possibility of failure.

LEVEL OF EVIDENCE

2.

Microendoscopic decompression for lumbosacral foraminal stenosis: a novel surgical strategy based on anatomical considerations using 3D image fusion with MRI/CT

OBJECTIVE

Persistent lumbar foraminal stenosis (LFS) is one of the most common reasons for poor postoperative outcomes and is a major contributor to "failed back surgery syndrome." The authors describe a new surgical strategy for LFS based on anatomical considerations using 3D image fusion with MRI/CT analysis.

METHODS

A retrospective review was conducted on 78 consecutive patients surgically treated for LFS at the lumbosacral junction (2013-2017). The location and extent of stenosis, including the narrowest site and associated pathology (bone or soft tissue), were measured using 3D image fusion with MRI/CT. Stenosis was defined as medial intervertebral foraminal (MF; inner edge to pedicle center), lateral intervertebral foraminal (LF; pedicle center to outer edge), or extraforaminal (EF; outside the pedicle). Lumbar (low-back pain, leg pain) and patient satisfaction visual analog scale (VAS) scores and Japanese Orthopaedic Association (JOA) scores were evaluated. Surgical outcome was evaluated 2 years postoperatively.

RESULTS

Most instances of stenosis existed outside the pedicle's center (94%), including LF (58%), EF (36%), and MF (6%). In all MF cases, stenosis resulted from soft-tissue structures. The narrowest stenosis sites were localized around the pedicle's outer border. The areas for sufficient nerve decompression were extended in MF+LF (10%), MF+LF+EF (14%), LF+EF (39%), LF (11%), and EF (26%). No iatrogenic pars interarticularis damage occurred. The JOA score was 14.9 ± 2.6 points preoperatively and 22.4 ± 3.5 points at 2 years postoperatively. The JOA recovery rate was 56.0% ± 18.6%. The VAS score (low-back and leg pain) was significantly improved 2 years postoperatively (p < 0.01). According to patients' self-assessment of the minimally invasive surgery, 62 (79.5%) chose "surgery met my expectations" at follow-up. Nine patients (11.5%) selected "I did not improve as much as I had hoped but I would undergo the same surgery for the same outcome."

CONCLUSIONS

Most LFS existed outside the pedicle's center and was rarely noted in the pars region. The main regions of stenosis were localized to the pedicle's outer edge. Considering this anatomical distribution of LFS, the authors recommend that lateral fenestration should be the first priority for foraminal decompression. Other surgical options including foraminotomy, total facetectomy, and hemilaminectomy likely require more bone resections than LFS treatment. The microendoscopic surgery results were very good, indicating that this minimally invasive surgery was suitable for treating this disease.

The Haleem-Botchu classification: a novel CT-based classification for lumbar foraminal stenosis

PURPOSE

No clinical CT-based classification system is currently in use for lumbar foraminal stenosis. MRI scanners are not easily available, are expensive and may be contraindicated in an increasing number of patients. This study aimed to propose and evaluate the reproducibility of a novel CT-based classification for lumbar foraminal stenosis.

MATERIALS AND METHODS

The grading was developed as four grades: normal foramen-Grade 0, anteroposterior (AP)/superoinferior (SI) (single plane) fat compression-Grade 1, both AP/SI compression (two planes) without distortion of nerve root-Grade 2 and Grade 2 with distortion of nerve root-Grade 3. A total of 800 lumbar foramen of a cohort of 100 random patients over the age of 60 who had undergone both CT and MRI scans were reviewed by two radiologists independently to assess agreement of the novel CT classification against the MRI-based grading system of Lee et al. Interobserver(n = 400) and intraobserver agreement(n = 160) was also evaluated. Agreement analysis was performed using the weighted kappa statistic.

RESULTS

A total of 100 patients (M:F = 45:55) with a mean age of 68.5 years (range 60-83 years were included in the study. The duration between CT and MRI scans was 98 days (range 0-540, SD-108). There was good correlation between CT and MRI with kappa scores (k = 0.81) and intraobserver kappa of 0.89 and 0.98 for the two readers.

CONCLUSION

The novel CT-based classification correlates well with the MRI grading system and can safely and accurately replace it where required.

Full-endoscopic Decompression of Foraminal Stenosis Caused by Facet Hypertrophy Contralateral to the Dominant Hand in a Baseball Pitcher: A Case Report

Back pain and lower extremity pain have various causes and occasionally occur simultaneously, creating diagnostic difficulties. In addition, athletes require special consideration in terms of treatment. Here, we report a case of foraminal stenosis as a result of lumbar disc prolapse combined with facet hypertrophy contralateral to the dominant hand in a baseball pitcher that was successfully treated by minimally invasive full-endoscopic surgery. A 31-year-old left-handed male baseball pitcher presented with complaints of low back pain and right buttock pain while pitching. A diagnosis of foraminal stenosis caused by a disc bulge combined with facet hypertrophy contralateral to the dominant hand was made on the basis of physical and radiological findings. His symptoms improved immediately after transforaminal full-endoscopic lumbar discectomy and foraminoplasty under local anesthesia. He returned to play 3 months after surgery. Foraminal stenosis due to facet hypertrophy may occur in the side contralateral to the throwing arm in pitchers. Minimally invasive decompression using a full-endoscopic procedure is required for high-level athletes at this position.

Comparative Effectiveness Between Primary and Revision Foraminotomy for the Treatment of Lumbar Foraminal Stenosis

BACKGROUND

Foraminotomy has demonstrated clinical benefit in patients with lumbar foraminal stenosis (LFS), as evidenced by several small retrospective investigations. However, there is a subset of patients who have recurrent symptoms following the operation and therefore require revision surgery. Yet, despite this phenomenon, the relative efficacy of revision foraminotomy (RF) is not well elucidated due to limited literature on the quality of life (QOL) outcomes and cost associated with primary foraminotomy (PF) and RF.

PURPOSE

To compare the effectiveness of PF and RF in terms of QOL outcomes and relative costs.

STUDY DESIGN/SETTING

This is a retrospective cohort study conducted at a single tertiary-care institution. The patient sample consisted of patients undergoing foraminotomy for the treatment of LFS between 2008 and 2016. The primary outcome measure was improvement in postoperative QOL, as measured by EuroQol 5-Dimensions (EQ-5D), and secondary outcome measures included Pain Disability Questionnaire (PDQ) and Patient Health Questionnaire-9 (PHQ-9) perioperative cost as well as minimum clinically important difference (MCID).

METHODS

A retrospective chart review was conducted to identify individuals who underwent PF or RF for LFS and to collect clinical, operative, and demographic data. QOL scores (EQ-5D, PDQ, and PHQ-9) were collected between 2008 and 2016, and perioperative financial data were extracted via the institution's cost utilization engine. Paired t tests were used to assess changes within treatment groups, and Fisher exact tests were used for intercohort comparisons.

RESULTS

Five hundred seventy-nine procedures were eligible: 476 (82%) PF and 103 (18%) RF. A significantly higher proportion of males underwent RF than PF (71% versus 59%, P = .03), and PF was done on a significantly higher number of vertebral levels (2.2 versus 2.0, P = .04). There were no other significant differences in demographics. Preoperatively, mean PDQ-Functional scores (50 versus 54, P = .04) demonstrated significantly poorer QOL in the RF cohort. Postoperatively, EQ-5D index showed significant improvement in both the PF (0.547→0.648, P < .0001) and the RF (0.507→0.648, P < .0001) cohorts. Similarly, total PHQ-9 improved significantly in the PF cohort (7.84→5.91, P < .001) and in the RF cohort (8.55→5.53, P = .02), as did total PDQ (PF: 77→63, P < .0001; RF: 85→70, P = .04). QOL scores were also compared between groups preoperatively and postoperatively, and the only significant difference between PF and RF was observed in the preoperative PDQ-Functional score (49.7 versus 54.3, P = .04). The proportion of patients achieving MCID was not significantly associated with cohort. Finally, perioperative cost did not differ significantly between cohorts (PF: $13,383 versus RF: $13,595, P = .82).

CONCLUSIONS

Both PF and RF produced significant improvement in nearly all measures in patients with LFS. There was no significant difference in cost between PF and RF, but both PF and RF showed postoperative QOL improvements as compared with preoperative scores, indicating that RF remains a reasonable treatment option for patients with recurrent symptoms of LFS.

Morphologic Changes of Intervertebral Foramen After Minimally Invasive Transforaminal Lumbar Interbody Fusion: A Radiographic and Clinical Study

OBJECTIVE

We aimed to investigate the morphologic changes in the intervertebral foramen after minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF), and analyze the necessity of routinely performing contralateral intervertebral foraminal decompression in degenerative lumbar spondylolisthesis cases with bilateral symptoms.

METHODS

72 single-level degenerative lumbar spndylolisthesis patients with bilateral symptoms were included, all of whom underwent unilateral approach MIS-TLIF. Preoperative and postoperative foraminal height (FH), foraminal width (FW), disc height (DH), distance from existing nerve root to upper edge of lower pedicle (RTP), and contralateral side spinal canal area (CSCA) were measured at surgical and contralateral side. Clinical outcomes were evaluated using the visual analog scale, Oswestry Disability Index, and Japanese Orthopaedic Association score.

RESULTS

The preoperative values are comparable between operative and contralateral sides (P > .05). The postoperative values for FH on operative and contralateral sides were 16.23±2.48 mm and 16.10±2.42 mm, for FW were 11.36±2.58 mm and 11.31±2.71 mm, for IH were 8.18±1.58 mm and 8.42±1.54 mm, for RTP were 8.58±1.26 mm and 9.14±1.77 mm, and the CSCA of the spinal canal on the contralateral side were 211.59±48.12 mm², respectively. The difference between these was also not statistically significant (P > .05). The values increased significantly on the surgical and contralateral side (P < .05). The visual analog scale for low-back and leg pain, Japanese Orthopaedic Association, and Oswestry Disability Index improved significantly at 2-year follow-up.

CONCLUSIONS

Unilateral MIS-TLIF can effectively improve contralateral FH, DH, FW, RTP, and CSCA. It is not necessary to routinely perform contralateral intervertebral foramen decompression in degenerative lumbar spondylolisthesis with bilateral symptoms when symptoms are mild on one side.

Technical and Conceptual Review on the L5-S1 Oblique Lateral Interbody Fusion Surgery (OLIF51)

Lumbar lateral interbody fusion (LLIF) has been gaining popularity among the spine surgeons dealing with degenerative spinal diseases while LLIF on L5-S1 is still challenging for its technical and anatomical difficulty. OLIF51 procedure achieves effective anterior interbody fusion based on less invasive anterior interbody fusion via bifurcation of great vessels using specially designed retractors. The technique also achieves seamless anterior interbody fusion when combined with OLIF25. A thorough understanding of the procedures and anatomical features is mandatory to avoid perioperative complications.

Long-term complications of minimally-open anterolateral interbody fusion for L5-S1

BACKGROUND

Multiple surgical techniques and approaches exist to obtain lumbar interbody fusion. Anterolateral (oblique) is a relatively recent technique. Controversy exists for its use at the L5-S1 level. We performed this study in order to show the safety and efficacy of this technique. The aim of this study was to report the long-term complications and fusion rates of minimally-open (mini-open) anterolateral interbody fusion at the L5-S1 level.

METHODS

We retrospectively analyzed all patients who underwent mini-open anterolateral interbody fusion for L5-S1 level in our department. The data collected were the following: age, sex, surgical indication, acute (less than four weeks) and long-term complications (>3 months), fusion at six months and length of follow-up.

RESULTS

Seventeen patients (8M/9F) underwent mini-open anterolateral interbody fusion at L5-S1. The mean age was 64.5 years. The surgical indication was scoliosis in 10 cases, flat back in 4 cases, and spondylolisthesis in 3 cases. All patients underwent a complementary posterior procedure that included fixation. Mean blood loss was 252.9mL for the anterior procedure. Eight acute and minor complications occurred (anemia, delirium, and psoas paresis). Two acute complications required surgical intervention (cage displacement and hematoma). Long-term complications were observed in 2 cases and included proximal junction kyphosis and non-union. The fusion rate was evaluated at 88%. The mean follow-up period was 28.3 months.

CONCLUSIONS

Mini-open anterolateral interbody fusion at the L5-S1 level is safe and results in fusion at the same rate as anterior interbody fusion. Most acute complications are minor and resolve spontaneously.

Diffusion tensor imaging of lumbar spinal nerves reveals changes in microstructural integrity following decompression surgery associated with improvements in clinical symptoms: A case report

The outcomes from spinal nerve decompression surgery are highly variable with a sizable proportion of elderly foraminal stenosis patients not regaining good pain relief. A better understanding of nerve root compression before and following decompression surgery and whether these changes are mirrored by improvements in symptoms may help to improve clinical decision-making processes. This case study used a combination of diffusion tensor imaging (DTI), clinical questionnaires and motor neurophysiology assessments before and up to 3 months following spinal decompression surgery. In this case report, a 70-year-old women with compression of the left L5 spinal nerve root in the L5-S1 exit foramina was recruited to the study. At 3 months following surgery, DTI revealed marked improvements in left L5 microstructural integrity to a similar level to that seen in the intact right L5 nerve root. This was accompanied by a gradual improvement in pain-related symptoms, mood and disability score by 3 months. Using this novel multimodal approach, it may be possible to track concurrent improvements in pain-related symptoms, function and microstructural integrity of compressed nerves in elderly foraminal stenosis patients undergoing decompression surgery.

Diffusion tensor imaging reveals changes in microstructural integrity along compressed nerve roots that correlate with chronic pain symptoms and motor deficiencies in elderly stenosis patients

Age-related degenerative changes in the lumbar spine frequently result in nerve root compression causing severe pain and disability. Given the increasing incidence of lumbar spinal disorders in the aging population and the discrepancies between the use of current diagnostic imaging tools and clinical symptoms, novel methods of nerve root assessment are needed. We investigated elderly patients with stenosis at L4-L5 or L5-S1 levels. Diffusion tensor imaging (DTI) was used to quantify microstructure in compressed L5 nerve roots and investigate relationships to clinical symptoms and motor neurophysiology. DTI metrics (i.e. FA, MD, AD and RD) were measured at proximal, mid and distal segments along compressed (i.e. L5) and intact (i.e. L4 or S1) nerve roots. FA was significantly reduced in compressed nerve roots and MD, AD and RD were significantly elevated in the most proximal segment of the nerve root studied. FA was significantly correlated with electrophysiological measures of root function: minimum F-wave latency and peripheral motor conduction time (PMCT). In addition, FA along the compressed root also correlated with leg pain and depression score. There was also a relationship between RD and anxiety, leg pain and disability score and AD correlated with depression score. Taken together, these data show that DTI metrics are sensitive to nerve root compression in patients with stenosis as a result of age-related lumbar degeneration. Critically, they show that the changes in microstructural integrity along compressed L5 nerve roots are closely related to a number of clinical symptoms associated with the development of chronic pain as well as neurophysiological assessments of motor function. These inherent relationships between nerve root damage and phenotype suggest that the use DTI is a promising method as a way to stratify treatment selection and predict outcomes.

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DTI can be used to quantify lumbar spinal nerve root compression in elderly patients.

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Diffusion parameters correlate with functional neurophysiology and clinical symptoms.

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DTI has the potential to be used to predict treatment outcomes.

Spondylolisthesis with Uncommon Congenital Deformity of L4-L5 Vertebral Fusion Treated by Oblique Lumbar Interbody Fusion

BACKGROUND

Diagnosis and management of congenital anomalies of the spine can be a challenge because of their complex presentations. We present an uncommon case of congenital deformity of the spine with L4-L5 vertebral fusion, mimicking a single vertebra, and L3 spondylolisthesis treated by oblique lumbar interbody fusion (OLIF).

CASE DESCRIPTION

A 69-year-old woman presented with increasing lower back pain radiating to the left leg, with aggravation of symptoms for the past 6 months, causing difficulty in walking. She also complained of paresthesia along the L3-L5 dermatomes in both legs, with more prominence on the left side. Imaging revealed fusion deformity of the L4-L5 vertebrae, as well as degenerative spondylolisthesis at the L3-L4 level. After treatment with OLIF, the patient had an uneventful recovery period. Comparisons were made between the preoperative and 6-month follow-up visual analog scale and the Oswestry Disability Index scores. The patient showed significant improvement in the scores, as well as in her symptoms.

CONCLUSIONS

OLIF is a promising technique that can be applied in the management of degenerative disk diseases and also for deformities that may be formidable to treat by adopting the traditional posterior approach.

A less invasive surgery using a full-endoscopic system for L5 nerve root compression caused by lumbar foraminal stenosis

Background

Percutaneous endoscopic lumbar discectomy (PELD) is a relatively less invasive treatment for lumbar disc herniation (LDH). This study investigated the usefulness of a full-endoscopic system for PELD to treat L5 nerve root compression caused by lumbar foraminal stenosis (L5-LFS).

Methods

Between November 2016 and December 2017, a total of 10 patients with unilateral leg pain due to L5-LFS underwent surgery using a full-endoscopic system for PELD. Patients with bilateral L5-LFS or L5-LFS with coexisting LDH and/or spondylolysis were excluded from this study. A percutaneous endoscopic translaminar approach (PETA) was performed via the ipsilateral vertebral isthmus using a 3.5-mm diameter high-speed drill. Preoperative and postoperative statuses were evaluated using the modified Japanese Orthopedic Association (mJOA) and Numerical Rating Scale (NRS) scores.

Results

The patients' mean age was 62.2 years; there were 7 male and 3 female patients. The mean recovery rate was 58.2% with the mJOA score; mean pre- and postoperative NRS scores were 7.4 and 2.3, respectively. The mean operative time was 77.6 min. Although there were no major complications, pain did not improve in an 80-year-old woman with coexisting spondylolisthesis (Meyerding grade 2).

Conclusions

PETA using a full-endoscopic system is a safe and effective minimally invasive treatment for L5-LFS, with potential to be an alternative surgical strategy for L5-S1 interbody fusion.

Unilateral Biportal Endoscopic Spinal Surgery Using a 30° Arthroscope for L5-S1 Foraminal Decompression

Foraminal decompression using a minimally invasive technique to preserve facet joint stability and function without fusion reportedly improves the radicular symptoms in approximately 80% of patients and is considered one of the good surgical treatment choices for lumbar foraminal or extraforaminal stenosis. However, proper decompression was not possible because of the inability to access the foramen at the L5–S1 level due to prominence of the iliac crest. To overcome this challenge, endoscopy-based minimally invasive spine surgery has recently gained attention. Here, we report the technical skills required in unilateral extraforaminal biportal endoscopic spinal surgery using a 30° arthroscope to enable foraminal decompression at the L5–S1 level. Two 0.8-cm portals were created 2 cm lateral from the lateral border of the pedicles at the L5–S1 level. After sufficient working space was made, half of the superior articular process (SAP) in the hypertrophied facet joint was removed using a high-speed burr and a 5-mm wide osteotome, whereas the remaining inside part of the SAP was removed using a Kerrison punch and pituitary punch. The foraminal ligamentum flavum should be removed to inspect the conditions of the L5 exiting root and disc. Removing of the extruded disc could decompress the L5 root. The extraforaminal approach using a 30° arthroscope is considered a minimally invasive alternative technique for decompressing foraminal stenosis at the L5–S1 level that preserves facet stability and provides symptomatic relief.

Clinical effects of transforaminal and interlaminar percutaneous endoscopic discectomy for lumbar disc herniation: A retrospective study

The aim of this study is to observe the therapeutic effect of percutaneous endoscopic discectomy and its influencing factors for lumbar disc herniation and compare the advantages and disadvantages of transforaminal and interlaminar of percutaneous endoscopy.Data from 143 patients with lumbar disc herniation were respectively collected, including demographic and clinical data. Study population were divided into curative effect group and poor curative effect group, and logistic regression was used to explore the influencing factors of curative effect. The operation data and pre-and post-operation scores were compared to explore the effect of transforaminal and interlaminar approach on surgery efficacy.The rate of curative effect was 93.7%. 120 patients were classified as curative group and 23 patients were categorized as poor effective group. Univariate analysis found that the patients in the curative effect group tended to receive the interlaminar approach (58.3% vs 34.8%, P = .038). Multivariate logistic regression did not find operation approach was not related to curative effect of operation (transforaminal and interlaminar). But age ≥45 (odd risk (OR) = 6.43, P = .016), course of disease >12 month (OR = 3.77, P = .003), back and leg pain (OR = 3.46, P = .026), history of trauma (OR = 3.88, P = .014), Pfirrmann level IV (OR = 4.84, P = .004), and pre-Visual Analogue Scale (VAS) <5.3 (OR = 3.63, P = .015) were associated with operation efficacy. Compared with transforaminal group, the interlaminar group has less operative time (P = .000), less fluoroscopy time (P = .000), less puncture time (P = .000), less blood loss (P = .011).The transforaminal or interlaminar did not affect the treatment efficacy of percutaneous endoscopic discectomy for lumbar disc herniation. The selection of surgery approach depended on anatomical structure and physiological characteristics. It should be noted that 45 years of age or older, in the course of more than 12 months, both lumbocrural pain and lumbar disc herniation with grade IV, with history of trauma, may have impact on the efficacy of surgery.

The compression of L5 nerve root, single or double sites?-radiographic graded signs, intra-operative detect technique and clinical outcomes

Background

The L5 nerve root could be compressed at both L4-5 and L5-S1 regions. If L5 nerve root has confirmed compression at L4-5 level and questionable compression at L5-S1 foramina, performing both surgeries at L4-5 and L5-S1 levels may induce unnecessary extra surgery on L5-S1; however, ignoring foraminal stenosis of L5/S1 may require re-exploration.

Methods

Two hundred seventeen patients with L5 nerve root compressed at L4-5 lateral access were performed with L4-5 decompression and interbody fusion. Lee et al. grade classification was used to assess the foraminal stenosis of L5-S1 preoperatively. Nerve root probe was designed and used to detect if there were foraminal stenosis at L5-S1 level that compressing the exiting L5 nerve root. Visual analog scale (VAS) of low back pain, leg pain and Oswestry Disability Index (ODI) were used to assess clinical outcomes.

Results

For all of 217 patients who underwent L4-5 surgery, L5-S1 foramina were preoperatively assessed as: grade 0: 125 cases, grade 1: 58 cases, grade 2: 23 cases, and grade 3: 11 cases. After intra-operative L5 nerve root detection, 11/11 patients with grade 3 radiographic foraminal stenosis, 6/23 (26.1%) with grade 2 and 2/58 (3.4%) who had grade 1 underwent L4-5 and L5-S1 transforaminal lumbar interbody fusion (TLIF), the others received only L4-5 TLIF. Compared to pre-operative baseline data, both L4-5 TLIF and L4-5 and L5-S1 TLIF groups had significant decreased VAS of low back pain and leg pain, and ODI at 3 and 24 months after operation.

Conclusions

We suggested that our novel nerve root probe combined with pre-operative radiographic grade may be helpful to surgeons to identify the single or double compression of L5 nerve root and make a more precise surgical strategy to improve surgical outcome than the method depended on pre-operative radiographic grade alone.

Clinical classification criteria for nonspecific low back pain: A Delphi-survey of clinical experts

BACKGROUND

Nonspecific low back pain (NSLBP) is a common problem. Attempts have been made to classify NSLBP patients into homogenous subgroups. Classification systems based on identifying the underlying mechanism(s) driving the disorder are clinically useful to guide specific interventions.

OBJECTIVE

To establish consensus among experts regarding clinical criteria suggestive of a dominance of 'articular', 'myofascial', 'neural', 'central', and 'sensorimotor control' dysfunction patterns (DPs) in NSLBP patients.

STUDY DESIGN

A 2-phase sequential design of a focus group and Delphi-study.

METHODS

A focus group with 10 academic experts was organized to elaborate on the different DPs discernible in LBP patients. Consecutively, a 3-round online Delphi-survey was designed to obtain consensual symptoms and physical examination findings for the 5 DPs resulting from the focus group.

RESULTS

Fifteen musculoskeletal physical therapists from Belgium and the Netherlands experienced in assessing and treating LBP patients completed the Delphi-survey. Respectively, 34 (response rate, 100.0%), 20 (58.8%) and 15 (44.12%) respondents replied to rounds 1, 2 and 3. Twenty-two 'articular', 20 'myofascial', 21 'neural', 18 'central' and 11 'sensorimotor control' criteria reached a predefined ≥80% consensus level. For example, after round 2, 85.0% of the Delphi-experts agreed to identify 'referred pain below the knee' as a subjective examination criterion suggestive for a predominant 'neural DP'.

CONCLUSION

These indicators suggestive of a clinical dominance of the proposed DPs could help clinicians to assess and diagnose NSLBP patients. Future reliability and validity testing is needed to determine how these criteria may help to improve physical therapy outcome for NSLBP patients.