Lumbar foraminal stenosis was associated with back pain and leg pain: epidemiological evidence from a population-based cohort.

OBJECTIVES: To determine the characteristics of lumbar foraminal stenosis (LFS) on magnetic resonance (MR) images and their association with back pain and radiating leg pain in a population-based sample of Chinese subjects. METHODS: This study was an extension of the Hangzhou Lumbar Spine Study, a cross-sectional study focusing on back pain and lumbar spine MR imaging findings. Questionnaire data, including demographics, lifestyle, occupational exposures, back pain and radiating leg pain were included. On lumbar spine MR images, disc degeneration was assessed using Pfirrmann grade and Modic changes were evaluated. Using Lee's scale, the L3-S1 intervertebral foramina were evaluated, with grade 2-3 representing substantial LFS and grade 0-1 no LFS. Characteristics of LFS were noted, and associations of LFS with back pain and radiating leg pain were examined. RESULTS: Among the 644 study subjects, 141 (21.9%) had at least one LFS, and its occurrence was associated with greater age (OR = 1.93 for each 10 years, p < 0.001). Substantial LFS was associated with the presence of back pain (OR = 1.92, p = 0.001) and the intensity of the worst back pain (Coef = 8.30, p < 0.001) over the past 12 months, and disabling back pain during their lifetime (OR = 2.25, p < 0.001). Substantial LFS was also associated with leg pain (OR = 14.27, p < 0.001), with a sensitivity of 75.7% for the presence of radiating leg pain and a specificity of 81.4%. CONCLUSION: Substantial LFS on MR images was a common age-related degenerative phenotype in adults, and appears to be an independent risk factor for back pain and leg pain.

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.

[Contralateral endoscopic approach for lumbar foraminal stenosis using unilateral biportal endoscopic surgery].

OBJECTIVE: To assess the feasibility and imaging outcomes of unilateral biportal endoscopic technique in the treatment of lumbar foraminal stenosis through contralateral approach. METHODS: The clinical data of 33 patients with lumbar foraminal stenosis treated with unilateral biportal endoscopic technique from January 2021 to July 2022 were retrospectively analyzed. There were 17 males and 16 females;age ranging from 34 to 72 years old with an average of (56.00±7.89) years old;operation time and perioperative complications were recorded;visual analogue scale (VAS) of pain was recorded, to evaluate the degree of low back pain and lower extremity pain, and Oswestry disability index (ODI) to evaluate the lumbar spine function. At the latest follow-up, the modified Macnab score was used to evaluate the clinical efficacy. RESULTS: All patients successfully completed the operation. The operation time ranged from 47 to 65 minutes, with an average of (56.10±5.19) minutes. The postoperative follow-up ranged from 12 to 18 months, with an average of (14.9±2.3) months. The VAS of low back and lower extermity pain before operation were (7.273±1.442) and (7.697±1.447) scores, ODI was (69.182±9.740)%. Postoperative lumbocrural pain VAS were (3.394±0.966) and (2.818±0.727) scores, ODI was (17.30±4.78) %. At the latest follow-up, VAS of back and lower extermity pain was (2.788±0.650) and (2.394±0.704) scores, ODI was (14.33±350)%. There were significant differences in VAS of low back and lower extremity pain and ODI before and after operation(P<0.05). At the latest follow-up, according to the modified Macnab criteria, 24 patients got excellent result, 5 as good, 2 as fair, and 2 as poor. CONCLUSION: Unilateral biportal endoscopic treatment of lumbar foraminal stenosis through the contralateral approach is a safe and efficient method, with few complications, quick postoperative recovery, and satisfactory clinical outcomes. During the follow-up period, no iatrogenic lumbar instability was observed.

Transforaminal endoscopic lumbar foraminotomy for octogenarian patients.

Background: Radiculopathy caused by lumbar foraminal stenosis in older people has become more common in the aging general population. However, patients aged ≥80 years rarely undergo conventional open surgery under general anesthesia because of the high risk of peri-operative morbidity and adverse events. Therefore, less invasive surgical alternatives are needed for older or medically handicapped patients. Transforaminal endoscopic lumbar foraminotomy (TELF) under local anesthesia may be helpful in at-risk patients, although only limited information is available regarding the clinical outcomes of this procedure in octogenarians. Therefore, this study aimed to investigate the safety and efficacy of TELF for treating radiculopathy induced by foraminal stenosis in octogenarian patients. Methods: Overall, 32 consecutive octogenarian patients with lumbar foraminal stenosis underwent TELF between January 2019 and January 2021. The inclusion criterion was unilateral radiculopathy secondary to lumbar foraminal stenosis. The pain focus was confirmed using imaging studies and selective nerve blocks. Full-scale foraminal decompression was performed using a percutaneous transforaminal endoscopic approach under local anesthesia. Surgical outcomes were assessed using the visual analog pain score, Oswestry Disability Index, and modified MacNab criteria. Results: The pain scores and functional outcomes improved significantly during the 24-month follow-up period, and the rate of clinical improvement was 93.75% in 30 of the 32 patients. None of the patients experienced systemic complications. Conclusion: TELF under local anesthesia is an effective and safe treatment for foraminal stenosis in octogenarian or medically compromised patients. The mid-term follow-up did not reveal any significant progression in spinal stability. Therefore, this endoscopic procedure can be an effective alternative to aggressive surgery for managing lumbar foraminal stenosis in octogenarian patients with intractable radiculopathy.

Outcomes and Vertebral Osteophytes and Bulging Intervertebral Discs Occupancy as a Decision-Making Tool for Surgical Success in Patients Undergoing Microendoscopic Foraminotomy for Lumbar Foraminal Stenosis.

OBJECTIVE: The objective of this study was to determine the long-term outcomes of microendoscopic foraminotomy in treating lumbar foraminal stenosis and identify the optimal extent of decompression that yields improved results and fewer complications. METHODS: A retrospective cohort study reviewed the medical records of 95 consecutive patients who underwent microendoscopic foraminotomy for lumbar foraminal stenosis. Clinical outcomes were assessed using the Japanese Orthopaedic Association scoring system and visual analog scale for low back and leg pain. Surgical success was determined by meeting significant improvement thresholds for back and leg pain at 2 years postoperatively. Multiple regression analysis identified factors associated with improved pain scores. Receiver operating characteristic curve analysis determined the cut-off values for successful surgeries. RESULTS: Significant improvements were observed in Japanese Orthopaedic Association and visual analog scale scores for back and leg pain 2 years postoperatively compared with preoperative scores (P < 0.0001) and sustained over a ≥5-year follow-up period. Reoperation rates were low and did not significantly increase over time. Multiple regression analysis identified occupancy of the vertebral osteophytes and bulging intervertebral discs (O/D complex) as surgical success predictors. A 45.0% O/D complex occupancy cutoff value was determined, displaying high sensitivity and specificity for predicting surgical success. CONCLUSIONS: This study provides evidence supporting the long-term efficacy of microendoscopic foraminotomy for lumbar foraminal stenosis and predicting surgical success. The 45.0% O/D complex occupancy cut-off value can guide patient selection and outcome prediction. These insights contribute to informed surgical decision-making and underscore the importance of evaluating the O/D complex in preoperative planning and predicting outcomes.

Reliability of Conventional Two-Dimensional Magnetic Resonance Imaging for Diagnosing Extraforaminal Stenosis in Lumbosacral Transition.

Introduction: Three-dimensional (3D) magnetic resonance imaging (MRI) is reportedly superior to two-dimensional (2D) MRI for diagnosing lumbar foraminal stenosis at L5-S1. In this study, we strictly distinguished the intra- and extraforaminal regions and compared the diagnostic reliability and accuracy of 2D and 3D MRI in each region. Methods: A total of 92 surgical cases of unilateral L5 radiculopathy were selected for imaging analysis, including 46 of foraminal stenosis at L5-S1 (Group F) and 46 of intraspinal canal stenosis at L4-5 (Group C) (48 men, 44 women; mean age, 66 years). The 2D and 3D MRI sets were assessed twice by two examiners. They were informed only of the laterality of the lesion in each case and asked to select among the following for each modality: "absence of foraminal stenosis," "intraforaminal stenosis," "extraforaminal stenosis," and "coincident intraforaminal and extraforaminal stenosis." The intra- and interobserver reliabilities were evaluated using kappa (κ) statistics for the intra- and extraforaminal regions and compared between 2D and 3D MRI. For each case, disagreements between examiners were resolved through discussion to obtain a diagnostic judgment for each modality. Subsequently, the final diagnosis of intra- and/or extraforaminal stenosis in Group F was made using multiple modalities and intraoperative findings. A comparison between 2D and 3D MRI in terms of diagnostic accuracy was performed for the intra- and extraforaminal regions. Results: No significant difference was observed in the κ statistics between 2D and 3D MRI for the intraforaminal region, whereas 3D MRI had significantly larger κ statistic than 2D MRI for the extraforaminal region. Ultimately, 3D MRI perfectly judged the extraforaminal region, whereas 2D MRI detected only 44.8% of the cases of extraforaminal stenosis. Conclusions: More than half of extraforaminal stenosis was overlooked by 2D MRI, suggesting that it is unreliable for diagnosing extraforaminal stenosis at L5-S1.

Factors affecting return to work following endoscopic lumbar foraminal stenosis surgery: A single-center series.

Background: This study evaluates the factors affecting the return to work of endoscopic surgery for lumbar foraminal stenosis (LFS), including symptoms, functional status, complications, and reoperation rates. Methods: The authors' retrospective cohort study included 100 consecutive patients (50 males and 50 females) diagnosed with LFS who underwent endoscopic surgery at Trotsky National Research Center of Surgery between January 2018 and December 2021. Results: There were no significant differences in age and preoperative visual analog scale and Oswestry disability index scores between the male and female groups, time to return to work for different patient groups after undergoing endoscopic lumbar foraminotomy (ELF). However, patients with more severe stenosis and comorbidities may take longer to recover. Confounding factors were patient age, preoperative physical function, and job requirements. Conclusion: This study confirms that study ELF can effectively improve symptoms associated with lumbar radiculopathy, as well as back pain, and improve patients' quality of life. Comorbidity, smoking status, and complications prolong the time to return to work following ELF surgery compared to healthy subjects.

Risk Factors of Restenosis After Full Endoscopic Foraminotomy for Lumbar Foraminal Stenosis: Case-Control Study.

OBJECTIVE: To investigate risk factors associated with postoperative restenosis after full endoscopic lumbar foraminotomy (FELF) in patients with lumbar foraminal stenosis (LFS). METHODS: A single-center, retrospective case-control study was conducted on patients diagnosed with foraminal stenosis who underwent FELF between August 2019 and April 2022. The study included 56 patients, comprising 18 cases and 38 controls. Clinical data, radiologic assessments, and surgical types were compared between the groups. The cutoff values of radiologic parameters that differentiate the 2 groups were investigated. RESULTS: No significant difference in age, sex distribution, or presence of adjacent segment disease or grade I spondylolisthesis was observed between the groups. Cases had a higher degree of disc wedging angle (DWA) (3.0° ± 1.1° vs. 0.5° ± 1.4°, p < 0.001), larger coronal Cobb angle (CCA) (8.8° ± 5.1° vs. 4.7° ± 2.5°, p = 0.004), and smaller segmental lumbar lordosis (SLL) than controls (11.0 ± 7.4 vs. 18.0 ± 5.4, p = 0.001). Optimal cutoff values for DWA, CCA, and SLL were estimated as 1.8°, 7.9°, and 17.1°, respectively. A significant difference in surgical types was observed between cases and controls (p = 0.004), with the case group having a higher distribution of patients undergoing discectomy in addition to TELF. CONCLUSION: The study identified potential risk factors for restenosis after FELF in patients with LFS, including higher DWA, larger CCA, smaller SLL angle. We believe that discectomy should be perform with caution during FELF, as it can lead to subsequent restenosis.

Are T1-Weighted Three-Dimensional Magnetic Resonance Images Inferior to T2-Weighted Images for Diagnosing Lumbar Foraminal Stenosis in the Fifth Lumbar Nerve Root? A Prospective, Comparative Study in Identical Patients.

Introduction: Imaging analysis of foraminal stenosis in the fifth lumbar (L5) nerve root remains to be a challenge because of the anatomical complexity of the lumbosacral transition. T2-weighted three-dimensional (3D) magnetic resonance images (MRI) have been dominantly used for diagnosis of lumbar foraminal stenosis, while the reliability of T1-weighted images (WI) has also been proven. In this study, we aim to compare the reliability and reproducibility of T1- and T2-weighted 3D MRI in diagnosing lumbar foraminal stenosis (LFS) of the L5 nerve root. Methods: In this study, 39 patients with unilateral L5 radiculopathy (20 had L4-L5 intracanal stenosis; 19 had L5-S foraminal stenosis) were enrolled, prospectively. T1- and T2-weighted 3D lumbar MRI were obtained from each patient. T1WI and T2WI were blinded and then separately reviewed twice by four examiners randomly. The examiners were instructed to answer the side of LFS or absence of LFS. The correct answer rate, sensitivity, specificity, and area under the curve were analyzed and compared between T1WI and T2WI. Also, intra- and interobserver agreements were calculated using kappa (κ)-statistics and compared in the same manner. Results: The average correct answer rate, sensitivity, specificity, and area under the curve of the T1WI/T2WI were 84.6%/80.1%, 82.9%/80.3%, 86.3%/81.3%, and 0.846/0.801, respectively. The intraobserver κ-values of the four examiners ranged from 0.692 to 0.916 (average: 0.762) and from 0.669 to 0.801 (average: 0.720) for T1WI and T2WI, respectively. The interobserver κ-values calculated in a round-robin manner (24 combinations in total) ranged from 0.544 to 0.790 (average: 0.657) and from 0.524 to 0.828 (average: 0.652), respectively. Conclusions: As per our findings, T1- and T2-weighted 3D MRI were determined to have nearly equivalent reliability and reproducibility in terms of diagnosing LFS of the L5 nerve root.

Radical decompression without fusion for L5 radiculopathy due to foraminal stenosis.

Background: The highest incidence of lumbar foraminal stenosis (LFS) occurs in the L5-S1 segment and its anatomical features differ from those of other segments. Few previous reports have exhaustively assessed surgical outcomes after decompression surgery, limiting the materials to patients with LFS at the L5-S1 segment. We aimed to prospectively investigate instability and neurological improvement following our novel surgical technique for LFS at L5-S1, named "radical decompression" of the nerve root. Methods: Patients with foraminal stenosis at L5-S1 who underwent surgery using our technique were prospectively evaluated two years postoperatively. The Japanese Orthopaedic Association (JOA) score and the JOA Back Pain Evaluation Questionnaire (JOABPEQ) were evaluated preoperatively and two years postoperatively. The following radiological parameters at L5-S1 were measured: lateral translation, sagittal translation, the difference in sagittal translation (DST) between flexion and extension, disc wedging angle, lordotic angle, the difference in lordotic angle (DLA) between flexion and extension, and disc height. Pre- and postoperative data were compared using paired t-tests. In addition, the patients were classified into a disc group (Group D) and a non-disc group (Group ND) according to whether a discectomy was performed intraoperatively. Changes in each parameter before and after surgery were compared between the groups. Results: Twenty-eight patients were included in this analysis. The JOA scores improved in all patients. The mean preoperative and two-year postoperative JOA scores were 14.5±3.2 (range, 8-21) and 24.3±3.3 (range, 18-29), respectively (P<0.01). All JOABPEQ categories improved two years postoperatively (P<0.05). None of the patients underwent revision surgery. No significant changes were observed in any of the radiological parameters. No significant differences in the changes in each parameter before and after surgery were found between groups D and ND. Conclusions: Our surgical technique resulted in good neurological recovery and was associated with a low risk of postoperative segmental instability, regardless of additional discectomy.

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.

Biportal endoscopic paraspinal decompressive foraminotomy for lumbar foraminal stenosis: clinical outcomes and factors influencing unsatisfactory outcomes.

BACKGROUND: Lumbar foraminal stenosis (LFS) is an important pathologic entity that causes lumbar radiculopathies. Unrecognized LFS may be associated with surgical failure, and LFS remains challenging to treat surgically. This retrospective cohort study aimed to evaluate the clinical outcomes and prognostic factors of decompressive foraminotomy performed using the biportal endoscopic paraspinal approach for LFS. METHODS: A total of 102 consecutive patients with single-level unilateral LFS who underwent biportal endoscopic paraspinal decompressive foraminotomy were included. We evaluated the Visual Analogue Scale (VAS) score and the Oswestry Disability Index (ODI) before and after surgery. Demographic, preoperative data, and radiologic parameters, including the coronal root angle (CRA), were investigated. The patients were divided into Group A (satisfaction group) and Group B (unsatisfaction group). Parameters were compared between these two groups to identify the factors influencing unsatisfactory outcomes. RESULTS: In Group A (78.8% of patients), VAS and ODI scores significantly improved after biportal endoscopic paraspinal decompressive foraminotomy (p < 0.001). However, Group B (21.2% of patients) showed higher incidences of stenosis at the lower lumbar level (p = 0.009), wide segmental lordosis (p = 0.021), and narrow ipsilateral CRA (p = 0.009). In the logistic regression analysis, lower lumbar level (OR = 13.82, 95% CI: 1.33-143.48, p = 0.028) and narrow ipsilateral CRA (OR = 0.92, 95% CI: 0.86-1.00, p = 0.047) were associated with unsatisfactory outcomes. CONCLUSIONS: Significant improvement in clinical outcomes was observed for a year after biportal endoscopic paraspinal decompressive foraminotomy. However, clinical outcomes were unsatisfactory in 21.2% of patients, and lower lumbar level and narrow ipsilateral CRA were independent risk factors for unsatisfactory outcomes.

Safety of Epidural Hyaluronic Acid Injections in Managing the Symptoms of Lumbar Foraminal Stenosis: A Prospective Preliminary Study.

Lumbar foraminal stenosis (LFS) of degenerative origin is a common reason for distorted neurodynamics of nerve roots, causing radicular pain that is difficult to resolve with conservative treatments. A hyaluronic acid (HA), providing a sliding layer in the mechanical interface of a nerve root in a narrowed lateral recess, could potentially improve its neurodynamics and the trophic, leading to radicular pain reduction and improvement of function. This study aimed to assess the usefulness of ultrasound-guided HA epidural injections combined with neuromobilization in the conservative treatment of LFS. A group of 10 consecutively admitted patients with MRI-confirmed LFS and reduced straight leg raise (SLR) test results were qualified for a single HA epidural injection along with self-performed neuromobilization. Three measurement tools were used for primary outcomes: the numeric rating scale (NRS) for pain intensity, the Oswestry disability index (ODI) and the Roland-Morris questionnaire (RMQ) for disability level, and the angle of pain-free elevation in the SLR test as a functional assessment. The treatment was accomplished in all patients (100%). Overall, 60% of the patients completed all follow-up visits. There were no statistically significant differences regarding the results of the NRS, ODI, or RMQ; however, a statistically significant increase in the results of the SLR test was noted (p = 0.015). Three patients reported a flare-up of the symptoms shortly after injection but without neurological deficits. In conclusion, an epidural HA injection combined with a self-administered exercise program is a promising method and might be a beneficial way to enhance the neurodynamics of nerve roots in LFS and offer an option for steroid treatment. However, this method of epidural HA administration in LFS should be verified in further studies to confirm its efficiency and safety.

Is navigation beneficial for transforaminal endoscopic lumbar foraminotomy? A preliminary comparison study with fluoroscopic guidance.

PURPOSE: The primary purpose of this study was to determine radiation exposure of the surgeon during transforaminal endoscopic lumbar foraminotomy (TELF). Secondary purpose of this study was to compare clinical and radiologic outcomes between TELF under C-arm fluoroscopic guidance (C-TELF) and O-arm navigation-guided TELF (O-TELF). METHODS: The author reviewed patients' medical records who underwent TELF at our institute from June 2015 to November 2022. A total of 40 patients were included (18 patients with C-TELF and 22 with O-TELF). Basic demographic data were collected. Preoperative/postoperative visual analog scale (VAS) and Oswestry Disability Index (ODI) were recorded at the outpatient clinic. Radiologic features were compared on X-rays at each follow-up. The degree of foraminal expansion was measured/compared through MRI. In the C-TELF group, the amount of exposure was calculated with a dosimeter. RESULTS: Average surgeon's effective dose in the C-TELF group was 0.036 mSv. In the case of the O-TELF group, there was no radiation exposure during operation. However, the operation time in the O-TELF group was about 37 min longer than that in the C-TELF group. There were significant improvements in VAS/ODI after operation in both groups. Complications were identified in three patients. CONCLUSION: O-TELF showed similarly favorable clinical and radiologic outcomes to C-TELF in lumbar foraminal stenosis, including complication rate. Compared to C-TELF, O-TELF has an advantage of not wearing a lead apron since the operator is not exposed to radiation. However, the operation time was longer with O-TELF due to O-arm setting time. Because there are pros and cons, the choice of surgical method depends on the surgeon's preference.

SPINE: High heterogeneity and no significant differences in clinical outcomes of endoscopic foraminotomy vs fusion for lumbar foraminal stenosis: a meta-analysis.

Objective: This study aimed to systematically review the literature for comparative and non-comparative studies reporting on clinical outcomes of patients with lumbar foraminal stenosis treated by either endoscopic foraminotomy or fusion. Methods: In adherence with Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines, a literature search was done on January 17, 2022, using Medline and Embase. Clinical studies were eligible if they reported outcomes following fusion or endoscopic foraminotomy, in patients with primary lumbar foraminal stenosis. Two independent reviewers screened titles, abstracts, and full-texts to determine eligibility; performed data extraction; and assessed the quality of eligible studies according to the Joanna Briggs Institute (JBI) checklist. Results: The search returned 827 records; 266 were duplicates, 538 were excluded after title/abstract/full-text screening, and 23 were eligible, with 16 case series reporting on endoscopic foraminotomy, 7 case series reporting on fusion, and no comparative studies. The JBI checklist indicated that 21 studies scored ≥4 points. When comparing endoscopic foraminotomy to fusion, pooled data revealed reduced operative time (69 vs 119 min, P < 0.01) but similar Oswestry disability index (19 vs 20, P = 0.67), lower back pain (2 vs 2, P = 0.11), leg pain (2 vs 2, P = 0.15), complication rates (10% vs 5%, P = 0.22), and reoperation rates (5% vs 0%, P = 0.16). The proportions of patients with good/excellent MacNab criteria were similar for endoscopic foraminotomy and fusion (82-91% vs 85-91%). Conclusions: There were high heterogeneity and no significant differences in clinical outcomes, complication rates, and reoperation rates between endoscopic foraminotomy and fusion for the treatment of lumbar foraminal stenosis; although endoscopic foraminotomy has reduced operative time.

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.

Correlation between leg pain at rest and spinal nerve edema in symptomatic lumbar foraminal stenosis.

BACKGROUND: Previous studies reported that spinal nerve edema on magnetic resonance myelography (MRM) and leg pain at rest were specifically observed in symptomatic lumbar foraminal stenosis patients. However, the correlation between leg pain at rest and spinal nerve edema in symptomatic foraminal stenosis has not been reported. HYPOTHESIS: The purpose of this prospective study is to reveal a correlation between leg pain at rest and spinal nerve edema focusing on the pathophysiology of symptomatic foraminal stenosis. PATIENTS AND METHODS: Clinical findings and MRM findings were surveyed among 30 patients with symptomatic foraminal stenosis diagnosed by MR imaging (MRI) and selective nerve root block. Comparisons of patient characteristics and clinical findings between the prevalence and absence groups of spinal nerve edema on MRM were analyzed. A correlation between the visual analogue scale (VAS) for leg pain at rest and the spinal edema ratio calculated as maximum intensity value of the affected spinal nerve/maximum intensity value of the asymptomatic side from region of interest (ROI) made on MRM was evaluated. RESULTS: Twenty symptomatic foraminal stenosis cases (67%) showed the affected spinal nerve edema on MRM. The prevalence and VAS of leg pain at rest were significantly higher in the presence of spinal nerve edema group (95% and 67.0±36.4, respectively). The correlation coefficient between the VAS for leg pain at rest (53.0±33.6) and the spinal nerve edema ratio (1.3±0.3) was 0.647 (p<0.01). DISCUSSION: Our study revealed the substantial correlation found between the spinal nerve edema ratio on MRM and the VAS for leg pain at rest in symptomatic foraminal stenosis. The correlation between spinal nerve edema and leg pain at rest has potential to clarify the pathology of symptomatic foraminal stenosis. LEVEL OF EVIDENCE: IV.

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.

Morphometric change in intervertebral foramen after percutaneous endoscopic lumbar foraminotomy: an in vivo radiographic study based on three-dimensional foramen reconstruction.

PURPOSE: This study aimed to perform in vivo three-dimensional (3D) quantitative measurements of morphometric changes in the foramen in patients with lumbar foraminal stenosis (LFS) undergoing percutaneous endoscopic lumbar foraminotomy (PELF) and investigate the relationship between anatomical changes in the foramen and clinical outcomes. METHODS: We retrospectively reviewed consecutive patients with LFS treated with PELF between January 2016 and September 2020 at our centre. Clinical outcomes were evaluated. Foraminal volume (FV) and foraminal minimal area (FMA) were calculated using a novel vertebral and foramen segmentation method. A comparison of the anatomical parameters of the foramen were conducted between the satisfied and unsatisfied groups divided based on the modified MacNab criteria. RESULTS: A total of 26 eligible patients with a mean follow-up of 3.6 years were enrolled. A significant increase was found in overall FV (71.5%) from 1.436 ± 0.396 to 2.464 ± 0.719 cm3 (P < 0.001) and FMA (109.5%) from 0.849 ± 0.207 to 1.780 ± 0.524 cm2. All clinical outcomes were significantly improved (P < 0.001) after PELF. No significant difference was found in changes in neither FV nor FMA between the two groups. CONCLUSION: Clinical results and foraminal dimensions improved significantly after PELF, indicating that PELF was a prominent technique suitable for LFS because of the direct decompression at impingement structures. No relationship was found between morphometric changes and clinical outcomes, revealing that full-scale endoscopic decompression is necessary and adequate for LFS, and unsatisfactory outcomes are less likely to result from decompression procedure.

Indirect decompression via oblique lumbar interbody fusion is sufficient for treatment of lumbar foraminal stenosis.

Oblique lumbar interbody fusion (OLIF) is a popular technique for the treatment of degenerative lumbar spinal disease. There are no clear guidelines on whether direct posterior decompression (PD) is necessary after OLIF. The purpose of this study was to analyze the effect of the indirect decompression obtained from OLIF in patients with lumbar foraminal stenosis. We retrospectively reviewed 33 patients who underwent OLIF surgery for degenerative lumbar spinal disease between 1 January 2018, and 30 June 2019. The inclusion criteria included patients who were diagnosed with lumbar foraminal stenosis by preoperative MRI. The exclusion criteria included the presence of central canal stenosis, spinal infection, vertebral fractures, and spinal malignancies. The clinical results, evaluated using the visual analogue scale of back pain (VAS-Back), VAS of leg pain (VAS-Leg), and Oswestry disability index (ODI), were recorded. The radiologic parameters were also measured. The VAS-Back, VAS-Leg, and ODI showed significant improvement in both the PD and non-posterior decompression (Non-PD) groups postoperatively (all, p < 0.05). Patients in the Non-PD group showed better results than those in the PD group in the VAS-Back at 12- and 24 months postoperatively (0.00 vs. 3.00 postoperatively at 12 months, p = 0.030; 0.00 vs. 4.00 postoperatively at 24 months, p = 0.009). In addition, the ODI at 24 months postoperatively showed better improvement in the Non-PD group (8.89 vs. 24.44, p = 0.038). The disc height in both the PD and the Non-PD groups increased significantly postoperatively (all, p < 0.05), but the restoration of foraminal height was significantly different only in the Non-PD group. There was no statistically significant difference in cage position, cage subsidence, fusion grade, or screw loosening between the PD and the Non-PD groups. Indirect decompression via OLIF for lumbar foraminal stenosis showed favorable outcomes. The use of interbody cages and posterior instrumentation was sufficient for relieving symptoms in patients with lumbar foraminal stenosis. Additional direct posterior decompression may deteriorate results in the follow-up period.