Dural Sac Cross-sectional Area Research Articles

Unilateral biportal endoscopy vs. open decompression for lumbar epidural lipomatosis-cohort study using a prospective registry.

This study aimed to compare the outcomes of unilateral biportal endoscopy, unilateral laminectomy bilateral decompression (UBE-ULBD), and open lumbar decompression (OLD) in patients with lumbar epidural lipomatosis (LEL). This prospective observational study was conducted from March 2019 to May 2022 and encompassed 33 patients with LEL who underwent lumbar decompression. The study included 15 cases of UBE-ULBD decompression and 18 cases of open decompression, which were followed up for 1 year. The baseline characteristics, initial clinical manifestations, and surgical details [including estimated blood loss (EBL) and preoperative complications] of all patients were recorded. Radiographic evaluation included the cross-sectional area (CSA) of the thecal sac and paraspinal muscles on MRI. Clinical results were analyzed using the Short Form-36 Score (SF-36), the Numeric Pain Rating Scale (NRS) for lumbar and leg pain, creatine kinase, the Roland and Morris Disability Questionnaire (RMDQ), and the Oswestry Disability Index (ODI). The dural sac CSA increased considerably at the 1-year postoperative follow-up in both groups (p < 0.001). The operative duration in the OLD group (48.2 ± 7.2 min) was shorter than that in the UBE-ULBD group (67.7 ± 6.3 min, p < 0.001). The OLD group (97.2 ± 19.8 mL) was associated with more EBL than the UBE-ULBD group (40.6 ± 13.6 mL, p < 0.001). The duration of hospitalization in the OLD group (5.4 ± 1.3 days) was significantly longer compared with the UBE-ULBD group (3.5 ± 1.2 days, p < 0.01). The SF-36, NRS, RMDQ, and ODI scores improved in both groups postoperatively (p < 0.001). Serum creatine kinase values in the UBE-ULBD group (101.7 ± 15.5) were significantly lower than those in the OLD group (330.8 ± 28.1 U/L) 1 day after surgery (p < 0.001). The degree of paraspinal muscle atrophy in the UBE-ULBD group (4.81 ± 1.94) was significantly lower than that in the OLD group (12.15 ± 6.99) at 1 year (p < 0.001). UBE-ULBD and OLD demonstrated comparable clinical outcomes in treating LEL. However, UBE-ULBD surgery was associated with shorter hospital stays, lower rates of incision infection, lighter paravertebral muscle injury, and lower EBL than OLD surgery. Consequently, UBE-ULBD can be recommended in patients with LEL if conservative treatment fails.

Ultrasonic bone curette-assisted unilateral approach for bilateral decompression with MIS-TLIF for severe lumbar spinal stenosis

PurposeWe aimed to evaluate the clinical efficacy of bilateral decompression with minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) assisted by an ultrasonic bone curette (UBC) for treating severe degenerative lumbar spinal stenosis (DLSS) and traditional tool laminectomy decompression MIS-TLIF for treating severe DLSS.MethodsThe clinical data of 128 patients with single-segment severe DLSS who were admitted between January 2017 and December 2021 were retrospectively analyzed. Among them, 67 patients were treated with unilateral fenestration and bilateral decompression MIS-TLIF using an ultrasonic bone curette (UBC group), whereas 61 patients were treated with unilateral fenestration and bilateral decompression MIS-TLIF using traditional tools (traditional group, control). A visual analog scale (VAS) was used to evaluate back and lower limb pain before the operation,immediate postoperative, and one week, 3, 6, 12, and 24 months after the operation. Oswestry disability index (ODI) and Zurich claudication score (ZCQ) were employed to evaluate the improvement in low back and lower limb function. At the last follow-up, the Bridwell bone graft fusion standard was utilized to evaluate bone graft fusion.ResultsThe decompression time of laminectomy was significantly shorter in the UBC group than in the traditional group (control group), and the intraoperative blood loss and postoperative drainage volume were significantly less in those in the control group (P < 0.05). The VAS, ODI, and ZCQ scores of the two groups after the operation were significantly improved compared to those before the operation (P < 0.05). The UBC group had better VAS back scores than the control group immediate postoperative and one week after the operation(P < 0.05). The UBC group had better VAS lower limb scores than the control group immediate postoperative (P < 0.05).The incidence of perioperative complications, hospitalization time, dural sac cross-sectional area (CSA), and dural sac CSA improvement rate did not differ significantly between the two groups (P > 0.05). VAS and ODI scores did not differ significantly between the two groups before,three, six months, one year, and two years after surgery (P > 0.05). The ZCQ scores did not differ significantly between the two groups before the operation at one week, six months, one year, and two years after the operation (P > 0.05). According to the Bridwell bone graft fusion standard, bone graft fusion did not occur significantly between the two groups (P > 0.05) at the last follow-up.ConclusionsUBC unilateral fenestration bilateral decompression MIS-TLIF in treating severe DLSS can achieve clinical efficacy as traditional tool unilateral fenestration bilateral decompression MIS-TLIF and reduce intraoperative blood loss and postoperative drainage. It can also shorten the operation time, effectively reduce the work intensity of the operator, and reduce the degree of low back pain during short-term follow-ups. Therefore, this is a safe and effective surgical method.

One-hole split endoscope versus unilateral biportal endoscopy for lumbar spinal stenosis: a retrospective propensity score study

BackgroundThe one-hole split endoscopy (OSE) was first proposed and clinically applied in China in 2019. The aim of this study was to compare the clinical efficacy of one-hole split endoscopy (OSE) and unilateral biportal endoscopy (UBE) for treating lumbar spinal stenosis (LSS).MethodsOne hundred sixty patients with LSS who met the inclusion from November 2020 to August 2022 were analyzed and divided into OSE and UBE groups. The propensity score matching (PSM) method was used to adjust the imbalanced confounding variables between the two groups. After matching, surgical outcomes were recorded, and clinical data, including functional scores and imaging findings, were compared. Functional scores included the visual analog scale of leg pain (VAS-LP) and back pain (VAS-BP), the Japanese Orthopedic Association score (JOA), and the Oswestry Disability Index (ODI). Imaging data included dural sac cross-sectional area (DCSA), lumbar range of motion (ROM), and sagittal translation (ST).ResultsAfter PSM, 104 LSS patients were included in the study, and all covariates were well-balanced between the two groups. Among the matched patients, the OSE showed advantages over the UBE regarding operative time (62.42 ± 4.86 vs. 68.96 ± 4.56) and incision length (2.30 ± 0.14 vs. 2.70 ± 0.15) (P < 0.001). However, differences between the two groups in intraoperative blood loss, hospital length of stay, and complication rates were not statistically significant (P > 0.05). There was no statistically significant difference regarding VAS-BP, VAS-LP, JOA, and ODI between the two groups (P > 0.05). However, all clinical and functional scores significantly improved postoperatively (P < 0.05). Postoperative DCSA of both groups was significantly found to be improved (P < 0.05), ROM and ST remained within the normal range, and no cases of lumbar instability were recorded. According to the modified MacNab criteria, the excellent and good rates in the OSE and UBE groups were 94.23% and 90.38%, respectively, with no statistically significant difference (P = 0.713).ConclusionOSE is an alternative technique to UBE for the treatment of LSS, with similar satisfactory clinical outcomes, shorter operative time, and smaller incision length. Further studies are needed for long-term efficacy.

Time Course of Asymptomatic Stenosis in Multiple Lumbar Spinal Stenosis-Five-Year Results of Selective Decompression of Symptomatic Levels.

Background: In the diagnosis of lumbar spinal stenosis (LSS), finding stenosis with magnetic resonance imaging (MRI) does not always correlate with symptoms such as sciatica or intermittent claudication. We perform decompression surgery only for cases where the levels diagnosed from neurological findings are symptomatic, even if multiple stenoses are observed on MRI. The objective of this study was to examine the time course of asymptomatic stenosis in patients with LSS after they underwent decompression surgery for symptomatic stenosis. Materials and Methods: The participants in this study comprised 137 LSS patients who underwent single-level L4-5 decompression surgery from 2003 to 2013. The dural sac cross-sectional area at the L3-4 disc level was calculated based on preoperative MRI. A cross-sectional area less than 50 mm2 was defined as stenosis. The patients were grouped, according to additional spinal stenosis at the L3-4 level, into a double group (16 cases) with L3-4 stenosis, and a single group (121 cases) without L3-4 stenosis. Incidences of new-onset symptoms originating from L3-4 and additional L3-4-level surgery were examined. Results: Five years after surgery, 98 cases (72%) completed follow-up. During follow-up, 2 of 12 patients in the double group (16.7%) and 9 of 86 patients in the single group (10.5%) presented with new-onset symptoms originating from L3-4, showing no significant difference between groups. Additional L3-4 surgery was performed for one patient (8.3%) in the double group and three patients (3.5%) in the single group; again, no significant difference was shown. Conclusion: Patients with asymptomatic L3-4 stenosis on preoperative MRI were not prone to develop new symptoms or need additional L3-4-level surgery within 5 years after surgery when compared to patients without preoperative L3-4 stenosis. These results indicate that prophylactic decompression for asymptomatic levels is unnecessary.

Dural Sac Cross-sectional area change from preoperatively and up to 2 years after decompressive surgery for central lumbar spinal stenosis: investigation of operated levels, data from the NORDSTEN study.

The aim of the present study was to investigate how canal area size changed from before surgery and up to 2 years after decompressive lumbar surgery lumbar spinal stenosis. Further, to investigate if an area change postoperatively (between 3 months to 2 years) was associated with any preoperative demographic, clinical or MRI variables or surgical method used. The present study is analysis of data from the NORDSTEN- SST trial where 437 patients were randomized to one of three mini-invasive surgical methods for lumbar spinal stenosis. The patients underwent MRI examination of the lumbar spine before surgery, and 3 and 24 months after surgery. For all operated segments the dural sac cross-sectional area (DSCA) was measured in mm2. Baseline factors collected included age, gender, BMI and smoking habits. Furthermore, surgical method, index level, number of levels operated, all levels operated on and baseline Schizas grade were also included in the analysis. 437 patients were enrolled in the NORDSTEN-SST trial, whereof 310 (71%) had MRI at 3 months and 2 years. Mean DSCA at index level was 52.0mm2 (SD 21.2) at baseline, at 3 months it increased to 117.2mm2 (SD 43.0) and after 2 years the area was 127.7mm2 (SD 52.5). Surgical method, level operated on or Schizas did not influence change in DSCA from 3 to 24 months follow-up. The spinal canal area after lumbar decompressive surgery for lumbar spinal stenosis increased from baseline to 3 months after surgery and remained thereafter unchanged 2 years postoperatively.

Clinical significance of redundant nerve roots in patients with lumbar spinal stenosis undergoing oblique lumbar interbody fusion combined with percutaneous internal fixation

BackgroundWhile there have been previous studies on the surgical efficacy of patients with redundant nerve roots (RNRs), a persistent issue is that some patients continue to experience redundancy even after surgery. Furthermore, the clinical significance of RNRs remains unclear. Notably, there is a lack of research regarding RNRs within the context of oblique lumbar interbody fusion (OLIF) combined with percutaneous internal fixation. Therefore, the primary objective of this study is to investigate the correlation between RNRs and clinical outcomes following OLIF combined with percutaneous internal fixation.MethodsEighty-seven patients diagnosed with lumbar spinal stenosis (LSS) who underwent single-segment OLIF combined with percutaneous internal fixation were categorized into three groups. Group 1 comprised patients with positive RNRs both before and after the operation. Group 2 included patients with positive RNRs preoperatively but negative RNRs postoperatively. Group 3 consisted of patients with consistently negative RNRs before and after the operation. Comprehensive patient data were collected, including operation time, intraoperative blood loss, and any recorded complications. Radiographic parameters, both pre- and post-operative, were assessed, encompassing the number of stenosis segments, disc height (DH), lumbar lordotic angle, dural sac cross-sectional area, and the placement of the fusion cage. Furthermore, the Visual Analogue Scale was applied to gauge back and leg pain, while the Oswestry Disability Index was employed to appraise daily living activities. A comparative analysis was carried out among the three patient groups.ResultsIn this study, all 87 LSS patients successfully underwent surgery. Among them, 35 patients (40.2%) showed preoperative MRI assessment indicating positive RNRs. In the postoperative MRI assessment, 14 of these patients maintained positive RNRs status, and they were grouped into Group 1. The remaining 21 patients saw a transition to negative RNRs status and were included in Group 2. Among the 52 patients who had preoperative MRI assessments showing negative RNRs, their postoperative RNRs status remained negative, forming Group 3. All patients received follow-up, which ranged from 8 to 18 months, and no complications occurred during this period. In this study, the postoperative efficacy and parameters such as DH and Dural Sac CSA significantly improved compared to preoperative values for all 87 patients. Patients with preoperative RNRs had more stenosis segments, smaller dural sac CSA, and more severe symptoms. In all three groups, postoperative efficacy scores significantly improved compared to preoperative scores. Group 2 patients had their fusion cages placed more in the middle, while Group 1 patients had their fusion cages more anteriorly located. Group 2 patients exhibited greater recovery in dural sac CSA postoperatively compared to Group 1 patients. Additionally, Group 2 patients had better ODI efficacy scores compared to Group 1 patients.ConclusionsIrrespective of the presence or absence of RNRs, patients experienced improvement after undergoing OLIF combined with percutaneous internal fixation. Preoperative RNRs appear to be linked to multi-segmental lumbar spinal stenosis, a reduction in dural sac CSA, and symptom severity. Patients with negative postoperative RNRs demonstrated better treatment efficacy. Furthermore, the placement of the fusion cage appears to have a significant impact on postoperative efficacy and RNRs outcomes.

Consecutive Case Series of Uniportal Full-endoscopic Unilateral Laminotomy for Bilateral Decompression in Lumbar Spinal Stenosis: Relationship between Decompression Range and Functional Outcomes.

Uniportal full-endoscopic unilateral laminotomy for bilateral decompression (UFE-ULBD) has been used to treat lumbar spinal stenosis (LSS) with satisfactory outcomes. However, a limited number of studies have investigated the relationship between decompression range and clinical outcomes. This study aimed to investigate the efficacy of UFE-ULBD for single-segment LSS and to explore the relationship between the decompression range and functional outcomes. Single-segment LSS patients who had undergone UFE-ULBD using an interlaminar approach between November 2021 and February 2023 were retrospectively analyzed. Patient demographics, visual analogue scale (VAS) scores for leg and back pain, Oswestry disability index (ODI) scores, modified MacNab grades, and radiological outcomes, including the decompression ratio of the disc-flava ligament space and osseous lateral recess, the enlargement ratio of superior articular process interval, lamina interval dural sac cross-sectional area (DSCA), were collected. The independent sample t-tests, paired sample t-tests, chi-square tests, Fisher's exact tests, and Pearson's and Spearman's correlation analyses were used. Forty patients (23 males, and 17 females) were retrospectively enrolled in this study. The mean follow-up period was 12 months. At the last follow-up, VAS scores for leg pain and back pain decreased from 6.0 ± 0.8 to 1.0 ± 1.9 (p < 0.001), and from 6.0 ± 0.8 to 1.2 ± 1.8 (p < 0.001) respectively; ODI score decreased from 71.7 ± 6.2 to 24.3 ± 21.3 (p < 0.001). According to the modified MacNab criteria, the results were excellent in 28 (70%), good in 5 (12.5%), fair in 6 (15%), and poor in 1 (2.5%), with an excellent-good rate of 82.5%. The postoperative DSCA enlarged from 57.69 ± 21.86 to 150.75 ± 39.33 mm2 (p < 0.001), with an enlargement ratio of 189.43 ± 107.83%. No difference in clinical or radiological parameters was detected between patients with excellent, good, fair, or poor outcomes based on the modified MacNab criteria. UFE-ULBD can provide satisfactory clinical and radiological outcomes in single-segment LSS patients. With sufficient exposure to the dural sac boundary, the functional outcome was not related to the radiological decompression range in LSS patients who had undergone UFE-ULBD.

Response to Letter to the Editor Regarding "Postoperative Dural Sac Cross-sectional Area as an Association for Outcome After Surgery for Lumbar Spinal Stenosis: Clinical and Radiological Results From the NORDSTEN-Spinal Stenosis Trial (Spine, May 15 2023)".

Response to Letter to the Editor Regarding "Postoperative Dural Sac Cross-sectional Area as an Association for Outcome After Surgery for Lumbar Spinal Stenosis: Clinical and Radiological Results From the NORDSTEN-Spinal Stenosis Trial (Spine, May 15 2023)".

Efficacy of OLIF combined with pedicle screw internal fixation for lumbar spinal stenosis on spinal canal changes before and after surgery

PurposeThe purpose of the study was to evaluate the efficacy of OLIF combined with pedicle screw internal fixation in the treatment of lumbar spinal stenosis by assessing the changes in spinal canal before and after surgery.MethodsIn this retrospective study, we included sixteen patients who underwent a combination of single-segment OLIF and pedicle screw internal fixation for the treatment of lumbar spinal stenosis at the Affiliated Hospital of Jiangxi University of Chinese Medicine between February 2018 and August 2022. The patients' pre- and post-operative data were compared. Intraoperative bleeding, duration of surgery, visual analogue score (VAS), Oswestry Disability Index (ODI), disc height (DH), cross-sectional area of vertebral canal (CSAVC), cross-sectional area of dural sac (CSADS), cross-sectional area of intervertebral foramen (CSAIF), spinal canal volume (SCV), spinal canal volume expansion rate, lumbar lordosis, and sagittal vertical axis were observed and recorded. The efficacy of OLIF combined with pedicle screw internal fixation for lumbar spinal stenosis on spinal canal changes before and after surgery was summarized.ResultsThe results showed that OLIF combined with pedicle screw internal fixation effectively restored disc height and increased the cross-sectional area of the spinal canal. It also had an indirect decompression effect. The intraoperative bleeding and duration of surgery were within acceptable ranges. The VAS and ODI scores significantly improved after surgery, indicating a reduction in pain and improvement in functional disability. The CSAVC, CSADS, CSAIF, SCV, and spinal canal volume expansion rate were all increased postoperatively. Additionally, there was improvement in lumbar lordosis and sagittal vertical axis. We conducted a follow-up of all patients at 1 year after the surgery. The results revealed that the parameter values at 1 year post-surgery showed varying degrees of decrease or increase compared to the immediate postoperative values. However, these values remained statistically significant when compared to the preoperative parameter values (P < 0.05).ConclusionsOLIF combined with pedicle screw internal fixation effectively restores disc height and increases the cross-sectional area of the vertebral canal in patients with LSS, reflecting the indirect decompression effect. Measuring parameters such as DH, CSAVC, CSADS, CSAIF, SCV, and SCV expansion rate before and after surgery provides valuable information for evaluating the efficacy and functional recovery of the lumbar spine in LSS patients treated with OLIF surgery.

Letter to the editor re - "Postoperative Dural Sac Cross-Sectional Area as an Association for Outcome After Surgery for Lumbar Spinal Stenosis: Clinical and Radiological Results From the NORDSTEN-Spinal Stenosis Trial" (Spine, May 15 2023).

Letter to the editor re - "Postoperative Dural Sac Cross-Sectional Area as an Association for Outcome After Surgery for Lumbar Spinal Stenosis: Clinical and Radiological Results From the NORDSTEN-Spinal Stenosis Trial" (Spine, May 15 2023).

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

BackgroundWe 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).MethodsThe 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.ResultsThe 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.ConclusionIn 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 registrationThe study is registered at ClinicalTrials.gov (22.11.2013) under the identifier NCT02007083.

Value of nerve root sedimentation sign in diagnosis and surgical indication of lumbar spinal stenosis

BackgroundLumbar spinal stenosis (LSS) is a prevalent and disabling cause of low back and leg pain in elderly people and nerve root sedimentation sign (NRSS) has been demonstrated to have high sensitivity and specificity in diagnosing LSS in selected patients. The purpose of this study was to investigate the diagnosis of LSS and the predictive value of NRSS.MethodsThe clinical and imaging data of 176 patients diagnosed with LSS and 156 patients with non-specific low back pain (LBP) were analyzed retrospectively. Transverse magnetic resonance images (MRI) of the narrowest spinal canal in all patients were acquired and graded by two experienced doctors using the Braz classification, Schizas classification and Chen Jia classification. Receiver operating curve (ROC) was used to compare the diagnostic efficacy of the three classifications. Univariate and multivariate logistic regression models were established to predict the surgical indications of LSS patients.ResultThe diagnostic efficacy of Schizas classification (AUC:0.943; 95%CI:0.918,0.969) and Chen Jia classification (AUC:0.942; 95%CI:0.918,0.966) was significantly higher than that of Braz classification (AUC:0.853; 95%CI:0.808,0.898). Chen Jia classification had the highest correlation with the degree of dural sac cross-sectional area (DCSA) stenosis. In the multivariate analysis of LSS surgical indications, Chen Jia classification (odds ratio [OR], 2.127; 95%CI:1.596,2.835), DCSA (OR,0.398; 95%CI:0.169,0.802) and intermittent claudication (OR,9.481; 95%CI:3.439,26.142) were associated with surgical indications.ConclusionAmong the three types, it is found that Chen Jia classification has better diagnostic efficacy in differentiating LSS from LBP. In addition, Chen Jia classification is simple to be implemented in clinical practice and has high clinical application value. Hence, Chen Jia classification can be used as an effective surgical treatment indicator for LSS patients.

Poor muscle health and low preoperative ODI are independent predictors for slower achievement of MCID after minimally invasive decompression

Although some previous studies have analyzed predictors of non-improvement, most of these have focused on demographic and clinical variables and have not accounted for radiological predictors. In addition, while several studies have examined the degree of improvement after decompression, there is less data on the rate of improvement. To identify the risk factors and predictors (both radiological and non-radiological) for slower as well as non-achievement of minimal clinically important difference (MCID) after minimally invasive decompression. Retrospective cohort PATIENT SAMPLE: Patients who underwent minimally invasive decompression for degenerative lumbar spine conditions and had a minimum of 1-year follow-up were included. Patients with preoperative Oswestry Disability Index (ODI) <20 were excluded. MCID achievement in ODI (cut off 12.8). Patients were stratified into two groups (achieved MCID, did not achieve MCID) at two timepoints (early ≤3 months, late ≥6 months). Non-radiological (age, gender, BMI, comorbidities, anxiety, depression, number of levels operated, preoperative ODI, preoperative back pain) and radiological (MRI - Schizas grading for stenosis, dural sac cross-sectional area, Pfirrmann grading for disc degeneration, psoas cross-sectional area and Goutallier grading, facet cyst/effusion; X-ray - spondylolisthesis, lumbar lordosis, spinopelvic parameters) variables were assessed with comparative analysis to identify risk factors and with multiple regression models to identify predictors for slower achievement of MCID (MCID not achieved by ≤3 months) and non-achievement of MCID (MCID not achieved at ≥6 months). 338 patients were included. At ≤3 months, patients who did not achieve MCID had significantly lower preoperative ODI (40.1 vs. 48.1, p<0.001) and worse psoas Goutallier grading (p=0.048). At ≥6 months, patients who did not achieve MCID had significantly lower preoperative ODI (38 vs. 47.5, p<0.001), higher age (68 vs. 63 years, p=0.007), worse average L1-S1 Pfirrmann grading (3.5 vs. 3.2, p=0.035), and higher rate of pre-existing spondylolisthesis at the operated level (p=0.047). When these and other probable risk factors were put into a regression model, low preoperative ODI (p=0.002) and poor Goutallier grading (p=0.042) at the early timepoint and low preoperative ODI (p<0.001) at the late timepoint came out as independent predictors for MCID non-achievement. After minimally invasive decompression, low preoperative ODI and poor muscle health are risk factors and predictors for slower achievement of MCID. For non-achievement of MCID, low preoperative ODI, higher age, greater disc degeneration, and spondylolisthesis are risk factors and low preoperative ODI is the only independent predictor.

Characteristics of the Patients with Poor Clinical Outcomes After Symptomatic Postoperative Lumbar Epidural Hematoma.

Symptomatic postoperative lumbar epidural hematoma (PLEH) may lead to poor outcomes even after evacuation. This study aimed to verify the short-term clinical outcomes after the evacuation of PLEH and to clarify the characteristics of the patients with poor postoperative outcomes. Twenty-five patients (average age; 70.4years) underwent PLEH evacuation after lumbar spine surgery. The mean follow-up period was 12.0 (range 3-37) months. Pre and postoperative Japanese Orthopedic Association scores and visual analog scale (VAS) of low back pain (LBP), leg pain, and leg numbness were retrospectively collected. The dural sac cross-sectional area at the most compressed level was measured on magnetic resonance imaging. The patients were classified into 2 groups: poor outcome group (P group) had less than 50% of Japanese Orthopedic Associationrecovery rate and good group (G group) with 50% or more recovery rate. The rate of delayed evacuation (over 24hours of onset) was significantly higher in P group than in G group (P= 0.027). There was no significant difference in dural sac cross-sectional areabetween the 2 groups (P= 0.438). VAS of LBP, leg pain, and leg numbness in G group significantly improved postoperatively. Although VAS of LBP and leg pain in P group significantly improved postoperatively, there was no significant difference between the pre and postoperative VAS of leg numbness. Delayed evacuation of PLEH can lead to poor postoperative outcomes after lumbar spine surgery. Moreover, patients with poor outcomes remained with postoperative leg numbness. Early evacuation of symptomatic PLEH is key to avoid poor outcomes and persistent leg numbness.

The reliability, correlation with clinical symptoms and surgical outcomes of dural sac cross-sectional area, nerve root sedimentation sign and morphological grade for lumbar spinal stenosis

BackgroundNo study had directly compared the reliability, correlation with clinical symptoms, and surgical outcomes of dural sac cross-sectional area (DCSA), nerve root sedimentation sign (SedSign), and morphological grade for lumbar spinal stenosis (LSS).MethodsFrom January 2017 to December 2020, 202 patients with LSS were retrospectively analyzed. The narrowest segments were assessed via T2-weighted cross-sectional images using DCSA, morphological grade, and SedSign by two independent observers. Three classifications’ reliabilities were evaluated. Correlations between three classifications and between each of the classifications and symptoms or surgical outcomes 12 months postoperatively were evaluated.ResultsThere were 144 males and 58 females; 23, 52, and 127 patients had the narrowest segment in L2–3, L3–4, and L4–5, respectively. The intra-observer reliability of DCSA ranged from 0.91 to 0.93, and the inter-observer reliability was 0.90. The intra-observer reliability of SedSign ranged from 0.83 to 0.85, and the inter-observer reliability was 0.75. The intra-observer reliability of morphological grade ranged from 0.72 to 0.78, and the inter-observer reliability was 0.61. Each of these classifications was correlated with the other two (P < 0.01). For preoperative symptoms, DCSA was correlated with leg pain (LP) (r =  − 0.14), Oswestry Disability Index (ODI) (r =  − 0.17), and claudication (r =  − 0.19). Morphological grade was correlated with LP (r = 0.19) and claudication (r = 0.27). SedSign was correlated with ODI (r = 0.23). For postoperative outcomes, morphological grade was correlated with LP (r =  − 0.14), and SedSign was correlated with ODI (r = 0.17).ConclusionsSubstantial to almost perfect intra and inter-observer reliabilities for the three classifications were found; however, these classifications had either weak correlations with symptoms and surgical outcomes or none at all. Based on our findings, using one of them without conducting other tests for LSS will have limited or uncertain value in surgical decision-making or evaluating the prognostic value.

Is Repeated Preoperative Magnetic Resonance Imaging Necessary Before Planned Decompressive Surgery for Lumbar Spinal Stenosis?

Currently, there are different routines in Norwegian hospitals regarding how recent magnetic resonance imaging (MRI) of the lumbar spine should be performed before surgery. Patients with lumbar spinal stenosis from the Norwegian degenerative spondylolisthesis and spinal stenosis study, who had 2 preoperative MRIs performed within the year before surgery, were included. The aim of the present study was to evaluate the utility of repeated preoperative MRI for patients undergoing decompressive spine surgery for degenerative spinal stenosis. For all included patients, the changes between the 2 preoperative MRIs were investigated for disc degeneration (Pfirrmann's classification), foraminal stenosis (Lee's classification), spondylolisthesis, and central canal stenosis (Schizas score and dural sac cross-sectional area). A total of 65 patients (78 levels) were included. Thirty-seven patients were women, and the mean age was 67 (range 48-79) years. Schizas score showed a clinically meaningful change of ±2 or 3 grades in 5 levels, and dural sac cross- sectional area was reduced in 47 levels with a mean change of -2.3 mm2. Three levels had a clinically relevant change in grade of foraminal stenosis of ±2. For disc degeneration, 53 of the levels had no change, and the rest of the levels had a change of ±1 grade. Increased spondylolisthesis was measured at 21 levels, and the mean slip was <2 mm. Also, 4 levels had >2 mm slip. For patients undergoing surgery for lumbar spinal stenosis, repeated MRI within the year before planned surgery showed few significant changes in common radiological parameters. The benefit for the surgeon of repeat MRI is therefore limited.

Diagnostic value of a new axial loading MRI device in patients with suspected lumbar spinal stenosis.

This study was carried out to investigate a new device for axial loading MRI (alMRI) in the diagnosis of lumbar spinal stenosis (LSS). A total of 87 patients with suspected LSS sequentially underwent conventional MRI and alMRI using a new device with pneumatic shoulder-hip compression mode. Four quantitative parameters of dural sac cross-sectional area (DSCA), sagittal vertebral canal diameter (SVCD), disc height (DH), and ligamentum flavum thickness (LFT) at L3-4, L4-5, and L5-S1 in both examinations were measured and compared. Eight qualitative indicators were compared as valuable diagnostic information. Image quality, examinee comfort, test-retest repeatability, and observer reliability were also assessed. Using the new device, all 87 patients successfully completed alMRI with no statistically significant differences in image quality and examinee comfort from conventional MRI. Statistically significant changes were observed in DSCA, SVCD, DH, and LFT after loading (p < 0.01). SVCD, DH, LFT, and DSCA changes were all positively correlated (r = 0.80, 0.72, 0.37, p < 0.01). Eight qualitative indicators increased from 501 to 669 after axial loading, for a total increase of 168 (33.5%). Nineteen patients (21.8%, 19/87) developed absolute stenosis after axial loading and 10 of them (11.5%, 10/87) also had a significant reduction in DSCA (> 15 mm2). The test-retest repeatability and observer reliability were good to excellent. The new device is stable for performing alMRI and can exacerbate the severity of spinal stenosis, providing more valuable information for diagnosing LSS and reducing missed diagnoses. •The new axial loading MRI (alMRI) device could detect a higher frequency of patients with lumbar spinal stenosis (LSS). •The new device with pneumatic shoulder-hip compression mode was used to investigate its applicability in alMRI and diagnostic value for LSS. •The new device is stable for performing alMRI and can provide more valuable information for diagnosing LSS.

Decompression via unilateral biportal endoscopy for severe degenerative lumbar spinal stenosis: A comparative study with decompression via open discectomy.

Previous studies have shown that the Unilateral Biportal Endoscopy is an effective and safety surgery for sufficient decompression of degenerative lumbar spinal stenosis. However, data are lacking in terms of its benefits when compared with conventional open lumbar discectomy (OLD), especially in patients with severe degenerative lumbar spinal stenosis (DLSS). To compare the clini cal outcomes of two types decompressive surgery: unilateral biportal endoscopy-unilateral laminectomy bilateral decompression (UBE-ULBD) and conventional open lumbar discectomy (OLD) in severe degenerative lumbar spinal stenosis (DLSS). We retrospectively analyzed patients who underwent UBE-ULBD (n = 50, operated at 50 levels; UBE-ULBD group) and conventional open lumbar discectomy (n = 59, operated at 47 levels; OLD group) between February 2019 and July 2021. All patients were diagnosed with severe stenosis based on the Schizas classification (Grade C or D) on MRI. We compared radiographic and clinical outcome scores [including the visual analog scale (VAS), Oswestry Disability Index (ODI), and Zurich Claudication Questionnaire (ZCQ)] between the 2 groups at 1 year of follow-up. The radiographic evaluation included the cross-sectional area (CSA) of the thecal sac and paraspinal muscles on MRI. Fasting blood was drawn before and 1 and 7 days after the operation to detect creatine kinase (CK). Surgical data perioperative complications were also investigated. The baseline demographic data of the 2 groups were comparable, including VAS, ODI and ZCQ scores, the cross-sectional area of the thecal sac and paraspinal muscles and creatine kinase levels. The dural sac CSA significantly increased post -operatively in both groups, which confirmed they benefited from comparable decompressive effects. The operative duration in the OLD group was less than the UBE-ULBD group (43.9 ± 5.6 min vs. 74.2 ± 9.3 min, p < 0.05). The OLD group was associated with more estimated blood loss than the UBE-ULBD group (111.2 ± 25.0 ml vs. 41.5 ± 22.2 ml, P < 0.05). The length of hospital stay (HS) was significantly longer in the OLD group than in the UBE-ULBD group (6.8 ± 1.6 vs. 4.0 ± 1.4 days, P < 0.05). The VAS, ODI, and ZCQ scores improved in both groups after the operation. Serum creatine kinase values in the UBE-ULBD group were significantly lower than in the OLD group at 1 day after surgery (108. 1 ± 11.9 vs. 347.0 ± 19.5 U/L, P < 0.05). The degree of paraspinal muscle atrophy in the UBE-ULBD group was significantly lower than in the OLD group at 1 year (4.50 ± 0.60 vs. 11.42 ± 0.87, P < 0.05). UBE-ULBD and conventional OLD demonstrate comparable short-term clinical outcomes in treating severe DLSS. However, UBE-ULBD surgery was associated with a shorter hospital stay, less EBL and paravertebral muscle injury than OLD surgery.

Comparison of Clinical Outcomes of Cervical Laminoplasty for Cervical Spondylotic Myelopathy: Double-Door With Lamina Staple, Single-Door With Miniplate, and Double-Door With Spacer-A 2-Year Follow-Up Study.

There were few studies to compare the outcomes of different types of cervical laminoplasties. To compare the clinical outcomes of double-door cervical laminoplasty with lamina staple (double-door staple), single-door cervical laminoplasty with miniplate (single-door miniplate), and double-door cervical laminoplasty with spacer (double-door spacer). The study involved 166 patients with cervical spondylotic myelopathy (CSM). Fifty-two patients underwent double-door staple, 63 patients underwent single-door miniplate, and 51 patients underwent double-door spacer. The clinical outcomes were measured. There was no significant difference in Japanese Orthopedic Association score among the 3 groups ( P > .05). The operation time was significantly shorter in double-door staple and single-door miniplate groups than in the double-door spacer group ( P < .005). The estimated blood loss was significantly more in the single-door miniplate group than in double-door staple and double-door spacer groups ( P < .005). The expansion ratio of cervical intraspinal cross-sectional area decreased in the order of double-door staple > double-door spacer > single-door miniplate. There were no significant differences in the expansion ratio of dural sac cross-sectional area among the 3 groups. Double-door staple, double-door spacer, and single-door miniplate can achieve favorable clinical outcomes for CSM. The blood loss of double-door staple is less than that of single-door miniplate, and the operation time of double-door staple is shorter than that of double-door spacer. The mean expansion ratio of cervical intraspinal cross-sectional area decreased in the order of double-door staple > double-door spacer > single-door miniplate. Overall, double-door staple is a safe and innovative alternative choice for treatment of CSM.

Clinical efficacy and imaging outcomes of unilateral biportal endoscopy with unilateral laminotomy for bilateral decompression in the treatment of severe lumbar spinal stenosis.

To investigate the clinical efficacy and imaging outcomes of unilateral biportal endoscopy (UBE) with unilateral laminotomy for bilateral decompression (ULBD) in the treatment of severe lumbar spinal stenosis (SLSS). We retrospectively analyzed 50 patients with SLSS treated with UBE-ULBD from October 2018 to March 2021. Visual analog scale (VAS) for back and legs pain, Oswestry disability index (ODI), modified Macnab criteria, complications, hospital stay, preoperative and postoperative dural sac cross-sectional area (DSCA) and Schizas grade, mean angle of facetectomy and osseous lateral recess decompression rate were examined. The mean follow-up period was 10.7 months. The mean hospital stay was 2.76 ± 1.02 days. At the final follow-up, VAS for back pain and legs pain decreased from 7.22 ± 0.95 to 1.26 ± 0.44 and from 7.88 ± 0.69 to 1.18 ± 0.39, respectively; ODI decreased from 69.88 ± 6.32% to 14.96 ± 2.75%. According to the modified Macnab criteria, the results were excellent in 24 (48%), good in 22 (44%), and fair in 4 (8%). Excellent or good results (a satisfactory outcome) were obtained in 92% of the patients. There were 2 cases of complications of dural sac tear. The postoperative DSCA was significantly enlarged compared with that before surgery, from 44.74 ± 9.85 to 126.86 ± 14.81 mm2. According to Schizas grade, the stenosis grade changes from preoperative grade C in 16 cases, grade D in 34 cases, to postoperative grade A in 40 cases, and grade B in 10 cases. The mean angle of facetectomy of the ipsilateral facet joint was 70.87 ± 5.68 , contralateral was 65.07 ± 4.98 . The decompression rate was 70.81 ± 4.43% (ipsilateral side) and 71.22 ± 3.68% (contralateral). UBE-ULBD has a good clinical effect in the treatment of SLSS, and has achieved satisfactory results in spinal canal enlargement, undercutting of facet joints, and decompression effect. It is a safe and effective surgical for SLSS.