The Effect of Paraspinal Fatty Muscle Infiltration and Cumulative Lumbar Spine Degeneration on the Outcome of Patients With Lumbar Spinal Canal Stenosis: Analysis of the Lumbar Stenosis Outcome Study (LSOS) Data.

STUDY DESIGN: Prospective. OBJECTIVE: To investigate the influence of paraspinal fatty muscle infiltration (FMI) and cumulative lumbar spine degeneration as assessed by magnetic resonance imaging on long-term clinical outcome measures in patients with lumbar spinal canal stenosis (LSCS) of the Lumbar Stenosis Outcome Study (LSOS) cohort. SUMMARY OF BACKGROUND DATA: Past studies have tried to establish correlations of morphologic imaging findings in LSCS with clinical endpoints. However, the impact of FMI and overall lumbar spinal degeneration load has not been examined yet. MATERIALS AND METHODS: Patients from the LSOS cohort with moderate to severe LSCS were included. Two radiologists assessed the degree of LSCS as well as cumulative degeneration of the lumbar spine. FMI was graded using the Goutallier scoring system. Spinal Stenosis Measure (SSM) was used to measure the severity level of symptoms and disability. European Quality of Life 5 Dimensions 3 Level Version (EQ-5D-3L) was used to measure health-related quality of life. RESULTS: The nonsurgically treated group consisted of 116 patients (age 74.8±8.5 yr), whereas the surgically treated group included 300 patients (age 72.3±8.2 yr). Paraspinal FMI was significantly different between the groups (54.3% vs. 32.0% for Goutallier grade ≥2; P <0.001). Total degeneration score was comparable in both groups (9.5±2.0 vs. 9.3±2.0; P =0.418). FMI was associated with lower SSM function and lower EQ-5D-3L (all P <0.05), but not with SSM symptoms. Total degeneration of the lumbar spine was associated neither with SSM symptoms, nor with SSM function, nor with EQ-5D-3L (all P >0.05). CONCLUSIONS: FMI is associated with higher disability and worse health-related quality of life of LSCS patients in the LSOS cohort. There was no significant association between total cumulative lumbar spine degeneration and the outcome of either surgically or nonsurgically treated patients. LEVEL OF EVIDENCE: 3.

Incidence of Revision Surgery After Decompression With vs Without Fusion Among Patients With Degenerative Lumbar Spinal Stenosis.

Importance: Only limited data derived from large prospective cohort studies exist on the incidence of revision surgery among patients who undergo operations for degenerative lumbar spinal stenosis (DLSS). Objective: To assess the cumulative incidence of revision surgery after 2 types of index operations-decompression alone or decompression with fusion-among patients with DLSS. Design, Setting, and Participants: This cohort study analyzed data from a multicenter, prospective cohort study, the Lumbar Stenosis Outcome Study, which included patients aged 50 years or older with DLSS at 8 spine surgery and rheumatology units in Switzerland between December 2010 and December 2015. The follow-up period was 3 years. Data for this study were analyzed between October and November 2021. Exposures: All patients underwent either decompression surgery alone or decompression with fusion surgery for DLSS. Main Outcomes and Measures: The primary outcome was the cumulative incidence of revision operations. Secondary outcomes included changes in the following patient-reported outcome measures: Spinal Stenosis Measure (SSM) symptom severity (higher scores indicate more pain) and physical function (higher scores indicate more disability) subscale scores and the EuroQol Health-Related Quality of Life 5-Dimension 3-Level questionnaire (EQ-5D-3L) summary index score (lower scores indicate worse quality of life). Results: A total of 328 patients (165 [50.3%] men; median age, 73.0 years [IQR, 66.0-78.0 years]) were included in the analysis. Of these, 256 (78.0%) underwent decompression alone and 72 (22.0%) underwent decompression with fusion. The cumulative incidence of revisions after 3 years of follow-up was 11.3% (95% CI, 7.4%-15.1%) for the decompression alone group and 13.9% (95% CI, 5.5%-21.5%) for the fusion group (log-rank P = .60). There was no significant difference in the need for revision between the 2 groups over time (unadjusted absolute risk difference, 2.6% [95% CI, -6.3% to 11.4%]; adjusted absolute risk difference, 3.9% [95% CI, -5.2% to 17.0%]; adjusted hazard ratio, 1.40 [95% CI, 0.63-3.13]). The number of revisions was significantly associated with higher SSM symptom severity scores (ß, 0.171; 95% CI, 0.047-0.295; P = .007) and lower EQ-5D-3L summary index scores (ß, -0.061; 95% CI, -0.105 to -0.017; P = .007) but not with higher SSM physical function scores (ß, 0.068; 95% CI, -0.036 to 0.172; P = .20). The type of index operation was not significantly associated with the corresponding outcomes. Conclusions and Relevance: This cohort study showed no significant association between the type of index operation for DLSS-decompression alone or fusion-and the need for revision surgery or the outcomes of pain, disability, and quality of life among patients after 3 years. Number of revision operations was associated with more pain and worse quality of life.

Intraoperative Monitoring of CSF Pressure in Patients with Degenerative Cervical Myelopathy (COMP-CORD Study): A Prospective Cohort Study.

Degenerative cervical myelopathy (DCM) is hallmarked by spinal canal narrowing and related cord compression and myelopathy. Cerebrospinal fluid (CSF) pressure dynamics are likely disturbed due to spinal canal stenosis. The study aimed to investigate the diagnostic value of continuous intraoperative CSF pressure monitoring during surgical decompression. This prospective single center study (NCT02170155) enrolled DCM patients who underwent surgical decompression between December 2019 and May 2021. Data from n = 17 patients were analyzed and symptom severity graded with the modified Japanese Orthopedic Score (mJOA). CSF pulsations were continuously monitored with a lumbar intrathecal catheter during surgical decompression. Mean patient age was 62 ± 9 years (range 38-73; 8 female), symptoms were mild-moderate in most patients (mean mJOA 14 ± 2, range 10-18). Measurements were well tolerated without safety concerns. In 15/16 patients (94%), CSF pulsations increased at the time of surgical decompression. In one case, responsiveness could not be evaluated for technical reasons. Unexpected CSF pulsation decrease was related to adverse events (i.e., CSF leakage). Median CSF pulsation amplitudes increased from pre-decompression (0.52 mm Hg, interquartile range [IQR] 0.71) to post-decompression (0.72 mm Hg, IQR 0.96; p = 0.001). Mean baseline CSF pressure increased with lower magnitude than pulsations, from 9.5 ± 3.5 to 10.3 ± 3.8 mm Hg (p = 0.003). Systematic relations of CSF pulsations were confined to surgical decompression, independent of arterial blood pressure (p = 0.927) or heart rate (p = 0.102). Intraoperative CSF pulsation monitoring was related to surgical decompression while in addition adverse events could be discerned. Further investigation of the clinical value of intraoperative guidance for decompression in complex DCM surgery is promising.

Long-term Results After Surgical or Nonsurgical Treatment in Patients With Degenerative Lumbar Spinal Stenosis: A Prospective Multicenter Study.

STUDY DESIGN: Prospective, multicenter cohort study. OBJECTIVE: The aim of our study was to assess the course of patients over a period of 3 years undergoing surgical or nonsurgical treatments for degenerative lumbar spinal stenoses (DLSS) based on data from the Lumbar Stenosis Outcome Study (LSOS), prospectively performed in eight hospitals. SUMMARY OF BACKGROUND DATA: The optimal treatment strategy for patients with DLSS is still debated. METHODS: The outcomes of patients with verified DLSS were quantified by Spinal Stenosis Measure (SSM) symptoms- and SSM function-scores, and EQ-5D-3L (quality of life) summary index (SI) over time (up to 36-month follow-up), and minimal clinically important difference (MCID) in SSM symptoms, SSM function, and EQ-5D-3L SI from baseline to 36-month follow-up. RESULTS: For this study, 601 patients met the inclusion criteria; 430 underwent surgery, 18 of them only after more than a year after enrolment, 171 received nonsurgical treatment only. At baseline, patients in the surgical and nonsurgical groups had similar values for the SSM symptoms and SSM function scores, but patients in the surgical group suffered significantly more from buttocks pain and reported more worsening symptoms over the last 3 months before enrollment in the study. Surgically treated patients (except changers) performed significantly better in all clinical outcome measures (P < 0.001) with a plateau at 12-month follow-up staying constant until the follow-up ended. Further, two-thirds of patients in the surgical group had a relevant improvement in function, symptoms, and quality of life, compared with only about half of those in terms of symptoms and even less in terms of function and quality of life with nonsurgical treatment. CONCLUSIONS: Surgical treatment of DLSS results in more favorable clinical outcomes with a sustained effect over time, compared to nonsurgical treatment. LEVEL OF EVIDENCE: 3.

Two-year outcome comparison of decompression in 14 lipomatosis cases with 169 degenerative lumbar spinal stenosis cases: a Swiss prospective multicenter cohort study.

PURPOSE: Spinal epidural lipomatosis (SEL) is defined as an abnormal and extensive accumulation of unencapsulated adipose tissue within the spinal epidural space. To date, there is a lack of high-level evidence studies reporting the outcome of surgical treatment of symptomatic SEL in patients with lumbar spinal stenosis (LSS). The aim was to compare clinical outcomes in patients with symptomatic LSS with and without SEL who underwent decompression surgery alone at the 12- and 24-month follow-up. METHODS: One hundred and eighty-three patients met the inclusion criteria, of which 14 had mainly SEL on at least one level operated in addition to possible degenerative changes on other levels and 169 degenerative LSS only. The main outcomes were pain (Spinal Stenosis Measure (SSM) symptoms), disability (SSM function), and quality of life [EQ-5D-3L summary index (SI)] at 24-month follow-up, and minimal clinically important difference (MCID) in SSM symptoms, SSM function, and EQ-5D-3L SI. RESULTS: The multiple regression linear models showed that SEL was associated with worse SSM symptoms (p = 0.045) and EQ-5D-3L SI scores (p = 0.026) at 24-month follow-up, but not with worse SSM function scores. Further, depression (in all models) was negatively associated with better clinical outcomes at 24-month follow-up. In the outcomes SSM symptoms and EQ-5D-3L SI, distinctly more patients in the classical LSS group reached MCID than in the SEL group (71.3% and 62.3% vs. 50.0% and 42.9%). CONCLUSIONS: Our study demonstrated that decompression alone surgery was associated with significant improvement in disability in both groups at 2 years, but not in pain and quality of life in patients with SEL.

The influence of endplate (Modic) changes on clinical outcomes in lumbar spinal stenosis surgery: a Swiss prospective multicenter cohort study.

PURPOSE: To investigate if the presence or absence of preoperative endplate Modic changes (MC) is predictive for clinical outcomes in degenerative lumbar spinal stenosis (DLSS) patients undergoing decompression-alone or decompression with instrumented fusion surgery. METHODS: Two hundred five patients were included and categorized into four groups; 102 patients into the decompression-alone group with MCs, 41 patients into the fusion group with MCs, 46 patients into the decompression-alone group without MCs, and 16 patients into the fusion group without MCs. Clinical outcome was quantified with changes in spinal stenosis measure (SSM) symptoms, SSM function, NRS pain, and EQ-5D-3L sum score over time (measured at baseline, 12-, 24-, and 36-month follow-up) and minimal clinically important difference (MCID) in SSM symptoms, SSM function, and NRS pain from baseline to 36-month follow-up. To investigate if possible effects of MCs had been modified or hidden by confounding variables, we used the group LASSO method to search for good prognostic models. RESULTS: There were no obvious differences in any of the clinical outcome measures between groups at baseline. At 12 months, most patients have improved in all outcomes and maintained improved conditions over time (no significant group differences). Between 70 and 90 percent of the patients maintained a clinically important improvement up to 36 months. CONCLUSIONS: Endplate MCs have no significant influence on clinical outcome parameters in patients with lumbar spinal stenosis compared to patients without MCs, independent of the chosen surgical strategy. All patients benefitted from surgical therapy up to 36-month follow-up. These slides can be retrieved under Electronic Supplementary Material.

Evaluating the Minimal Clinically Important Difference of EQ-5D-3L in Patients With Degenerative Lumbar Spinal Stenosis: A Swiss Prospective Multicenter Cohort Study.

STUDY DESIGN: Analysis of a prospective, multicenter cohort study. OBJECTIVE: The aim of our study was to compare thresholds of published minimal clinically important differences (MCID) for the three-level EuroQol-5D health survey (EQ-5D-3L) summary index (range -0.53 to 1.00) with our anchor-based estimate and evaluate how useful these thresholds are in determining treatment success in patients undergoing surgery for degenerative lumbar spinal stenosis (DLSS). SUMMARY OF BACKGROUND DATA: MCID values for EQ-5D-3L are specific to the underlying disease and only three studies have been published for DLSS patients reporting different values. METHODS: Patients of the multicenter Lumbar Stenosis Outcome Study with confirmed DLSS undergoing first-time decompression or fusion surgery with 12-month follow-up were enrolled in this study. To calculate MCID we used the Spinal Stenosis Measure satisfaction subscale as anchor. RESULTS: For this study, 364 patients met the inclusion criteria; of these, 196 were very satisfied, 72 moderately satisfied, 43 somewhat satisfied, and 53 unsatisfied 12 months after surgery. The MCID calculation estimated for EQ-5D-3L a value of 0.19. Compared with published MCID values (ranging from 0.30 to 0.52), our estimation is less restrictive. CONCLUSIONS: In patients with LSS undergoing surgery, we estimated an MCID value for EQ-5D-3L summary index of 0.19 with the help of the average change anchor-based method, which we find to be the most suitable method for assessing patient change scores. LEVEL OF EVIDENCE: 3.

Outcome of unilateral versus standard open midline approach for bilateral decompression in lumbar spinal stenosis: is "over the top" really better? A Swiss prospective multicenter cohort study.

OBJECTIVEIn this retrospective analysis of a prospective multicenter cohort study, the authors assessed which surgical approach, 1) the unilateral laminotomy with bilateral spinal canal decompression (ULBD; also called "over the top") or 2) the standard open bilateral decompression (SOBD), achieves better clinical outcomes in the long-term follow-up. The optimal surgical approach (ULBD vs SOBD) to treat lumbar spinal stenosis remains controversial.METHODSThe main outcomes of this study were changes in a spinal stenosis measure (SSM) symptoms score, SSM function score, and quality of life (sum score of the 3-level version of the EQ-5D tool [EQ-5D-3L]) over time. These outcome parameters were measured at baseline and at 12-, 24-, and 36-month follow-ups. To obtain an unbiased result on the effect of ULBD compared to SOBD the authors used matching techniques relying on propensity scores. The latter were calculated based on a logistic regression model including relevant confounders. Additional outcomes of interest were raw changes in main outcomes and in the Roland and Morris Disability Questionnaire from baseline to 12, 24, and 36 months.RESULTSFor this study, 277 patients met the inclusion criteria. One hundred forty-nine patients were treated by ULBD, and 128 were treated by SOBD. After propensity score matching, 128 patients were left in each group. In the matched cohort, the mean (95% CI) estimated differences between ULBD and SOBD for change in SSM symptoms score from baseline to 12 months were -0.04 (-0.25 to 0.17), to 24 months -0.07 (-0.29 to 0.15), and to 36 months -0.04 (-0.28 to 0.21). For change in SSM function score, the estimated differences from baseline to 12 months were 0.06 (-0.08 to 0.21), to 24 months 0.08 (-0.07 to 0.22), and to 36 months 0.01 (-0.16 to 0.17). Differences in changes between groups in EQ-5D-3L sum scores were estimated to be -0.32 (-4.04 to 3.40), -0.89 (-4.76 to 2.98), and -2.71 (-7.16 to 1.74) from baseline to 12, 24, and 36 months, respectively. None of the group differences between ULBD and SOBD were statistically significant.CONCLUSIONSBoth surgical techniques, ULBD and SOBD, may provide effective treatment options for DLSS patients. The authors further determined that the patient outcome results for the technically more challenging ULBD seem not to be superior to those for the SOBD even after 3 years of follow-up.

Correlation of listhesis on upright radiographs and central lumbar spinal canal stenosis on supine MRI: is it possible to predict lumbar spinal canal stenosis?

OBJECTIVE: To investigate whether upright radiographs can predict lumbar spinal canal stenosis using supine lumbar magnetic resonance imaging (MRI) and to investigate the detection performance for spondylolisthesis on upright radiographs compared with supine MRI in patients with suspected lumbar spinal canal stenosis (LSS). MATERIALS AND METHODS: In this retrospective study, conventional radiographs and MR images of 143 consecutive patients with suspected LSS (75 female, mean age 72 years) were evaluated. The presence and extent of listhesis (median ± interquartile range) were assessed on upright radiographs and supine MRI of L4/5. In addition, the grade of central spinal stenosis of the same level was evaluated on MRI according to the classification of Schizas and correlated with the severity/grading of anterolisthesis on radiographs. RESULTS: Anterolisthesis was detected in significantly more patients on radiographs (n = 54; 38%) compared with MRI (n = 28; 20%), p < 0.001. Pairwise comparison demonstrated a significantly larger extent of anterolisthesis on radiographs (9 ± 5 mm) compared with MRI (5 ± 3 mm), p < 0.001. A positive correlation was found regarding the extent of anterolisthesis measured on radiographs and the grade of stenosis on MRI (r = 0.563, p < 0.001). Applying a cutoff value of ≥5 mm anterolisthesis on radiographs results in a specificity of 90% and a positive predictive value of 78% for the detection of patients with LSS, as defined by the Schizas classification. CONCLUSION: Upright radiographs demonstrated more and larger extents of anterolisthesis compared with supine MRI. In addition, in patients with suspected LSS, the extent of anterolisthesis on radiographs (particularly ≥5 mm) is indicative of LSS and warrants lumbar spine MRI.

Does Preoperative Degenerative Spondylolisthesis Influence Outcome in Degenerative Lumbar Spinal Stenosis? Three-Year Results of a Swiss Prospective Multicenter Cohort Study.

BACKGROUND: Decompression alone to treat degenerative lumbar stenosis with and without concomitant degenerative spondylolisthesis (DS; non-DS) has shown ambiguous results in the literature. OBJECTIVE: The aim is to compare clinical outcomes in DS and non-DS patients with lumbar stenosis who underwent decompression alone surgery without fusion on 1-3 adjacent levels after 6-month, 12-month, 24-month, and 36-month follow-up. METHODS: We conducted a prospective cohort study at 8 medical centers. The main outcomes of this study are changes in Spinal Stenosis Measure (SSM) symptoms score, SSM function score, and quality of life (EQ-5D-3L sum score) over time. Propensity score matching for DS versus non-DS was applied. RESULTS: One hundred seventy-seven patients met the inclusion criteria, 68 of whom had DS. In the matched cohort (n = 136), the estimated difference in SSM symptoms score of DS versus non-DS for changes from baseline to 36 months was 0.21 (95% CI, -0.15 to 0.57). For SSM function score, the estimated difference from baseline to 36 months was 0.05 (-0.21 to 0.31). Differences in changes between groups in EQ-5D-3L sum score were estimated to be -3.66 (-10.63 to 3.31) from baseline to 36 months. None of the group differences between the non-DS and the DS group was statistically significant. All matched patients improved over time in all additional outcomes. CONCLUSIONS: Even after 3 years of follow-up, we show that among patients with degenerative lumbar spinal stenosis, both groups (DS and non-DS) distinctively take advantage of decompression alone without fusion.

Decompression Surgery Alone Versus Decompression Plus Fusion in Symptomatic Lumbar Spinal Stenosis: A Swiss Prospective Multicenter Cohort Study With 3 Years of Follow-up.

STUDY DESIGN: Retrospective analysis of a prospective, multicenter cohort study. OBJECTIVE: To estimate the added effect of surgical fusion as compared to decompression surgery alone in symptomatic lumbar spinal stenosis patients with spondylolisthesis. SUMMARY OF BACKGROUND DATA: The optimal surgical management of lumbar spinal stenosis patients with spondylolisthesis remains controversial. METHODS: Patients of the Lumbar Stenosis Outcome Study with confirmed DLSS and spondylolisthesis were enrolled in this study. The outcomes of this study were Spinal Stenosis Measure (SSM) symptoms (score range 1-5, best-worst) and function (1-4) over time, measured at baseline, 6, 12, 24, and 36 months follow-up. In order to quantify the effect of fusion surgery as compared to decompression alone and number of decompressed levels, we used mixed effects models and accounted for the repeated observations in main outcomes (SSM symptoms and SSM function) over time. In addition to individual patients' random effects, we also fitted random slopes for follow-up time points and compared these two approaches with Akaike's Information Criterion and the chi-square test. Confounders were adjusted with fixed effects for age, sex, body mass index, diabetes, Cumulative Illness Rating Scale musculoskeletal disorders, and duration of symptoms. RESULTS: One hundred thirty-one patients undergoing decompression surgery alone (n = 85) or decompression with fusion surgery (n = 46) were included in this study. In the multiple mixed effects model the adjusted effect of fusion compared with decompression alone surgery on SSM symptoms was 0.06 (95% confidence interval: -0.16-0.27) and -0.07 (95% confidence interval: -0.25-0.10) on SSM function, respectively. CONCLUSION: Among the patients with degenerative lumbar spinal stenosis and spondylolisthesis our study confirms that in the two groups, decompression alone and decompression with fusion, patients distinctively benefited from surgical treatment. When adjusted for confounders, fusion surgery was not associated with a more favorable outcome in both SSM scores as compared to decompression alone surgery. LEVEL OF EVIDENCE: 3.

The Influence of Single-level Versus Multilevel Decompression on the Outcome in Multisegmental Lumbar Spinal Stenosis: Analysis of the Lumbar Spinal Outcome Study (LSOS) Data.

STUDY DESIGN: This is prospective multicenter cohort study. OBJECTIVE: To assess whether patients with confirmed multisegmental lumbar spinal stenosis benefit more from a single-level or a multilevel decompression. SUMMARY OF BACKGROUND DATA: In multisegmental lumbar spinal stenotic cases, the decision as to how many levels of stenosis need to be operated to achieve the best possible clinical outcome is still unknown and remains a controversy between spine surgeons. MATERIALS AND METHODS: Patients of the Swiss Lumbar Stenosis Outcome Study (LSOS) with confirmed multisegmental LSS undergoing first-time decompression without fusion were enrolled in this study. The main outcomes of this study were Spinal Stenosis Measure (SSM) symptoms and function over time, measured at baseline, 6, 12, and 24 months follow-up. Further outcomes of interest were changes in SSM, numeric rating scale, feeling thermometer, the EQ-5D-EL, and the Roland and Morris disability questionnaire from baseline to 6, 12, and 24 months. RESULTS: After 12 months, a total of 141 patients met the inclusion criteria; of these, 33 (23%) underwent a single-level and 108 (77%) a multilevel decompression. Multilevel decompression was associated with a significantly less favorable SSM symptoms and function score, respectively, as compared with single-level decompression. In all further outcomes of interest single-level as well as multilevel patients improved over time. CONCLUSIONS: Our study showed that in multisegmental stenotic cases a single-level decompression was associated with a significantly more favorable SSM symptoms and function score, respectively, as compared with multilevel decompression. This study provides evidence that in multisegmental stenotic cases a single-level decompression might be sufficient to improve patient's symptoms and function.

Decompression surgery for lumbar spinal canal stenosis in octogenarians; a single center experience of 121 consecutive patients.

INTRODUCTION: With increasing age, ubiquitous degeneration processes lead to a narrowing of the spinal canal. Degenerative lumbar spinal stenosis (DLSS) causes functional disability and is associated with back and lower extremity pain in older individuals. The goal of this study was to determine if decompression surgery can be performed safely and provide a stable benefit in our octogenarian patient population. METHODS: In this retrospective study, 121 patients over the age of 80 (mean age: 82.7 years SD: 2.4 years) with the diagnosis of central spinal canal stenosis who underwent posterior decompression surgery without fusion for DLSS between January 2006 and August 2013 were followed up from November to December 2013. Peri- and post-operative complications were recorded. Walking distances and visual analogue scale (VAS) scores were determined before surgery and at follow up time (mean follow up time 36 months). Patient's satisfaction with treatment was documented with the overall satisfaction degree scale in Zurich Claudicatio Questionnaire (ZCQ). RESULTS: The peri-operative complication rate was 6.6% with five dural tears, two wound infections and one epidural haematoma. Four patients required revision surgery (three re-decompression and one secondary spondylodesis). Walking distance improved from 147 meters (SD ±110 m) to 340 m (SD ±170 m) p < .001. Pain improved with change of the VAS scores from 7.2 (SD ±1.2) to 4.5 (SD ±1.0), p < .001. The overall satisfaction scale in ZCQ was 2.2 at follow up. CONCLUSION: A minimal surgical intervention, namely decompression, improves walking ability, decreases pain and has marginal potential for complications in patients with DLSS who are over 80 years old.

The impact of incidental durotomy on the outcome of decompression surgery in degenerative lumbar spinal canal stenosis: analysis of the Lumbar Spinal Outcome Study (LSOS) data--a Swiss prospective multi-center cohort study.

BACKGROUND: Incidental durotomy is a well-known complication during surgery for degenerative lumbar spinal stenosis (DLSS). In this prospective multicenter cohort study including eight medical centers our aim was to assess whether incidental durotomy during first-time lumbar spinal stenosis decompression surgery without fusion has an impact on long-term outcome. METHODS: Patients of the multi-center Lumbar Stenosis Outcome Study (LSOS) with confirmed DLSS undergoing first-time decompression without fusion were enrolled in this study. Baseline patient characteristics and outcomes were analyzed at 6, 12, and 24 months follow-up respectively with the Spinal Stenosis Measure (SSM), the Numeric Rating Scale (NRS), Feeling Thermometer (FT), the EQ-5D-EL, and the Roland and Morris Disability Questionnaire (RMDQ). RESULTS: A total of 167 patients met the inclusion criteria. Fifteen (9%) of those patients had an incidental durotomy. Baseline characteristics were similar between the durotomy and no-durotomy group. All patients improved over time. In the group of durotomy patients, the median improvement in SSM symptoms scale was 1.1 points at 6 months, 1.1 points at 12 months, and 1.6 points at 24 months after baseline. For the no-durotomy group, these improvements were 0.8, 0.9, and 0.9. For SSM function the improvements were 1.0, 0.8, and 0.9 in the durotomy group, and 0.6, 0.8, and 0.8 in the no-durotomy group. None of the between-group differences were statistically significant. CONCLUSIONS: Incidental durotomy in patients with DLSS undergoing first-time decompression surgery without fusion did not have negative effect on long-term outcome and quality of life. However, only 15 patients were included in the durotomy group but these findings remained even after adjusting for observed differences in baseline characteristics.

The Impact of Obesity on the Outcome of Decompression Surgery in Degenerative Lumbar Spinal Canal Stenosis: Analysis of the Lumbar Spinal Outcome Study (LSOS): A Swiss Prospective Multicenter Cohort Study.

STUDY DESIGN: Prospective, multicenter cohort study including 8 medical centers of the Cantons Zurich, Lucerne, and Thurgau, Switzerland. OBJECTIVE: The aim of the study was to assess whether obese patients benefit after decompression surgery for degenerative lumbar spinal stenosis (DLSS). SUMMARY AND BACKGROUND DATA: Lumbar decompression surgery has been shown to improve quality of life in patients with DLSS. In the existing literature, the efficacy of lumbar decompression in the obese population remains controversial. METHODS: Baseline patient characteristics and outcomes were analyzed at 6 and 12 months follow-up with the Spinal Stenosis Measure (SSM), the Numeric Rating Scale (NRS), Feeling Thermometer (FT), the EQ-5D-EL, and the Roland and Morris Disability Questionnaire (RMDQ). Body mass index (BMI) was classified into 3 categories according to the WHO. Minimal clinically important differences (MCIDs) in SSM for different BMI categories were considered as main outcome. RESULTS: Of the 656 patients in the Lumbar Spinal Outcome Study database as of end of October 2014, 166 patients met the inclusion criteria. Fifty (30.1%) had a BMI less than 25 (underweight and normal weight group), 72 (43.4%) had a BMI between 25 and less than 30 (preobesity group), and 44 (26.5%) patients had a BMI at least 30 (obese group). We found for the main outcome that in obese patients 36% reached MCID at 6 months, and 48% at 12 months. The estimated odds ratios for MCID in the obese group were 0.78 (0.34-1.82) at 6 months and 0.99 (0.44-2.23) at 12 months in a logistic regression model adjusting for levels of laminectomy. In the additional outcomes, SSM, NRS, FT, and RMDQ showed statistically significant mean improvements in the 6 and 12 months follow-up. CONCLUSION: Obese patients can expect clinical improvement after lumbar decompression for DLSS, but the percentage of patients with a meaningful improvement is lower than in the group of patients with underweight, normal weight, and preobese weight at 6 and 12 months.

Early detection of cervical spondylotic myelopathy using diffusion tensor imaging: Experiences in 1.5-tesla magnetic resonance imaging.

The purpose of this study was to investigate the usefulness of diffusion tensor imaging (DTI) for early detection of pathological alterations in the myelon in patients with cervical spondylotic myelopathy (CSM) without T2-weighted imaging (T2W) signal abnormalities but with a narrowed spinal canal with corresponding clinical correlation. Axial DTI at 1.5T together with routine magnetic resonance imaging was performed on 18 patients fulfilling above mentioned criteria. Quantitative fractional anisotropy (FA) and apparent diffusion coefficient (ADC) maps were generated. Values at the narrowest cervical levels were compared to pre- and poststenotic levels and the interindividual means were tested for statistically significant differences by means of paired t-tests. The correlation between the grade and width of canal stenosis in the axial plane was measured. FA was significantly reduced at the stenotic level, compared to prestenotic level, whereas no significant differences were found when compared to poststenotic level. No significant differences between ADC values at stenotic level versus both adjacent non-stenotic levels were found, suggesting very early stage of degeneration. ADC values correlated significantly with the width of the spinal canal at the prestenotic level, but not at the poststenotic level. Findings indicate sufficient robustness of routine implementation of DTI at 1.5T to detect abnormalities in the spinal cord of CSM patients, before apparent T2W signal abnormalities and marked clinical deterioration. Therefore, larger and long-term studies should be conducted to establish the DTI scalar metrics that would indicate early intervention for a better clinical outcome in patients with clinical signs of CSM.

The supraorbital keyhole approach: how I do it.

BACKGROUND: Improvements in image guidance, endoscopy, and instruments, have significantly advanced "keyhole" neurosurgery. We describe the concept and technique of the supraorbital keyhole approach. METHODS: The supraorbital keyhole approach is performed through an eyebrow skin incision. Image guidance may be used to define the optimal surgical trajectory. A limited supraorbital craniotomy is fashioned. The frontal lobe is mobilized and the central skull base approached, without the need for brain retractors. Endoscopy is used to enhance visualization, and tube-shaft instruments to improve manipulation through the narrow surgical corridor. CONCLUSIONS: The supraorbital keyhole approach provides a safe method to access selected skull base lesions.

Clinical outcome in lumbar decompression surgery for spinal canal stenosis in the aged population: a prospective Swiss multicenter cohort study.

STUDY DESIGN: This is a prospective, multicenter cohort study including 8 medical centers in the metropolitan area of the Canton Zurich, Switzerland. OBJECTIVES: To examine whether outcome and quality of life might improve after decompression surgery for degenerative lumbar spinal stenosis (DLSS) even in patients older than 80 years and to compare data with a younger patient population from our own patient collective. SUMMARY AND BACKGROUND DATA: Lumbar decompression surgery without fusion has been shown to improve quality of life in lumbar spinal canal stenosis. In the population older than 80 years, treatment recommendations for DLSS show conflicting results. METHODS: Eight centers in the metropolitan area of Zurich, Switzerland agreed on the classification of DLSS, surgical principles, and follow-up protocols. Patients were followed from baseline, at 6 months, and 12 months. Baseline characteristics were analyzed with 5 different questionnaires "Spinal Stenosis Measure, Feeling Thermometer, Numeric Rating Scale, 5D-3L, and Roland and Morris Disability Questionnaire." In addition, our study population was compared with a younger control group. Furthermore, we calculated the minimal clinically important differences. RESULTS: Thirty-seven patients with an average age of 82.5 ± 2.5 years reached the 12-month follow-up. Spinal Stenosis Measure scores, the Feeling Thermometer, the Numeric Rating Scale, and the Roland and Morris Disability Questionnaire showed significant improvements at the 6-month and 12-month follow-ups (P < 0.001). One EQ-5D-3Lsubgroup "anxiety/depression" showed no significant improvement (P = 0.109) at 12-month follow-up. The minimal clinically important difference for the "Symptom Severity scale" in the Spinal Stenosis Measure was achieved with improvement of 70% in the older patient population. CONCLUSION: Patients 80 years or older can expect a clinically meaningful improvement after lumbar decompression for symptomatic DLSS. Our patient population showed significant positive development in quality of life in the short- and long-term follow-ups. LEVEL OF EVIDENCE: 3.

Quantification of Corticospinal Tracts with Diffusion Tensor Imaging in Brainstem Surgery: Prognostic Value in 14 Consecutive Cases at 3T Magnetic Resonance Imaging.

OBJECTIVE: In this study, we investigated the potential prognostic role of morphologic and quantitative diffusion tensor imaging (DTI) in patients with brainstem cavernoma (BSC) in terms of postoperative outcome. METHODS: In this retrospective study of 14 brainstem cavernoma patients, we analyzed pre- and postoperative DTI data. White matter tractography of corticospinal tracts (CSTs) was performed with the Fiber Assignment by Continuous Tracking algorithm, and morphologic characteristics of CSTs were compared with clinically assessed motor strength. Fractional anisotropy (FA) and apparent diffusion coefficient (ADC) were measured in ipsi- and contralesional regions of interest at the lesion level, as well as levels caudal and rostral to the lesion. Correlation analysis was performed between lateral index (LI) of ipsi-/contralateral FA and ADC values and patients' motor function. RESULTS: Preoperatively, normal morphologic features of CSTs corresponded to normal motor function in 4 patients. The other 10 morphologically abnormal preoperative CSTs didn't show corresponding motor impairment either in pre- or postoperative follow-up period. The sensitivity, specificity, positive predictive, and negative predictive values of white matter tractographic morphology on preoperative motor function were 100%, 57.1%, 70%, and 100%, respectively. The corresponding values on follow-up motor function were 100%, 33.3%, 20%, and 100%, respectively. The mean FA at lesion level was significantly lower than the corresponding FA at the contralateral hemisphere (P = 0.009). In areas caudal to the lesion the same trend yet without statistic significance was observed (P = 0.23). There was no significant laterality difference of mean FAs rostral to the level of the lesion. No correlation in LI of FA or ADC in the 3 anatomic levels with simultaneous and long-term follow up motor function was observed. Restoration of the morphology of the affected CST postoperatively was associated with a trend for decreasing ADC compared with the preoperative measurements. CONCLUSION: Intact CST morphology in DTI predicts a favorable postoperative outcome in patients with BSC. Interrupted CSTs and decreased FA values correlate well within BSC lesion level; nevertheless, morphologic characteristics and diffusion parameter changes at lesion level cannot predict poor prognosis. Caudal and rostral diffusion parameters can provide more information of the integrity of CSTs compared with morphologic study alone.