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.

Treatment Patterns in Patients with Diagnostic Imaging for Low Back Pain: A Retrospective Observational Study.

PURPOSE: Low back pain (LBP) is one of the most frequent reasons for medical consultations. Literature suggests a large evidence-performance gap, especially regarding pain management. Therefore, the monitoring of treatment patterns is important to ensure high quality of treatment. This study aimed to describe treatment patterns specific to patients with diagnostic imaging of the spine for LBP. PATIENTS AND METHODS: The study was retrospective observational and based on health claims data from 2015 to 2019 provided by a Swiss health insurance company covering around 12% of the population. Patients, ≥18 years of age, with diagnostic imaging of the spine were included and observed 12 months before and after imaging. Patients with back surgery or comorbidities associated with the use of pain medications were excluded. RESULTS: In total, 60,822 patients (mean age: 53.5 y, 56.1% female) were included and 85% received at least one pain medication. Of these, non-steroidal anti-inflammatory drugs, paracetamol, or opioids were prescribed in 88.6%, 70.7%, and 40.3% of patients, respectively. Strong opioids were used in 17% of patients given opioids. Patients with combinations of diagnostic imaging methods had the highest odds of receiving pain medication prescriptions (1.81, 95% CI: 1.66, 1.96, P < 0.001). Prescribed defined daily doses corresponded to short-term therapies. CONCLUSION: Although the majority of patients received non-opioid short-term therapies, we found a substantial use of opioids, and in particular, a relative high usage of strong opioids. Our results highlighted the importance of both patient and healthcare provider awareness regarding the prudent treatment of LBP.

Iron deficiency anaemia and low BMI among adolescent girls in India: the transition from 2005 to 2015.

OBJECTIVE: The current study explored changes in trend of anaemia and BMI among currently pregnant nullipara adolescent women against socio-economic determinants in India from 2005 through 2015. The association between anaemia in currently pregnant nullipara adolescent women v. currently pregnant nullipara older women of reproductive age was also explored. DESIGN: We used the 2005 and the 2015 nationally representative Indian Demographic and Health Surveys (DHS). The outcomes of interest, anaemia and BMI, were measured based on the DHS methodology following WHO standards and indicators. Place of residence, educational attainment and wealth quintiles were used as determinants in the analysis. SETTING: India. PARTICIPANTS: In total, 696 adolescent girls from the India 2005 DHS and 3041 adolescent girls from the India 2015 DHS. RESULTS: The 10-year transition from 2005 to 2015 showed differences between the least and most wealthy sections of society, with heaviest gains in anaemia reduction over time among the latter (from 50·0 to < 40·0 %). The odds of anaemia were significantly higher among the adolescent population when compared with adult women both in 2005 and in 2015 (OR = 1·2). CONCLUSIONS: Despite an overall improvement in the prevalence of both BMI < 18·5 and anaemia among adolescents nullipara in India, the adjusted risk of anaemia in the latter category was still significantly higher as compared with their adult counterparts. Since the inequalities evidenced during the first round of DHS remained unchanged in 2015, more investments in universal health care are needed in India.

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.

What is the treatment effect of surgery compared with nonoperative treatment in patients with lumbar spinal stenosis at 1-year follow-up?

Objective: The aim of this study was to obtain an unbiased causal treatment estimate of the between-group difference of surgery versus nonoperative treatment with respect to outcomes on quality of life, pain, and disability in patients with degenerative lumbar spinal stenosis (DLSS) 12 months after baseline. Methods: The authors included DLSS patients from a large prospective multicenter observational cohort study. Propensity score matching was used, including 15 demographic, clinical, and MRI variables. Linear and logistic mixed-effects regression models were applied to quantify the between-group treatment effect. Unmeasured confounding was addressed in a sensitivity analysis, assessing the robustness of the results. Results: A total of 408 patients were included in this study, 222 patients after matching, with 111 in each treatment group. Patients with nonoperative treatment had lower quality of life at the 12-month follow-up (−6.21 points, 95% CI −9.93 to −2.49) as well as lower chances of reaching a minimal clinically important difference in Spinal Stenosis Measure (SSM) symptoms (OR 0.26, 95% CI 0.13 to 0.53) and SSM function (OR 0.26, 95% CI 0.14 to 0.49), than patients undergoing surgery. These results were very robust in case of unmeasured confounding. The surgical complication rate was low; 5 (4.5%) patients experienced a durotomy during intervention, and 5 (4.5%) patients underwent re-decompression. Conclusions: The authors used propensity score matching to assess the difference in treatment efficacy of surgery compared with nonoperative treatment in elderly patients with DLSS. This study delivers strong evidence that surgical treatment is superior to nonoperative treatment. It helps in clinical decision-making, especially when patients suffer for a long time, sometimes over many years, hoping for a spontaneous improvement of their symptoms. In light of these new results, the number of years with disability can hopefully be reduced by providing adequate treatment at the right time for this ever-growing elderly and frail population. Abbreviations: DLSS = degenerative lumbar spinal stenosis; HADS = Hospital Anxiety and Depression Scale; ITT = intention-to-treat; LSOS = Lumbar Stenosis Outcome Study; MCID = minimal clinically important difference; RCT = randomized controlled trial; SMD = standardized mean difference; SSM = Spinal Stenosis Measure.

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.

Prognostic function to estimate the probability of meaningful clinical improvement after surgery - Results of a prospective multicenter observational cohort study on patients with lumbar spinal stenosis.

BACKGROUND: Approximately two thirds of patients with lumbar spinal stenosis (LSS) who undergo surgical treatment benefit from the surgery. The objective of this study was to derive a prognostic probability function (PPF) to identify patients with a high probability of post-surgical improvement because there is currently no method available. METHODS: In this multicenter, prospective, observational study, we collected data from eight medical centers in Switzerland in which patients underwent surgery for LSS. The endpoints were meaningful clinically important differences (MCID) in pain and disability one year after baseline. We developed a PPF named PROCESS (PostopeRative OutComE Spinal Stenosis), based on a large set of prognostic indicators extracted from the literature. The PPF was derived using data from a random subset of two thirds of the patients and validated in the remaining third. We addressed overfitting by shrinking the regression coefficients. The area under the ROC curve (AUC) and calibration determined the accuracy of the PPF. RESULTS: In this study, 452 LSS patients received surgery. 73% of the 300 patients in the derivation subset reached an MCID in pain and 68% reached an MCID in disability. The corresponding values were 70% and 63% in the validation subset, respectively. In the derivation subsample, the AUC was 0.64 (95% CI 0.57 to 0.71) for of the PPF predicting MCID in pain and 0.71 (0.64 to 0.77) for MCID in disability, after shrinkage. The corresponding numbers were 0.62 (0.52 to 0.72) and 0.70 (0.60 to 0.79) in the validation subsample, and the PPF showed good calibration. CONCLUSIONS: Surgical treatment for patients with lumbar spinal stenosis is being performed with increasing frequency. PROCESS is conditional on the individual pattern of preoperatively available prognostic indicators, and may be helpful for clinicians in counselling patients and in guiding the discussion on individual treatment decision in the era of personalized medicine.

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.

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.