***TASK*** the task is to summarize an input biomedical literature in six sentences 
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    Input: BACKGROUND CONTEXT Laminectomy for lumbar stenosis-associated radiculopathy is associated with improvement in pain , disability , and quality of life . However , given rising health-care costs , attention has been turned to question the cost-effectiveness of lumbar decompressive procedures . The cost-effectiveness of multilevel hemilaminectomy for radiculopathy remains unclear . PURPOSE To assess the comprehensive medical and societal costs of multilevel hemilaminectomy at our institution and determine its cost-effectiveness in the treatment of degenerative lumbar stenosis . STUDY DESIGN Prospect i ve single cohort study . PATIENT SAMPLE Fifty-four consecutive patients undergoing multilevel hemilaminectomy for lumbar stenosis-associated radiculopathy after at least 6 months of failed conservative therapy were included . OUTCOME MEASURES Self-reported measures were assessed using an outcomes question naire that incorporated total back-related medical re source utilization , missed work , and improvement in leg pain ( visual analog scale for leg pain [ VAS-LP ] ) , disability ( Oswestry Disability Index [ ODI ] ) , quality of life ( Short Form-12 [ SF-12 ] ) , and health state values ( quality -adjusted life years [ QALYs ] , calculated from EuroQuol 5D [ EQ-5D ] with US valuation ) . METHODS Over a 2-year period , total back-related medical re source utilization , missed work , and improvement in leg pain ( VAS-LP ) , disability ( ODI ) , quality of life ( SF-12 ) , and health state values ( QALYs , calculated from EQ-5D with US valuation ) were assessed . Two-year re source use was multiplied by unit costs based on Medicare national allowable payment amounts ( direct cost ) , and patient and caregiver workday losses were multiplied by the self-reported gross-of-tax wage rate ( indirect cost ) . Mean total 2-year cost per QALY gained after multilevel hemilaminectomy was assessed . RESULTS Compared with preoperative health states reported after at least 6 months of medical management , a significant improvement in VAS-LP , ODI , and SF-12 ( physical and mental components ) was observed 2 years after multilevel hemilaminectomy , with a mean 2-year gain of 0.72 QALYs . Mean±st and ard deviation total 2-year  cost of multilevel hemilaminectomy was $ 24,264±10,319 ( surgery cost , $ 10,220±80.57 ; outpatient re source utilization cost , $ 3,592±3,243 ; and indirect cost , $ 10,452±9,364 ) . Multilevel hemilaminectomy was associated with a mean 2-year cost per QALY gained of $ 33,700 . CONCLUSIONS Multilevel hemilaminectomy  improved pain , disability , and quality of life in patients with lumbar stenosis-associated radiculopathy . Total cost per QALY gained for multilevel hemilaminectomy was $ 33,700 when evaluated 2 years after surgery with Medicare fees , suggesting that multilevel hemilaminectomy is a cost-effective treatment of lumbar radiculopathy BACKGROUND Neurogenic claudication due to symptomatic lumbar spinal stenosis ( LSS ) is a painful condition causing significant functional disability . While the cause of LSS is multifactorial , thickened ligamentum flavum ( LF ) accounts for up to 85 % of spinal canal narrowing . mild percutaneous lumbar decompression allows debulking of the hypertrophic LF while avoiding the morbidities frequently associated with more invasive surgical procedures . METHODS In this prospect i ve case series study , consecutive LSS patients presenting with neurogenic claudication were treated with percutaneous lumbar decompression .  Efficacy was evaluated using the Pain Disability Index ( PDI ) and Rol and -Morris Disability Question naire . Pre- and postprocedure St and ing Time , Walking Distance , and Visual Analog Score ( VAS ) were also monitored . Significant device- or procedure-related adverse events were reported . RESULTS The mild procedure was successfully performed on forty patients . At twelve months , both PDI and Rol and -Morris showed significant improvement of 22.6 points ( ANOVA , P<0.0001 ) and 7.7 points ( ANOVA , P<0.0001 ) , respectively . Walking Distance , St and ing Time , and VAS improvements were also statistically significant , increasing from 246 to 3,956 feet ( ANOVA , P<0.0001 ) , 8 to 56 minutes ( ANOVA , P<0.0001 ) , and 7.1 to 3.6 points ( ANOVA , P<0.0001 ) , respectively . Tukey HSD test found improvement in all 5- outcome measures to be significant from baseline at each follow-up interval . No significant device- or procedure-related adverse events were reported . CONCLUSION This study demonstrated significant functional improvement as well as decreased disability secondary to neurogenic claudication after mild procedure . Safety , cost-effectiveness , and quality -of-life outcomes are best compared with comprehensive medical management in a r and omized controlled fashion and , where ethical , to open lumbar decompression surgery BACKGROUND The efficacy of fusion surgery in addition to decompression surgery in patients who have lumbar spinal stenosis , with or without degenerative spondylolisthesis , has not been substantiated in controlled trials . METHODS We r and omly assigned 247 patients between 50 and 80 years of age who had lumbar spinal stenosis at one or two adjacent vertebral levels to undergo either decompression surgery plus fusion surgery ( fusion group ) or decompression surgery alone ( decompression-alone group ) . R and omization was stratified according to the presence of preoperative degenerative spondylolisthesis ( in 135 patients ) or its absence . Outcomes were assessed with the use of patient-reported outcome measures , a 6-minute walk test , and a health economic evaluation . The primary outcome was the score on the Oswestry Disability Index ( ODI ; which ranges from 0 to 100 , with higher scores indicating more severe disability ) 2 years after surgery . The primary analysis , which was a per- protocol analysis , did not include the 14 patients who did not receive the assigned treatment and the 5 who were lost to follow-up . RESULTS There was no significant difference between the groups in the mean score on the ODI at 2 years ( 27 in the fusion group and 24 in the decompression-alone group , P=0.24 ) or in the results of the 6-minute walk test ( 397 m in the fusion group and 405 m in the decompression-alone group , P=0.72 ) . Results were similar between patients with and those without spondylolisthesis . Among the patients who had 5 years of follow-up and were eligible for inclusion in the 5-year analysis , there were no significant differences between the groups in clinical outcomes at 5 years . The mean length of hospitalization was 7.4 days in the fusion group and 4.1 days in the decompression-alone group ( P<0.001 ) . Operating time was longer , the amount of bleeding was greater , and surgical costs were higher in the fusion group than in the decompression-alone group . During a mean follow-up of 6.5 years , additional lumbar spine surgery was performed in 22 % of the patients in the fusion group and in 21 % of those in the decompression-alone group . CONCLUSIONS Among patients with lumbar spinal stenosis , with or without degenerative spondylolisthesis , decompression surgery plus fusion surgery did not result in better clinical outcomes at 2 years and 5 years than did decompression surgery alone . ( Funded by an Uppsala institutional Avtal om Läkarutbildning och Forskning [ Agreement concerning Cooperation on Medical Education and Research ] and others ; Swedish Spinal Stenosis Study Clinical Trials.gov number , NCT01994512 . ) Study Design Prospect i ve observational study . Objective To describe our experience with the first 50 cases of  minimally invasive lumbar canal decompression in terms of patient outcome up to 2 years , the learning curve incurred , and complications when compared with our most recent 50 cases . Summary of Background Data Lumbar canal stenosis is a common condition in the elderly population , the symptoms of which respond well to surgical decompression . A minimally invasive approach offers potential short and long-term benefits to patients but the technique is associated with a learning curve and equivalence to open surgery regarding efficacy and complications needs to be demonstrated . Methods Fifty patients ( mean age 70 y ) who presented with clinical and radiological features of lumbar canal stenosis and who had failed a period of conservative management underwent lumbar canal decompression through a paramedian oblique , muscle splitting approach using a 16 to 18 mm operating tube and microscope .  Outcome was assessed using the Oswestry Disability Index and Short Form-36 at 3 months , 1 year , and 2 years . Results Significant clinical improvements were seen at 3 months that were sustained at 1 and 2 years . Clinical outcome improved whereas operative time and complications fell as experience increased , helping to define the learning curve with this technique . Conclusions Minimally invasive lumbar decompression seems to offer patients a clinical benefit comparable to that observed in published open series , with potential advantages in terms of postoperative pain and recovery . However , there is a learning curve and whether this technique offers long-term benefits with regard to a reduction in back pain or postoperative spondylolisthesis is not yet known The effect of the duration of symptoms on the outcome of lumbar decompression surgery is not known . The aim of our study was to determine the predictors of functional outcome of lumbar decompression surgery for degenerative spinal stenosis with particular emphasis on the duration of symptoms . In this prospect i ve cohort study , we recruited 100 patients with a full data set available at 1-year and 85 % at 2-year follow-ups : 49 females and 51 males with an average age of 62 ( range 52–82 ) . The pre- and post-operative outcome measures were Oswestry disability index ( ODI ) , low back outcome score ( LBOS ) , pain visual analogue score ( VAS ) , modified somatic perception ( MSP ) and modified Zung depression ( MZD ) score . Dural tear occurred in 14 % , and there was one post-operative extra-dural heamatoma . Overall , the ODI improved from a pre-operative of 56 ( ±13 ) to a 1-year ODI of 40 ( ±22 ) and at 2-year ODI of 40 ( ±21 ) . The VAS improved from an average of 8 to 5.2 at 1 year and 4.9 at 2 years . There was a statistical significant association between symptom duration and the change in ODI ( P=0.007 at 1-year follow-up , P=0.001 at 2-year follow-up ) , LBOS ( P=0.001 at 1-year follow-up , P<0.001 at 2-year follow-up ) and VAS ( P=0.003 at 1-year follow-up , P=0.001 at 2-year follow-up ) . Subgroup analyses showed that patients with symptom duration of less than 33 months had a more favourable result . In addition , the patients who rated the operation as excellent had a statistically significantly shorter duration of symptoms . We have not found a predictive value for age at operation , MSP or MZD . The number of levels of decompression and the different types of decompression surgery did not influence the surgical results . Our study indicates that the symptom duration of more than 33 months has a less favourable functional outcome Study Design . A prospect i ve study to evaluate the outcomes of 2 different decompressive techniques for lumbar spinal stenosis . Objective . To explore a more effective and less invasive decompression technique without instrument and fusion for lumbar spinal stenosis . Summary of Background Data . The traditional surgical decompression of spinal stenosis involves laminectomy or unilateral laminotomy . Even in unilateral laminotomy cases , 85.3 % had an excellent-to-fair operative result , and the incidence of complications was 9.8 % . Although the addition of instrumentation does not increase the complication rate , but compared to the efficiency , the higher costs was controversial . Minimal invasion and destabilization are recommended . Methods . This prospect i ve study included 152 consecutive patients , sequentially divided into 2 groups ,  underwent Windows technique  ( group A ) and decompressive laminectomy ( group B ) by 2 groups of surgeons . Results . The evaluation of the back pain , leg pain , walking tolerance , and neurologic recovery were performed before surgery and after surgery . In group A , at the final evaluation , the overall results were good to excellent in 89 % ( 68/76 ) of the patients , fair 11 % ( 8/76 ) , and poor 0 % . In group B , at the final evaluation , the overall results were good to excellent in 63 % ( 48/76 ) of the patients , fair 30 % ( 23/76 ) , and poor 7 % ( 5/76 ) . Conclusion . Degenerative spinal stenosis can be decompressed adequately with preserving the posterior elements . The “ Windows technique ” laminoforaminotomy , which obtained satisfactory long-term outcomes with few complications and low cost , can be a st and ard procedure for the surgical treatment of the degenerative spinal stenosis even with slight congenital spinal stenosis BACKGROUND CONTEXT Few studies have analyzed the results of an interspinous distraction device in patients with lumbar spinal stenosis . It is still unknown whether the outcomes of an interspinous implant are related to the severity of stenosis . 
    Output:
    
Conclusion Patients with lumbar spinal stenosis experience rapid symptom reduction after surgery , but should still expect to experience mild-to-moderate pain and disability 60 months later