***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
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    Input: Study Design . Single blind r and omized study . Objectives . To compare the effectiveness of  lumbar instrumented fusion with cognitive intervention and exercises in patients with chronic low back pain and disc degeneration . Summary of Background Data . To the authors ’ best knowledge , only one r and omized study has evaluated the effectiveness of lumbar fusion . The Swedish Lumbar Spine Study reported that lumbar fusion was better than continuing physiotherapy and care by the family physician . Patients and Methods . Sixty-four patients aged 25–60 years with low back pain lasting longer than 1 year and evidence of disc degeneration at L4–L5 and /or L5–S1 at radiographic examination were r and omized to either lumbar fusion with posterior transpedicular screws and postoperative physiotherapy , or cognitive intervention and exercises . The cognitive intervention consisted of a lecture to give the patient an underst and ing that ordinary physical activity would not harm the disc and a recommendation to use the back and bend it . This was reinforced by three daily physical exercise sessions for 3 weeks . The main outcome measure was the Oswestry Disability Index . Results . At the 1-year follow-up visit , 97 % of the patients , including 6 patients who had either not attended treatment or changed groups , were examined . The Oswestry Disability Index was significantly reduced from 41 to 26 after surgery , compared with 42 to 30 after cognitive intervention and exercises . The mean difference between groups was 2.3 ( −6.7 to 11.4 ) ( P = 0.33 ) . Improvements inback pain , use of analgesics , emotional distress , life satisfaction , and return to work were not different . Fear-avoidance beliefs and fingertip-floor distance were reduced more after nonoperative treatment , and lower limb pain was reduced more after surgery . The success rateaccording to an independent observer was 70 % after surgery and 76 % after cognitive intervention and exercises .  The early complication rate in the surgical group was 18 % . Conclusion . The main outcome measure showed equal improvement in patients with chronic low back pain and disc degeneration r and omized to cognitive intervention and exercises , or lumbar fusion BACKGROUND Management of degenerative spondylolisthesis with spinal stenosis is controversial . Surgery is widely used , but its effectiveness in comparison with that of nonsurgical treatment has not been demonstrated in controlled trials . METHODS Surgical c and i date s from 13 centers in 11 U.S. states who had at least 12 weeks of symptoms and image-confirmed degenerative spondylolisthesis were offered enrollment in a  r and omized cohort or an  observational cohort . Treatment was st and ard decompressive laminectomy ( with or without fusion ) or usual nonsurgical care . The primary outcome measures were the Medical Outcomes Study 36-Item Short-Form General Health Survey ( SF-36 ) bodily pain and physical function scores ( 100-point scales , with higher scores indicating less severe symptoms ) and the modified Oswestry Disability Index ( 100-point scale , with lower scores indicating less severe symptoms ) at 6 weeks , 3 months , 6 months , 1 year , and 2 years . RESULTS We enrolled 304 patients in the r and omized cohort and 303 in the observational cohort . The baseline characteristics of the two cohorts were similar . The one-year crossover rates were high in the r and omized cohort ( approximately 40 % in each direction ) but moderate in the observational cohort ( 17 % crossover to surgery and 3 % crossover to nonsurgical care ) . The intention-to-treat analysis for the r and omized cohort showed no statistically significant effects for the primary outcomes . The as-treated analysis for both cohorts combined showed a significant advantage for surgery at 3 months that increased at 1 year and diminished only slightly at 2 years . The treatment effects at 2 years were 18.1 for bodily pain ( 95 % confidence interval [ CI ] , 14.5 to 21.7 ) , 18.3 for physical function ( 95 % CI , 14.6 to 21.9 ) , and -16.7 for the Oswestry Disability Index ( 95 % CI , -19.5 to -13.9 ) . There was little evidence of harm from either treatment . CONCLUSIONS In nonr and omized as-treated comparisons with careful control for potentially confounding baseline factors , patients with degenerative spondylolisthesis and spinal stenosis treated surgically showed substantially greater improvement in pain and function during a period of 2 years than patients treated nonsurgically . ( Clinical Trials.gov number , NCT00000409 [ Clinical Trials.gov ] . ) BACKGROUND CONTEXT Patient-based quality of life scales have become a critical element of post-op assessment for lumbar fusion surgery . The most extensive outcomes data have been generated through FDA -regulated IDE trials for new technologies , which produce excellent data but are constrained by strict enrollment criteria and limited indications . This raises a question as to whether the excellent results seen in these IDE trials can be reproduced in st and ard clinical practice . PURPOSE The purpose of this study was to analyze surgical results based upon st and ardized outcome tools , across a spectrum of interventions , for one- and two-level lumbar spine fusion procedures . DESIGN / SETTING This study is a retrospective review of prospect ively collected patient based outcomes data . PATIENT SAMPLE Four hundred ninety-seven patients , who underwent 1- or 2-level lumbar spine fusion at five participating spine centers , utilizing a variety of surgical techniques . Enrollment criteria included available demographic , surgical and clinical outcome data . At a minimum , patients had pre-op and one year post-op SF-36 data . In many cases two-year post-op SF-36 data and concomitant Oswestry Disability Index ( ODI ) data was available . OUTCOME MEASURES SF36 and ODI . METHODS The patient population included 270 females and 227 males , with a mean age of 47 years . Sixty-five percent ( N=324 ) had one level fusions and 35 % ( N=173 ) had two level fusions . Demographic data collected included age , gender , BMI , surgical history , smoking history and work status . Data was analyzed with repeated measures analysis of variance ( ANOVA ) . RESULTS SF-36 Physical Composite Score ( PCS ) improved a mean 9.9 points at one year post-op and 9.5 points at two years post-op . ODI improved a mean 22.2 points at one year post-op and 22.1 points at two years post-op . SF-36 PCS data for surgical approach subgroups revealed greater improvement ( p=.03 ) in the ALIF group as compared to the PSF , PLIF/TLIF , or 360 degrees fusion groups ( 12.6 points vs. 8.8 , 9.3 , 8.4 points ) at 1 year post-op . At 2 years post-op , there was greater improvement ( p=.02 ) in the ALIF and PSF groups as compared to the PLIF/TLIF and 360 degrees fusion groups ( 13.8 and 11.2 points vs. 7.7 and 6.3 points ) . SF-36 PCS data demonstrated similar baseline scores for patients with and without prior decompression , but a significantly greater rate of improvement ( 11.3 vs. 7.2 points , p=.002 ) for patients without prior lumbar decompression surgery . The ODI data indicated a significantly greater disability at baseline in the prior decompression group , with greater improvement ( 21.7 vs. 17.5 points ) in patients without prior surgery . CONCLUSIONS This study documents improved outcomes , based on SF-36 and ODI scores , in patients undergoing lumbar fusion for one and two level degenerative disc disease . The findings also demonstrate efficacy for all of the surgical techniques studied , suggesting that surgeons can appropriately select the surgical strategy with which they are most adept BACKGROUND Numerous pre clinical and clinical studies have reported on the use of platelet concentrates to promote tissue healing . The results in spinal fusion applications are limited and controversial . PURPOSE The purpose of the current prospect i ve clinical cohort study is to assess the effect of Autologous Growth Factors ( AGF ) on lumbar interbody fusion with specific attention paid to determination of clinical and radiographic outcomes . STUDY DESIGN / SETTING Prospect i ve clinical study PATIENT SAMPLE C and i date s for anterior-posterior lumbar fusion with diagnosis of degenerative disc disease and /or up to grade I spondylolytic spondylolisthesis based on positive provocative discography . OUTCOME MEASURES Clinical ( visual analogue pain scale/functional outcome assessment ) and radiographic outcomes ( fusion on computed tomography at 6 months and plain radiographs at 12 and 24 months ) . METHODS Thirty-seven patients were assigned to st and ard anterior-posterior interbody fusion L2-S1 ( single or two-level ) using iliac crest bone graft ( autograft group : 22 patients with 32 levels operated ) or allograft combined with autogenous growth factors ( AGF group : 15 patients with 25 levels operated ) . Radiographic outcomes were collected at 6 months postsurgery with computed tomography and at 12 and 24 months with plain radiographs . Pre- and postoperative clinical outcome measures included visual analog scores ( VAS ) for back and leg pain ( 0 - 10 ) , SF-36 scores , and Oswestry disability determination . Average clinical and radiographic follow-up for the autograft group was 24.3+/-5.6 months ( 12 - 36 months ) and AGF was 25.7+/-7.5 ( 6 - 40 months ) . RESULTS Fusion incorporation at each end plate was determined at 56 % in both autograft and AGF ( p = NS ) patients based on computed tomography at 6 months with minimal subsidence noted and no direct correlation between the incidence or degree of cage subsidence and bone graft technique . The 12- and 24-month radiographic results confirmed an 85 % arthrodesis rate for the autograft patients , whereas the AGF patients had an 89 % fusion rate ( p = NS ) . Clinical outcomes were similar for both groups and no significant differences were noted for pain or functional outcome improvements . CONCLUSIONS AGF combined with an allograft carrier is equivalent in radiographic and clinical outcomes to autograft in one- or two-level lumbar interbody fusion with supplemental posterior fixation and , thus , eliminates any morbidity from iliac crest bone graft harvesting . AGF combined with an appropriate carrier is a reasonable alternative to autograft and expensive bone induction technologies . Further research is still required to examine the optimum carriers , preparation and formulation , and platelet concentrations for this technology Study Design . Retrospective outcome measurement after circumferential reconstructive surgery with lumbar fusion in patients with chronic discogenic low back pain . Objective . To examine the effect of the number of fusion levels on surgical outcomes in patients with chronic discogenic low back pain using provocative pressure-controlled diskography as a primary diagnostic tool . Summary of Background Data . Although there is general agreement that construct length adversely affects arthrodesis success rates , the effect of the number of levels on lumbar fusion surgery outcome has not been reported . Previous fusion outcome studies have generally relied on magnetic resonance imaging or conventional diskography for diagnosis . Methods . From 1994 through 2000 , prospect ively collected medical records of patients who underwent reconstructive lumbar spine surgery with confirmation of the pain generator by pressure-controlled diskography were retrospectively analyzed . Data were subdivided into 2 groups of patients . The first group , design ated the  short segment group , contained patients who underwent fusion at 1 or 2 levels .  The second group , design ated the  long segment  group , contained patients who underwent fusion at 3−5 levels .  Surgical methods included circumferential reconstruction of the lumbar spine by either posterior or combined anterior and posterior approach . Surgeries included posterior decompression necessary to relieve documented regions of neural compression , combined with interbody arthrodesis at selective levels , augmented by posterior segmental spinal instrumentation and posterolateral arthrodesis . All patients completed a preoperative aquatic-conditioning program . Whenever possible , coexisting medical conditions were corrected or stabilized before surgery . A preoperative Short Form R AND 36-Item Health Survey ( SF-36 ) was completed , and repeated at 1 and 2 years after surgery . The short and long segment groups contained 142 and 82 patients , respectively , who completed the preoperative SF-36 question naire completely . Results . One hundred patients in the short segment group ( vide infra ) were available for 1-year follow-up , and 68 were available for 2-year follow-up . In the long segment group , 81 patients were available for 1-year follow-up , and 49 were available for 2-year follow-up . Mean ages were 41.0 and 47.6 years in the short and the long segment groups , respectively . The 2 groups did not differ significantly in gender , smoking habits , workers ’ compensation , or litigation ( P > 0.05 ) . In the short segment group , postoperative 1-year mean Physical Component Summary ( PCS ) and Mental Component Summary scores significantly improved ( P < 0.001 and P = 0.002 , respectively ) . Domains other than general health perceptions showed significantly improved 1-year follow-up scores ( P ≤ 0.001 ) . Two-year follow-up scores showed significant improvement ( P < 0.001 for physical function [ PF ] , role function as limited by physical problems [ RP ] , bodily pain [ BP ] , social function [ SF ] , and PCS ) . The vitality ( VT ) 
    Output:
    
The body of literature supports fusion surgery as a viable treatment option for reducing pain and improving function in patients with chronic LBP refractory to nonsurgical care when a diagnosis of disc degeneration can be made