***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 
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    Input: Study Design . This study evaluated clinical and magnetic resonance imaging differences of patients treated surgically for lumbar disc herniation . Clinical follow-up and magnetic resonance imaging evaluation of epidural fibrosis were used to assess patient outcome . Objectives . The purpose of this study was to evaluate the difference in clinical outcome with either free-fat graft , Golfoam , or no interposition membrane placed in the laminectomy defect after nerve root decompression . Summary of Background Data . Epidural fibrosis has been considered a cause of recurrent symptoms after lumbar laminectomy , and numerous material s have been evaluated for prophylaxis of the “ laminectomy membrane . ” These have been mainly histologic and animal studies with no data correlating clinical symptoms and postoperative epidural scar formation . Methods . One hundred fifty-six patients who were treated surgically for lumbar disc herniation were r and omly assigned to one of three groups and followed prospect ively for at least 1 year . Thirty-three of these patients were received magnetic resonance imaging evaluations after 6 months by an idependent radiologist who grade d the amount of epidural scar formation . The patients were assessed at 1 year and given a rating of excellent , good , fair , or poor , and the scar was grade d as none , minimal , or moderate . Results . Although 97 % of all patients improved , 83 % were rated excellent or good . There were no statistical differences between the three groups clinical ly and radiographically . Patients with workers compensation had a statistically significant lower success rate ( P < 0.001 ) . Conclusions . Clinical outcome after lumbar disc surgery does not correlate with the use or type of interposition membrane used to prevent epidural fibrosis Abstract This single-blind r and omised clinical trial compared osteopathic manipulative treatment with chemonucleolysis ( used as a control of known efficacy ) for symptomatic lumbar disc herniation . Forty patients with sciatica due to this diagnosis ( confirmed by imaging ) were treated either by chemonucleolysis or manipulation . Outcomes ( leg pain , back pain and self-reported disability ) were measured at 2 weeks , 6 weeks and 12 months . The mean values for all outcomes improved in both groups . By 12 months , there was no statistically significant difference in outcome between the treatments , but manipulation produced a statistically significant greater improvement for back pain and disability in the first few weeks . A similar number from both groups required additional orthopaedic intervention ; there were no serious complications . Crude cost analysis suggested an overall financial advantage from manipulation . Because osteopathic manipulation produced a 12-month outcome that was equivalent to chemonucleolysis , it can be considered as an option for the treatment of  symptomatic lumbar disc herniation  , at least in the absence of clear indications for surgery . Further study into the value of manipulation at a more acute stage is warranted Study design : This was a prospect i ve , r and omized , multicenter , double-blind study . Objectives : The study evaluated the use of ADCON ® -L Anti-Adhesion Barrier Gel to inhibit peridural fibrosis and reduce fibrosis-related symptoms after first-time lumbar discectomy . Summary of background data : Peridural scarring causes tethering of dura and nerve roots , contributing to pain and functional limitation , and that symptoms are evident by 6 months after surgery . Methods : Following discectomy , ADCON-L was applied to patients in the active treatment group . Outcome measures were reduction of peridural scar and postoperative pain . Results : There is an association between peridural scar and recurrent radicular pain . Patients having extensive peridural scar were three times more likely to experience recurrent radicular pain than those patients with less extensive scarring . ADCON-L inhibited peridural scar . Compared to the control group , there was a 23 % reduction in the number of patients with extensive peridural scar and a 120 % increase in the number of patients having minimal or no scar . ADCON-L  reduced the incidence of activity-related pain . There was up to a 50 % reduction in the number of patients reporting increased pain while doing typical activities of daily living . Conclusions : ADCON-L is safe , reduces peridural fibrosis , and improves postoperative patient outcome Retrospectively reported results of spinal cord stimulation compare favorably with those of neurosurgical treatment alternatives for the treatment of failed back surgery syndrome , including reoperation and ablative procedures . There has been no direct prospect i ve comparison , however , between SCS and other techniques for pain management . Therefore , we have design ed a prospect i ve , r and omized comparison of spinal cord stimulation and reoperation in patients with persistent radicular pain , with and without low back pain , after lumbosacral spine surgery . Patients selected for reoperation by st and ard criteria are r and omly assigned to initial treatment by one or the other technique . The primary outcome measure is the frequency of crossover to the alternative procedure , if the results of the first have been unsatisfactory after 6 months . Results for the first 27 patients reaching the 6-month crossover point show a statistically significant ( p = 0.018 ) advantage for spinal cord stimulation  over reoperation . Many other potentially important outcome measures will now be followed long-term as a larger overall study population accumulates CONTEXT Lumbar diskectomy is the most common surgical procedure performed for back and leg symptoms in US patients , but the efficacy of the procedure relative to nonoperative care remains controversial . OBJECTIVE To assess the efficacy of surgery for lumbar intervertebral disk herniation . DESIGN , SETTING , AND PATIENTS The Spine Patient Outcomes Research Trial , a r and omized clinical trial enrolling patients between March 2000 and November 2004 from 13 multidisciplinary spine clinics in 11 US states . Patients were 501 surgical c and i date s ( mean age , 42 years ; 42 % women ) with imaging-confirmed lumbar intervertebral disk herniation and persistent signs and symptoms of radiculopathy for at least 6 weeks . INTERVENTIONS St and ard open diskectomy vs nonoperative treatment individualized to the patient . MAIN OUTCOME MEASURES Primary outcomes were changes from baseline for the Medical Outcomes Study 36-item Short-Form Health Survey bodily pain and physical function scales and the modified Oswestry Disability Index ( American Academy of Orthopaedic Surgeons MODEMS version ) at 6 weeks , 3 months , 6 months , and 1 and 2 years from enrollment . Secondary outcomes included sciatica severity as measured by the Sciatica Bothersomeness Index , satisfaction with symptoms , self-reported improvement , and employment status . RESULTS Adherence to assigned treatment was limited : 50 % of patients assigned to surgery received surgery within 3 months of enrollment , while 30 % of those assigned to nonoperative treatment received surgery in the same period . Intent-to-treat analyses demonstrated substantial improvements for all primary and secondary outcomes in both treatment groups . Between-group differences in improvements were consistently in favor of surgery for all periods but were small and not statistically significant for the primary outcomes . CONCLUSIONS Patients in both the surgery and the nonoperative treatment groups improved substantially over a 2-year period . Because of the large numbers of patients who crossed over in both directions , conclusions about the superiority or equivalence of the treatments are not warranted based on the intent-to-treat analysis . TRIAL REGISTRATION clinical trials.gov Identifier : NCT00000410 Sixty patients with single-level lumbar disc herniation confirmed by computerized tomography were studied in a r and omized prospect i ve study . The aim was to see if there was any difference between the microscopic removal of a disc herniation and the st and ard procedure . All patients were operated on by the same surgeon by either method . They were all followed up by an impartial observer at 3 weeks , 2 months , 6 months , and 1 year . There were no differences between the groups regarding perioperative bleeding , complications , inpatient stay , time off work , or end result . The authors concluded that the decision to use the operating microscope may be left to the surgeon , because it had no effect on the short-term results or those at 1 year In this study two strategies in the treatment of Mechanical Spinal Discogenic Pain have been compared : Disc Coablation and Epidural Injection of Steroids . In 2003 50 patients treated with one or two epidural injections have been selected " ad r and om " and 50 patients treated with disc coablation .  Comparison of the data indicated an improvement of average VAS when relaxed for both groups ( p < 0.01 ) , while after slight-moderate strain , this value was significant only after coablation ( p < 0.001 ) . Finally , average VAS was clearly lower ( p < 0.01 ) after coablation as compared to epidural injections OBJECT Although good surgical technique is effective in reducing postoperative epidural fibrosis , compression or tethering of the nerve root may cause recurrent radicular pain and physical impairment . The implantation of a bioresorbable gel on the dura may further decrease the amount of scar formation after surgery and thus improve the patient 's ability to perform activities of daily living ( ADL ) . This study is a 12-month evaluation of the safety and effectiveness of Oxiplex/SP Gel ( FzioMed , Inc. , San Luis Obispo , CA ) in the reduction of pain and radiculopathy after lumbar discectomy . METHODS A pilot r and omized single-blind multicenter clinical trial was conducted to evaluate the performance of Oxiplex/SP Gel in patients who underwent surgery for unilateral herniation of the lumbar disc at L4 - 5 or L5-S1 . Eighteen patients with severe leg pain and lower-extremity weakness ( 11 women and seven men ) were r and omly assigned intraoperatively to receive the gel at the conclusion of surgery ( treatment group ) or to undergo surgery alone ( control group ) . Self- assessment question naires ( Lumbar Spine Outcomes Question naire ) to assess pain , symptoms , and ADL were completed preoperatively and at scheduled postoperative intervals ( 30 days , 90 days , 6 months , and 12 months ) . The authors examined the spine and lower extremities of patients scheduled for discectomy to assess neurological function and pain . Treated patients received sufficient Oxiplex/SP Gel ( 1 - 3 ml ) to coat the nerve root and fill the epidural space . Postoperative clinical evaluations were performed at 30 and 90 days . Patients completed the self- assessment question naires at baseline and were contacted by telephone or mail for the completion of the postoperative self- assessment question naires . Surgical procedures were well tolerated ; no device-related adverse events and no clinical ly significant laboratory results were reported . The 11 patients with severe leg pain and lower-extremity weakness who were treated with Oxiplex/SP Gel had a reduction in those symptoms at 30 days , 90 days , 6 months , and 12 months after discectomy , compared with the seven control patients who underwent surgery only . CONCLUSIONS Oxiplex/SP Gel was easy to use and safe in patients who underwent unilateral discectomy . A greater benefit in clinical outcome measures was seen over the 12-month follow-up period in gel-treated patients BACKGROUND Postoperative epidural fibrosis is a major causative factor of low-back pain even if microsurgical techniques are adopted to reduce this phenomenon . To prevent the recurrent radicular pain caused by this problem , we utilized adipose tissue drawn from the same patient ; at the end of surgical procedure , the fat was placed around the spinal root or the dural sac . This procedure was evaluated by a prospect i ve , r and omised study . METHOD From 180 patients operated on for lumbar discectomy between January 2000 to December 2001 , 74 were enclosed in the study . In 37 patients , the spinal root was covered by autologous fat ( group A ) , in the other 37 ( control group , B ) , this procedure was not adopted . One year after surgery , all the patients were evaluated with clinical and radiological ( Magnetic Resonance Imaging ) follow-up . Only two patients were lost to follow-up . FINDINGS 71 % of the patients in group A had 100 % of clinical and radiological post-operative outcome score ; this result was obtained only in 35 % of the patients in group B. A clinical score evaluating pain syndrome ( from grade 0 to 5 ) and a radiological score evaluating postoperative fibrosis ( from grade 0 to 4 ) was adopted . Therefore , group A had best outcome as compared to control group . CONCLUSIONS The authors found a positive effect in the reconstruction of epidural fat with autograft of adipose tissue to prevent postoperative scarring and failed-back syndrome related to postoperative fibrosis Ninety-three patients with lumbar disc prolapse of less than six months duration were treated with Chymoral or an identical placebo in a double-blind study . Those patients given Chymoral exhibited significantly greater improvement of straight-leg raising and received significantly fewer analgesics . However , no difference was apparent with regard to other parameters , and similar numbers from both groups required further therapy . Over-all , the value of Chymoral in the treatment of lumbar disc prolapse seemed little better than a placebo Abstract Epidural scarring is one of the possible complications after lumbar disc surgery . Perineural scar tissue has been considered responsible for recurrent neurological symptoms in patients operated on for disc herniation and leads to a high rate of unsatisfactory results . In addition , postoperative scars may increase the technical difficulty and risk of subsequent procedures . Various material s have been used in animal studies to try to affect the degree of epidural scar tissue with controversial results . In particular , free fat transplantation has been described to reduce the degree of intraspinal scar tissue . We therefore performed a prospect i ve , double-blind , r and omized study comparing clinical and social factors of patients being operated on for the first time for lumbar disc herniation . A total of 92 patients received an implantation of autologous fat graft , 94 did not .  After a median of 
    Output:
    
However , other trials show that discectomy produces better clinical outcomes than chemonucleolysis and that in turn is better than placebo .
Microdiscectomy gives broadly comparable results to  st and ard discectomy .
Recent trials of an inter-position gel covering the dura ( five trials ) and of fat ( four trials ) show that they can reduce scar formation , though there is limited evidence about the effect on clinical outcomes .
There is insufficient evidence on other percutaneous discectomy techniques to draw firm conclusions .
AUTHORS ' CONCLUSIONS Surgical discectomy for carefully selected patients with sciatica due to lumbar disc prolapse provides faster relief from the acute attack than conservative management , although any positive or negative effects on the lifetime natural history of the underlying disc disease are still unclear .
Microdiscectomy gives broadly comparable results to open discectomy .