***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*** 
    ***EXAMPLES*** 
    Input: Summary of Background Data . The Spine Patient Outcomes Research Trial ( SPORT ) was design ed to assess the relative efficacy and cost-effectiveness of  surgical and nonsurgical approaches to the treatment of common conditions associated with low back and leg pain . Objectives . To describe the rationale and design of the SPORT project and to discuss its strengths and limitations . Study Design . Descriptive . Methods . First , the authors explain the rationale for embarking on SPORT , i.e. , deficiencies in the existing scientific knowledge base for treatment of these conditions . Second , the authors describe the design of SPORT , including topics such as specific aims , participating sites , study population , recruitment and enrollment , study interventions , follow-up , outcomes , statistical analysis , and study governance and organization . Finally , issues that complicate the performance of r and omized trials in surgery as they relate to the design and conduct of SPORT are discussed . Results . The SPORT project is being conducted at 11 clinical centers around the United States . It involves the simultaneous conduct of three multicenter , r and omized , controlled clinical trials . The study includes patients with the three most common diagnoses for which spine surgery is performed : intervertebral disc herniation , spinal stenosis , and degenerative spondylolisthesis , and it compares the most commonly used st and ard surgical and nonsurgical treatments for patients with these diagnoses . By the end of enrollment the authors anticipate a total of 500 patients with intervertebral disc herniation , 370 patients with spinal stenosis , and 300 patients with degenerative spondylolisthesis in the r and omized trials . Patients who meet the eligibility criteria but decline to be r and omized are invited to participate in an observational cohort study . Patients are being followed for a minimum of 24 months with visits scheduled at 6 weeks and at 3 , 6 , 12 , and 24 months . Conclusions . The results of this study will provide high- quality scientific evidence to aid clinical decision-making and improve treatment outcomes for these common , costly , and , in some instances , debilitating conditions Pragmatic trials are important for informing routine clinical practice , but current design s have shortcomings . Clare Relton and colleagues outline the new “ cohort multiple r and omised controlled trial ” design , which could help address the problems associated with existing BACKGROUND Percutaneous radiofrequency thermocoagulation of the trigeminal ganglion ( PRTTG ) is regarded as the first choice for most patients with trigeminal neuralgia ( TN ) because of its safety and feasibility . However , neuronavigator-guided PRTTG has been seldom reported . The purpose of this study was to assess the safety and efficacy of neuronavigator-guided PRTTG for the treatment of intractable TN . METHODS Between January 2000 and December 2004 , 54 patients with intractable TN were enrolled into this study and were r and omly divided into two groups . The patients in navigation group ( n = 26 ) underwent PRTTG with frameless neuronavigation , and those in control group ( n = 28 ) received PRTTG without neuronavigation . Three months after the operation , the efficacy , side effects , and complications of the surgery were recorded . The patients in the control group were followed up for 10 to 54 months ( mean , 34 + /- 5 ) , and those in the navigation group were followed up for 13 to 58 months ( mean , 36 + /- 7 ) . Kaplan-Meier analyses of the pain-free survival curves were used for the censored survival data , and the log-rank test was used to compare survival curves of the two groups . RESULTS The immediate complete pain-relief rate of the navigation group was 100 % , whereas it was 95 % in the control . The proportion of sustained pain-relief rates at 12 , 24 and 36 months after the procedure were 85 % , 77 % , and 62 % in the navigation group , and 54 % , 40 % , and 35 % in the control . Recurrences in the control group were more common than that in the navigation group . Annual recurrence rate in the first and second years were 15 % and 23 % in the navigation group , and 46 % , 60 % in the control group . No side-effect and complication was noted in the navigation group except minimal facial hypesthesia . CONCLUSION Neuronavigator-guided PRTTG is a safe and promising method for treatment of intractable TN with better short- and long-term outcomes and lower complication rate than PRTTG without neuronavigation Surgery and other invasive therapies are complex interventions , the assessment of which is challenged by factors that depend on operator , team , and setting , such as learning curves , quality variations , and perception of equipoise . We propose recommendations for the assessment of surgery based on a five-stage description of the surgical development process . We also encourage the widespread use of prospect i ve data bases and registries . Reports of new techniques should be registered as a professional duty , anonymously if necessary when outcomes are adverse . Case series studies should be replaced by prospect i ve development studies for early technical modifications and by prospect i ve research data bases for later pre-trial evaluation . Protocol s for these studies should be registered publicly . Statistical process control techniques can be useful in both early and late assessment . R and omised trials should be used whenever possible to investigate efficacy , but adequate pre-trial data are essential to allow power calculations , clarify the definition and indications of the intervention , and develop quality measures . Difficulties in doing r and omised clinical trials should be addressed by measures to evaluate learning curves and alleviate equipoise problems . Alternative prospect i ve design s , such as interrupted time series studies , should be used when r and omised trials are not feasible . Established procedures should be monitored with prospect i ve data bases to analyse outcome variations and to identify late and rare events . Achievement of improved design , conduct , and reporting of surgical research will need concerted action by editors , funders of health care and research , regulatory bodies , and professional societies OBJECT Stereotactic radiosurgery is an alternative to conventional surgery for the treatment of trigeminal neuralgia . The authors conducted a prospect i ve evaluation of the safety and efficacy of this method in a large series of patients . METHODS A total of 100 patients presenting with trigeminal neuralgia were treated and followed up for a minimum of 12 months . The mean age was 68.2 years ; 54 patients were male , and 46 were female . Seven had a history of multiple sclerosis , and 42 had already received conventional surgical treatment for trigeminal neuralgia . The intervention consisted of gamma knife surgery to the retrogasserian cisternal portion of the fifth cranial nerve . The median dose used at the maximum was 85 Gy ( range 70 - 90 Gy ) . The number and intensity of pain attacks were recorded by the patient from 3 months before radiosurgery to a minimum of 12 months after treatment . Before and a minimum of 12 months after treatment , the patient completed a quality -of-life question naire . Neurological examination and quantitative sensory testing to evaluate sensory perception were performed by an independent neurologist over this same time period . At the last visit 83 of 100 patients were reported to be pain free . Fifty-eight of these 83 patients had stopped taking medication during the study . All quality -of-life parameters were improved ( p < 0.001 ) . Six patients reported facial paresthesia , and four patients reported hypesthesia . These symptoms were classified as mild . None of the complications reported for other techniques were observed . CONCLUSIONS Radiosurgery is a safe and effective alternative treatment for trigeminal neuralgia and is associated with a particularly low rate of hypesthesia BACKGROUND The management of degenerative spondylolisthesis associated with spinal stenosis remains controversial . Surgery is widely used and has recently been shown to be more effective than nonoperative treatment when the results were followed over two years . Questions remain regarding the long-term effects of surgical treatment compared with those of nonoperative treatment . METHODS Surgical c and i date s from thirteen centers with symptoms of at least twelve weeks ' duration as well as confirmatory imaging showing degenerative spondylolisthesis with spinal stenosis were offered enrollment in a r and omized cohort or observational cohort . Treatment consisted of st and ard decompressive laminectomy ( with or without fusion ) or usual nonoperative care . Primary outcome measures were the Short Form-36 ( SF-36 ) bodily pain and physical function scores and the modified Oswestry Disability Index at six weeks , three months , six months , and yearly up to four years . RESULTS In the r and omized cohort ( 304 patients enrolled ) , 66 % of those r and omized to receive surgery received it by four years whereas 54 % of those r and omized to receive nonoperative care received surgery by four years . In the observational cohort ( 303 patients enrolled ) , 97 % of those who chose surgery received it whereas 33 % of those who chose nonoperative care eventually received surgery . The intent-to-treat analysis of the r and omized cohort , which was limited by nonadherence to the assigned treatment , showed no significant differences in treatment outcomes between the operative and nonoperative groups at three or four years . An as-treated analysis combining the r and omized and observational cohorts that adjusted for potential confounders demonstrated that the clinical ly relevant advantages of surgery that had been previously reported through two years were maintained at four years , with treatment effects of 15.3 ( 95 % confidence interval , 11 to 19.7 ) for bodily pain , 18.9 ( 95 % confidence interval , 14.8 to 23 ) for physical function , and -14.3 ( 95 % confidence interval , -17.5 to -11.1 ) for the Oswestry Disability Index . Early advantages ( at two years ) of surgical treatment in terms of the secondary measures of bothersomeness of back and leg symptoms , overall satisfaction with current symptoms , and self-rated progress were also maintained at four years . CONCLUSIONS Compared with patients who are treated nonoperatively , patients in whom degenerative spondylolisthesis and associated spinal stenosis are treated surgically maintain substantially greater pain relief and improvement in function for four years PURPOSE To test the hypothesis that increasing the nerve length within the treatment volume for trigeminal neuralgia radiosurgery would improve pain relief . METHODS AND MATERIAL S Eighty-seven patients with typical trigeminal neuralgia were r and omized to undergo retrogasserian gamma knife radiosurgery ( 75 Gy maximal dose with 4-mm diameter collimators ) using either one ( n = 44 ) or two ( n = 43 ) isocenters . The median follow-up was 26 months ( range 1 - 36 ) . RESULTS Pain relief was complete in 57 patients ( 45 without medication and 12 with low-dose medication ) , partial in 15 , and minimal in another 15 patients . The actuarial rate of obtaining complete pain relief ( with or without medication ) was 67.7 % + /- 5.1 % . The pain relief was identical for one- and two-isocenter radiosurgery . Pain relapsed in 30 of 72 responding patients . Facial numbness and mild and severe paresthesias developed in 8 , 5 , and 1 two-isocenter patients vs. 3 , 4 , and 0 one-isocenter patients , respectively ( p = 0.23 ) . Improved pain relief correlated with younger age ( p = 0.025 ) and fewer prior procedures ( p = 0.039 ) and complications ( numbness or paresthesias ) correlated with the nerve length irradiated ( p = 0.018 ) . CONCLUSIONS Increasing the treatment volume to include a longer nerve length for trigeminal neuralgia radiosurgery does not significantly improve pain relief but may increase complications The aim of this study was to prospect ively evaluate and compare the effects of radiofrequency thermocoagulation of the first division branches of the trigeminal nerve ( trigeminal peripheral division radiofrequency thermocoagulation , PRT ) versus conventional radiofrequency ( CRF ) in the treatment of first division idiopathic trigeminal neuralgia ( ITN ) . Fifty patients with first division ITN were r and omly divided into two groups . The 20 patients in group 1 were treated with CRF , while the remaining 30 patients in group 2 were treated using PRT . The immediate therapeutic effects , side effects and recurrence rate of idiopathic trigeminal neuralgia were evaluated . The immediate efficacy rates were 95 % and 93 % in groups 1 and 2 , respectively . The recurrence rates of ITN at the 3-year follow-up were 25 % and 27 % for group 1 and group 2 , respectively , and 35 % and 40 % , respectively , 5 years after treatment . There were no significant differences between groups 1 and 2 at any time . Our study demonstrates that PRT is an effective way to treat first division ITN The overall crude incidence rate of trigeminal neuralgia per 100,000 population in Rochester , Minnesota , for 1945 through 1984 was 4.3 for both sexes combined . The age‐adjusted ( to total 1980 US population ) rate for women ( 5.9 ) was significantly higher than that for men ( 3.4 ) . Annual incidence rates increased significantly with age in both women and men . Data based on evidence in the medical records suggest that trigeminal neuralgia is a rather rare and unpredictable disease : The number of episodes varies from 1 to 11 , and length of episode from 1 day to 4 years . This study indicates an elevated relative risk associated with hypertension ( both overall and among women in the cohort ) . Also , prevalence of multiple sclerosis was significantly greater among the group of 75 patients who had trigeminal neuralgia . Since the data on treatment in this study do not correspond to a r and omized clinical trial , they are presented as empirical results only and show no single treatment of choice for trig 
    Output:
    
Increased age and prior surgery were predictors for poorer pain relief .
Both techniques produced pain relief ( not significantly in favour of neuronavigation ( RR 0.70 , 95 % CI 0.46 to 1.04 ) but relief was more sustained and side effects fewer if a neuronavigation system was used .
There is very low quality evidence for the efficacy of most neurosurgical procedures for trigeminal neuralgia because of the poor quality of the trials .
All procedures produced variable pain relief , but many result ed in sensory side effects .
There were no studies of microvascular decompression which observational data suggests gives the longest pain relief .
There is little evidence to help comparative decision making about the best surgical procedure .