***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: The authors hypothesized that the placement of the interspinous implant would show a similar clinical outcome to the posterior lumbar interbody fusion ( PLIF ) in patients having spinal stenosis with mild segmental instability and that this method would be superior to PLIF without significantly affecting degeneration at the adjacent segments . Forty two adult patients having degenerative spinal stenosis with mild segmental instabilit who underwent implantation of Coflex ™ ( Spine motion , Germany ) or PLIF at L4 - 5 between January 2000 and December 2003 were consecutively selected and studied for one-year clinical outcome . At 12 months after surgery , both groups showed a significant improvement in the visual analogue scale score and Oswestry disability index score for both lower extremity pain and low back pain . However , the range of motion at the upper adjacent segments ( L3 - 4 ) increased significantly after surgery in the PLIF group , which was not manifested in the Coflex ™ group during the follow-up . The authors assumed that interspinous implantation can be an alternative treatment for the spinal stenosis with segmental instability in selected conditions posing less stress on the superior adjacent level than PLIF OBJECT To assess the safety and efficacy of the DIAM implant , the authors compared the mean 12-month outcomes in patients who underwent lumbar surgery with DIAM placement  and in those who underwent lumbar surgery only . METHODS Of 62 patients who underwent simple lumbar surgery ( laminectomy and /or microdiscectomy ) in a 24-month period , 31 underwent concomitant surgical placement of a DIAM interspinous process spacer  ( 33 devices total ) . Radiographic imaging , pain scores , and clinical assessment s were obtained postoperatively to a mean of 12 months ( range 8 - 25 months ) . Patients who did not undergo implantation of an interspinous process spacer ( Group C ) were compared with and stratified against patients who underwent placement of a DIAM implant ( Group D ) . In Group D , no statistically significant differences were noted in anterior or posterior disc height when comparing patients pre- and postoperatively . Compared with Group C , a relative kyphosis of less than 2 degrees was noted on postoperative images obtained in Group D. No statistically significant differences in visual analog scale ( VAS ) pain scores or MacNab outcomes were noted between Groups C and D at a mean of 12 months of follow up . Complications in Group D included three intraoperative spinous process fractures and one infection . CONCLUSIONS After simple lumbar surgery , the placement of a DIAM interspinous process spacer did not alter disc height or sagittal alignment at the mean 12-month follow-up interval . No adverse local or systemic reaction to the DIAM was noted . No difference in VAS or MacNab outcome scores was noted between the groups treated with or without the DIAM implants , particularly when the DIAM was used to alleviate low-back pain The authors report a series of 43 patients suffering from lower limb pain , almost constantly associated with chronic or acute backpain , treated by microsurgical nerve root decompression and by implantation of a soft intervertebral prothesis ( DIAM ) .  Satisfying results were obtained in 97 % of cases , inducing the authors to consider the device a reliable tool for curing low-back pain and sciatica . Selection criteria are exposed and discussed OBJECT This study was conducted to compare the quality of life ( QOL ) in patients with neurogenic intermittent claudication ( NIC ) secondary to lumbar spinal stenosis ( LSS ) . Using the 36-Item Short Form ( SF-36 ) question naire , the authors compared the results obtained in patients treated with the X STOP Interspinous Process Decompression ( IPD ) System with those obtained in patients who underwent nonoperative therapies . METHODS Patients with LSS were enrolled in a prospect i ve 2-year multicenter study and r and omized either to the X STOP or nonoperative group . The SF-36 survey was used to assess the QOL before treatment and at 6 weeks , 6 months , 1 year , and 2 years posttreatment . An analysis of variance was used to compare individual pre- and posttreatment mean SF-36 domain scores between the two groups and within each treatment group . At all posttreatment time points , the authors observed the following : ( 1 ) mean domain scores in X STOP-treated patients were significantly greater than those in patients treated nonoperatively , with the exception of the mean General Health ( GH ) , Role Emotional , and Mental Component Summary scores at 2 years ; and ( 2 ) mean posttreatment domain scores documented in X STOP-treated patients were significantly greater than mean pretreatment scores , with the exception of mean GH scores at 6 , 12 , and 24 months . CONCLUSIONS The results of this study demonstrate that the X STOP device is significantly more effective than nonoperative therapy in improving the QOL in patients with LSS . The results are comparable with those reported in other studies involving traditional decompressive techniques for LSS and suggest that the X STOP implant can provide an effective treatment compared with nonoperative and conventional surgical therapies Study Design . A r and omized , controlled , prospect i ve multicenter trial comparing the outcomes of neurogenic intermittent claudication ( NIC ) patients treated with the interspinous process decompression system ( X STOP ) with patients treated nonoperatively . Objective . To determine the safety and efficacy of the X STOP interspinous implant . Summary of Background Data . Patients suffering from NIC secondary to lumbar spinal stenosis have been limited to a choice between nonoperative therapies and decompressive surgical procedures , with or without fusion . The X STOP was developed to provide an alternative therapeutic treatment . Methods . 191 patients were treated , 100 in the X STOP group and 91 in the control group .  The primary outcomes measure was the Zurich Claudication Question naire , a patient-completed , vali date d instrument for NIC . Results . At every follow-up visit , X STOP patients had significantly better outcomes in each domain of the Zurich Claudication Question naire . At 2 years , the X STOP patients improved by 45.4 % over the mean baseline Symptom Severity score compared with 7.4 % in the control group ; the mean improvement in the Physical Function domain was 44.3 % in the X STOP group and −0.4 % in the control group . In the X STOP group , 73.1 % patients were satisfied with their treatment compared with 35.9 % of control patients . Conclusions . The X STOP provides a conservative yet effective treatment for patients suffering from lumbar spinal stenosis . In the continuum of treatment options , the X STOP offers an attractive alternative to both conservative care and decompressive surgery Abstract . A first-generation implant for non-rigid stabilization of lumbar segments was developed in 1986 . It included a titanium interspinous blocker and an artificial ligament made of dacron . Following an initial observational study in 1988 and a prospect i ve controlled study from 1988 to 1993 , more than 300 patients have been treated for degenerative lesions with this type of implant with clinical and mechanical follow-up . After careful analysis of the points that could be improved , a second-generation implant called the " Wallis " implant , was developed . This interspinous blocker , which was made of metal in the preliminary version , is made of PEEK ( polyetheretherketone ) in the new model . The overall implant constitutes a " floating " system , with no permanent fixation in the vertebral bone , to avoid the risk of loosening . It achieves an increase in the rigidity of destabilized segments beyond normal values . The clinical trials of the first-generation implant provided evidence that the interspinous system of non-rigid stabilization is efficacious against low-back pain due to degenerative instability and free of serious complications . The first-generation devices achieved marked , significant resolution of residual low-back pain . These results warrant confirmation . A r and omized clinical trial and an observational study of the new implant are currently underway . Non-rigid fixation clearly appears to be a useful technique in the management of initial forms of degenerative intervertebral lumbar disc disease . This method should rapidly assume a specific role along with total disc prostheses in the new step-wise surgical strategy to obviate definitive fusion of degenerative intervertebral segments . At present , the Wallis system is recommended for lumbar disc disease in the following indications : ( i ) discectomy for massive herniated disc leading to substantial loss of disc material , ( ii ) a second discectomy for recurrence of herniated disc , ( iii ) discectomy for herniation of a transitional disc with sacralization of L5 , ( iv ) degenerative disc disease at a level adjacent to a previous fusion , and ( v ) isolated Modic I lesion leading to chronic low-back pain A technique is described for widening the lumbar vertebral canal in the treatment of lumbar stenosis . This method , which preserves part of the posterior arches , has the aim of avoiding the instability which accompanies extensive laminectomies of the whole lumbar spine . The preservation of the posterior arches allows a ligamentoplasty to be made with dacron in stable spines and a combined fusion with internal fixation applied to the posterior arches to be made in cases of spondylolisthesis . The results of a prospect i ve series of 32 patients have confirmed the effectiveness of the method both on the stenosis and on the post-operative spinal stability Study Design A prospect i ve cohort study of patients with lumbar spinal stenosis recruited from the practice s of orthopedic surgeons and neurosurgeons throughout Maine . Objective To assess 1‐year outcomes of patients with lumbar spinal stenosis treated surgically or nonsurgically .  Summary of Background Data No r and omized trials and few nonexperimental studies have compared surgical and nonsurgical treatment of patients with lumbar spinal stenosis . The authors ' goal was to assess 1‐year outcomes of patients with lumbar spinal stenosis treated surgically or nonsurgically . Methods Eligible , consenting patients participated in baseline interviews and were then mailed follow‐up question naires at 3 , 6 , and 12 months . Clinical data were obtained from a physician question naire . Outcomes included patient‐reported symptoms of leg and back pain , functional status , disability , and satisfaction with care . Results One hundred forty‐eight patients with lumbar spinal stenosis were enrolled , of whom 81 were treated surgically and 67 treated nonsurgically . On average , patients in the surgical group had more severe imaging findings and symptoms and worse functional status than patients in the nonsurgical group at entry . Few patients with mild symptoms were treated surgically , and few patients with severe symptoms were treated nonsurgically . However , of the patients with moderate symptoms , a similar percent were treated surgically or nonsurgically . One year after study entry , 28 % of nonsurgically and 55 % of surgically treated patients reported definite improvement in their predominant symptoms ( P = 0.003 ) . For patients with moderate symptoms , outcomes for surgically treated patients were also improved compared with those of nonsurgically treated patients . Surgicla treatment remained a significant determinant of 1‐year outcome , even after adjustment for differences between treatment groups at entry ( P = 0.05 ) . The maximal benefit of surgery was observed by the time of the first follow‐up evaluation , which was at 3 months . Although few nonsurgically treated patients experienced a worsening of their condition , there was little improvement in symptoms and functional status compared with study entry . Conclusions At a 1‐year evaluation of patient‐reported outcomes , patients with severe lumbar spinal stenosis who were treated surgically had greater improvement than patients treated nonsurgically . Comparisons of outcomes by treatment received must be made cautiously because of differences in baseline characteristics . A determination of whether the outcomes observed persist requires long‐term follow‐up Background Lumbar spinal stenosis ( LSS ) is often a position-dependent condition that is aggravated in extension and relieved in flexion . Methods Ten consecutive elderly patients with LSS were assessed postoperatively by magnetic resonance imaging and the Swiss Spinal Stenosis Question naire . Cross-sectional areas of the dural sac and intervertebral foramina at the stenotic level were measured postoperatively and compared with the preoperative values . Results Postoperatively the cross-sectional area of the dural sac increased 16.6 mm2 or 22.3 % and intervertebral foramina increased 22 mm2 or 36.5 % . The intervertebral angle and the posterior disc height changed significantly . Seventy percent of the patients were satisfied with the surgical outcome . Conclusion This new surgical method is effective in elderly LSS patients STUDY DESIGN A prospect i ve cohort study of patients with lumbar spinal stenosis recruited from the practice s of orthopedic surgeons and neurosurgeons throughout Maine . OBJECTIVE To assess 4-year outcomes for patients with lumbar spinal stenosis treated surgically or nonsurgically .  SUMMARY OF BACKGROUND DATA Surgery for lumbar spinal stenosis has increased dramatically despite the lack of r and omized trials comparing surgical with nonsurgical treatments . Long-term evaluation of surgical series has documented deterioration in initial symptomatic improvement , but few studies have compared long-term outcomes of surgical and nonsurgical treatment . METHODS Eligible , consenting patients had baseline interviews with mailed follow-up question naires at 3 , 6 , and 12 months , then annually thereafter . Clinical data were obtained at baseline from a physician question naire . Outcomes included patient-reported symptoms of leg and back pain , functional status , and satisfaction . RESULTS Of 148 patients with lumbar spinal stenosis initially enrolled , 4-year outcomes were available on 119 patients ( 80.4 % ) : 67 of 81 ( 83 % ) treated surgically and 52 of 67 ( 78 % ) treated nonsurgically . The surgically treated patients had more severe symptoms 
    Output:
    
The biomechanical studies with all the devices showed that ISPs have a beneficial effect on the kinematics of the degenerative spine .
Studies on the other devices show satisfactory outcome to varying degrees .
However , due to small number and poor design of the studies , it is difficult to clearly define indications for their use in lumbar degenerative disease .
Lumbar ISPs may have a potential beneficial effect in select group of patients with degenerative disease of the lumbar spine .