human
***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: Study Design . Prospect i ve longitudinal study with a minimum 2-year follow-up . Objective . To assess the long-term outcome of a group of patients with chronic discogenic low back pain who had failed to improve with comprehensive nonoperative care and who were subsequently treated with intradiscal electrothermal therapy ( IDET ) .  Summary of Background Data . Previous reports of patient outcomes at 1 year after IDET have demonstrated statistically significant improvement . Methods . The study group comprised 58 patients with chronic symptoms of more than 6 months who failed to improve with nonoperative care and subsequently underwent IDET .  VAS pain scores , SF-36 scores , and sitting tolerance times were collected pretreatment and at 6 , 12 , and 24 months . Results . Mean duration of pre-IDET symptoms was 60.7 months . The minimum follow-up at data collection was 24 months . The study group ( n = 58 ) demonstrated a significant improvement in pain as demonstrated by statistically significant improvement in VAS scores and bodily pain SF-36 scores . The IDET-treated group demonstrated a significant improvement in physical function as noted by statistically significant improvement in sitting tolerance times and physical function SF-36 scores . Bodily pain and physical function scores demonstrated significant improvement between the 1- and 2-year observation points . Additionally , quality of life improvement was demonstrated by a statistically significant improvement in all the SF-36 subscales . Conclusions . A cohort of patients with chronic discogenic low back pain who had failed to improve with comprehensive nonoperative care demonstrated a statistically significant improvement in pain , physical function , and quality of life at 2 years after IDET 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 . A prospect i ve double-blind r and omized trial in 28 patients . Objectives . To assess the clinical effect of percutaneous intradiscal radiofrequency thermocoagulation for reducing pain , functional disability , and physical impairment in patients with chronic discogenic low back pain . Summary of Background Data . Chronic discogenic low back pain is a challenging problem in western countries . A treatment option is radiofrequency heating of the affected disc . Its clinical efficacy has never been formally tested in a controlled trial . Methods . Twenty-eight patients with a history of at least 1 year of chronic low back pain were selected on the basis of a diagnostic anesthetization of the lower intervertebral discs . Only patients with one putative painful level were selected and r and omly assigned to one of two treatment groups . Each patient in the radiofrequency treatment group ( n = 13 ) received a 90-second 70 C lesion of the intervertebral disc . Patients in the control group ( n = 15 ) underwent the same procedure , but without use of radiofrequency current . Both the treating physician and the patients were blinded to the group assignment . Before treatment , physical impairment , rating of pain , the degree of disability , and quality of life were assessed by a blinded investigator . Results . Eight weeks after treatment , there was one success in the radiofrequency group ( n = 13 ) and two in the control group ( n = 15 ) . The adjusted and unadjusted odds ratio was 0.5 and 1.1 , respectively ( not significant ) . Also , visual analog scores for pain , global perceived effect , and the Oswestry disability scale showed no differences between the two groups . Conclusions . Percutaneous intradiscal radiofrequency thermocoagulation ( 90 seconds , 70 C ) is not effective in reducing chronic discogenic low back pain Study Design . A prospect i ve , r and omized , multicenter , Food and Drug Administration-regulated Investigational Device Exemption clinical trial . Objective . To evaluate the safety and effectiveness of the ProDisc ® -L ( Synthes Spine , West Chester , PA ) lumbar total disc replacement compared to circumferential spinal fusion for the treatment of discogenic pain at 1 vertebral level between L3 and S1 . Summary of Background Data . As part of the Investigational Device Exemption clinical trial , favorable single center results of lumbar total disc replacement with the ProDisc ® -L have been reported previously . Methods . Two hundred eighty-six ( 286 ) patients were treated on protocol . Patients were evaluated before and after surgery , at 6 weeks , 3 , 6 , 12 , 18 , and 24 months . Evaluation at each visit included patient self- assessment s , physical and neurologic examinations , and radiographic evaluation . Results . Safety of ProDisc ® -L implantation was demonstrated with 0 % major complications . At 24 months , 91.8 % of investigational and 84.5 % of control patients reported improvement in the Oswestry Low Back Pain Disability Question naire ( Oswestry Disability Index [ ODI ] ) from preoperative levels , and 77.2 % of investigational and 64.8 % of control patients met the ≥15 % Oswestry Disability Index improvement criteria . Overall neurologic success in the investigational group was superior to the control group ( 91.2 % investigational and 81.4 % control ; P = 0.0341 ) . At 6 weeks and 3 months follow-up time points , the ProDisc ® -L patients recorded SF-36 Health Survey scores significantly higher than the control group ( P = 0.018 , P = 0.0036 , respectively ) . The visual analog scale pain assessment showed statistically significant improvement from preoperative levels regardless of treatment ( P < 0.0001 ) . Visual analog scale patient satisfaction at 24 months showed a statistically significant difference favoring investigational patients over the control group ( P = 0.015 ) . Radiographic range of motion was maintained within a normal functional range in 93.7 % of investigational patients and averaged 7.7 ° . Conclusions . ProDisc ® -L has been found to be safe and efficacious . In properly chosen patients , ProDisc ® -L has been shown to be superior to circumferential fusion by multiple clinical criteria OBJECT The authors report the results of a prospect i ve r and omized multicenter study in which the results of cervical disc arthroplasty were compared with anterior cervical discectomy and fusion ( ACDF ) in patients treated for symptomatic single-level cervical degenerative disc disease ( DDD ) . METHODS Five hundred forty-one patients with single-level cervical DDD and radiculopathy were enrolled at 32 sites and r and omly assigned to one of two treatment groups : 276 patients in the investigational group underwent anterior cervical discectomy and decompression and arthroplasty with the PRESTIGE ST Cervical Disc System ( Medtronic Sofamor Danek ) ;  265 patients in the control group underwent decompressive ACDF . Eighty percent of the arthroplasty-treated patients ( 223 of 276 ) and 75 % of the control patients ( 198 of 265 ) completed clinical and radiographic follow-up examinations at routine intervals for 2 years after surgery . Analysis of all currently available postoperative 12- and 24-month data indicated a two-point greater improvement in the neck disability index score in the investigational group than the control group . The arthroplasty group also had a statistically significant higher rate of neurological success ( p = 0.005 ) as well as a lower rate of secondary revision surgeries ( p = 0.0277 ) and supplemental fixation ( p = 0.0031 ) . The mean improvement in the 36-Item Short Form Health Survey Physical Component Summary scores was greater in the investigational group at 12 and 24 months , as was relief of neck pain . The patients in the investigational group returned to work 16 days sooner than those in the control group , and the rate of adjacent-segment reoperation was significantly lower in the investigational group as well ( p = 0.0492 , log-rank test ) . The cervical disc implant maintained segmental sagittal angular motion averaging more than 7 degrees . In the investigational group , there were no cases of implant failure or migration . CONCLUSIONS The PRESTIGE ST Cervical Disc System maintained physiological segmental motion at 24 months after implantation and was associated with improved neurological success , improved clinical outcomes , and a reduced rate of secondary surgeries compared with ACDF Study Design . This was a prospect i ve multicenter clinical trial of a lumbar interbody fusion cage with a minimum of 4 years ’ follow-up . Objectives . To determine whether the early positive clinical results in fusions with lumbar cages , such as the Bagby and Kuslich ( BAK ) cage , are maintained beyond 2 years . Summary of Background Data . Threaded cages have been used increasingly for the treatment of symptomatic degenerative intervertebral disc disease . Concerns about the long-term clinical outcomes of this procedure have been posed , particularly regarding bony fusion viability , revision rates , potential adjacent level disease , and late complications . Methods . The study cohort was a 196-patient subset from a prospect i ve investigational device exemption . In addition to early postoperative examinations , these patients were examined biannually with a minimum of 4 years ’ follow-up . Patient outcome was assessed by a 6-point scale that evaluated pain relief , and functional improvement was determined by changes in activities of daily living . Fusion rates and return to work were determined . Complications and secondary operations were reported and categorized as non – device related or device related . Results . The patient cohort with 4-year follow-up represented 25.6 % of the original study population eligible at that time . Overall , the largest percentage of pain relief and functional improvements occurred by 3 months , and these improvements were maintained at each follow-up . Overall fusion rate was 91.7 % and 95.1 % at 2 and 4 years , respectively . In this cohort , 39.5 % of patients were working or were able to work within 3 months of surgery . After 4 years , 62.7 % of patients were gainfully employed or able to work . The late-occurring complication rate in this cohort was 13.8 % ( 27/196 ) . Complications necessitating a second operation occurred in 8.7 % ( 17/196 ) , whereas reoperations that were deemed device related were performed in 3.1 % ( 6/196 ) . Conclusions . This study indicates that the early positive benefits of interbody fusion cage procedures are maintained through 4 years with acceptably low morbidity Study Design . Prospect i ve nonr and omized clinical series . Objectives . To evaluate the efficacy of ProDisc lumbar artificial disc replacement ( ADR ) in smokers versus nonsmokers . Summary of Background Data . Smoking is a negative predictor in fusion surgery . To date , a prospect i ve study of the treatment of incapacitating discogenic low back pain using ADR in smokers versus nonsmokers has not been described . Methods . A prospect i ve analysis was performed on 104 patients with disabling discogenic low back pain treated with single-level lumbar ProDisc total disc arthroplasty . Smokers and nonsmokers were assessed before surgery and after surgery using patient satisfaction , Oswestry , and Visual Analog Scores . Additionally , preoperative and postoperative neurologic , radiographic , and pain medication assessment s were performed at 
    Output:
    
agent
RESULTS The results of this review confirm and help quantify the significant differences that existed in the terminology and all the areas of diagnosis and treatment of presumed discogenic pain .
Our findings show that suspected discogenic pain , despite its extensive affirmation in the literature and enormous re sources regularly devoted to it , currently lacks clear diagnostic criteria and uniform treatment or terminology
***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: Study Design . Prospect i ve longitudinal study with a minimum 2-year follow-up . Objective . To assess the long-term outcome of a group of patients with chronic discogenic low back pain who had failed to improve with comprehensive nonoperative care and who were subsequently treated with intradiscal electrothermal therapy ( IDET ) .  Summary of Background Data . Previous reports of patient outcomes at 1 year after IDET have demonstrated statistically significant improvement . Methods . The study group comprised 58 patients with chronic symptoms of more than 6 months who failed to improve with nonoperative care and subsequently underwent IDET .  VAS pain scores , SF-36 scores , and sitting tolerance times were collected pretreatment and at 6 , 12 , and 24 months . Results . Mean duration of pre-IDET symptoms was 60.7 months . The minimum follow-up at data collection was 24 months . The study group ( n = 58 ) demonstrated a significant improvement in pain as demonstrated by statistically significant improvement in VAS scores and bodily pain SF-36 scores . The IDET-treated group demonstrated a significant improvement in physical function as noted by statistically significant improvement in sitting tolerance times and physical function SF-36 scores . Bodily pain and physical function scores demonstrated significant improvement between the 1- and 2-year observation points . Additionally , quality of life improvement was demonstrated by a statistically significant improvement in all the SF-36 subscales . Conclusions . A cohort of patients with chronic discogenic low back pain who had failed to improve with comprehensive nonoperative care demonstrated a statistically significant improvement in pain , physical function , and quality of life at 2 years after IDET 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 . A prospect i ve double-blind r and omized trial in 28 patients . Objectives . To assess the clinical effect of percutaneous intradiscal radiofrequency thermocoagulation for reducing pain , functional disability , and physical impairment in patients with chronic discogenic low back pain . Summary of Background Data . Chronic discogenic low back pain is a challenging problem in western countries . A treatment option is radiofrequency heating of the affected disc . Its clinical efficacy has never been formally tested in a controlled trial . Methods . Twenty-eight patients with a history of at least 1 year of chronic low back pain were selected on the basis of a diagnostic anesthetization of the lower intervertebral discs . Only patients with one putative painful level were selected and r and omly assigned to one of two treatment groups . Each patient in the radiofrequency treatment group ( n = 13 ) received a 90-second 70 C lesion of the intervertebral disc . Patients in the control group ( n = 15 ) underwent the same procedure , but without use of radiofrequency current . Both the treating physician and the patients were blinded to the group assignment . Before treatment , physical impairment , rating of pain , the degree of disability , and quality of life were assessed by a blinded investigator . Results . Eight weeks after treatment , there was one success in the radiofrequency group ( n = 13 ) and two in the control group ( n = 15 ) . The adjusted and unadjusted odds ratio was 0.5 and 1.1 , respectively ( not significant ) . Also , visual analog scores for pain , global perceived effect , and the Oswestry disability scale showed no differences between the two groups . Conclusions . Percutaneous intradiscal radiofrequency thermocoagulation ( 90 seconds , 70 C ) is not effective in reducing chronic discogenic low back pain Study Design . A prospect i ve , r and omized , multicenter , Food and Drug Administration-regulated Investigational Device Exemption clinical trial . Objective . To evaluate the safety and effectiveness of the ProDisc ® -L ( Synthes Spine , West Chester , PA ) lumbar total disc replacement compared to circumferential spinal fusion for the treatment of discogenic pain at 1 vertebral level between L3 and S1 . Summary of Background Data . As part of the Investigational Device Exemption clinical trial , favorable single center results of lumbar total disc replacement with the ProDisc ® -L have been reported previously . Methods . Two hundred eighty-six ( 286 ) patients were treated on protocol . Patients were evaluated before and after surgery , at 6 weeks , 3 , 6 , 12 , 18 , and 24 months . Evaluation at each visit included patient self- assessment s , physical and neurologic examinations , and radiographic evaluation . Results . Safety of ProDisc ® -L implantation was demonstrated with 0 % major complications . At 24 months , 91.8 % of investigational and 84.5 % of control patients reported improvement in the Oswestry Low Back Pain Disability Question naire ( Oswestry Disability Index [ ODI ] ) from preoperative levels , and 77.2 % of investigational and 64.8 % of control patients met the ≥15 % Oswestry Disability Index improvement criteria . Overall neurologic success in the investigational group was superior to the control group ( 91.2 % investigational and 81.4 % control ; P = 0.0341 ) . At 6 weeks and 3 months follow-up time points , the ProDisc ® -L patients recorded SF-36 Health Survey scores significantly higher than the control group ( P = 0.018 , P = 0.0036 , respectively ) . The visual analog scale pain assessment showed statistically significant improvement from preoperative levels regardless of treatment ( P < 0.0001 ) . Visual analog scale patient satisfaction at 24 months showed a statistically significant difference favoring investigational patients over the control group ( P = 0.015 ) . Radiographic range of motion was maintained within a normal functional range in 93.7 % of investigational patients and averaged 7.7 ° . Conclusions . ProDisc ® -L has been found to be safe and efficacious . In properly chosen patients , ProDisc ® -L has been shown to be superior to circumferential fusion by multiple clinical criteria OBJECT The authors report the results of a prospect i ve r and omized multicenter study in which the results of cervical disc arthroplasty were compared with anterior cervical discectomy and fusion ( ACDF ) in patients treated for symptomatic single-level cervical degenerative disc disease ( DDD ) . METHODS Five hundred forty-one patients with single-level cervical DDD and radiculopathy were enrolled at 32 sites and r and omly assigned to one of two treatment groups : 276 patients in the investigational group underwent anterior cervical discectomy and decompression and arthroplasty with the PRESTIGE ST Cervical Disc System ( Medtronic Sofamor Danek ) ;  265 patients in the control group underwent decompressive ACDF . Eighty percent of the arthroplasty-treated patients ( 223 of 276 ) and 75 % of the control patients ( 198 of 265 ) completed clinical and radiographic follow-up examinations at routine intervals for 2 years after surgery . Analysis of all currently available postoperative 12- and 24-month data indicated a two-point greater improvement in the neck disability index score in the investigational group than the control group . The arthroplasty group also had a statistically significant higher rate of neurological success ( p = 0.005 ) as well as a lower rate of secondary revision surgeries ( p = 0.0277 ) and supplemental fixation ( p = 0.0031 ) . The mean improvement in the 36-Item Short Form Health Survey Physical Component Summary scores was greater in the investigational group at 12 and 24 months , as was relief of neck pain . The patients in the investigational group returned to work 16 days sooner than those in the control group , and the rate of adjacent-segment reoperation was significantly lower in the investigational group as well ( p = 0.0492 , log-rank test ) . The cervical disc implant maintained segmental sagittal angular motion averaging more than 7 degrees . In the investigational group , there were no cases of implant failure or migration . CONCLUSIONS The PRESTIGE ST Cervical Disc System maintained physiological segmental motion at 24 months after implantation and was associated with improved neurological success , improved clinical outcomes , and a reduced rate of secondary surgeries compared with ACDF Study Design . This was a prospect i ve multicenter clinical trial of a lumbar interbody fusion cage with a minimum of 4 years ’ follow-up . Objectives . To determine whether the early positive clinical results in fusions with lumbar cages , such as the Bagby and Kuslich ( BAK ) cage , are maintained beyond 2 years . Summary of Background Data . Threaded cages have been used increasingly for the treatment of symptomatic degenerative intervertebral disc disease . Concerns about the long-term clinical outcomes of this procedure have been posed , particularly regarding bony fusion viability , revision rates , potential adjacent level disease , and late complications . Methods . The study cohort was a 196-patient subset from a prospect i ve investigational device exemption . In addition to early postoperative examinations , these patients were examined biannually with a minimum of 4 years ’ follow-up . Patient outcome was assessed by a 6-point scale that evaluated pain relief , and functional improvement was determined by changes in activities of daily living . Fusion rates and return to work were determined . Complications and secondary operations were reported and categorized as non – device related or device related . Results . The patient cohort with 4-year follow-up represented 25.6 % of the original study population eligible at that time . Overall , the largest percentage of pain relief and functional improvements occurred by 3 months , and these improvements were maintained at each follow-up . Overall fusion rate was 91.7 % and 95.1 % at 2 and 4 years , respectively . In this cohort , 39.5 % of patients were working or were able to work within 3 months of surgery . After 4 years , 62.7 % of patients were gainfully employed or able to work . The late-occurring complication rate in this cohort was 13.8 % ( 27/196 ) . Complications necessitating a second operation occurred in 8.7 % ( 17/196 ) , whereas reoperations that were deemed device related were performed in 3.1 % ( 6/196 ) . Conclusions . This study indicates that the early positive benefits of interbody fusion cage procedures are maintained through 4 years with acceptably low morbidity Study Design . Prospect i ve nonr and omized clinical series . Objectives . To evaluate the efficacy of ProDisc lumbar artificial disc replacement ( ADR ) in smokers versus nonsmokers . Summary of Background Data . Smoking is a negative predictor in fusion surgery . To date , a prospect i ve study of the treatment of incapacitating discogenic low back pain using ADR in smokers versus nonsmokers has not been described . Methods . A prospect i ve analysis was performed on 104 patients with disabling discogenic low back pain treated with single-level lumbar ProDisc total disc arthroplasty . Smokers and nonsmokers were assessed before surgery and after surgery using patient satisfaction , Oswestry , and Visual Analog Scores . Additionally , preoperative and postoperative neurologic , radiographic , and pain medication assessment s were performed at 
    Output:
    