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: Purpose This multicenter clinical study was performed to assess the safety and effectiveness of Trinity Evolution ® ( TE ) , a viable cellular bone allograft , in combination with a PEEK interbody spacer and supplemental anterior fixation in patients undergoing anterior cervical discectomy and fusion ( ACDF ) . Methods In a prospect i ve , multi-center study , 31 patients that presented with symptomatic cervical degeneration at one vertebral level underwent ACDF with a PEEK interbody spacer ( Orthofix , Inc. , Lewisville , TX , USA ) and supplemental anterior fixation . In addition all patients had the bone graft substitute , Trinity Evolution ( Musculoskeletal Transplant Foundation , Edison , NJ , USA ) , placed within the interbody spacer . At 6 and 12 months , radiographic fusion was evaluated as determined by independent radiographic review of angular motion ( ≤4 ° ) from flexion/extension X-rays combined with presence of bridging bone across the adjacent endplates on thin cut CT scans . In addition other metrics were measured including function as assessed by the Neck Disability Index ( NDI ) , and neck and arm pain as assessed by individual Visual Analog Scales ( VAS ) . Results The fusion rate for patients using a PEEK interbody spacer in combination with TE was 78.6 % at 6 months and 93.5 % at 12 months . When considering high risk factors , 6-month fusion rates for patients that were current or former smokers , diabetic , overweight or obese/extremely obese were 70 % ( 7/10 ) , 100 % ( 1/1 ) , 70 % ( 7/10 ) , and 82 % ( 9/11 ) , respectively . At 12 months , the fusion rates were 100 % ( 12/12 ) , 100 % ( 2/2 ) , 100 % ( 11/11 ) and 85 % ( 11/13 ) , respectively . Neck function , and neck/arm pain were found to significantly improve at both time points . No serious allograft related adverse events occurred and none of the 31 patients had subsequent additional cervical surgeries . Conclusions Patients undergoing single-level ACDF with TE in combination with a PEEK interbody spacer and supplemental anterior fixation had a high rate of fusion success without serious allograft-related adverse events Study Design . Prospect i ve , multicenter , nonr and omized , institutional review board-approved clinical and radiographic study . Objective . To evaluate and summarize the 2-year outcomes of patients treated with Osteocel Plus cellular allograft as part of an anterior cervical discectomy and fusion procedure . Summary of Background Data . Osteocel Plus is an allograft cellular bone matrix containing native mesenchymal stem cells and osteoprogenitor cells that is intended to mimic the performance of iliac crest autograft without the morbidity associated with its harvest . Methods . A total of 182 patients were treated with anterior cervical discectomy and fusion using Osteocel Plus in a polyetheretherketone cage and anterior plating at 1 or 2 consecutive levels . Clinical outcomes included visual analogue scale for neck and arm pain , neck disability index , and SF-12 physical and mental component scores . Computed tomography and plain film radiographic measures included assessment of bridging bone , disc height , disc angle , and segmental range of motion . Results . A total of 249 levels were treated in 182 patients .  Mean procedure time was 100 minutes , blood loss was less than 50 mL in 93 % of patients , and hospital stay was 1 day or less in 84 % of patients . Significant ( P < 0.05 ) average improvements in clinical outcomes from preoperatively to 24 months included the following : neck disability index : 21.5 % ; visual analogue scale neck : 34 mm ; visual analogue scale arm : 35 mm ; SF-12 physical component score : 11.2 ; SF-12 mental component score : 6.8 . At 24 months , 93 % of patients were satisfied with their outcome . In patients treated at a single level with a minimum of 24-month follow-up , 92 % ( 79/86 ) of levels achieved solid bridging and 95 % of levels demonstrated range of motion of less than 3 ° . In combined single- and 2-level procedures , 87 % ( 157/180 ) of levels achieved solid bridging and 92 % ( 148/161 ) had range of motion of less than 3 ° at 24 months . No patient required revision for pseudarthrosis . Conclusion . Improvements in clinical results at 2 years , high patient satisfaction , and high radiographic and clinical fusion rates provide confidence in Osteocel Plus as an effective alternative to structural allograft or autograft in anterior cervical discectomy and fusion procedures . Level of Evidence : BACKGROUND CONTEXT Anterior cervical discectomy and fusion ( ACDF ) using autogenous iliac bone graft may lead to donor-site morbidity . This has led some surgeons to use alternatives to iliac bone graft , but often the alternatives have greater rates of nonunion and delayed union . Bone morphogenic protein ( BMP ) studies have found high arthrodesis rates in lumbar fusions . PURPOSE The objective of this pilot study was to compare the success of BMP combined with bone allograft with iliac bone autograft in ACDF patients . STUDY DESIGN / SETTING The institutional review board approved a prospect i ve but nonr and omized study of 66 consecutive patients who had primary one- to three-level ACDF with either iliac-crest bone autograft or BMP allograft ( 0.9 mg BMP per level ) followed prospect ively over a 2- to 3-year period . PATIENT SAMPLE Consecutive patients who had primary one- to three-level ACDF with either iliac-crest bone autograft ( n=36 ) or BMP-allograft ( n=30 ) . Patients in both iliac bone graft and BMP-allograft groups had comparable preoperative pain and disability . OUTCOME MEASURES Visual analog scale pain , pain drawing , Oswestry index , pain medication use , opinion of treatment success , and neurological recovery . RESULTS Given the nonr and omized nature of the study , the study groups were not matched . Within this limitation , both groups of patients had similar improvement in all outcome scales ( visual analog scale pain , pain drawing , Oswestry index , pain medication use , and opinion of treatment success ) and neurological recovery over the 2- to 3-year follow-up period . Patients in the iliac bone graft group had two pseudarthroses and two complications of the iliac-crest donor site . In the BMP-allograft group , one patient had a pseudarthrosis , but 50 % had neck swelling presenting as dysphagia , which was substantially more common than the 14 % present in the iliac bone graft group . Patients in the BMP-allograft group had slightly shorter surgery time , but implant and hospitalization costs were higher . CONCLUSIONS ACDF performed with BMP ( 0.9 mg BMP per level ) allograft is as effective as iliac bone graft in terms of patient outcomes and fusion rates . Safety concerns related to neck swelling and higher initial costs were associated with patients in the bone morphogenic protein group Study Design Prospect i ve r and omized noninferiority trial . Purpose To evaluate whether the union rate of anterior cervical discectomy and fusion ( ACDF ) using a polyetheretherketone ( PEEK ) cage filled with a mixture of hydroxyapatite ( HA ) and demineralized bone matrix ( DBM ) is inferior to that of a mixture of β-tricalcium phosphate ( β-TCP ) and HA . Overview of Literature There have been no clinical trials investigating the outcomes of a mixture of HA and DBM in a PEEK cage in ACDF . Methods Eighty-five eligible patients were r and omly assigned to group B ( n=43 ) , in which a PEEK cage with a mixture of HA and DBM was used , or group C ( n=42 ) , in which a PEEK cage with a mixture of HA and β-TCP was used . The primary study endpoint was the fusion rate , which was assessed with dynamic radiographs and computed tomography ( CT ) scans . Secondary endpoints included pain intensity using a visual analogue scale , functional outcome using a neck disability index score , laboratory tests of inflammatory profiles , and the infection rate . Results Seventy-seven patients ( 38 in group B and 39 in group C ) were included in the final analysis . One year postoperatively , bone fusion was achieved in 87 % of group B patients and 87 % of group C patients on dynamic radiographs , and 87 % of group B patients and 72 % of group C patients on CT scans ( p=1.00 and 0.16 , respectively ) . There were also no between-groups differences with respect to the secondary endpoints . Conclusions A HA/DBM mixture inside a PEEK cage can provide noninferior outcomes compared to a HA/TCP mixture in ACDF OBJECTIVE The pseudarthrosis rate after multisegment anterior cervical fusion is directly related to the number of levels surgically fused . The advent of osteobiological adjuvants offers an opportunity to reduce both the likelihood of failed arthrodesis and the need for posterior instrumentation . Collagen-hydroxyapatite matrix is osteoconductive and has been used with autogenous bone marrow aspirate ( BMA ) to promote fusion . We report our results of using collagen-hydroxyapatite matrix with BMA for multilevel anterior cervical discectomy and fusion and anterior cervical corpectomy and fusion ( ACCF ) . METHODS Sixty-six consecutively treated patients underwent a multilevel anterior cervical discectomy and fusion and /or ACCF during a period of 16 months . In all cases , a Smith-Robinson decompression was performed followed by allograft fibula strut grafting filled with collagen-hydroxyapatite matrix and BMA , and anterior semiconstrained cervical plating . A vacuum chamber was used to draw the BMA slowly through the collagen-hydroxyapatite sponges . No patient underwent simultaneous posterior instrumentation . Clinical outcome was determined by an independent observer who evaluated patients on the basis of symptom and neurological examination results . Radiographic fusion was determined by dynamic x-rays and computed tomographic scanning during an 18-month follow-up period . RESULTS With the inclusion of discectomies performed in ACCF procedures , patients were fused between two and five disc levels ( mean , 3.1 levels ) . Seventeen patients underwent one to four-level corpectomies ( mean , two levels ) . Clinical improvement was observed in 49 patients . Conditions in nine patients remained unchanged , and two patients had radicular palsies . In all , 60 patients were followed and analyzed for radiographic fusion .  All but two patients demonstrated successful radiographic fusion . CONCLUSION Collagen-hydroxyapatite matrix with BMA can be a safe , effective adjuvant for promoting fusion in multilevel anterior cervical discectomy and fusion and ACCF . Although r and omized , controlled studies are necessary to determine whether or not the fusion rates are superior to those obtained from using allograft alone , these results compare favorably to historical data in the literature Study Design . A review of the smoking habits in 426 patients who had been followed prospect ively for 2 years after a lumbar spinal fusion procedure was conducted . Objective . To analyze the effect of pre- and postoperative smoking on clinical and functional outcome after lumbar spinal fusion . Summary of Background Data . Several animal models have shown a negative effect of nicotine on spinal fusion . At this writing , the clinical effect of nicotine on spinal fusion has not been fully clarified . Methods . The study comprised 426 patients who underwent lumbar spinal fusion between 1993 and 1997 . These patients received a mailed question naire regarding their tobacco consumption before and after their surgery . All other data , including preoperative clinical and functional status , were collected prospect ively during a 2-year follow-up period . To assess functional outcome , the Dallas Pain Question naire was used . Results . The question naire was answered by 396 patients ( 93 % ) . Of these patients , 54.5 % ( 20 % more than the background population ) were smokers before the operation . Smoking of more than 10 cigarettes daily before the operation and attempted fusion at two or more levels increased the risk of nonunion : odds ratio , 2.01 ( P < 0.016 ) and odds ratio , 3.03 ( P < 0.001 ) , respectively . Smoking cessation increased fusion rates to near those of nonsmokers . Smoking had no influence on functional outcome , as assessed by the Dallas Pain Question naire , but preoperative smoking predicted a negative answer to the question “ Would you undergo the same treatment again , now that you know the result ? ” ( odds ratio , 1.65;P < 0.054 ) . Conclusions . Smoking was shown to have a negative effect on fusion and overall patient satisfaction , but no measurable influence on the functional outcome as assessed by the Dallas Pain Question naire Background The purpose of this prospect i ve semi-r and omised comparative study was to compare fusion rates , course of fusion , and occurrence of collapse and subsidence of autologous and allogenic bone grafts in instrumented anterior cervical fusion . The number of fused levels and the smoking status were investigated as potential factors influencing the bone-healing process . No similar prospect i ve study on instrumented anterior cervical discectomy and fusion was found in the literature . Methods Seventy-nine consecutive patients were operated on using the Smith – Robinson technique with a single instrumentation system at one or two levels . Seventy-six cadaverous fibular bone grafts and 37 autologous iliac-crest bone grafts were inserted . All 
    Output:
    
agent
***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: Purpose This multicenter clinical study was performed to assess the safety and effectiveness of Trinity Evolution ® ( TE ) , a viable cellular bone allograft , in combination with a PEEK interbody spacer and supplemental anterior fixation in patients undergoing anterior cervical discectomy and fusion ( ACDF ) . Methods In a prospect i ve , multi-center study , 31 patients that presented with symptomatic cervical degeneration at one vertebral level underwent ACDF with a PEEK interbody spacer ( Orthofix , Inc. , Lewisville , TX , USA ) and supplemental anterior fixation . In addition all patients had the bone graft substitute , Trinity Evolution ( Musculoskeletal Transplant Foundation , Edison , NJ , USA ) , placed within the interbody spacer . At 6 and 12 months , radiographic fusion was evaluated as determined by independent radiographic review of angular motion ( ≤4 ° ) from flexion/extension X-rays combined with presence of bridging bone across the adjacent endplates on thin cut CT scans . In addition other metrics were measured including function as assessed by the Neck Disability Index ( NDI ) , and neck and arm pain as assessed by individual Visual Analog Scales ( VAS ) . Results The fusion rate for patients using a PEEK interbody spacer in combination with TE was 78.6 % at 6 months and 93.5 % at 12 months . When considering high risk factors , 6-month fusion rates for patients that were current or former smokers , diabetic , overweight or obese/extremely obese were 70 % ( 7/10 ) , 100 % ( 1/1 ) , 70 % ( 7/10 ) , and 82 % ( 9/11 ) , respectively . At 12 months , the fusion rates were 100 % ( 12/12 ) , 100 % ( 2/2 ) , 100 % ( 11/11 ) and 85 % ( 11/13 ) , respectively . Neck function , and neck/arm pain were found to significantly improve at both time points . No serious allograft related adverse events occurred and none of the 31 patients had subsequent additional cervical surgeries . Conclusions Patients undergoing single-level ACDF with TE in combination with a PEEK interbody spacer and supplemental anterior fixation had a high rate of fusion success without serious allograft-related adverse events Study Design . Prospect i ve , multicenter , nonr and omized , institutional review board-approved clinical and radiographic study . Objective . To evaluate and summarize the 2-year outcomes of patients treated with Osteocel Plus cellular allograft as part of an anterior cervical discectomy and fusion procedure . Summary of Background Data . Osteocel Plus is an allograft cellular bone matrix containing native mesenchymal stem cells and osteoprogenitor cells that is intended to mimic the performance of iliac crest autograft without the morbidity associated with its harvest . Methods . A total of 182 patients were treated with anterior cervical discectomy and fusion using Osteocel Plus in a polyetheretherketone cage and anterior plating at 1 or 2 consecutive levels . Clinical outcomes included visual analogue scale for neck and arm pain , neck disability index , and SF-12 physical and mental component scores . Computed tomography and plain film radiographic measures included assessment of bridging bone , disc height , disc angle , and segmental range of motion . Results . A total of 249 levels were treated in 182 patients .  Mean procedure time was 100 minutes , blood loss was less than 50 mL in 93 % of patients , and hospital stay was 1 day or less in 84 % of patients . Significant ( P < 0.05 ) average improvements in clinical outcomes from preoperatively to 24 months included the following : neck disability index : 21.5 % ; visual analogue scale neck : 34 mm ; visual analogue scale arm : 35 mm ; SF-12 physical component score : 11.2 ; SF-12 mental component score : 6.8 . At 24 months , 93 % of patients were satisfied with their outcome . In patients treated at a single level with a minimum of 24-month follow-up , 92 % ( 79/86 ) of levels achieved solid bridging and 95 % of levels demonstrated range of motion of less than 3 ° . In combined single- and 2-level procedures , 87 % ( 157/180 ) of levels achieved solid bridging and 92 % ( 148/161 ) had range of motion of less than 3 ° at 24 months . No patient required revision for pseudarthrosis . Conclusion . Improvements in clinical results at 2 years , high patient satisfaction , and high radiographic and clinical fusion rates provide confidence in Osteocel Plus as an effective alternative to structural allograft or autograft in anterior cervical discectomy and fusion procedures . Level of Evidence : BACKGROUND CONTEXT Anterior cervical discectomy and fusion ( ACDF ) using autogenous iliac bone graft may lead to donor-site morbidity . This has led some surgeons to use alternatives to iliac bone graft , but often the alternatives have greater rates of nonunion and delayed union . Bone morphogenic protein ( BMP ) studies have found high arthrodesis rates in lumbar fusions . PURPOSE The objective of this pilot study was to compare the success of BMP combined with bone allograft with iliac bone autograft in ACDF patients . STUDY DESIGN / SETTING The institutional review board approved a prospect i ve but nonr and omized study of 66 consecutive patients who had primary one- to three-level ACDF with either iliac-crest bone autograft or BMP allograft ( 0.9 mg BMP per level ) followed prospect ively over a 2- to 3-year period . PATIENT SAMPLE Consecutive patients who had primary one- to three-level ACDF with either iliac-crest bone autograft ( n=36 ) or BMP-allograft ( n=30 ) . Patients in both iliac bone graft and BMP-allograft groups had comparable preoperative pain and disability . OUTCOME MEASURES Visual analog scale pain , pain drawing , Oswestry index , pain medication use , opinion of treatment success , and neurological recovery . RESULTS Given the nonr and omized nature of the study , the study groups were not matched . Within this limitation , both groups of patients had similar improvement in all outcome scales ( visual analog scale pain , pain drawing , Oswestry index , pain medication use , and opinion of treatment success ) and neurological recovery over the 2- to 3-year follow-up period . Patients in the iliac bone graft group had two pseudarthroses and two complications of the iliac-crest donor site . In the BMP-allograft group , one patient had a pseudarthrosis , but 50 % had neck swelling presenting as dysphagia , which was substantially more common than the 14 % present in the iliac bone graft group . Patients in the BMP-allograft group had slightly shorter surgery time , but implant and hospitalization costs were higher . CONCLUSIONS ACDF performed with BMP ( 0.9 mg BMP per level ) allograft is as effective as iliac bone graft in terms of patient outcomes and fusion rates . Safety concerns related to neck swelling and higher initial costs were associated with patients in the bone morphogenic protein group Study Design Prospect i ve r and omized noninferiority trial . Purpose To evaluate whether the union rate of anterior cervical discectomy and fusion ( ACDF ) using a polyetheretherketone ( PEEK ) cage filled with a mixture of hydroxyapatite ( HA ) and demineralized bone matrix ( DBM ) is inferior to that of a mixture of β-tricalcium phosphate ( β-TCP ) and HA . Overview of Literature There have been no clinical trials investigating the outcomes of a mixture of HA and DBM in a PEEK cage in ACDF . Methods Eighty-five eligible patients were r and omly assigned to group B ( n=43 ) , in which a PEEK cage with a mixture of HA and DBM was used , or group C ( n=42 ) , in which a PEEK cage with a mixture of HA and β-TCP was used . The primary study endpoint was the fusion rate , which was assessed with dynamic radiographs and computed tomography ( CT ) scans . Secondary endpoints included pain intensity using a visual analogue scale , functional outcome using a neck disability index score , laboratory tests of inflammatory profiles , and the infection rate . Results Seventy-seven patients ( 38 in group B and 39 in group C ) were included in the final analysis . One year postoperatively , bone fusion was achieved in 87 % of group B patients and 87 % of group C patients on dynamic radiographs , and 87 % of group B patients and 72 % of group C patients on CT scans ( p=1.00 and 0.16 , respectively ) . There were also no between-groups differences with respect to the secondary endpoints . Conclusions A HA/DBM mixture inside a PEEK cage can provide noninferior outcomes compared to a HA/TCP mixture in ACDF OBJECTIVE The pseudarthrosis rate after multisegment anterior cervical fusion is directly related to the number of levels surgically fused . The advent of osteobiological adjuvants offers an opportunity to reduce both the likelihood of failed arthrodesis and the need for posterior instrumentation . Collagen-hydroxyapatite matrix is osteoconductive and has been used with autogenous bone marrow aspirate ( BMA ) to promote fusion . We report our results of using collagen-hydroxyapatite matrix with BMA for multilevel anterior cervical discectomy and fusion and anterior cervical corpectomy and fusion ( ACCF ) . METHODS Sixty-six consecutively treated patients underwent a multilevel anterior cervical discectomy and fusion and /or ACCF during a period of 16 months . In all cases , a Smith-Robinson decompression was performed followed by allograft fibula strut grafting filled with collagen-hydroxyapatite matrix and BMA , and anterior semiconstrained cervical plating . A vacuum chamber was used to draw the BMA slowly through the collagen-hydroxyapatite sponges . No patient underwent simultaneous posterior instrumentation . Clinical outcome was determined by an independent observer who evaluated patients on the basis of symptom and neurological examination results . Radiographic fusion was determined by dynamic x-rays and computed tomographic scanning during an 18-month follow-up period . RESULTS With the inclusion of discectomies performed in ACCF procedures , patients were fused between two and five disc levels ( mean , 3.1 levels ) . Seventeen patients underwent one to four-level corpectomies ( mean , two levels ) . Clinical improvement was observed in 49 patients . Conditions in nine patients remained unchanged , and two patients had radicular palsies . In all , 60 patients were followed and analyzed for radiographic fusion .  All but two patients demonstrated successful radiographic fusion . CONCLUSION Collagen-hydroxyapatite matrix with BMA can be a safe , effective adjuvant for promoting fusion in multilevel anterior cervical discectomy and fusion and ACCF . Although r and omized , controlled studies are necessary to determine whether or not the fusion rates are superior to those obtained from using allograft alone , these results compare favorably to historical data in the literature Study Design . A review of the smoking habits in 426 patients who had been followed prospect ively for 2 years after a lumbar spinal fusion procedure was conducted . Objective . To analyze the effect of pre- and postoperative smoking on clinical and functional outcome after lumbar spinal fusion . Summary of Background Data . Several animal models have shown a negative effect of nicotine on spinal fusion . At this writing , the clinical effect of nicotine on spinal fusion has not been fully clarified . Methods . The study comprised 426 patients who underwent lumbar spinal fusion between 1993 and 1997 . These patients received a mailed question naire regarding their tobacco consumption before and after their surgery . All other data , including preoperative clinical and functional status , were collected prospect ively during a 2-year follow-up period . To assess functional outcome , the Dallas Pain Question naire was used . Results . The question naire was answered by 396 patients ( 93 % ) . Of these patients , 54.5 % ( 20 % more than the background population ) were smokers before the operation . Smoking of more than 10 cigarettes daily before the operation and attempted fusion at two or more levels increased the risk of nonunion : odds ratio , 2.01 ( P < 0.016 ) and odds ratio , 3.03 ( P < 0.001 ) , respectively . Smoking cessation increased fusion rates to near those of nonsmokers . Smoking had no influence on functional outcome , as assessed by the Dallas Pain Question naire , but preoperative smoking predicted a negative answer to the question “ Would you undergo the same treatment again , now that you know the result ? ” ( odds ratio , 1.65;P < 0.054 ) . Conclusions . Smoking was shown to have a negative effect on fusion and overall patient satisfaction , but no measurable influence on the functional outcome as assessed by the Dallas Pain Question naire Background The purpose of this prospect i ve semi-r and omised comparative study was to compare fusion rates , course of fusion , and occurrence of collapse and subsidence of autologous and allogenic bone grafts in instrumented anterior cervical fusion . The number of fused levels and the smoking status were investigated as potential factors influencing the bone-healing process . No similar prospect i ve study on instrumented anterior cervical discectomy and fusion was found in the literature . Methods Seventy-nine consecutive patients were operated on using the Smith – Robinson technique with a single instrumentation system at one or two levels . Seventy-six cadaverous fibular bone grafts and 37 autologous iliac-crest bone grafts were inserted . All 
    Output:
    