***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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    ***EXAMPLES*** 
    Input: Study Design . Radiographic results from a prospect i ve , r and omized , multicenter trial assessing patients who underwent lumbar total disc replacement ( TDR ) or circumferential arthrodesis for 1-level degenerative disc disease . Objective . To quantify the relative segmental contribution to total lumbar range of motion ( ROM ) at the operative level at each adjacent level in lumbar TDR and arthrodesis . Summary of Background Data . Although previous studies have evaluated ROM in TDR and fusion , no study has quantified or compared the relative segmental contribution to total lumbar ROM . Further , no study to the best of our knowledge has evaluated the kinematic profile of the more cranial adjacent segments ( i.e. , the second or third adjacent levels ) following implantation of either TDR or fusion . Methods . Radiographic data collected from all r and omized 1-level degenerative disc disease patients operated at L4/5 or L5/S1 that participated in the multicenter , prospect i ve , r and omized IDE study comparing ProDisc-L with circumferential lumbar arthrodesis were evaluated before surgery and at 24 months . Radiographic measurements were performed independently using custom digitized image stabilization software to generate ROM at the operative level , and at each cranial and caudal adjacent level . Results . There were 200 total patients included ( 155 ProDisc-L , average age 39 years ; 45 arthrodesis , average age 40 years ) . At 24 months , the L4/5 TDR group experienced a significant improvement in total lumbar ROM from baseline ( + 6.3 ° ) , whereas there was no change seen with L5/S1 TDR or any fusion group . Between-group comparisons from baseline to 24 months postoperatively revealed : ( 1 ) significantly more contribution from the operative level towards total lumbar range in TDR  at operative level L4/5 ( TDR : −2.5 % , fusion : −16.8 % , P = 0.006 ) , and operative level L5/S1 ( TDR : −5.1 % , fusion : −15.9 % , P < 0.001 ) , and ( 2 ) the relative contribution towards total lumbar range of motion from the first cranial adjacent segment to fusion at L5/S1 increased by 12.1 % , compared with −1.2 % seen in TDR ( P = 0.03 ) . There were elevated contributions from the more cranial adjacent levels to a fusion when compared with TDR , however , these differences were not statistically significant . At operative level L4/5 , there was significantly increased ROM from the first caudal segment below TDR ( 6 % , P = 0.03 ) , but not below fusion ( 3.1 % , P = 0.59 ) . Conclusion . In conclusion , patients with TDR lost slight relative contribution to total lumbar motion from the operative level which was mostly compensated for by the caudal adjacent level ( if operated at L4/5 ) . In contrast , the significant loss of relative range of motion contribution from the operative level in fusions was redistributed among multiple cranial adjacent levels , most notably at the first cranial adjacent level 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 Study Design Prospect i ve clinical study . Objective To compare the amount of segmental motion in the sagittal plane after lumbar total disc arthroplasty ( TDA ) measured by using the Cobb technique , quantitative motion analysis ( QMA ) , and radiostereometric analysis ( RSA ) . Summary of Background Data The aim of TDA is preservation of motion and therefore essential to properly quantify the motion . Clinical ly , segmental motion is measured by using the Cobb technique , which involves either the endplates or the implant as radiographic l and marks . This technique has been reported to have large intraobserver and interobserver variability . QMA and RSA are in vivo techniques that can measure the segmental motion with accuracy , but have not been compared with each other or compared with the Cobb technique in the literature . Methods Ten patients ( 6 males and 4 females , 47±7 y ) with lumbar disc degeneration were surgically treated with ProDisc-L ( Synthes Inc ) .  Intraoperatively , tantalum beads were inserted into each vertebra and patients were followed postoperatively at 1 month , 1 year , and 2 years . At each follow-up time-point , biplanar flexion/extension radiographs were obtained and sagittal range of motion ( ROM ) of the index level was calculated by using the RSA technique . Clinical flexion/extension radiographs were also obtained and the sagittal ROM at the same level was calculated by using a modified Cobb technique . The clinical films were additionally analyzed by Medical Metrics for sagittal ROM using QMA . The results of the 3 measurement techniques were statistically analyzed and compared in pairwise fashion . Results A significant difference ( P=0.02 ) was observed between the Cobb technique ( 5.9±4.9 ) and RSA ( 3.5±2.4 ) . A trend ( P=0.069 ) was also seen between QMA ( 5.7±4.7 ) and RSA . On paired- sample s correlation , a significantly high correlation was seen between Cobb technique and QMA ( r=0.868 , P<0.001 ) . A larger variability was seen when using the Cobb technique or QMA in comparison to the RSA . Conclusions Sagittal ROM after TDA was similar between QMA and digital Cobb technique . A larger variability was seen between these techniques and RSA BACKGROUND CONTEXT Previous attempts to measure vertebral motion in vivo have been either static measure , imprecise , two-dimensional , or overly invasive to be applied to serial studies . PURPOSE This study evaluated the efficacy of a unique high-speed biplane X-ray system for tracking lumbar vertebrae in vivo during dynamic motion . Additional goals were to determine parameters for future studies using this tool and to obtain preliminary data on the effects of lumbar fusion on vertebral kinematics . STUDY DESIGN / SETTING A high-speed biplane radiographic X-ray system was used to measure the three-dimensional ( 3D ) relative rotation between fused and adjacent vertebrae in vivo during muscle driven movement . Subjects were tested 2 , 3 , and 6 months after fusion procedures to assess vertebral motion of fused and adjacent vertebrae . PATIENT SAMPLE Five subjects received lumbar fusion surgery .  OUTCOME MEASURES Physiologic measures included 3D vertebral rotation of fused and adjacent vertebrae . METHODS Tantalum beads were implanted into lumbar vertebrae during fusion operations . Radiographic data was collected continuously at 50 frames per second during flexion-extension , lateral bending , and axial twist movements serially , at 2 , 3 , and 6 months after fusion surgery . RESULTS Implanted beads were tracked with an accuracy of 0.18 mm during dynamic motion . Vertebral rotation was not necessarily linearly related to trunk rotation , supporting the use of continuous data collection during movement ; collecting only movement start and end points may not be sufficient . Some movements indicated fusion was complete , whereas others indicated incomplete fusion . This suggests patients be tested performing a variety of movements to test for complete fusion . The fusion site often acted as a pivot point for vertebral rotation , with vertebrae superior to the fusion rotating in the direction of the trunk and vertebrae inferior rotating opposite trunk rotation . CONCLUSIONS This technique is sufficiently accurate for in vivo serial studies of vertebral motion during muscle driven movements . A variety of movements should be performed to assess surgical results , and the data should be collected continuously through the entire range of motion , not just at the movement endpoints . However , care must be exercised in subject selection , in camera location , and in the placement of tracking beads in relation to implanted instrumentation BACKGROUND CONTEXT The CHARITE artificial disc , a lumbar spinal arthroplasty device , was approved by the United States Food and Drug Administration in 2004 based on two-year safety and effectiveness data from a multicenter , prospect i ve , r and omized investigational device exemption ( IDE ) study . No long-term , r and omized , prospect i ve study on the CHARITE disc or any other artificial disc has been published to date . PURPOSE The purpose of this study was to compare the safety and effectiveness at the five-year follow-up time point of lumbar total disc replacement using the CHARITE artificial disc ( DePuy Spine , Raynham , MA ) with that of anterior lumbar interbody fusion ( ALIF ) with BAK cages and iliac crest autograft , for the treatment of single-level degenerative disc disease from L4 to S1 , unresponsive to nonoperative treatment . STUDY DESIGN / SETTING R and omized controlled trial-five-year follow-up . PATIENT SAMPLE Ninety CHARITE patients and 43 BAK patients . OUTCOME MEASURES Self-reported measures : visual analog scale ( VAS ) ; vali date d Oswestry disability index ( ODI version 1.0 ) ; Short-Form 36 Question naire , and patient satisfaction . Physiologic measures : radiographic range of motion , disc height , and segmental translation . Functional measures : work status . METHODS Of the 375 subjects enrolled in the CHARITE IDE trial , 277 were eligible for the five-year study and 160 patients thereof completed the five-year follow-up . The completers included 133 r and omized patients .  Overall success was defined as improvement > or = 15 pts in ODI vs. baseline , no device failure , absence of major complications , and maintenance or improvement of neurological status . Additional clinical outcomes included an ODI question naire as well as VAS , SF-36 , and patient satisfaction surveys . Work status was tracked for all patients . Safety assessment s included occurrence and severity of adverse events and device failures . Radiographic analyses such as index- and adjacent-level range of motion , segmental translation , disc height , and longitudinal ossification were also carried out . RESULTS Overall success was 57.8 % in the CHARITE group vs. 51.2 % in the BAK group ( Blackwelder 's test : p=0.0359 , Delta=0.10 ) . In addition , mean changes from baseline for ODI ( CHARITE : -24.0 pts vs. BAK : -27.5 pts ) , VAS pain scores ( CHARITE : -38.7 vs. BAK : -40.0 ) , and SF-36 question naires ( SF-36 Physical Component Scores [ PCS ] : CHARITE : 12.6 pts vs. BAK : 12.3 pts ) were similar across groups . In patient satisfaction surveys , 78 % of CHARITE patients were satisfied vs. 72 % of BAK patients . A total of 65.6 % patients in the CHARITE group vs. 46.5 % patients in the BAK group were employed full-time . This difference was statistically significant ( p=0.0403 ) . Long-term disability was recorded for 8.0 % of CHARITE patients and 20.9 % of BAK patients , a difference that was also statistically significant ( p=0.0441 ) . Additional index-level surgery was performed in 7.7 % of CHARITE patients and 16.3 % of BAK patients . Radiographic findings included operative and adjacent-level range of motion ( ROM ) , intervertebral disc height and segmental translation . At the five-year follow-up , the mean ROM at the index level was 6.0 degrees for CHARITE patients and 1.0 degrees for BAK patients . Changes in disc height were also similar for both CHARITE and BAK patients ( 0.7 mm for both groups , p=0.9827 ) . Segmental translation was 0.4 and 0.8 mm in patients implanted with CHARITE at L4-L5 vs. L5-S1 , respectively , and 0.1 mm in BAK patients . CONCLUSIONS The results of this five-year , prospect i ve , r and omized multicenter study are consistent with the two-year reports of noninferiority of CHARITE artificial disc vs. ALIF with BAK and iliac crest autograft . No statistical differences were found in clinical outcomes between groups . In addition , CHARITE patients reached a statistically greater rate of part- and full-time employment and a statistically lower rate of long-term disability , compared with BAK patients . Radiographically , the ROMs at index- and adjacent levels were not statistically different from those observed at two-years postsurgery The authors studied the effects of a “ lumbar trapezoid plate ” ( spinal plate and pedicle screwing ) , performed for lumbar spondylolisthesis , observing the effect on the remaining adjacent discs with regard to preoperative and postoperative instability . The authors examined changes in preoperative and postoperative lumbar ROM ( range of motion ) , displacement of motor unit levels , and occurrence of instability in the remaining discs , such as horizontal and rotational displacement , in 26 patients who were followed up for a mean of 29 postoperative months ; 13 patients had spondylolytic spondylolisthesis and 13 patients degenerative spondylolis 
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Conclusions There appears to be no overall kinematic changes at the rostral or caudal levels adjacent to a fusion , but some patients ( ~20–30 % ) develop excessive kinematic changes ( i.e. , instability ) at the rostral adjacent level .
The overall lumbar ROM after fusion appears to decrease after a spinal fusion