***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 . Multicenter r and omized controlled trial . Objective . To compare the efficacy and safety of balloon kyphoplasty ( BKP ) with nonsurgical management ( NSM ) during 24 months in patients with painful vertebral compression fractures ( VCFs ) . Summary of Background Data . Recently , several large r and omized controlled trials have been conducted and reported how vertebral augmentation compares with NSM for patients with acute VCFs . Few of these trials report on the surgical aspects and radiographical vertebral deformity results . Methods . Adults with 1 to 3 VCFs were r and omized within 3 months of pain to undergo bilateral BKP ( n = 149 ) or NSM ( n = 151 ) . Surgical parameters , subjective quality of life assessment s and objective functional ( timed up and go ) and radiographical assessment s were collected . Results . Compared with NSM , the BKP group had greater improvements in SF-36 physical component summary ( PCS ) scores at 1 month ( 5.35 points ; 95 % CI , 3.41−7.30 ; P < 0.0001 ) and when averaged across the 24 months ( overall treatment effect 2.71 points ; 95 % CI , 1.34–4.09 ; P = 0.0001 ) . The kyphoplasty group also had greater functionality by assessing timed up and go ( overall treatment effect −2.49 s ; 95 % CI , −0.82 to −4.15 ; P = 0.0036 ) . At 24 months , the change in index fracture kyphotic angulation was statistically significantly improved in the kyphoplasty group ( average 3.13 ° of correction for kyphoplasty compared with 0.82 ° in the control , P = 0.003 ) . Number of baseline prevalent fractures ( P = 0.0003 ) and treatment assignment ( P = 0.004 ) are the most predictive variables for PCS improvement ; however , in patients who underwent BKP , there may also be a link with kyphotic angulation . In BKP , the highest quart for kyphotic angulation correction had higher PCS improvement ( 13.4 points ) than the quart having lowest correction of angulation ( 7.40 points , P = 0.0146 for difference ) . The most common adverse events temporally related to surgery ( i.e. , within 30 d ) were back pain ( 20 BKP , 11 NSM ) new VCF ( 11 BKP , 7 NSM ) , nausea/vomiting ( 12 BKP , 4 NSM ) , and urinary tract infection ( 10 BKP , 3 NSM ) . Several other adverse events were possibly related to patient positioning in the operating room . Conclusion . Compared with NSM , BKP improves patient quality of life and pain averaged during 24 months and results in better improvement of index vertebral body kyphotic angulation . Perioperative complications may be reduced with more care in patient positioning . Level of Evidence : Summary Bone pain and spinal axial deformity are major concerns in aged patients suffering from osteoporotic vertebral compression fracture ( VCF ) . Pain can be relieved by vertebroplasty or kyphoplasty procedures , in which the compressed vertebral body is filled with substitutes . We r and omly assigned 100 patients with osteoporotic compression fracture at the thoraco-lumbar ( T-L ) junction into two groups : vertebroplasty and kyphoplasty ; we used polymethylmethacrylate ( PMMA ) as the bone filler . Pain before and after treatment was assessed with visual analog scale ( VAS ) scores and vertebral body height and kyphotic wedge angle were measured from reconstructed computed tomography images . More PMMA was used in the kyphoplasty group than in the vertebroplasty group ( 5.56 ± 0.62 vs. 4.91 ± 0.65 mL , p < 0.001 ) . Vertebral body height and kyphotic wedge angle of the T-L spine were also improved ( p < 0.001 ) . VAS pain scores did not differ significantly between the treatment groups . The duration of follow-up was 6 months . Two patients in the kyphoplasty group had an adjacent segment fracture . In terms of clinical outcome there was little difference between the treatment groups . Thus , owing to the higher cost of the kyphotic balloon procedure , we recommend vertebroplasty over kyphoplasty for the treatment of osteoporotic VCFs . Introduction Spinal axial deformities are major concerns in aged patients suffering from osteoporotic vertebral compression fracture . Pain may be relieved by vertebroplasty or kyphoplasty . We investigated the radiological and clinical outcomes of these procedures . Methods One hundred cases of VCF at the thoraco-lumbar junction were r and omly assigned into two groups : vertebroplasty or kyphoplasty ( 50 cases each ) . We used polymethylmethacrylate as the bone filler . Pain before and after treatment was assessed with visual analog scale scores and vertebral body height and kyphotic wedge angle were measured from reconstructed computed tomography images . Results More PMMA was used in the kyphoplasty group than in the vertebroplasty group ( 5.56 ± 0.62 vs. 4.91 ± 0.65 mL , p < 0.001 ) . Vertebral body height and kyphotic wedge angle of the T-L spine were also improved ( p < 0.001 ) . VAS pain scores did not differ significantly between the treatment groups . The duration of follow-up was 6 months . Two patients in the kyphoplasty group had an adjacent segment fracture . Conclusions In terms of clinical outcome there was little difference between the treatment groups . Thus , with the higher cost of the kyphotic balloon procedure , we recommend vertebroplasty over kyphoplasty for the treatment of osteoporotic VCFs Abstract : The purpose of this r and omized , double-masked , placebo-controlled study was to determine the efficacy and safety of risedronate in the prevention of vertebral fractures in postmenopausal women with established osteoporosis . The study was conducted at 80 study centers in Europe and Australia . Postmenopausal women ( n= 1226 ) with two or more prevalent vertebral fractures received risedronate 2.5 or 5 mg/day or placebo ; all subjects also received elemental calcium 1000 mg/day , and up to 500 IU/day vitamin D if baseline levels were low . The study duration was 3 years ; however , the 2.5 mg group was discontinued by protocol amendment after 2 years . Lateral spinal radiographs were taken annually for assessment of vertebral fractures , and bone mineral density was measured by dual-energy X-ray absorptiometry at 6-month intervals . Risedronate 5 mg reduced the risk of new vertebral fractures by 49 % over 3 years compared with control ( p<0.001 ) . A significant reduction of 61 % was seen within the first year ( p= 0.001 ) . The fracture reduction with risedronate 2.5 mg was similar to that in the 5 mg group over 2 years . The risk of nonvertebral fractures was reduced by 33 % compared with control over 3 years ( p= 0.06 ) . Risedronate significantly increased bone mineral density at the spine and hip within 6 months . The adverse-event profile of risedronate , including gastrointestinal adverse events , was similar to that of control . Risedronate 5 mg provides effective and well-tolerated therapy for severe postmenopausal osteoporosis , reducing the incidence of vertebral fractures and improving bone density in women with established disease In a prospect i ve study , we aim ed to evaluate the potential use of kyphoplasty ( KP ) and vertebroplasty ( VP ) as complementary techniques in the treatment of  painful osteoporotic vertebral compression fractures ( VCFs ) . After 1 month of conservative treatment for VCFs , patients with intractable pain were offered treatment with KP or VP according to a treatment algorithm that considers time from fracture ( Δt ) and amount of vertebral body collapse . Bone biopsy was obtained intra-operatively to exclude patients affected by malignancy or osteomalacia . 164 patients were included according to the above criteria . Mean age was 67.6 years . Mean follow-up was 33 months . 10 patients ( 6.1 % ) were lost to follow-up and 154 reached the minimum 2-year follow-up . 118 ( 69.5 % ) underwent VP and 36 ( 30.5 % ) underwent KP . Complications affected five patients treated with VP , whose one suffered a transient intercostal neuropathy and four a subsequent VCF ( two at adjacent level ) . Results in terms of visual analogue scale and Oswestry scores were not different among treatment groups . In conclusion , at an average follow-up of almost 3 years from surgical treatment of osteoporotic VCFs , VP and KP show similar good clinical outcomes and appear to be complementary techniques with specific different indications BACKGROUND Vertebroplasty has become a common treatment for painful osteoporotic vertebral fractures , but there is limited evidence to support its use . METHODS We performed a multicenter , r and omized , double-blind , placebo-controlled trial in which participants with one or two painful osteoporotic vertebral fractures that were of less than 12 months ' duration and unhealed , as confirmed by magnetic resonance imaging , were r and omly assigned to undergo vertebroplasty or a sham procedure . Participants were stratified according to treatment center , sex , and duration of symptoms ( < 6 weeks or > or = 6 weeks ) . Outcomes were assessed at 1 week and at 1 , 3 , and 6 months . The primary outcome was overall pain ( on a scale of 0 to 10 , with 10 being the maximum imaginable pain ) at 3 months . RESULTS A total of 78 participants were enrolled , and 71 ( 35 of 38 in the vertebroplasty group and 36 of 40 in the placebo group ) completed the 6-month follow-up ( 91 % ) . Vertebroplasty did not result in a significant advantage in any measured outcome at any time point . There were significant reductions in overall pain in both study groups at each follow-up assessment . At 3 months , the mean ( + /-SD ) reductions in the score for pain in the vertebroplasty and control groups were 2.6+/-2.9 and 1.9+/-3.3 , respectively ( adjusted between-group difference , 0.6 ; 95 % confidence interval , -0.7 to 1.8 ) . Similar improvements were seen in both groups with respect to pain at night and at rest , physical functioning , quality of life , and perceived improvement . Seven incident vertebral fractures ( three in the vertebroplasty group and four in the placebo group ) occurred during the 6-month follow-up period . CONCLUSIONS We found no beneficial effect of vertebroplasty as compared with a sham procedure in patients with painful osteoporotic vertebral fractures , at 1 week or at 1 , 3 , or 6 months after treatment . ( Australian New Zeal and Clinical Trials Registry number , ACTRN012605000079640 . BACKGROUND Percutaneous vertebroplasty is increasingly used for treatment of pain in patients with osteoporotic vertebral compression fractures , but the efficacy , cost-effectiveness , and safety of the procedure remain uncertain . We aim ed to clarify whether vertebroplasty has additional value compared with optimum pain treatment in patients with acute vertebral fractures . METHODS Patients were recruited to this open-label prospect i ve r and omised trial from the radiology departments of six hospitals in the Netherl and s and Belgium . Patients were aged 50 years or older , had vertebral compression fractures on spine radiograph ( minimum 15 % height loss ; level of fracture at Th5 or lower ; bone oedema on MRI ) , with back pain for 6 weeks or less , and a visual analogue scale ( VAS ) score of 5 or more . Patients were r and omly allocated to percutaneous vertebroplasty or conservative treatment by computer-generated r and omisation codes with a block size of six . Masking was not possible for participants , physicians , and outcome assessors . The primary outcome was pain relief at 1 month and 1 year as measured by VAS score . Analysis was by intention to treat . This study is registered at Clinical Trials.gov , number NCT00232466 . FINDINGS Between Oct 1 , 2005 , and June 30 , 2008 , we identified 431 patients who were eligible for r and omisation . 229 ( 53 % ) patients had spontaneous pain relief during assessment , and 202 patients with persistent pain were r and omly allocated to treatment ( 101 vertebroplasty , 101 conservative treatment ) . Vertebroplasty result ed in greater pain relief than did conservative treatment ; difference in mean VAS score between baseline and 1 month was -5·2 ( 95 % CI -5·88 to -4·72 ) after vertebroplasty and -2·7 ( -3·22 to -1·98 ) after conservative treatment , and between baseline and 1 year was -5·7 ( -6·22 to -4·98 ) after vertebroplasty 
    Output:
    
We observed no significant difference between single balloon and double balloon bipedicular kyphoplasty in visual analog scale ( VAS ) , angle ( kyphotic angle and Cobb angle ) , consumption ( operation time , cement volume and volume of bleeding ) , vertebral height ( anterior height , medium height and posterior height ) and complications ( cement leakage and new VCFs ) , while the cost of single balloon bipedicular kyphoplasty is lower than that of double balloon bipedicular kyphoplasty .
The results of our meta- analysis also demonstrated that single balloon can significantly improve the VAS , angle and vertebral height of  patients suffering from  VCFs  .
Conclusion This systematic review and meta- analysis collectively concludes that single balloon bipedicular kyphoplasty is as effective as double balloon bipedicular kyphoplasty in improving clinical symptoms , deformity and complications of VCFs but not so expensive .