***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: Introduction Arthroscopic subacromial decompression ( ASD ) is the most commonly performed surgical intervention for shoulder pain , yet evidence on its efficacy is limited . The rationale for the surgery rests on the tenet that symptom relief is achieved through decompression of the rotator cuff tendon passage . The primary objective of this superiority trial is to compare the efficacy of ASD versus diagnostic arthroscopy ( DA ) in patients with shoulder impingement syndrome ( SIS ) , where DA differs only by the lack of subacromial decompression . A third group of supervised progressive exercise therapy ( ET ) will allow for pragmatic assessment of the relative benefits of surgical versus non-operative treatment strategies . Methods and Analysis Finnish Subacromial Impingement Arthroscopy Controlled Trial is an ongoing multicentre , three-group r and omised controlled study . We performed two-fold concealed allocation , first by r and omising patients to surgical ( ASD or DA ) or conservative ( ET ) treatment in 2:1 ratio and then those allocated to surgery further to ASD or DA in 1:1 ratio . Our two primary outcomes are pain at rest and at arm activity , assessed using visual analogue scale ( VAS ) . We will quantify the treatment effect as the difference between the groups in the change in the VAS scales with the associated 95 % CI at 24 months . Our secondary outcomes are functional assessment ( Constant score and Simple shoulder test ) , quality of life ( 15D and SF-36 ) , patient satisfaction , proportions of responders and non-responders , reoperations/treatment conversions , all at 2 years post-r and omisation , as well as adverse effects and complications .  We recruited a total of 210 patients from three tertiary referral centres . We will conduct the primary analysis on the intention-to-treat basis . Ethics and Dissemination The study was approved by the Institutional Review Board of the Pirkanmaa Hospital District and duly registered at Clinical Trials.gov . The findings of this study will be disseminated widely through peer- review ed publications and conference presentations . Trial registration number NCT00428870 ; Pre- results Summary Background Arthroscopic sub-acromial decompression ( decompressing the sub-acromial space by removing bone spurs and soft tissue arthroscopically ) is a common surgery for subacromial shoulder pain , but its effectiveness is uncertain . We did a study to assess its effectiveness and to investigate the mechanism for surgical decompression . Methods We did a multicentre , r and omised , pragmatic , parallel group , placebo-controlled , three-group trial at 32 hospitals in the UK with 51 surgeons . Participants were patients who had subacromial pain for at least 3 months with intact rotator cuff tendons , were eligible for arthroscopic surgery , and had previously completed a non-operative management programme that included exercise therapy and at least one steroid injection . Exclusion criteria included a full-thickness torn rotator cuff . We r and omly assigned participants ( 1:1:1 ) to arthroscopic subacromial decompression , investigational arthroscopy only , or no treatment ( attendance of one re assessment appointment with a specialist shoulder clinician 3 months after study entry , but no intervention ) . Arthroscopy only was a placebo as the essential surgical element ( bone and soft tissue removal ) was omitted . We did the r and omisation with a computer-generated minimisation system . In the surgical intervention groups , patients were not told which type of surgery they were receiving ( to ensure masking ) . Patients were followed up at 6 months and 1 year after r and omisation ; surgeons coordinated their waiting lists to schedule surgeries as close as possible to r and omisation . The primary outcome was the Oxford Shoulder Score ( 0 [ worst ] to 48 [ best ] ) at 6 months , analysed by intention to treat . The sample size calculation was based upon a target difference of 4·5 points ( SD 9·0 ) . This trial has been registered at Clinical Trials.gov , number NCT01623011 . Findings Between Sept 14 , 2012 , and June 16 , 2015 , we r and omly assigned 313 patients to treatment groups ( 106 to decompression surgery , 103 to arthroscopy only , and 104 to no treatment ) . 24 [ 23 % ] , 43 [ 42 % ] , and 12 [ 12 % ] of the decompression , arthroscopy only , and no treatment groups , respectively , did not receive their assigned treatment by 6 months . At 6 months , data for the Oxford Shoulder Score were available for 90 patients assigned to decompression , 94 to arthroscopy , and 90 to no treatment . Mean Oxford Shoulder Score did not differ between the two surgical groups at 6 months ( decompression mean 32·7 points [ SD 11·6 ] vs arthroscopy mean 34·2 points [ 9·2 ] ; mean difference −1·3 points ( 95 % CI −3·9 to 1·3 , p=0·3141 ) . Both surgical groups showed a small benefit over no treatment ( mean 29·4 points [ SD 11·9 ] , mean difference vs decompression 2·8 points [ 95 % CI 0·5–5·2 ] , p=0·0186 ; mean difference vs arthroscopy 4·2 [ 1·8–6·6 ] , p=0·0014 ) but these differences were not clinical ly important . There were six study -related complications that were all frozen shoulders ( in two patients in each group ) . Interpretation Surgical groups had better outcomes for shoulder pain and function compared with no treatment but this difference was not clinical ly important . Additionally , surgical decompression appeared to offer no extra benefit over arthroscopy only . The difference between the surgical groups and no treatment might be the result of , for instance , a placebo effect or postoperative physiotherapy . The findings question the value of this operation for these indications , and this should be communicated to patients during the shared treatment decision-making process . Funding Arthritis Research UK , the National Institute for Health Research Biomedical Research Centre , and the Royal College of Surgeons ( Engl and ) BACKGROUND The treatment effect of acromioplasty for chronic subacromial pain syndrome ( SAPS ) on long-term shoulder function and rotator cuff deterioration has still to be determined . This study aim ed to determine the long-term clinical and radiologic treatment effect of arthroscopic acromioplasty in patients with chronic SAPS . METHODS In this double-blind , r and omized clinical trial , 56 patients with chronic SAPS ( median age , 47 years ; age range , 31 - 60 years ) were r and omly allocated to arthroscopic bursectomy alone or to bursectomy combined with acromioplasty and were followed up for a median of 12 years . The primary outcome was the Constant score . Secondary outcomes included the Simple Shoulder Test , visual analog scale ( VAS ) for pain , VAS for shoulder functionality , and rotator cuff integrity assessed with magnetic resonance imaging or ultrasound . RESULTS A total of 43 patients ( 77 % ) were examined at a median of 12 years ' follow-up . Intention-to-treat analysis at 12 years ' follow-up did not show a significant additional treatment effect of acromioplasty on bursectomy alone in improvement in Constant score ( 5 points ; 95 % confidence interval , -5.1 to 15.6 ) , Simple Shoulder Test score , VAS score for pain , or VAS score for shoulder function . The prevalence of rotator cuff tears was not significantly different between the bursectomy group ( 17 % ) and acromioplasty group ( 10 % ) . CONCLUSIONS There were no relevant additional effects of arthroscopic acromioplasty on bursectomy alone with respect to clinical outcomes and rotator cuff integrity at 12 years ' follow-up . These findings bring the effectiveness of acromioplasty into question and may support the idea of a more conservative approach in the initial treatment of SAPS Background : The long-term outcome after the treatment of subacromial impingement syndrome ( SAIS ) with either nonsurgical or surgical methods has not been thoroughly investigated . Hypothesis/ Purpose : The purpose was to evaluate the long-term clinical outcome and the presence of rotator cuff injuries and osteoarthritis ( OA ) after the surgical and nonsurgical treatment of SAIS . The hypothesis was that , at a minimum 10 years after the initial treatment , patients who had undergone acromioplasty  would have a better clinical outcome and run a lower risk of developing rotator cuff ruptures and OA as compared with those treated with physical therapy . Study Design : R and omized controlled trial ; Level of evidence , 2 . Methods : Eighty-seven patients with SAIS were r and omized to 3 groups : open acromioplasty ( open surgery group [ OSG ] ) , arthroscopic acromioplasty ( arthroscopic surgery group [ ASG ] ) , and nonsurgical treatment ( physical therapy group [ PTG ] ) . The Constant score , the Watson and Sonnabend score , and the 36-Item Short Form Health Survey ( SF-36 ) question naire were used as outcome measurements . Furthermore , bilateral ultrasound examinations were performed to detect rotator cuff ruptures and bilateral radiographs to detect OA . Sixty-six patients ( 76 % ) attended the clinical follow-up at least 10 years after the initial treatment . Results : The groups were demographically comparable at baseline . The Constant score improved significantly at follow-up for the OSG ( P = .003 ) and ASG ( P = .011 ) , while no significant improvement was detected for the PTG . The OSG revealed a significant improvement versus the PTG at follow-up ( P = .011 ) ; otherwise , no significant differences were found . For the Watson and Sonnabend score , the OSG revealed a significant improvement in 13 of 14 questions . The corresponding finding was made for the ASG and PTG in 9 of 14 questions ( P = .14 ) . According to ultrasound , 1 of 20 patients in the OSG had a full-thickness rotator cuff rupture on the index side . The corresponding finding was made for 1 of 18 patients in the ASG and 4 of 28 in the PTG ( P = .29 ) . Per the radiographs , 3 of 20 patients in the OSG had moderate or severe OA in the index shoulder . The corresponding finding was made for 1 of 18 patients in the ASG and 0 of 28 in the PTG ( P = .12 ) . Conclusion : After a minimum 10 years of follow-up , the surgical treatment of SAIS appears to render better clinical results than physical therapy alone . No significant differences were found among the groups in terms of the presence of full-thickness rotator cuff ruptures and OA Purpose To compare the results two to three years after intervention , using either surgical or non-operative treatment . Methods Eighty-seven patients with subacromial impingement syndrome ( SAIS ) were r and omised into  open acromioplasty ( OS group ) , arthroscopic acromioplasty ( AS group ) or physiotherapy ( PT group ) treatment . The assessment s comprised the Constant score , the Watson and Sonnabend score , the SF-36 evaluation and a clinical examination performed by an independent observer . Fifty-five patients attended the clinical follow-up . Results The groups were comparable at baseline in terms of demographics and clinical assessment s. No significant differences in terms of the clinical assessment s or health-related quality of life ( QoL ) were found between the study groups at follow-up . The Constant score had improved significantly at follow-up in both the OS group and the AS group ( p = 0.003 and 0.008 , respectively ) . At follow-up , the OS group revealed improved strength compared with before intervention ( p = 0.012 ) . All groups revealed a significantly improved internal rotation ( OSG p = 0.01 , ASG p = 0.005 , PTG p = 0.004 ) . The SF-36 was significantly improved in some scales within all three groups . The Watson and Sonnabend score was significantly improved in 12/14 questions for the OS group , in 5/14 questions for the AS group and in 6/14 for the PT group ( p < 0.02 OS group vs. AS group , p < 0.05 OS group vs. PT group ) . Conclusion In this r and omised study , the Constant score , other clinical assessment s and subjective health-related QoL revealed no significant differences between the 3 groups two to three years after intervention in patients with SAIS . The OS group showed a greater improvement over time . Level of evidence CT with low follow-up rate , Level II Background Arthroscopic subacromial decompression ( ASAD ) is a commonly performed surgical intervention for shoulder pain . The rationale is that removal of a bony acromial spur relieves symptoms by decompressing rotator cuff tendons passing through the subacromial space . However , the efficacy of this procedure is uncertain . The objective of this trial was to compare the efficacy and cost-effectiveness of ASAD in patients with subacromial pain using appropriate control groups , including placebo intervention . Methods / Design The trial is a three-group , parallel design , pragmatic , r and omised controlled study . The intervention content for each group ( ASAD , active monitoring with specialist re assessment ( AMSR ) and investigational shoulder arthroscopy only ( AO ) ) enables assessment of ( 1 ) the efficacy of the surgery against no surgery ; ( 2 ) the need for a specific component of the surgery — namely , removal of the bony spur ; and ( 3 ) quantification of the placebo effect . Concealed allocation was performed using a 1:1:1 r and omisation ratio and using age , sex , baseline Oxford Shoulder Score ( OSS ) and centre as minimisation criteria . The primary outcome measure is the OSS at 
    Output:
    
Subacromial decompression surgery provided no important benefit compared with placebo surgery or exercise therapy , and probably carries a small risk of serious harms .