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: Background : The indications for resurfacing of the glenoid in patients who have osteoarthritis of the shoulder are not clearly defined ; some investigators routinely perform hemiarthroplasty whereas others perform total shoulder arthroplasty . Methods : Forty-seven patients ( fifty-one shoulders ) who were scheduled to have a shoulder arthroplasty for the treatment of degenerative osteoarthritis were r and omly assigned , according to a r and om-numbers table , to one of two groups : replacement of the humeral head with resurfacing of the glenoid with a polyethylene component with cement ( total shoulder arthroplasty [ twenty-seven shoulders ] ) or replacement of the humeral head without resurfacing of the glenoid ( hemiarthroplasty [ twenty-four shoulders ] ) . All patients received the same type of humeral component , and all operations were performed by or under the direct supervision of the same surgeon . The patients were followed for a mean of thirty-five months ( range , twenty-four to seventy-two months ) postoperatively . Evaluation was performed with use of the scoring systems of the University of California at Los Angeles and the American Shoulder and Elbow Surgeons . Results : No difference was observed between the preoperative scores for the two groups of patients . Postoperatively , the mean scores with use of the University of California at Los Angeles system and the American Shoulder and Elbow Surgeons system were 23.2 points ( range , 10 to 31 points ) and 65.2 points ( range , 15 to 94 points ) , respectively , after hemiarthroplasty and 27.4 points ( range , 9 to 34 points ) and 77.3 points ( range , 3 to 100 points ) , respectively , after total shoulder arthroplasty . With the numbers available for study , no significant difference was found between the two operative groups with respect to the postoperative score . ( Thirty-five subjects per group would be needed , assuming an effect size of 0.60 and a power of 0.80 . ) Total shoulder arthroplasty provided significantly greater pain relief ( p = 0.002 ) and internal rotation ( p = 0.003 ) than hemiarthroplasty did . Total shoulder arthroplasty also provided superior results in the specific areas of patient satisfaction , function , and strength , although none of these differences were found to be significant , with the numbers available . Total shoulder arthroplasty was associated with increased cost ( $ 1177 ) , operative time ( thirty-five minutes ) , and blood loss ( 150 milliliters ) per patient compared with hemiarthroplasty . To date , none of the total shoulder arthroplasties in the study group have been revised . Hemiarthroplasty yielded equivalent results for elevation and external rotation . Three of the twenty-five patients who had had a hemiarthroplasty needed a subsequent operation for resurfacing of the glenoid . The mean cost for the revision operations was $ 15,998 . Conclusions : Total shoulder arthroplasty provided superior pain relief compared with hemiarthroplasty in patients who had glenohumeral osteoarthritis , but it was associated with an increased cost of $ 1177 per patient BACKGROUND We compared hemiarthroplasty ( HA ) and total shoulder replacement ( TSR ) for the treatment of  osteoarthritis at minimum of 10 years from primary arthroplasty . METHODS Thirty-three patients ( 13 HA and 20 TSR ) were intraoperatively r and omized to HA or TSR after glenoid exposure and were assessed to a minimum of 10 years postoperatively . Apart from those who died , no patients were lost to follow-up . RESULTS At 6 months and 1 year , the TSR patients had less pain than the HA patients ( P < .05 ) , and this became more apparent at 2 years postoperatively ( P < .02 ) . There were no statistically significant differences between the groups at 10 years with respect to pain , function , and daily activities . No patients in the HA group rated their shoulders as pain-free at 10 years ; however , 42 % of the surviving TSR patients rated their shoulders as pain-free at 10 years . Four HA patients were revised to TSR due to severe pain secondary to glenoid erosion . Two shoulders in the TSR group have been revised . Nine of the 13 HA patients ( 69 % ) and 18 of the 20 TSR patients ( 90 % ) remained in situ at death or at the 10-year review . CONCLUSION TSR has advantages over HA with respect to pain and function at 2 years , and there has not been a reversal of the outcomes on longer follow-up . This longer-term review does not support the contention that HA will avoid later TSR complications , and in particular , an unacceptable rate of glenoid component failure Background : Because of specific method ological difficulties in conducting r and omized trials , surgical research remains dependent predominantly on observational or non‐r and omized studies . Few vali date d instruments are available to determine the method ological quality of such studies either from the reader 's perspective or for the purpose of meta‐ analysis . The aim of the present study was to develop and vali date such an instrument Background Glenohumeral osteoarthritis has been a well-described complication of open procedures to correct shoulder instability . What remains unknown is whether chondral injuries sustained during instability episodes contribute to osteoarthritis or whether the cause is primarily the stabilization procedure itself . Purpose To determine the prevalence of osteoarthrosis in a large data base of patients with acute and chronic shoulder instability before primary stabilization surgery . Study Design Retrospective review of prospect ively collected data . Methods Surgical and demographic data were collected on 422 patients with a diagnosis of shoulder instability who underwent arthroscopic examination and shoulder stabilization .  Results There was a significant association between the grade of osteoarthrosis and the presence of osteoarthritis ( grade III or IV chondral damage ) with time from injury to surgery . Patients with osteoarthritis  were significantly older than those without ( 34.9 versus 29.6 years ) . Multivariate analysis identified older age and time from injury to surgery as independent predictors of osteoarthritis . We found no association between direction of instability and the presence of osteoarthritis . Conclusion The overall prevalence of glenohumeral osteoarthrosis was low . Predictors of osteoarthritis included time from injury to surgery and age 
    Output:
    
agent
Complication and reoperation rates are higher compared to shoulder arthroplasty for primary glenohumeral joint arthritis ; however , the difference is not statistically significant .
When reverse shoulder arthroplasties ( RSA ) were considered as a subgroup and compared to anatomic shoulder replacements ( total shoulders and hemiarthroplasties ) , they showed a lower revision rate
***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: Background : The indications for resurfacing of the glenoid in patients who have osteoarthritis of the shoulder are not clearly defined ; some investigators routinely perform hemiarthroplasty whereas others perform total shoulder arthroplasty . Methods : Forty-seven patients ( fifty-one shoulders ) who were scheduled to have a shoulder arthroplasty for the treatment of degenerative osteoarthritis were r and omly assigned , according to a r and om-numbers table , to one of two groups : replacement of the humeral head with resurfacing of the glenoid with a polyethylene component with cement ( total shoulder arthroplasty [ twenty-seven shoulders ] ) or replacement of the humeral head without resurfacing of the glenoid ( hemiarthroplasty [ twenty-four shoulders ] ) . All patients received the same type of humeral component , and all operations were performed by or under the direct supervision of the same surgeon . The patients were followed for a mean of thirty-five months ( range , twenty-four to seventy-two months ) postoperatively . Evaluation was performed with use of the scoring systems of the University of California at Los Angeles and the American Shoulder and Elbow Surgeons . Results : No difference was observed between the preoperative scores for the two groups of patients . Postoperatively , the mean scores with use of the University of California at Los Angeles system and the American Shoulder and Elbow Surgeons system were 23.2 points ( range , 10 to 31 points ) and 65.2 points ( range , 15 to 94 points ) , respectively , after hemiarthroplasty and 27.4 points ( range , 9 to 34 points ) and 77.3 points ( range , 3 to 100 points ) , respectively , after total shoulder arthroplasty . With the numbers available for study , no significant difference was found between the two operative groups with respect to the postoperative score . ( Thirty-five subjects per group would be needed , assuming an effect size of 0.60 and a power of 0.80 . ) Total shoulder arthroplasty provided significantly greater pain relief ( p = 0.002 ) and internal rotation ( p = 0.003 ) than hemiarthroplasty did . Total shoulder arthroplasty also provided superior results in the specific areas of patient satisfaction , function , and strength , although none of these differences were found to be significant , with the numbers available . Total shoulder arthroplasty was associated with increased cost ( $ 1177 ) , operative time ( thirty-five minutes ) , and blood loss ( 150 milliliters ) per patient compared with hemiarthroplasty . To date , none of the total shoulder arthroplasties in the study group have been revised . Hemiarthroplasty yielded equivalent results for elevation and external rotation . Three of the twenty-five patients who had had a hemiarthroplasty needed a subsequent operation for resurfacing of the glenoid . The mean cost for the revision operations was $ 15,998 . Conclusions : Total shoulder arthroplasty provided superior pain relief compared with hemiarthroplasty in patients who had glenohumeral osteoarthritis , but it was associated with an increased cost of $ 1177 per patient BACKGROUND We compared hemiarthroplasty ( HA ) and total shoulder replacement ( TSR ) for the treatment of  osteoarthritis at minimum of 10 years from primary arthroplasty . METHODS Thirty-three patients ( 13 HA and 20 TSR ) were intraoperatively r and omized to HA or TSR after glenoid exposure and were assessed to a minimum of 10 years postoperatively . Apart from those who died , no patients were lost to follow-up . RESULTS At 6 months and 1 year , the TSR patients had less pain than the HA patients ( P < .05 ) , and this became more apparent at 2 years postoperatively ( P < .02 ) . There were no statistically significant differences between the groups at 10 years with respect to pain , function , and daily activities . No patients in the HA group rated their shoulders as pain-free at 10 years ; however , 42 % of the surviving TSR patients rated their shoulders as pain-free at 10 years . Four HA patients were revised to TSR due to severe pain secondary to glenoid erosion . Two shoulders in the TSR group have been revised . Nine of the 13 HA patients ( 69 % ) and 18 of the 20 TSR patients ( 90 % ) remained in situ at death or at the 10-year review . CONCLUSION TSR has advantages over HA with respect to pain and function at 2 years , and there has not been a reversal of the outcomes on longer follow-up . This longer-term review does not support the contention that HA will avoid later TSR complications , and in particular , an unacceptable rate of glenoid component failure Background : Because of specific method ological difficulties in conducting r and omized trials , surgical research remains dependent predominantly on observational or non‐r and omized studies . Few vali date d instruments are available to determine the method ological quality of such studies either from the reader 's perspective or for the purpose of meta‐ analysis . The aim of the present study was to develop and vali date such an instrument Background Glenohumeral osteoarthritis has been a well-described complication of open procedures to correct shoulder instability . What remains unknown is whether chondral injuries sustained during instability episodes contribute to osteoarthritis or whether the cause is primarily the stabilization procedure itself . Purpose To determine the prevalence of osteoarthrosis in a large data base of patients with acute and chronic shoulder instability before primary stabilization surgery . Study Design Retrospective review of prospect ively collected data . Methods Surgical and demographic data were collected on 422 patients with a diagnosis of shoulder instability who underwent arthroscopic examination and shoulder stabilization .  Results There was a significant association between the grade of osteoarthrosis and the presence of osteoarthritis ( grade III or IV chondral damage ) with time from injury to surgery . Patients with osteoarthritis  were significantly older than those without ( 34.9 versus 29.6 years ) . Multivariate analysis identified older age and time from injury to surgery as independent predictors of osteoarthritis . We found no association between direction of instability and the presence of osteoarthritis . Conclusion The overall prevalence of glenohumeral osteoarthrosis was low . Predictors of osteoarthritis included time from injury to surgery and age 
    Output:
    