***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 Inferior scapular notching following reverse shoulder arthroplasty is due to mechanical impingement and , in some studies , has been associated with poorer functional scores , lower patient satisfaction , and more limited shoulder motion . We aim ed to test the hypothesis that inferior positioning of the center of rotation with eccentric glenosphere design s decreases the adduction deficit before impingement occurs and improves clinical outcome . METHODS A r and omized , controlled , double-blinded trial was performed . According to the results of a power analysis , fifty patients undergoing reverse shoulder arthroplasty for the diagnosis of cuff tear arthropathy were r and omized intraoperatively to receive either a concentric or eccentric glenosphere . The glenoid baseplate was positioned flush to the inferior border of the glenoid before the glenosphere was then attached . Notching  was assessed using an  anteroposterior radiograph , and clinical outcome was assessed using the visual analog pain scale score , shoulder function rating , American Shoulder and Elbow Surgeons score , and Oxford shoulder score . Active forward elevation and external rotation were assessed . The outcome assessor was blinded to the treatment group . The mean follow-up period for the groups was forty-three and forty-seven months . RESULTS Patient demographics and preoperative scores were similar between the groups . At the time of the final follow-up , four patients ( 14.8 % ) in the concentric group had developed inferior scapular notching ( two with Nerot grade I and two with Nerot grade II ) , ranging in size from 1.1 to 7.4 mm , compared with one patient ( 4.3 % ; Nerot grade I ) in the eccentric group ( p = 0.36 ) . No notching occurred in any patient with glenoid overhang of > 3.5 mm . No significant difference between the groups was seen with respect to functional outcome scores , patient satisfaction , or shoulder motion . CONCLUSIONS There were no differences in notching rates or clinical outcomes between concentric and eccentric glenospheres following reverse shoulder arthroplasty . Inferior glenosphere overhang of > 3.5 mm , however , prevented notching . This may be achieved with a modified surgical technique , but eccentric glenospheres provide an additional option . LEVEL OF EVIDENCE Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence The choice is not clear cut and patients ’ expectations and preferences may affect the outcome In this issue Hay et al 1 report the results of a r and omised clinical trial evaluating the effectiveness of physiotherapy and corticosteroid injection  for patients with unilateral shoulder pain . Shoulder pain is a common complaint ; estimates of the annual incidence in general practice vary from 6.6 to 25 cases per 1000 patients .2–4 Most patients are treated in primary care . If treatment with analgesics or non-steroidal anti-inflammatory drugs ( NSAIDs ) is not successful , patients with persistent symptoms are often referred for physiotherapy or treated with local infiltration of a corticosteroid.4 Until recently , evidence on the effectiveness of these interventions was scarce , particularly for primary care patients . Over the past few years two r and omised trials have been published that directly compared the effects of physiotherapy with corticosteroid injections.5,6  Both trials were carried out in Dutch general practice . The trial by Hay et al adds important and relevant information to this existing evidence . The trial is characterised by a thorough design , enrolled a relatively large number of patients , used relevant outcome measures , and achieved a nearly complete six months ’ follow up of participants . When examining the results of these three primary care trials , three issues arise for discussion . Firstly , the short term findings are rather different , with the Dutch trials clearly showing better effects of corticosteroid injections  , whereas the English trial reports similar outcomes for the two interventions . Secondly , all three trials show minor and non-significant differences at long term follow up.1,6,7 Thirdly , the somewhat ambiguous overall evidence may leave substantial room for considering patient preferences and expectations when applying the results in clinical practice . Figure 1a shows the self reported change of symptoms at 5–7 weeks of follow up for BACKGROUND Glenoid component loosening remains a significant issue after anatomic shoulder arthroplasty .  Pegged glenoid components have shown better lucency rates than keeled components in the short term ; however , midterm to long-term results have not fully been determined . We previously reported early outcomes of the current r and omized controlled group of patients , with higher glenoid lucency rates in those with a keeled glenoid . The purpose of this study was to evaluate the radiographic and clinical outcomes of these components at minimum 5-year follow-up . METHODS Fifty-nine total shoulder arthroplasties were performed in patients with primary glenohumeral osteoarthritis . Patients were r and omized to receive either a pegged or keeled glenoid component . Three raters grade d radiographic glenoid lucencies . Clinical outcome scores and active mobility outcomes were collected preoperatively and at yearly postoperative appointments . RESULTS Of the 46 shoulders meeting the inclusion criteria , 38 ( 82.6 % ) were available for minimum 5-year radiographic follow-up . After an average of 7.9 years , radiographic lucency was present in 100 % of pegged and 91 % of keeled components ( P = .617 ) . Grade 4 or 5 lucency was present in 44 % of pegged and 36 % of keeled components ( P = .743 ) . There were no differences in clinical outcome scores or active mobility outcomes between shoulders with pegged and keeled components at last follow-up . Within the initial cohort , 20 % of the keeled shoulders ( 6 of 30 ) and 7 % of the pegged shoulders ( 2 of 29 ) underwent revision surgery ( P = .263 ) . Kaplan-Meier analysis showed no significant difference in survival rates between groups ( P = .560 ) . CONCLUSION At an average 7.9-year follow-up , non-ingrowth , all-polyethylene pegged glenoid implants are equivalent to keeled implants with respect to radiolucency , clinical outcomes , and need for revision surgery BACKGROUND Presently , there are no approved nonoperative therapies for the ongoing treatment of persistent shoulder pain .  Preliminary data suggest that intra-articular sodium hyaluronate injections may be beneficial for the treatment of persistent shoulder pain result ing from various etiologies . The present study evaluated the efficacy and safety of sodium hyaluronate ( Hyalgan ; molecular weight , 500 to 730 kDa ) for these patients . METHODS Six hundred and sixty patients with persistent shoulder pain and limitation result ing from glenohumeral joint osteoarthritis , rotator cuff tear , and /or adhesive capsulitis who had had a failure of conventional therapy were enrolled in this double-blind , r and omized , phosphate-buffered saline solution-controlled study , and 456 patients completed twenty-six weeks of follow-up . Patients were r and omized to receive either five weekly intra-articular injections of sodium hyaluronate , three weekly intra-articular injections of sodium hyaluronate followed by two weekly intra-articular injections of saline solution , or five weekly intra-articular injections of saline solution . The main outcomes were improvement in terms of shoulder pain on movement at thirteen weeks after the initiation of treatment ( as assessed with use of a 100-mm visual analog scale ) and the treatment effect throughout twenty-six weeks . RESULTS For the overall intent-to-treat population , patients who were managed with sodium hyaluronate had greater pain relief than controls did ; significant differences were noted at Week 7 ( for the five-injection hyaluronate group ) , Week 17 ( for the three and five-injection hyaluronate groups ) , and Week 26 ( for the three-injection hyaluronate group ) . Analysis of the stratified population s clearly established that this effect was due to benefits experienced by the patients with osteoarthritis . The treatment effect through twenty-six weeks was significant in patients with osteoarthritis in the three-injection ( p = 0.003 ) and five-injection ( p = 0.002 ) groups , with no significant difference for either regimen in patients without osteoarthritis . The safety profile was very favorable , with no product-related serious adverse effects and no between-group differences for any reported adverse event . CONCLUSIONS Although the primary end point of this study ( that is , improvement in terms of shoulder pain at thirteen weeks ) was not achieved , the overall findings , including secondary end points , indicate that sodium hyaluronate ( 500 to 730 kDa ) is effective and well tolerated for the treatment of osteoarthritis and persistent shoulder pain that is refractory to other st and ard nonoperative interventions BACKGROUND Controversy exists regarding the optimal technique of subscapularis mobilization during shoulder arthroplasty . The purpose of this study was to compare healing rates and subscapularis fatty infiltration in patients undergoing a lesser tuberosity osteotomy ( LTO ) versus subscapularis peel for exposure during shoulder arthroplasty . MATERIAL S AND METHODS Eighty-seven patients , with a mean age of 67.8 ± 10.9 years , undergoing shoulder arthroplasty , were r and omized to receive either an LTO ( n = 43 ) or peel ( n = 44 ) . Computed tomography scans were conducted preoperatively and at 12 months postoperatively . Outcome variables included healing rates and subscapularis Goutallier fatty infiltration grade , as well as subscapularis strength and Western Ontario Osteoarthritis of the Shoulder Index and American Shoulder and Elbow Surgeons outcome scores . RESULTS Computed tomography imaging was available in 91 % ( n = 79 ) of the cohort . The healing rates for the peel ( 100 % ) and for the LTO ( 95 % ) did not differ significantly ( P = .493 ) . Preoperatively , the mean fatty infiltration grade for the peel ( mean , 0.53 ) was not significantly different ( P = .925 ) from the LTO ( mean , 0.54 ) . Postoperatively , the Goutallier mean fatty infiltration grade for the peel ( mean , 0.95 ) did not differ significantly ( P = .803 ) from the LTO ( mean , 0.9 ) . A significant increase in subscapularis fatty infiltration grade occurred postoperatively from the preoperative status ( peel , P = .003 ; LTO , P = .0002 ) . No statistically significant associations were observed between postoperative fatty infiltration grade s and subscapularis strength , Western Ontario Osteoarthritis of the Shoulder Index scores , or American Shoulder and Elbow Surgeons scores . DISCUSSION No statistically significant differences were observed in the healing rates or subscapularis fatty infiltration grade s between the peel and the LTO . This trial does not show any clear difference in radiologic and clinical outcomes of one subscapularis management technique over the other BACKGROUND Both total shoulder arthroplasty and hemiarthroplasty have been used commonly to treat severe osteoarthritis of the shoulder ; however , their effect on disease-specific quality -of-life outcome is unknown . The purpose of this study was to compare the quality -of-life outcome following hemiarthroplasty with that following total shoulder arthroplasty in patients with osteoarthritis of the shoulder . METHODS Forty-two patients with a diagnosis of osteoarthritis of the shoulder were r and omized to receive a hemiarthroplasty or a total shoulder arthroplasty .  One patient died , and all others were evaluated preoperatively and at six weeks and three , six , twelve , eighteen , and twenty-four months postoperatively with use of a st and ardized format including a disease-specific quality -of-life measurement tool ( Western Ontario Osteoarthritis of the Shoulder [ WOOS ] index ) , general shoulder rating scales ( University of California at Los Angeles [ UCLA ] shoulder scale , Constant score , and American Shoulder and Elbow Surgeons [ ASES ] evaluation form ) , general pain scales ( McGill pain score and visual analogue scale ) , and a global health measure ( Short Form-36 [ SF-36 ] ) . When a patient required revision of a hemiarthroplasty to a total shoulder arthroplasty , the last score before he or she " crossed over " was used for the analysis . RESULTS Significant improvements in disease-specific quality of life were seen two years after both the total shoulder arthroplasties and the hemiarthroplasties . There were no significant differences in quality of life ( WOOS score ) between the group treated with total shoulder arthroplasty and that treated with hemiarthroplasty ( 90.6 + /- 13.2 and 81.5 + /- 24.1 points , respectively ; p = 0.18 ) . The other outcome measures demonstrated similar findings . Two patients in the hemiarthroplasty group crossed over to the other group by undergoing a revision to a total shoulder arthroplasty because of glenoid arthrosis . CONCLUSIONS Both total shoulder arthroplasty and hemiarthroplasty improve disease-specific and general quality -of-life measurements . With the small number of patients in our study , we found no significant differences in these measurements between the two treatment groups . LEVEL OF EVIDENCE Therapeutic Level OBJECTIVES : To determine , in a population based study , the influence of occupational factors on the occurrence of  shoulder pain and disability .  METHODS : A r and om sample of patients was selected from the register of a general practice in the Greater Manchester area of the United Kingdom . Information was collected by a posted question naire with specific 
    Output:
    
At two years , low- quality evidence from two trials ( down grade d for bias and imprecision ) suggested there may be a small but clinical ly uncertain improvement in pain and function .
Although it is an established procedure , no high- quality r and omised trials have been conducted to determine whether shoulder replacement might be more effective than other treatments for osteoarthritis or rotator cuff tear arthropathy of the shoulder .
We remain uncertain about which type or technique of shoulder replacement surgery is most effective in different situations .
When  humeral hemiarthroplasty  was compared to  TSR surgery for osteoarthritis , low- quality evidence led to uncertainty about whether there is a clinical ly important benefit for patient-reported pain or function and suggested there may be little or no difference in quality of life .
Evidence is insufficient to show whether TSR is associated with greater or less risk of harm than humeral hemiarthroplasty .
Although reverse TSR is now the most commonly performed type of shoulder replacement , we found no studies comparing reverse TSR to any other type of treatment