***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: Introduction Evidence to support or refute closed suction drainage ( CSD ) in primary total hip replacement ( THR ) is not conclusive . Our anecdotical experience was that persistent ooze from the drainage hole often delayed wound recovery . We hypothesized that , without CSD , wound care would be simplified without short or long term disadvantage . Material s and methods Hundred patients scheduled for primary THR were r and omly assigned for CSD or non-drainage . Drains were withdrawn at day 2 . Pain , wound hematoma , number of dressing changes , time of persistent discharge from the operation site ( skin incision and drain hole ) , total blood loss and number of blood transfusions were prospect ively recorded . Hip function , presence of heterotopic ossifications ( HTO ) and complications were recorded at a follow visit 1 year after surgery . Results Wound sites managed without CSD needed significantly less wound dressings ( P < 0.001 ) and were dry at an earlier time ( P < 001 ) . Despite a significant bigger subfascial hematoma in the non-drained group ( P < 0.05 ) , in terms of pain , thigh swelling , total blood loss , number of transfusions needed , hip function and HTO no difference was recorded between the groups ( P = 0.2–0.82 ) . Conclusion To omit CSD in primary THR results in simplified and more rapid wound management without any disadvantage at short and long term The aim of this study was to assess medium term results of patellar resurfacing in total knee arthroplasty , specifically looking at anterior knee pain , patellofemoral function and need for reoperation . A prospect i ve cohort study was conducted with patients undergoing staged bilateral knee arthroplasty with the patella being resurfaced only on one side . This was due to change in the clinical practice of the senior author . Sixty patients were review ed clinical ly and radiologically on a regular basis . The surgery was either performed or supervised by the senior author in all cases . All patients received the cemented press-fit condylar © prosthesis . The Knee Society clinical rating system was used . Scores were recorded pre-operatively and post-operatively at three months , one year , two years and three yearly thereafter . The mean age of patients in the study group was 75 years ( range : 62–89 years ) . There were 42 women and 18 men in the study . The mean duration of follow-up was 4.5 years ( range : 2–12 years ) . There was no significant difference in the pre-operative scores in both groups . There were significantly better scores ( p < 0.05 ) on the resurfaced side as compared to the non-resurfaced side at final follow-up . No revision was carried out for patellofemoral complications on the resurfaced side . Four patients required revision in the form of patellar resurfacing on the non-resurfaced side for persistent anterior knee pain .  Patellar resurfacing is recommended in total knee arthroplasty for better functional outcome with regards to anterior knee pain and patellofemoral function Patellofemoral problems are a common cause of morbidity and reoperation after total knee arthroplasty . We made a prospect i ve study of 52 patients who had bilateral arthroplasty ( 104 knees ) and in whom the patella was resurfaced on one side and not on the other . A movable-bearing prosthesis with an anatomical femoral groove was implanted on both sides by the same surgeon using an otherwise identical technique . The mean follow-up was 5.24 years ( 2 to 10 ) . In the 30 available patients ( 60 knees ) there was no difference between the two sides in subjective preference , performance on ascending and descending stairs or the incidence of anterior knee pain . Radiographs showed no differences in prosthetic alignment , femoral condylar height , patellar congruency or joint line position . The use of an appropriate prosthetic design and careful surgical technique can provide equivalent results after knee arthroplasty with or without patellar resurfacing . Given the indications and criteria , which we discuss , retention of the patellar surface is an acceptable option Most literature reporting the impressive results from knee and hip replacement derives from international data . Few Australian studies have comprehensively compared outcomes after joint replacement up to 1 year . This paper compares the patterns of recovery across physical and patient-centred outcomes following knee or hip replacement in an Australian cohort . One hundred and twenty-two consecutive patients undergoing knee or hip replacement were prospect ively followed . Serial assessment s were conducted ( preoperatively , and 2 , 6 , 12 , 26 and 52 weeks post-surgery ) . Joint pain , patient 's global improvement , timed mobility , and complications were monitored . English-proficient patients completed WOMAC ( Western Ontario and McMaster Universities Osteoarthritis Index ) and SF-36v2 ( Medical Outcomes Short-Form 36 version 2 ) question naires . At 1 year , 81 % ( 55 knee , 44 hip ) were available for follow-up . Significant , large improvements ( up to 254 % ) were evident for most outcomes . Global improvement was reported by 97 % . Recovery for both surgical groups was greatest within the first 26 weeks , but hip patients improved more quickly in most outcomes . Wound disturbances were the most common complication ( 23 in total , 23 % ) and 13 patients ( 13 % ) were readmitted for complications . Recovery patterns were similar to that observed elsewhere . The physical and patient-centred outcomes provide a useful Australian reference for clinicians of the temporal aspects of recovery as well the differences between hip and knee surgeries . Complication and readmission rates appeared high , possibly partly explained by the rigorous capture method We performed a prospect i ve , r and omised controlled trial to assess the differences in the use of a conventional suction drain , an Autologous Blood Transfusion ( ABT ) drain and no drain , in 168 patients . There was no significant difference between the drainage from ABT drains ( mean : 345 ml ) and the suction drain ( 314 ml ) . Forty percent of patients receiving a suction drain had a haemoglobin level less than 10 g/dL at 24 hours , compared to 35 % with no drain and 28 % with an ABT drain . Patients that had no drains had wounds that were dry significantly sooner , mean 3.0 days compared to a mean of 3.9 days with an ABT drain and a mean of 4 days with a suction drain . Patients that did not have a drain inserted stayed in hospital a significantly shorter period of time , compared with drains . We feel the benefits of quicker drying wounds , shorter hospital stays and the economic savings justify the conclusion that no drain is required after hip replacement BACKGROUND The purpose of this study was to determine the utility of closed suction drainage ( CSD ) in elective total hip arthroplasty ( THA ) . PATIENTS AND METHODS We r and omized 104 elective , consecutive THAs to receive drainage ( 53 ) or no drainage ( 51 ) . 60 arthroplasties were cemented and 44 hybrid . RESULTS In the drainage group , 2 hematomas and 2 superficial wound infections occurred ; there were no wound complications in the undrained group ( p = 0.04 ) . Patients receiving drainage had a greater reduction in hematocrit ( 10.4 vs 7.4 ) ( p = 0.03 ) , and longer hospital stay ( 5.1 days vs 4.7 ) ( p = 0.01 ) . At the 3-month follow-up , we found no deep wound infections in either group . INTERPRETATION We no longer use CSD in elective , primary , routine THA 
    Output:
    
Recommendations for routine use or not exist for some of the acute-care interventions examined .
Surgeon practice s vary widely even in the presence of high-level recommendations .
It is unclear whether further evidence alone would lessen unwarranted practice variation