***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: OBJECTIVE Intraarticular ( IA ) hylan injections constitute second-line therapy for osteoarthritis ( OA ) of the knee , but human studies suggesting a possible mechanism of action are lacking . We examined the effect of IA Hylan GF-20 injections on synovial fluid ( SF ) hyaluronan ( HA ) concentration , viscosity , and elasticity over a 6-month period in patients with mild to moderate OA of the knees . METHODS Patients with symptomatic knee OA ( Osteoarthritis Research Society International grade 1 - 2 ) had SF aspirated from the study knee pre- and 3 and 6 months post-Hylan injection . Primary endpoints included SF HA concentration , viscosity , and elasticity . SF HA concentration was determined using uronic acid assay , and rheology measured using a micro-Fourier rheometer . RESULTS Sequential SF sample s were available from 32 of 60 subjects injected at baseline ( 15 men , 17 women ; mean age 65 yrs ) at 3 months post-injection . The mean HA concentration had increased by 13 % ( p<0.0008 ) , and the complex shear modulus had increased by 16 % ( p<0.03 ) . Sufficient SF was also available from 19 of these subjects at 6 months post-injection when mean HA concentration was 2.24+/-0.62 mg/ml compared to their baseline mean of 2.02+/-0.52 mg/ml , an increase of 10 % ( p<0.053 ) . CONCLUSION This open-label study showed a statistically significant change from baseline in both SF HA concentration and complex shear modulus at 3 months following IA Hylan GF-20 injection among subjects with mild to moderate knee OA . These results suggest that one possible mechanism of action of viscosupplementation is to promote endogenous HA production . Longer-term studies are required to identify whether these changes in SF measures are important for modification of disease progression in knee OA The goal of this study was to determine whether hyaluronic acid ( HA ) or progressive knee exercises ( PE ) can improve functional parameters in patients with osteoarthritis ( OA ) of the knee . In a prospect i ve clinical trial 200 knees ( 105 patients ) with radiographic Kellgren Lawrence grade III OA were r and omized and received either three intra-articular injections of hyaluronic acid ( Hylan G-F 20 ) at one-week intervals or PE for 6 weeks . Patients were evaluated by use of the Hospital for Special Surgery ( HSS ) Knee Score and followed-up for 18 months . Total HSS score for HA and PE patients improved from 62.6±13.8 to 88.8±11.1 and from 65.4±12.3 to 88.3±9.1 , respectively , at the end of the trial ( P<0.01 ) . There were no statistically significant differences between the groups . Twenty-one patients of the HA group were excluded from the study because they had received another form of therapy . All patients in the PE group completed the trial . The patients who dropped out had also significant improvement from 57.0±12.9 to 76.7±11.9 ( P<0.01 ) . This prospect i ve r and omized trial confirmed that both HA injections and PE  result in functional improvement . HA injections also increase the levels of satisfaction of the OA patients To determine the safety and efficacy of viscosupplementation with hylan G-F 20 , a cross-linked hyaluronan preparation , used either alone or in combination with continuous non-steroidal anti-inflammatory drug ( NSAID ) therapy , a r and omized , controlled , multicenter clinical trial , assessed by a blinded assessor , was conducted in 102 patients with osteoarthritis ( OA ) of the knee . All patients were on continuous NSAID therapy for at least 30 days prior to entering the study . Patients were r and omized into three parallel groups : ( 1 ) NSAID continuation plus three control arthrocenteses at weekly intervals ; ( 2 ) NSAID discontinuation but with three weekly intra-articular injections of hylan G-F 20 ; and ( 3 ) NSAID continuation plus three injections , one every week , intra-articular injections of hylan G-F 20 . Outcome measures of pain and joint function were evaluated by both the patients and an evaluator at baseline and weeks 1 , 2 , 3 , 7 and 12 , with a follow-up telephone evaluation at 26 weeks . At 12 weeks all groups showed statistically significant improvements from baseline , but did not differ from each other . A statistical test for the equivalence , the q-statistic , demonstrated that viscosupplementation with hylan G-F 20 was at least as good or better than continuous NSAID therapy for all outcome measurements except activity restriction . At 26 weeks both groups receiving hylan G-F 20 were significantly better than the group receiving NSAIDs alone . A transient local reaction was observed in three patients after hylan G-F 20 injection ; only one patient withdrew from the study as a result and all recovered without any sequela . Hylan G-F 20 is a safe and effective treatment for OA of the knee and can be used either as a replacement for or an adjunct to NSAID therapy BACKGROUND The prevention of disability in activities of daily living ( ADL ) may prolong older persons ' autonomy ( older persons are defined in this study as those aged > or = 60 years ) . However , proved preventive strategies for ADL disability are lacking . A sedentary lifestyle is an important cause of disability . This study examines whether an exercise program can prevent ADL disability . METHODS A 2-center , r and omized , single-blind , controlled trial was conducted in which participants were assigned to an aerobic exercise program , a resistance exercise program , or an attention control group .  Of the 439 community-dwelling persons aged 60 years or older with knee osteoarthritis originally recruited , the 250 participants initially free of ADL disability were used for this study .  Incident ADL disability , defined as developing difficulty in transferring from a bed to a chair , eating , dressing , using the toilet , or bathing , was assessed quarterly during 18 months of follow-up . RESULTS The cumulative incidence of ADL disability was lower in the exercise groups ( 37.1 % ) than in the attention control group ( 52.5 % ) ( P = .02 ) . After adjustment for demographics and baseline physical function , the relative risk of incident ADL disability for assignment to exercise was 0.57 ( 95 % confidence interval , 0.38 - 0.85 ; P = .006 ) . Both exercise programs prevented ADL disability ; the relative risks were 0.60 ( 95 % confidence interval , 0.38 - 0.97 ; P = .04 ) for resistance exercise and 0.53 ( 95 % confidence interval , 0.33 - 0.85 ; P = .009 ) for aerobic exercise . The lowest ADL disability risks were found for participants with the highest compliance to exercise . CONCLUSIONS Aerobic and resistance exercise may reduce the incidence of ADL disability in older persons with knee osteoarthritis .  Exercise may be an effective strategy for preventing ADL disability and , consequently , may prolong older persons ' autonomy To describe the natural history of pain after total knee arthroplasty and to identify factors predicting excessive postoperative pain , we used a prospect i ve , observational study assessing clinical and radiographic variables preoperatively and at 1 , 3 , 6 , and 12 months after knee replacement .  Data sources included the visual analog pain scale and other measures of patient health , psychologic state , and component reliability . Regression analyses were conducted to identify specific factors predictive of postoperative pain , controlling for ine quality of variables , and confirmed using regression diagnostics . For 116 patients ( 149 knees ; mean age , 66 years ; 55.2 % women ) , significant pain was reported by 72.3 % , 44.4 % , 22.6 % , 18.4 % , and 13.1 % , respectively . No intergroup differences existed for anesthesia , weight , age , or gender . Patients with greater preoperative pain had more postoperative pain , used more home therapy , and postoperative manipulations . Preoperative depression and anxiety were associated with heightened pain at 1 year . Pain after knee replacement resolves quickly , declining to approximately 1/2 by 3 months . However , one in eight patients report moderate to severe pain 1 year after surgery despite an absence of clinical or radiographic abnormalities . Development of office-based preoperative screening tools and interventions for these patients may reduce postoperative costs and improve patient-perceived outcomes The index for hip disease ( ISH ) was established , vali date d and appraised as a new assessment test for the trial of new drugs as well as for long-term follow-up of patients , and to help with future indications for surgery . The ISH deals with pain , maximum walking distance , and some activities of daily living . Inter-observer reproducibility is good ( mean deviation 0.55 points ; p less than 0.05 ) . In a short-term , double-blind crossover trial , the ISH , judged according to its power to distinguish between the active drug period and the placebo period , appears as one of the best assessment tests . In the long term , total hip prosthesis is most often justified when the ISH score reaches 10 - 12 points . The index of severity for knee disease ( ISK ) was vali date d and appraised by the same statistical methods . Its value in non-steroidal anti-inflammatory drug ( NSAID ) or analgesic trials is lower than the value of the ISH . However , its use is still justified for that purpose , and for long-term follow-up of osteoarthritis of the knee Abstract Objectives : To determine whether a home based exercise programme can improve outcomes in patients with knee pain .  Design : Pragmatic , factorial r and omised controlled trial of two years ' duration . Setting : Two general practice s in Nottingham . Participants : 786 men and women aged—45 years with self reported knee pain . Interventions : Participants were r and omised to four groups to receive exercise therapy , monthly telephone contact , exercise therapy plus telephone contact , or no intervention . Patients in the no intervention and combined exercise and telephone groups were r and omised to receive or not receive a placebo health food tablet . Main outcome measures : Primary outcome was self reported score for knee pain on the Western Ontario and McMaster universities ( WOMAC ) osteoarthritis index at two years . Secondary outcomes included knee specific physical function and stiffness ( scored on WOMAC index ) , general physical function ( scored on SF-36 question naire ) , psychological outlook ( scored on hospital anxiety and depression scale ) , and isometric muscle strength . Results : 600 ( 76.3 % ) participants completed the study . At 24 months , highly significant reductions in knee pain were apparent for the pooled exercise groups compared with the non-exercise groups ( mean difference -0.82 , 95 % confidence interval -1.3 to -0.3 ) . Similar improvements were observed at 6 , 12 , and 18 months . Regular telephone contact alone did not reduce pain . The reduction in pain was greater the closer patients adhered to the exercise plan . Conclusions : A simple home based exercise programme can significantly reduce knee pain . The lack of improvement in patients who received only telephone contact suggests that improvements are not just due to psychosocial effects because of contact with the therapist OBJECTIVE To study the validity and feasibility of a computerized version of the Western Ontario and McMaster Universities ( WOMAC ) Osteoarthritis Index . METHODS Thirty patients with osteoarthritis ( OA ) of the knee completed both a paper and a computerized version of WOMAC in r and om order . The visual analog scaled version of WOMAC , VA3.0 , was used . We studied criterion validity by comparing the paper and computerized versions . RESULTS All patients completed the computerized version without undue difficulty . Criterion validity , based on aggregated subscale scores , was excellent : Pain , ICC = 0.89 , Stiffness , ICC = 0.87 , Physical Function , ICC = 0.95 . CONCLUSION The computerized version of WOMAC VA3.0 is a valid alternative to the paper version Within the context of a double blind r and omized controlled parallel trial of 2 nonsteroidal antiinflammatory drugs , we vali date d WOMAC , a new multidimensional , self-administered health status instrument for patients with osteoarthritis of the hip or knee . The pain , stiffness and physical function subscales fulfil conventional criteria for face , content and construct validity , reliability , responsiveness and relative efficiency . WOMAC is a disease-specific purpose built high performance instrument for evaluative research in osteoarthritis clinical trials OBJECTIVE To compare the efficacy and safety of intra-articular injections of two different hyaluronan preparations and placebo in patients with knee osteoarthritis . METHODS In a r and omized , patient- and observer-blind , placebo-controlled and multicentre trial with parallel groups , 210 patients , aged 60 yr or above , with knee osteoarthritis were included in a per protocol analysis . The patients were treated with three injections , once weekly , of either native high-molecular-weight hyaluronan ( Artzal((R ) ) ) or cross-linked hyaluronan ( Synvisc((R ) ) ) or with placebo and were followed for 52 weeks . The primary efficacy measures were weight-bearing pain during study weeks 0 - 
    Output:
    
Hylan G-F 20 significantly improved Western Ontario and McMaster Universities Osteoarthritis Index ( WOMAC ) physical function versus appropriate/conventional care or corticosteroid , it significantly improved loss of activity versus saline , and it had similar functional improvements compared with progressive knee exercises or nonsteroidal anti-inflammatory drugs .
Functional improvements with hylan G-F 20 also improved with pain relief .