***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 : To evaluate whether patient characteristics and /or radiographic disease patterns predict symptomatic response to treatment with glucosamine in osteoarthritis ( OA ) of the knee . Design : Exploratory prospect i ve correlational study . Setting : Institutional . Patients : 39 participants with chronic knee pain from the local community . Interventions : Glucosamine sulphate ( 1.5 g/day ) for 12 weeks . Main outcome measures : Pain and physical function were assessed with visual analogue scales ( VASs ) and participant-perceived global change scores ( GCSs ) . Regression modelling evaluated the relationship between treatment outcome and age , body mass index ( BMI ) , pain and function self-efficacy and presence/absence of osteophytes in the medial and lateral tibiofemoral joint ( TFJ ) and patellofemoral joint ( PFJ ) compartments . Results : 13 ( 33 % ) participants were men . The mean ( SD ) age and BMI were 53.6 ( 13.1 ) years and 27.9 ( 4.6 ) kg/m2 , respectively . 13 ( 33 % ) , 19 ( 49 % ) and 24 ( 62 % ) participants had medial TFJ , lateral TFJ and PFJ osteophytes , respectively . Glucosamine significantly improved pain ( mean change on VAS = −1.4 , 95 % CI −0.6 to −2.2 ; p = 0.002 ) and activity restriction ( −1.9 , 95 % CI −1.0 to −2.8 ; p<0.001 ) . At 12 weeks , 30 ( 77 % ) and 27 ( 69 % ) participants reported improvement in pain and physical function , respectively . Regression modelling showed that no evaluated variables predicted change in pain on VAS . Decreased function self-efficacy , presence of PFJ osteophytes and absence of medial TFJ osteophytes predicted functional improvement on VAS . BMI , pain self-efficacy and function self-efficacy predicted improvement in pain by GCS . Conclusions : Although glucosamine significantly improved symptoms , most of the variance in outcome at 12 weeks was unexplained by the predictors evaluated . However , glucosamine may be more effective at improving symptoms in patients with knee OA who have a lower BMI , PFJ osteophytes and lower functional self-efficacy OBJECTIVE To determine the effect of quadriceps strength in individuals with knee osteoarthritis ( OA ) on loss of cartilage at the tibiofemoral and patellofemoral joints ( assessed by magnetic resonance imaging [ MRI ] ) and on knee pain and function . METHODS We studied 265 subjects ( 154 men and 111 women , mean+/-SD age 67+/-9 years ) who met the American College of Rheumatology criteria for symptomatic knee OA and who were participating in a prospect i ve , 30-month natural history study of knee OA . Quadriceps strength was measured at baseline , isokinetically , during concentric knee extension . MRI of the knee at baseline and at 15 and 30 months was used to assess cartilage loss at the tibiofemoral and patellofemoral joints , with medial and lateral compartments assessed separately . At baseline and at followup visits , knee pain was assessed using a visual analog scale , and physical function was assessed using the Western Ontario and McMaster Universities Osteoarthritis Index . RESULTS There was no association between quadriceps strength and cartilage loss at the tibiofemoral joint . Results were similar in malaligned knees . However , greater quadriceps strength was protective against cartilage loss at the lateral compartment of the patellofemoral joint ( for highest versus lowest tertile of strength , odds ratio 0.4 [ 95 % confidence interval 0.2 , 0.9 ] ) . Those with greater quadriceps strength had less knee pain and better physical function over followup ( P<0.001 ) . CONCLUSION Greater quadriceps strength had no influence on cartilage loss at the tibiofemoral joint , including in malaligned knees . We report for the first time that greater quadriceps strength protected against cartilage loss at the lateral compartment of the patellofemoral joint , a finding that requires confirmation . Subjects with greater quadriceps strength also had less knee pain and better physical function over followup Background A recent study of adults aged ≥50 years reporting knee pain found an excess of radiographic knee osteoarthritis ( knee ROA ) in symptomatic males compared to females . This was independent of age , BMI and other clinical signs and symptoms . Since this finding contradicts many previous studies , our objective was to explore four possible explanations for this gender difference : X-ray views , selection , occupation and non-articular conditions . Methods A community-based prospect i ve study . 819 adults aged ≥50 years reporting knee pain in the previous 12 months were recruited by postal question naires to a research clinic involving plain radiography ( weight-bearing posteroanterior semiflexed , supine skyline and lateral views ) , clinical interview and physical examination . Any knee ROA , ROA severity , tibiofemoral joint osteoarthritis ( TJOA ) and patellofemoral joint osteoarthritis ( PJOA ) were defined using all three radiographic views . Occupational class was derived from current or last job title . Proportions of each gender with symptomatic knee ROA were expressed as percentages , stratified by age ; differences between genders were expressed as percentage differences with 95 % confidence intervals . Results 745 symptomatic participants were eligible and had complete X-ray data . Males had a higher occurrence ( 77 % ) of any knee ROA than females ( 61 % ) . In 50–64 year olds , the excess in men was mild knee OA ( particularly PJOA ) ; in ≥65 year olds , the excess was both mild and moderate/severe knee OA ( particularly combined TJOA/PJOA ) . This male excess persisted when using the posteroanterior view only ( 64 % vs. 52 % ) . The lowest level of participation in the clinic was symptomatic females aged 65 + . Within each occupational class there were more males with symptomatic knee ROA than females . In those aged 50–64 years , non-articular conditions were equally common in both genders although , in those aged 65 + , they occurred more frequently in symptomatic females ( 41 % ) than males ( 31 % ) . Conclusion The excess of knee ROA among symptomatic males in this study seems unlikely to be attributable to the use of comprehensive X-ray views . Although prior occupational exposures and the presence of non-articular conditions can not be fully excluded , selective non-participation bias seems the most likely explanation . This has implication s for future study design Objective Braces used to treat ( PF ) osteoarthritis ( OA ) may reduce contact stress across the PF joint . We hypothesised that in PF OA , braces would decrease knee pain and shrink PF bone marrow lesions ( BMLs ) . Methods Eligible subjects had painful PF OA . Subjects were r and omly allocated to brace or no brace for 6 weeks . Knee MRIs were acquired at baseline and 6 weeks . We measured BMLs on post-contrast fat suppressed sagittal and proton density weighted axial images . The primary symptom outcome was change in pain at 6 weeks during a preselected painful activity , and the primary structural outcome was BML volume change in the PF joint . Analyses used multiple linear regression . Results We r and omised 126 subjects aged 40–70 years ( mean age 55.5 years ; 72 females ( 57.1 % ) ) . Mean nominated visual analogue scale ( 0–10 cm ) pain score at baseline was 6.5 cm . 94 knees ( 75 % ) had PF BMLs  at baseline . Subjects wore the brace for a mean of 7.4 h/day . 6 subjects withdrew during the trial . After accounting for baseline values , the brace group had lower knee pain than the control group at 6 weeks ( difference between groups −1.3 cm , 95 % CI −2.0 to −0.7 ; p<0.001 ) and reduced PF BML volume ( difference −490.6 mm3 , 95 % CI −929.5 to −51.7 ; p=0.03 ) but not tibiofemoral volume ( difference −53.9 mm3 , 95 % CI −625.9 to 518.2 ; p=0.85 ) . Conclusions A PF brace reduces BML volume in the targeted compartment of the knee , and relieves knee pain . Trial registration number UK . IS RCT N50380458 OBJECTIVE To determine whether a complete anterior cruciate ligament ( ACL ) tear , a frequent incidental finding on magnetic resonance imagings ( MRIs ) of individuals with established knee osteoarthritis ( OA ) , increases the risk for further knee OA progression . METHODS We examined 265 participants ( 43 % women ) with symptomatic knee OA in a 30-month , prospect i ve , natural history study of knee OA . The more symptomatic knee was imaged using MRI at baseline , 15 and 30 months . Cartilage was scored at the medial and lateral tibiofemoral joint and at the patellofemoral joint using the Whole-Organ MRI Score ( WORMS ) semi-quantitative method . Complete ACL tear was determined on baseline MRI . At each visit , knee pain was assessed using a knee-specific visual analog scale and physical function was assessed using the Western Ontario and McMaster Universities ( WOMAC ) physical function subscale . RESULTS There were 49 participants ( 19 % ) with complete ACL tear at baseline . Adjusting for age , body mass index , gender and baseline cartilage scores , complete ACL tear increased the risk for cartilage loss at the medial tibiofemoral compartment [ odds ratio ( OR ) : 1.8 , 95 % confidence interval ( CI ) : 1.1 , 3.2 ] . However , following adjustment for the presence of medial meniscal tears , no increased risk for cartilage loss was further seen ( OR : 1.1 , 95 % CI : 0.6 , 1.8 ) . Knee pain and physical function were similar over follow-up between those with and without a complete ACL tear . CONCLUSIONS Individuals with knee OA and incidental complete ACL tear have an increased risk for cartilage loss that appears to be mediated by concurrent meniscal pathology . The presence of a complete ACL tear did not influence the level of knee pain or physical function over short-term follow-up Details of the development of early knee osteoarthritis ( OA ) are largely unknown . The prevalence and progression of  radiographic knee OA  over 6 years in middle-aged subjects with chronic knee pain is investigated . In a prospect i ve population -based study , tibiofemoral ( TF ) and patellofemoral ( PF ) radiographs were grade d in 128 subjects ( mean age 45 ± 6.2 years ) for the presence of osteophytes and joint space narrowing ( JSN ) . Radiographic progression was defined as : ( i ) the presence of osteophytes and /or JSN in subjects with no previous OA or ( ii ) an increase in the grade and /or number of already existing osteophytes and /or JSN . Altogether 56 % ( 72/128 ) of subjects had knee OA , the majority of them was diagnosed with OA grade 1 . In 57 % of cases , radiographic OA was based on the presence of osteophytes alone versus 13 % on JSN . More than 1/3 of subjects had isolated PF joint involvement . Knee OA progression rate over 6 years was 56 % ( 71/128 ) . During 6 years , a non-linear course of radiographic OA progression with intermittent periods of progression and stabilization was observed . Individual course of OA revealed distinct subsets of radiographic progression . Osteophytosis is an important early radiographic sign of OA and its progression . Isolated PF joint involvement is a frequent expression of knee OA . In middle-aged subjects , the progression rate of knee OA over 6 years was 56 % . A non-linear course of radiographic OA progression was observed . Several radiographic subsets refer to the heterogeneity of the OA process OBJECTIVE Patellofemoral joint osteoarthritis ( PFJ OA ) contributes considerably to knee OA symptoms . This study aim ed to determine the efficacy of a PFJ-targeted exercise , education manual-therapy and taping program compared to OA education alone , in participants with PFJ OA . METHODS A r and omised , participant-blinded and assessor-blinded clinical trial was conducted in primary -care physiotherapy . 92 people aged ≥40 years with symptomatic and radiographic PFJ OA participated . Physiotherapists delivered the PFJ-targeted exercise , education , manual-therapy and taping program , or the OA-education ( control condition ) in eight sessions over 12 weeks . Primary outcomes at 3-month ( primary ) and 9-month follow-up : ( 1 ) patient-perceived global rating of change ( 2 ) pain visual analogue scale ( VAS ) ( 100 mm ) ; and ( 3 ) activities of daily living ( ADL ) subscale of the Knee injury and Osteoarthritis Outcome Score ( KOOS ) . RESULTS 81 people ( 88 % ) completed the 3-month follow-up and data analysed on an intention-to-treat basis . Between-group baseline similarity for participant characteristics was observed 
    Output:
    
Prevalence of MRI findings was high in symptomatic and asymptomatic population .