***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 In this cross-sectional study , we conducted a comprehensive assessment of all articular elements that could be measured using knee MRI . We assessed the association of pathological change in multiple articular structures involved in the pathoanatomy of osteoarthritis . Methods  Knee MRI scans from patients over 45 years old were assessed using a semi-quantitative knee MRI assessment form . The form included six distinct elements : cartilage , bone marrow lesions , osteophytes , subchondral sclerosis , joint effusion and synovitis . Each type of pathology was grade d using an ordinal scale with a value of zero indicating no pathology and higher values indicating increasingly severe levels of pathology . The principal dependent variable for comparison was the mean cartilage disease score ( CDS ) , which captured the aggregate extent of involvement of articular cartilage . The distribution of CDS was compared to the individual and cumulative distributions of each articular element using the Chi-squared test . The correlations between pathological change in the various articular structures were assessed in a Spearman correlation table . Results Data from 140 patients were available for review . The cohort had a median age of 61 years ( range 45 - 89 ) and was 61 % female . The cohort included a wide spectrum of OA severity . Our analysis showed a statistically significant trend towards pathological change involving more articular elements as CDS worsened ( p-value for trend < 0.0001 ) . Comparison of CDS to change in the severity of pathology of individual articular elements showed statistically significant trends towards more severe pathology as CDS worsened for osteophytes ( p-value for trend < 0.0001 ) , bone marrow lesions ( p = 0.0003 ) , and subchondral sclerosis ( p = 0.009 ) , but not joint effusion or synovitis . There was a moderate correlation between cartilage damage , osteophytes and BMLs as well as a moderate correlation between joint effusion and synovitis . However , cartilage damage and osteophytes were only weakly associated with synovitis or joint effusion . Conclusion Our results support an inter-relationship of multiple articular elements in the pathoanatomy of knee OA . Prospect i ve studies of OA pathogenesis in humans are needed to correlate these findings to clinical ly relevant outcomes such as pain and function Summary We evaluated the association of bone mineral density ( BMD ) and osteoarthritis ( OA ) of the hip in elderly men . We found that elderly men with moderate to severe radiographic hip OA ( RHOA ) had significantly higher areal BMD ( aBMD ) and volumetric BMD ( vBMD ) at both the lumbar spine and hip compared to age similar controls without OA . Introduction We evaluated the association of BMD measured by dual energy X-ray absorptiometry ( DXA ) and quantitative computerized tomography ( integral , cortical , and trabecular vBMD ) and RHOA in a cohort of elderly men . Methods A cross-sectional analysis was conducted within the Study of Osteoporotic Fractures in Men , a prospect i ve cohort study of 5,995 US men age ≥ 65 years .  St and ing pelvic x-rays  were done in 4,024 subjects and scored for prevalent RHOA severity .  DXA was done in 3,886 subjects , and aBMD and vBMD associations were compared with RHOA score using linear regression , adjusting for covariates . Results Both moderate and severe RHOA groups had significantly higher aBMD at all BMD sites ( range , 3.7–10.0 % difference ; p value 0.0012 and p value < 0.005 ) compared to the control group with no RHOA . The difference remained strong after adjusting for covariates . While the total hip and lumbar spine cortical vBMD measurements of subjects with moderate or severe RHOA was increased compared to controls , trabecular vBMD was not . Conclusion Older men , with both moderate and severe RHOA , had significantly higher aBMD and integral vBMD at the hip and lumbar spine compared to controls without RHOA Objective To prospect ively evaluate prognostic factors for new onset or progression of degenerative change on follow-up MRI one year after knee trauma and the association with clinical outcome . Methods Within a prospect i ve observational cohort study in general practice , we studied a subgroup of 117 patients with acute knee trauma ( mean age 41 years , 43 % women ) .  Degenerative change was scored on MRI at baseline and after one year follow-up . Multivariate logistic regression analysis was performed to evaluate prognostic factors for new onset or progressive degenerative change on follow-up MRI . Association between new or progressive degeneration and clinical outcome after one year was assessed . Results On follow-up MRI 15 % of patients with pre-existing knee osteoarthritis showed progression and 26 % of patients demonstrated new degenerative change . The only statistically significant prognostic variable in the multivariate analysis was bone marrow oedema on initial MRI ( OR 5.29 ( 95 % CI 1.64–17.1 ) , p = 0.005 ) . A significant association between new or progressive degenerative change and clinical outcome was found ( p = 0.003 ) . Conclusion Bone marrow oedema on MRI for acute knee injury is strongly predictive of new onset or progression of degenerative change of the femorotibial joint on follow-up MRI one year after trauma , which is reflected in clinical outcome Objective To determine the association between cam impingement , which is hip incongruity by a non-spherical femoral head and development of osteoarthritis . Methods A nationwide prospect i ve cohort study of 1002 early symptomatic osteoarthritis patients ( CHECK ) , of which st and ardised anteroposterior pelvic radiographs were obtained at baseline and at 2 and 5 years follow-up . Asphericity of the femoral head was measured by the α angle . Clinical ly , decreased internal hip rotation ( ≤20 ° ) is suggestive of cam impingement . The strength of association between those parameters at baseline and development of incident osteoarthritis ( K&L grade 2 ) or end-stage osteoarthritis ( K&L grade s 3 , 4 , or total hip replacement ) within 5 years was expressed in OR using generalised estimating equations . Results At baseline , 76 % of the included hips had no radiographic signs of osteoarthritis and 24 % doubtful osteoarthritis . Within 5 years , 2.76 % developed end-stage osteoarthritis . A moderate ( α angle > 60 ° ) and severe ( α angle > 83 ° ) cam-type deformity result ed in adjusted OR of 3.67 ( 95 % CI 1.68 to 8.01 ) and 9.66 ( 95 % CI 4.72 to 19.78 ) , respectively , for end-stage osteoarthritis . The combination of severe cam-type deformity and decreased internal rotation at baseline result ed in an even more pronounced adjusted OR , and in a positive predictive value of 52.6 % for end-stage osteoarthritis . For incident osteoarthritis , only a moderate cam-type deformity was predictive OR=2.42 ( 95 % CI 1.15 to 5.06 ) . Conclusions Individuals with both severe cam-type deformity and reduced internal rotation are strongly predisposed to fast progression to end-stage osteoarthritis . As cam impingement might be a modifiable risk factor , early recognition of this condition is important OBJECTIVE To compare increased bone uptake of 99Tcm-MDP and magnetic resonance ( MR ) detected subchondral lesions , osteophytes , and cartilage defects in the knee in middle aged people with longst and ing knee pain . METHODS Fifty eight people ( aged 41–58 years , mean 50 ) with chronic knee pain , with or without radiographic knee osteoarthritis , were examined with bone scintigraphy . The pattern and the grade of increased bone uptake was assessed . On the same day , a MR examination on a 1.0 T imager was performed . The presence and the grade of subchondral lesions , osteophytes , and cartilage defects were registered . RESULTS The κ values describing the correlation between increased bone uptake and MR detected subchondral lesions varied between 0.79 and 0.49 , and between increased bone uptake and MR detected osteophytes or cartilage defects the values were < 0.54 . The κ values describing the correlation between the grade of bone uptake and the grade of the different MR findings was < 0.57 . CONCLUSIONS Good agreement was found between increased bone uptake and MR detected subchondral lesion . The agreement between increased bone uptake and osteophytes or cartilage defects was in general poor as well as the agreement between the grade of bone uptake and the grade of the MR findings OBJECTIVE To compare structural knee joint changes in obese patients with knee osteoarthritis ( OA ) that after an intensive weight loss therapy were r and omized to continuous dietetic support , a specialized knee exercise program , or ' no attention ' for 1 year . METHODS 192 obese individuals with knee OA underwent an intensive 16-week weight loss program with subsequent r and omization to one of the three treatment groups . Changes in cartilage loss , bone marrow lesions ( BMLs ) , synovitis , and effusion were assessed using semi quantitative assessment s of magnetic resonance imaging ( MRI ) obtained at weeks 0 and 68 applying the BLOKS score . RESULTS During the 52 weeks maintenance period the continuous dietary maintenance group support on average gained 1.1 kg ( 95 % CI : -0.3:2.5 ) body mass , the exercise group gained 6.6 kg ( 95 % CI 5.4:7.8 ) and the no-attention group gained 4.8 kg ( 95 % CI : 2.9:6.7 ) . There were no statistically significant between-group differences in changes in cartilage loss , synovitis or effusion at the follow-up ( analysis of covariance ; ANCOVA , P > 0.16 ) , while there was an increased number of medial tibiofemoral BMLs in the exercise group ( ANCOVA , P = 0.015 ) compared to both diet ( difference : -0.21 [ 95%CI -0.40:-0.03 ] ) and " no attention " ( difference : -0.26 [ 95%CI -0.44:-0.07 ] ) groups . CONCLUSION In this 1 year follow-up after weight-loss in obese knee OA patients , we found a potentially increased number of BMLs in the exercise group compared to the diet and no attention groups , with no between-group differences in changes in cartilage loss , synovitis or effusion . These findings should be interpreted with caution for exercise compliance , MRI methodology and follow-up time . ( Clinical Trials.gov identifier : NCT00655941 ) Objective To identify predictive factors for total knee replacement ( TKR ) using data from MRI of knee osteoarthritis patients in a phase III multicentre disease-modifying osteoarthritis drug ( DMOAD ) study . Methods Knee osteoarthritis patients from a 2-year clinical trial evaluating licofelone versus naproxen  were investigated for the incidence of TKR of the study knee . Patients ( n=161 ) who completed the study according to protocol were selected . Incidence of TKR was assessed blindly to the treatment following telephone interviews ( n=123 ) . Results 18 TKR ( 14.6 % ) were performed in 4–7 years following enrolment in the original study . More TKR were performed within the naproxen than the licofelone group ( 61 % vs 39 % , p=0.232 ) . Baseline score of bone marrow lesions ( BML ) in the medial compartment ( p=0.0001 ) , medial joint space width ( JSW ) as assessed by st and ardised radiographs ( p=0.0008 ) , presence of severe medial meniscal tear ( p=0.004 ) , medial meniscal extrusion ( p=0.013 ) , and C-reactive protein level ( p=0.049 ) were strong predictors of TKR . Changes at the end of the study also yielded strong predictors : change in cartilage volume of the medial compartment ( p=0.005 ) and of the global knee ( p=0.034 ) , reduction in the JSW of greater than 7 % ( p=0.009 ) , and WOMAC pain ( p=0.009 ) and function ( p=0.023 ) scores . Multivariate analysis showed that baseline severe medial meniscal tear ( p=0.023 ) and presence of medial BML ( p=0.025 ) were the strongest independent long-term predictors of TKR . Conclusion This study shows that in the context of osteoarthritis trials , clinical data and structural changes identified by MRI allow prediction of a ‘ hard ’ outcome such as TKR . The findings support the usefulness and predictive value of MRI in defining study outcome in DMOAD trials Introduction To determine if structural bone parameters obtained from dual energy X-ray absorptiometry ( DXA ) contribute to the prediction of progression of hip osteoarthritis ( OA ) and to test if the difference between the most affected ( OA ) hip and the contralateral hip adds to this prediction . Methods The study group involves a prospect i ve cohort of 189 patients that met the American College of R 
    Output:
    
BMLs , osteophytes and bone shape were independently associated with structural progression or joint replacement .
BMLs and bone shape were independently associated with longitudinal change in pain and incident frequent knee pain respectively .
ConclusionS ubchondral bone features have independent associations with structural progression , pain and joint replacement in peripheral OA in the hip and h and but especially in the knee .
For peripheral OA sites other than the knee , there are fewer associations and independent associations of bone pathologies with these important OA outcomes which may reflect fewer studies ; for example the foot and ankle were poorly studied .
Subchondral OA bone appears to be a relevant therapeutic target .