***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 To evaluate the longitudinal changes of bone marrow edema-like lesions ( BMELs ) in patients after anterior cruciate ligament ( ACL ) reconstruction  and to investigate the effect of BMELs on cartilage matrix composition changes measured using MR T1ρ and T2 mapping . METHODS Patients with acute ACL tear were enrolled in a prospect i ve study . MR imaging was performed at baseline ( before surgeries ) and at 6-month , 1-year and 2-year after ACL reconstruction . MR imaging included sagittal high-resolution , 3D fast spin-echo ( CUBE ) sequences for BMEL evaluation , and 3D T1ρ mapping and T2 mapping for cartilage assessment . BMELs were assessed using whole-organ magnetic resonance imaging score ( WORMS ) , and the volume of BMELs was measured by a semi-automatic method . Generalized estimating equation ( GEE ) was used to explore association between BMELs at baseline and cartilage changes during follow-up . RESULTS Fifty four patients were included in the present study and 39 patients had completed 2-year follow-up . BMELs were noted in 42 injured knees ( 77.8 % ) with 105 lesions and in 7 contralateral knees ( 13.0 % ) with 9 lesions ( χ2=45.763 , P<0.001 ) at the baseline . The WORMS and volume of BMELs of the injured knees were 2.36±0.65 and 386.98±382.54 mm3 ( r=0.681 , P<0.001 ) , respectively . 87 BMELs were found at baseline in 34 patients ( 87.2 % ) of the 39 patients who had completed 2 years follow-up . During the follow-up , 18 ( 20.7 % ) , 12 ( 13.8 % ) , and 5 ( 5.7 % ) baseline lesions were still seen at 6-month , 1-year and 2-year , respectively . The changes of BMELs prevalence regarding bone compartments over time points were statistically significant ( χ2=163.660 , P<0.001 ) . Except T2 value at 6 months , T1ρ and T2 values of cartilage overlying baseline BMELs in the injured knees were higher than that of anatomically matched cartilage in the contralateral knees at baseline and each follow-up time-point . In the injured knees , GEE analysis showed that baseline BMELs were significantly associated with higher T1ρ and T2 values of cartilage after adjustment of age , gender , body mass index ( BMI ) , effusion and meniscus tear . The association between BMELs and Knee Injury and Osteoarthritis Outcome Scores ( KOOS ) scores was not statistically significant . CONCLUSIONS BMEL is a common finding in patients with acute ACL injury and resolves rapidly over time after ACL reconstruction . It is often associated with increased T1ρ and T2 values of cartilage . BMEL at baseline is an independent predictor for faster cartilage degeneration during follow-up CONTEXT After an anterior cruciate ligament ( ACL ) injury , a majority of patients have a traumatic bone marrow lesion ( BML , or bone bruise ) . The clinical relevance of posttraumatic lesions remains unclear . OBJECTIVE To explore the cross-sectional associations between traumatic BML volume and self-reported knee pain and symptoms  among individuals within 4 weeks of ACL injury . DESIGN Cross-sectional exploratory analysis of a r and omized clinical trial . SETTING Orthopaedic departments at 2 hospitals in Sweden . PATIENTS OR OTHER PARTICIPANTS As part of a r and omized trial ( knee anterior cruciate ligament nonoperative versus operative treatment [ KANON ] study ) , 121 young active adults ( 74 % men , age = 26 ± 5 years , height = 1.8 ± 0.1 m , weight = 76 ± 13 kg ) with an ACL tear were studied . MAIN OUTCOME MEASURE(S ) The BML volume in the proximal tibia and distal femur was segmented using magnetic resonance images obtained within 4 weeks of injury . A radiologist evaluated the presence of depression fractures on the images . Pain and symptoms of the injured knee ( Knee Injury and Osteoarthritis Outcome Score [ KOOS ] pain and symptoms subscales ) were obtained the same day as imaging . We used linear regression models to assess the associations . RESULTS Most knees had at least 1 BML ( 96 % ) , and the majority ( 57 % ) had a depression fracture . Whole-knee BML volume was not related to knee pain for the entire cohort ( β = -0.09 , P = .25 ) . Among those without a depression fracture , larger whole-knee BML volume was associated with increased knee pain ( β = -0.46 , P = .02 ) , whereas no association was found for those with a depression fracture ( β = 0.0 , P = .96 ) . Larger medial ( β = -0.48 , P = .02 ) but not lateral ( β = -0.03 , P = .77 ) tibiofemoral BML volume was associated with greater pain . We found no association between BML volume and knee symptoms . CONCLUSIONS We confirmed the absence of relationships between whole-knee BML volume and pain and symptoms within 4 weeks of ACL injury . Our findings extend previous reports in identifying weak associations between larger BML volume in the medial compartment and greater pain and between BML volume and greater pain among those without a depression fracture OBJECTIVES To investigate changes in the knee during the first year after acute rupture of the anterior cruciate ligament ( ACL ) of volumes of joint fluid ( JF ) , bone marrow lesions ( BMLs ) , and cartilage volume ( VC ) , and cartilage thickness ( ThCcAB ) and cartilage surface area ( AC ) . To identify factors associated with these changes . METHODS Fifty-eight subjects ( mean age 26 years , 16 women ) with an ACL rupture to a previously un-injured knee were followed prospect ively using a 1.5 T MR imager at baseline ( within 5 weeks from injury ) , 3 months , 6 months , and 1 year . Thirty-four subjects were treated with ACL reconstruction followed by a structured rehabilitation program and 24 subjects were treated with structured rehabilitation only .  Morphometric data were acquired from computer-assisted segmentation of MR images . Morphometric cartilage change was reported as mean change divided by the st and ard deviation of change ( st and ard response mean , SRM ) . RESULTS JF and BML volumes gradually decreased over the first year , although BML persisted in 62 % of the knees after 1 year . One year after the ACL injury , a reduction of VC , AC and ThCcAB ( SRM -0.440 or greater ) was found in the trochlea femur ( TrF ) , while an increase of VC and ThCcAB was found in the central medial femur ( cMF ) ( SRM greater than 0.477 ) . ACL reconstruction was directly and significantly related to increased JF volume at 3 and 6 months ( P<0.001 ) , BML volume at 6 months ( P=0.031 ) , VC and ThCcAB in cMF ( P<0.002 ) and decreased cartilage area in TrF ( P=0.010 ) at 12 months . CONCLUSION Following an acute ACL tear , cMF and TrF showed the greatest consistent changes of cartilage morphometry . An ACL reconstruction performed within a mean of 6 weeks from injury was associated with increased ThCcAB and VC in cMF and decreased AC in TrF , compared to knees treated without reconstruction . This may suggest a delayed structural restitution in ACL reconstructed knees Background : The prevalence of comorbid knee pathology has been examined for sports-related anterior cruciate ligament ( ACL ) injuries , but it has not been examined in ice hockey players . Purpose : To compare concomitant bone bruising , collateral ligament injuries , and intra-articular injuries in ACL injuries suffered during ice hockey versus other sports .  Study Design : Cross-sectional study ; Level of evidence , 3 . Methods : A total of 20 patients with ACL injuries sustained during ice hockey were identified from a prospect i ve registry , of which 95 % were male and 90 % had a contact mechanism of injury ( MOI ) . Thirteen cases and 46 controls who sustained ACL injuries from ice hockey and other sports , respectively , were included . Inclusion criteria for cases and controls were male sex , contact MOI , no prior knee surgery , magnetic resonance imaging ( MRI ) within 6 weeks of injury , and surgery within 3 months of injury . Age , body mass index ( BMI ) , MRI findings ( bone bruising , medial and lateral collateral ligament [ MCL , LCL ] injuries ) , and arthroscopic findings ( meniscus tears , chondral injuries ) were compared for cases versus controls using t tests or exact chi-square tests . Results : Age ( 22.9 ± 8.8 vs 23.4 ± 10.4 years , P = .88 ) and BMI ≥25 kg/m2 ( 50 % vs 65.9 % , P = .66 ) did not differ between cases and controls . Cases had less lateral bone bruising ( lateral femoral condyle : 54.6 % vs 93 % , P = .01 ; lateral tibial plateau : 72.7 % vs 93 % , P = .09 ) and no medial bone bruising ( medial femoral condyle : 0 % vs 7 % , P = .06 ; medial tibial plateau : 0 % vs 32.6 % , P = .05 ) compared with controls . Cases had less frequent lateral meniscus tears than controls ( 23.1 % vs 58.5 % , P = .05 ) . There were no significant differences in MCL ( 40 % vs 31.2 % , P = .77 ) , LCL ( 0 % vs 3.9 % , P > .999 ) , medial meniscus tears ( 7.7 % vs 37 % , P = .08 ) , and chondral injuries ( 10 % vs 9.4 % , P > .999 ) for cases versus controls . Conclusion : Male ice hockey players with ACL injuries had less lateral femoral condyle and medial tibial plateau bone bruising compared with other sports injuries . They also had fewer lateral meniscus tears , and there was a trend toward fewer medial meniscus tears . These differences may reflect different MOIs , or the ability to dissipate energy , for contact ACL injuries that occur during ice hockey versus other sports Background : Concomitant injuries can occur in patients with combined anterior cruciate ligament ( ACL ) and medial collateral ligament ( MCL ) tears ; however , no studies have compared these injuries in patients undergoing ACL reconstruction with an MCL tear  to those with an intact MCL . Purpose : To compare bone bruising , meniscus tears , and chondral lesions in patients undergoing ACL reconstruction with an MCL tear ( cases ) to those with an intact MCL ( controls ) . Study Design : Case-control study ; Level of evidence , 3 . Methods : Thirty-two cases and 352 controls were identified from a prospect i ve registry .  Bone bruising was confirmed on magnetic resonance imaging , and meniscus tears and chondral lesions were confirmed arthroscopically . Demographics and concomitant injuries were compared between cases and controls using exact chi-square tests . Multivariate logistic regression was used to calculate odds ratios ( ORs ) and 95 % CIs adjusted for age , sex , body mass index , and mechanism and type of injury . Results : Cases had significantly more contact injuries than controls ( 58.1 % vs 21.3 % , P < .0001 ) . The prevalence and odds of bone bruising of the lateral tibial plateau ( 89.7 % vs 84.6 % ; P = .59 ; OR , 3.53 ; 95 % CI , 0.45 - 27.71 ) , lateral femoral condyle ( 82.8 % vs 72.8 % ; P = .28 ; OR , 1.94 ; 95 % CI , 0.64 - 5.88 ) , medial tibial plateau ( 20.7 % vs 31.7 % ; P = 0.29 ; OR , 0.53 ; 95 % CI , 0.19 - 1.53 ) , and medial femoral condyle ( 6.9 % vs 8.3 % ; P ≥ .999 ; OR , 1.07 ; 95 % CI , 0.21 - 5.40 ) did not differ significantly between cases and controls . The prevalence and odds of lateral meniscus tears ( 53.3 % vs 43 % ; P = .34 ; OR , 1.85 ; 95 % CI , 0.76 - 4.52 ) , medial meniscus tears ( 31.3 % vs 33.5 % ; P = .85 ; OR , 0.90 ; 95 % CI , 0.37 - 2.21 ) , and chondral lesions ( 16 % vs 10.8 % ; P = .50 ; OR , 0.70 ; 95 % CI , 0.15 - 3.21 ) also did not significantly differ between cases and controls . Conclusion : ACL-MCL injuries 
    Output:
    
Bone bruise has a high prevalence ( 78 % in the most recent papers ) , with distinct patterns related to the mechanism of injury .
This MRI finding is detectable only in a minority of cases the first few months after trauma , but its presence and persistence have been correlated to a more severe joint damage that may affect the degenerative progression of the entire joint , with recent evidence suggesting possible effects on long-term clinical outcome .
Conclusion This systematic review of the literature documented a growing interest on bone bruise associated with ACL injury , highlighting aspects which could provide to orthopaedic surgeons evidence -based suggestions in terms of clinical relevance when dealing with patients affected by bone bruise following ACL injury .