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Abstract The Observing Air–Sea Interactions Strategy (OASIS) is a new United Nations Decade of Ocean Science for Sustainable Development programme working to develop a practical, integrated approach for observing air–sea interactions globally for improved Earth system (including ecosystem) forecasts, CO2 uptake assessments called for by the Paris Agreement, and invaluable surface ocean information for decision makers. Our “Theory of Change” relies upon leveraged multi-disciplinary activities, partnerships, and capacity strengthening. Recommendations from >40 OceanObs’19 community papers and a series of workshops have been consolidated into three interlinked Grand Ideas for creating #1: a globally distributed network of mobile air–sea observing platforms built around an expanded array of long-term time-series stations; #2: a satellite network, with high spatial and temporal resolution, optimized for measuring air–sea fluxes; and #3: improved representation of air–sea coupling in a hierarchy of Earth system models. OASIS activities are organized across five Theme Teams: (1) Observing Network Design & Model Improvement; (2) Partnership & Capacity Strengthening; (3) UN Decade OASIS Actions; (4) Best Practices & Interoperability Experiments; and (5) Findable–Accessible–Interoperable–Reusable (FAIR) models, data, and OASIS products. Stakeholders, including researchers, are actively recruited to participate in Theme Teams to help promote a predicted, safe, clean, healthy, resilient, and productive ocean.

ObjectiveTo assess the impact of different types of physical activity types on longitudinal knee joint structural changes over 48 months in overweight and obese subjects.Materials and methodsWe included 415 subjects with a BMI ≥ 25 kg/m2, Kellgren-Lawrence scores ≤ 3 at baseline and Whole-Organ Magnetic Resonance Imaging Score (WORMS) scores available from the Osteoarthritis Initiative cohort. Regular self-reported participation in six physical activity types was assessed: ball sports, bicycling, jogging/running, elliptical-trainer, racquet sports, and swimming. Moreover, they were classified into high- and low-impact physical activity groups. Evaluation of structural knee abnormalities was performed using WORMS obtained by two independent observers blinded to the subjects' physical activity and time point. Linear regression models were used to assess the associations between participation in different physical activity types and changes in WORMS.ResultsNo significant differences in epidemiological data were found between the groups except for gender composition, and there were no significant differences in baseline WORMS. In the cohort as a whole and most exercise groups overall WORMS significantly increased during the observational period. Highest increases compared to the remainder of the group were found in the high impact group (increase in WORMS 4.65; [95% CI] [3.94,5.35]; p = 0.040) and the racquet sports group (6.39; [95% CI] [5.13,7.60]; p ≤ 0.001). Subjects using an elliptical-trainer showed the lowest increase in WORMS (- 1.50 [- 0.21, 3.22]; p = 0.002).ConclusionProgression of knee joint degeneration was consistently higher in subjects engaging in high-impact and racquet sports while subjects using an elliptical-trainer showed the smallest changes in structural degeneration. This work was presented during the 2020 Radiological Society of North America Annual meeting.

ObjectiveTo compare early hip osteoarthritis (OA) features on magnetic resonance imaging (MRI) in high-impact athletes with and without hip and/or groin pain, and to evaluate associations between early hip OA features, the International Hip Outcome Tool (iHOT33) and Copenhagen Hip and Groin Outcome Score (HAGOS).DesignThis case-control study evaluated data of the femoroacetabular impingement and hip osteoarthritis cohort (FORCe). One hundred and eighty-two symptomatic (hip and/or groin pain >6 months and positive flexion-adduction-internal-rotation (FADIR) test) and 55 pain-free high-impact athletes (soccer or Australian football (AF)) without definite radiographic hip OA underwent hip MRI. The Scoring Hip Osteoarthritis with MRI (SHOMRI) method quantified and graded the severity of OA features. Each participant completed the iHOT33 and HAGOS.ResultsHip and/or groin pain was associated with higher total SHOMRI (0-96) (mean difference 1.4, 95% CI: 0.7-2.2), labral score (adjusted incidence rate ratio (aIRR) 1.33, 95% CI: 1.1-1.6). Differences in prevalence of cartilage defects, labral tears and paralabral cysts between symptomatic and pain-free participants were inconclusive. There was a lower prevalence of effusion-synovitis in symptomatic participants when compared to pain-free participants (adjusted odds ratio (aOR) 0.46 (95% CI: 0.3-0.8). Early hip OA features were not associated with iHOT33 or HAGOS.ConclusionsA complex and poorly understood relationship exists between hip and/or groin pain and early hip OA features present on MRI in high-impact athletes without radiographic OA. Hip and/or groin pain was associated with higher SHOMRI and labral scores.

The tropical Atlantic is home to multiple coupled climate variations covering a wide range of timescales and impacting societally relevant phenomena such as continental rainfall, Atlantic hurricane activity, oceanic biological productivity, and atmospheric circulation in the equatorial Pacific. The tropical Atlantic also connects the southern and northern branches of the Atlantic meridional overturning circulation and receives freshwater input from some of the world's largest rivers. To address these diverse, unique, and interconnected research challenges, a rich network of ocean observations has developed, building on the backbone of the Prediction and Research Moored Array in the Tropical Atlantic (PIRATA). This network has evolved naturally over time and out of necessity in order to address the most important outstanding scientific questions and to improve predictions of tropical Atlantic severe weather and global climate variability and change. The tropical Atlantic observing system is motivated by goals to understand and better predict phenomena such as tropical Atlantic interannual to decadal variability and climate change; multidecadal variability and its links to the meridional overturning circulation; air-sea fluxes of CO2 and their implications for the fate of anthropogenic CO2; the Amazon River plume and its interactions with biogeochemistry, vertical mixing, and hurricanes; the highly productive eastern boundary and equatorial upwelling systems; and oceanic oxygen minimum zones, their impacts on biogeochemical cycles and marine ecosystems, and their feedbacks to climate. Past success of the tropical Atlantic observing system is the result of an international commitment to sustained observations and scientific cooperation, a willingness to evolve with changing research and monitoring needs, and a desire to share data openly with the scientific community and operational centers. The observing system must continue to evolve in order to meet an expanding set of research priorities and operational challenges. This paper discusses the tropical Atlantic observing system, including emerging scientific questions that demand sustained ocean observations, the potential for further integration of the observing system, and the requirements for sustaining and enhancing the tropical Atlantic observing system.

ObjectiveThe aim of this study was to assess cross-sectional and longitudinal effects of meniscal lesions on adjacent cartilage T1ρ and T2 relaxation times, patient-reported outcomes and gait biomechanics.DesignThirty patients with no cartilage morphological defects reported by Whole Organ MRI Score (WORMS) magnetic resonance imaging (MRI) grading and no radiographic osteoarthritis (OA) (Kellgren--Lawrence (KL) ≤ 1) were selected, 15 with posterior meniscus horn lesions and 15 matched controls without meniscal lesions. All were imaged on a 3T MR scanner for three consecutive years, except those who dropped from the study. Sagittal and frontal plane kinematic gait data were acquired at baseline. The Knee Injury and Osteoarthritis Outcome Score (KOOS) survey was taken each time. All images were automatically segmented and registered to an atlas for voxel-by-voxel cross-sectional and longitudinal analyses.ResultsRelaxation time comparisons between groups showed elevated T1ρ of the lateral tibia (LP) and elevated T2 of the medial tibia (MT) and LT at 1 and 2 years in the lesion group. Longitudinal comparisons within each group revealed greater relaxation time elevations over one and 2 years in the group with lesions. KOOS Quality of Life (QOL) was significantly different between the groups at all time points (P

ObjectiveTo determine in a 48-month longitudinal study the association of thigh muscle cross-sectional area (CSA) and strength on progression of morphologic knee cartilage degeneration using 3T magnetic resonance imaging (MRI).DesignSeventy Osteoarthritis Initiative (OAI) subjects aged 50-60 years, with no radiographic evidence of osteoarthritis (OA) and constant muscle strength over 48 months as measured by isometric knee extension testing were included. Baseline right thigh muscle CSAs were assessed on axial T1-weighted magnetic resonance (MR) images, and extensor to flexor CSA ratios were calculated. Degenerative knee abnormalities at baseline and 48-months were graded on right knee 3T MRIs using a modified whole organ MRI score (WORMS). Statistical analysis employed Student's t-tests and multivariable regression models adjusted for age, body mass index and gender.ResultsExtension strength was significantly and positively correlated with baseline thigh muscle CSA (r = 0.65, P

ObjectiveThis study aimed to investigate the associations between patellofemoral cartilage T1ρ and T2 relaxation times and knee flexion moment (KFM) and KFM impulse during gait.MethodKnee magnetic resonance (MR) images were obtained from 99 subjects with and without patellofemoral joint (PFJ) osteoarthritis (OA), using fast spin-echo, T1ρ and T2 relaxation time sequences. Patellar and trochlear cartilage relaxation times were computed for the whole cartilage, and superficial and deep layers (laminar analysis). Subjects also underwent three-dimensional (3D) gait analysis. Peak KFM and KFM impulse were calculated during the stance phase. Linear regressions were used to examine whether cartilage relaxation times were associated with knee kinetics during walking while adjusting age, sex, body mass index (BMI) and walking speed.ResultsHigher peak KFM and KFM impulse were significantly related to higher T1ρ and T2 relaxation times of the trochlear and patellar cartilage, with standardized regression coefficients ranging from 0.21 to 0.28. Laminar analysis showed that overall the superficial layer of patellofemoral cartilage showed stronger associations with knee kinetics. Subgroup analysis revealed that in subjects with PFJ OA, every standard deviation change in knee kinetics was related to greater increases in PFJ cartilage T1ρ and T2 (standardized coefficients: 0.29 to 0.41). Conversely, in subjects without OA, weaker relationships were observed between knee kinetics and PFJ cartilage T1ρ and T2.ConclusionsOur findings suggest that increased peak KFM and KFM impulse were related to worse cartilage health at the PFJ. This association is more prominent in superficial layer cartilage and cartilage with morphological lesions.

ObjectiveTo evaluate whether baseline T1ρ and T2 relaxation times of hip cartilage are associated with magnetic resonance imaging (MRI) based progression of hip osteoarthritis (OA) at 18 months.Methods3T MRI studies of the hip were obtained at baseline and 18-month follow-up for 54 subjects without evidence of severe OA at baseline [Kellgren-Lawrence (KL) score of 0-3]. 2D fast spin-echo sequences were used for semi-quantitative morphological scoring of cartilage lesions and a combined T1ρ/T2 sequence was used to quantitatively assess cartilage composition. Progression of hip OA was defined based on incident or progression of morphological semi-quantitative grade at 18 months. Baseline T1ρ and T2 relaxation times were compared between progressors and non-progressors using one-way analysis of variance and Mann-Whitney U tests and used to predict progression with binary logistic regression after adjusting for age, gender, body mass index, and KL score. Additionally, a novel voxel-based relaxometry technique was used to compare the spatial distribution of baseline T1ρ and T2 between progressors and non-progressors.ResultsSignificantly higher baseline T1ρ and T2 values were observed in hip OA progressors compared to non-progressors, particularly in the posterosuperior and anterior aspects of the femoral cartilage. Logistic regression showed that higher baseline T1ρ or T2 values in the femoral cartilage were significantly associated with progression of femoral cartilage lesions at 18 months.ConclusionT1ρ and T2 relaxation parameters are associated with morphological cartilage degeneration at 18 months and may serve as potential imaging biomarkers for progression of cartilage lesions in hip OA.

Gabriella de Medeiros Abreu,1,* Camila de Almeida Pereira Dias Soares,1,* Roberta Magalhães Tarantino,2,3 Ana Carolina Proença da Fonseca,1 Ritiele Bastos de Souza,1 Maria de Fátima Carvalho Pereira,4 Pedro Hernan Cabello,1,5 Melanie Rodacki,2 Lenita Zajdenverg,2 Verônica Marques Zembrzuski,1 Mário Campos Junior1 1Human Genetics Laboratory, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil; 2Diabetes and Nutrology Section, Internal Medicine Department, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil; 3Ambulatory of Diabetes, State Institute for Diabetes and Endocrinology Luiz Capriglione, Rio de Janeiro, Brazil; 4Clinical Pathology Department, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil; 5Laboratory of Genetics, School of Health Science, University of Grande Rio, Rio de Janeiro, Brazil*These authors contributed equally to this workCorrespondence: Mário Campos Junior JuniorHuman Genetics Laboratory,Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Pavilhão Leônidas Deane, Sala 615, Avenida Brasil 4365, Rio de Janeiro 21040-360, RJ, BrazilTel +55 21 3865 8192Email mario.junior@ioc.fiocruz.brPurpose: The aim of this study was to sequence the coding region of the PAX4 gene in a Brazilian cohort with clinical manifestations of monogenic diabetes.Patients and Methods: This study included 31 patients with autosomal dominant history of diabetes, age at diagnosis ≤ 40 years, BMI < 30 kg/m2, and no mutations in GCK or HNF1A, HNF4A, and HNF1B. Screening of the PAX4 coding region was performed by Sanger sequencing. In silico algorithms were used to assess the potential impact of amino acid substitutions on protein structure and function. Additionally, PAX4-MODY family members and 158 control subjects without diabetes were analyzed for the identified mutation.Results: The molecular analysis of PAX4 has detected one missense mutation, p.Arg164Gln (c.491G>A), segregating with diabetes in a large Brazilian family. The mutation was absent among the control group. The index case is a woman diagnosed at 32 years of age with polyneuropathy and treated with insulin. She did not present diabetic renal disease or retinopathy. Family members with the PAX4 p.Arg164Gln mutation have a heterogeneous clinical manifestation and treatment response, with age at diagnosis ranging from 24 years to 50 years.Conclusion: To the best of our knowledge, this is the first study to report a PAX4-MODY family in Brazil. The age of PAX4-MODY diagnosis in the Brazilian family seems to be higher than the classical criteria for MODY. Our results reinforce the importance of screening large monogenic diabetes families for the understanding of the clinical manifestations of rare forms of diabetes for the specific and personalized treatment.Keywords: diabetes mellitus, monogenic diabetes, MODY, PAX4, mutation

Background: Women are at a greater risk for knee osteoarthritis (OA), but reasons for this greater risk in women are not well understood. It may be possible that differences in cartilage composition and walking mechanics are related to greater OA risk in women. Questions/purposes: (1) Do women have higher knee cartilage and meniscus T 1ρ than men in young healthy, middle-aged non-OA and OA populations? (2) Do women exhibit greater static and dynamic (during walking) knee loading than men in young healthy, middle-aged non-OA and OA populations? Methods: Data were collected from three cohorts: (1) young active ( 1) (18 men, 25 women). T 1ρ and T 2 relaxation times for cartilage in the medial knee, lateral knee, and patellofemoral compartments and medial and lateral menisci were quantified with 3.0-T MRI. A subset of the participants underwent three-dimensional motion capture during walking for calculation of peak knee flexion and adduction moments, flexion and adduction impulses, and peak adduction angle. Differences in MR, radiograph, and gait parameters between men and women were compared in the three groups separately using multivariate analysis of variance. Results: Women had higher lateral articular cartilage T 1ρ (men = 40.5 [95% confidence interval {CI}, 38.8–42.3] ms; women = 43.3 [95% CI, 41.9–44.7] ms; p = 0.017) and patellofemoral T 1ρ (men = 44.4 [95% CI, 42.6–46.3] ms; women = 48.4 [95% CI, 46.9–50.0] ms; p = 0.002) in the OA group; and higher lateral meniscus T 1ρ in the young group (men = 15.3 [95% CI, 14.7–16.0] ms; women = 16.4 [95% CI, 15.6–17.2] ms; p = 0.045). The peak adduction moment in the second half of stance was lower in women in the middle-aged (men = 2.05 [95% CI, 1.76–2.34] %BW*Ht; women = 1.66 [95% CI, 1.44–1.89] %BW*Ht; p = 0.037) and OA (men = 2.34 [95% CI, 1.76–2.91] %BW*Ht; women = 1.42 [95% CI, 0.89–1.94] %BW*Ht; p = 0.022) groups. Static varus from radiographs was lower in women in the middle-aged (men = 178° [95% CI, 177°–179°]; women = 180° [95% CI, 179°–181°]; p = 0.002) and OA (men = 176° [95% CI, 175°–178°]; women = 180° [95% CI, 179°–181°]; p

Background Patellofemoral joint osteoarthritis is a highly prevalent disease and an important source of pain and disability. Nonetheless, biomechanical risk factors associated with this disease remain unclear. The purpose of this study was to compare biomechanical factors that are associated with patellofemoral joint loading during walking between individuals with isolated patellofemoral joint osteoarthritis and no osteoarthritis. Methods MR images of the knee were obtained using a 3D fast-spin echo sequence to identify patellofemoral joint cartilage lesions. Thirty-five subjects with isolated patellofemoral joint osteoarthritis (29 females) and 35 control subjects (21 females) walked at a self-selected speed and as fast as possible. Peak knee flexion moment, flexion moment impulse and peak patellofemoral joint stress during the first and second halves of the stance phase were compared between groups. Findings When compared to the controls, individuals with patellofemoral joint osteoarthritis demonstrated significantly higher peak knee flexion moment (P =.03, Eta2 =.07), higher knee flexion moment impulse (P =.03, Eta2 =.07) and higher peak patellofemoral joint stress (P =.01, Eta2 =.10) during the second half of the stance phase. No significant group difference was observed during the first half of the stance phase. Interpretation Findings of this study suggest that increased mechanical loading (i.e. knee flexion moment, impulse and patellofemoral joint stress) during the second half of the stance phase is associated with patellofemoral joint osteoarthritis. Prevention and rehabilitation programs for patellofemoral joint osteoarthritis may focus on reducing the loading on the patellofemoral joint, specifically during late stance.

ObjectiveThe objective of this study was to evaluate the effects of mechanical loading on knee articular cartilage T1ρ and T2 relaxation times in patients with and without osteoarthritis (OA).DesignMagnetic resonance (MR) images were acquired from 137 subjects with and without knee OA under two conditions: unloaded and loaded at 50% body weight. Three sequences were acquired: a high-resolution 3D-CUBE, a T1ρ relaxation time, and a T2 relaxation time sequences. Cartilage regions of interest included: medial and lateral femur (MF, LF); medial and lateral tibia (MT, LT), laminar analysis (superficial and deep layers), and subcompartments. Changes in relaxation times in response to loading were evaluated.ResultsIn response to loading, we observed significant reductions in T1ρ relaxation times in the MT and LT. In both the MF and LF, loading resulted in significant decreases in the superficial layer and significant increases in the deep layer of the cartilage for T1ρ and T2. All subcompartments of the MT and LT showed significant reduction in T1ρ relaxation times. Reductions were larger for subjects with OA (range: 13-19% change) when compared to healthy controls (range: 3-13% change).ConclusionsLoading of the cartilage resulted in significant changes in relaxation times in the femur and tibia, with novel findings regarding laminar and subcompartmental variations. In general, changes in relaxation times with loading were larger in the OA group suggesting that the collagen-proteoglycan matrix of subjects with OA is less capable of retaining water, and may reflect a reduced ability to dissipate loads.

To identify radiographic and MR features of hip osteoarthritis (OA) related to reduced hip extension during walking. Sixty six subjects, were stratified into those with (n = 36, KL = 2, 3) and without (n = 30, KL = 0, 1) radiographic hip OA. Cartilage and labrum lesions were graded semi-quantitatively on hip MRI. Alpha angle and lateral center edge (LCE) angle were measured. Sagittal kinematics and kinetics were calculated during walking at speed of 1.35 m/s using 3-D motion capture. All subjects completed Hip disability and Osteoarthritis Outcome Score (HOOS), timed up and go, and 6 min walk tests. Variables were compared between the two groups using one-way ANOVA (adjusting for age). Correlations of radiographic and MR parameters with peak hip extension were calculated. The OA group was older, had greater pain, and limitation of function. They also had lower peak hip extension and higher peak hip flexion; and worse acetabular and femoral cartilage lesions. Peak hip extension and flexion correlated with KL grade, cartilage lesions in the inferior and posterior femur. Reduced hip extension and greater hip flexion during walking are present in high functioning (HOOS > 85%) individuals with mild-moderate hip OA, and are associated with cartilage lesions.

ObjectivesTo compare thigh muscle intramuscular fat (intraMF) fractions and area between people with and without knee radiographic osteoarthritis (ROA); and to evaluate the relationships of quadriceps adiposity and area with strength, function and knee magnetic resonance imaging (MRI) lesions.MethodsNinety six subjects (ROA: Kellgren-Lawrence (KL) > 1; n = 30, control: KL = 0, 1; n = 66) underwent 3-T MRI of the thigh muscles using chemical shift-based water/fat MRI (fat fractions) and the knee (clinical grading). Subjects were assessed for isometric/isokinetic quadriceps/hamstrings strength, function Knee injury and Osteoarthritis Outcome Score (KOOS), stair climbing test (SCT), and 6-minute walk test (6MWT). Thigh muscle intraMF fractions, muscle area and strength, and function were compared between controls and ROA subjects, adjusting for age. Relationships between measures of muscle fat/area with strength, function, KL and lesion scores were assessed using regression and correlational analyses.ResultsThe ROA group had worse KOOS scores but SCT and 6MWT were not different. The ROA group had greater quadriceps intraMF fraction but not for other muscles. Quadriceps strength was lower in ROA group but the area was not different. Quadriceps intraMF fraction but not area predicted self-reported disability. Aging, worse KL, and cartilage and meniscus lesions were associated with higher quadriceps intraMF fraction.ConclusionQuadriceps intraMF is higher in people with knee OA and is related to symptomatic and structural severity of knee OA, whereas the quadriceps area is not. Quadriceps fat fraction from chemical shift-based water/fat MR imaging may have utility as a marker of structural and symptomatic severity of knee OA disease process.

ObjectiveTo evaluate the relationship of hip radiographic osteoarthritis (ROA) and MRI findings of cartilage lesions, labral tears, bone marrow edema-like lesions (BMELs) and subchondral cysts with self-reported and physical function.DesignEighty five subjects were classified as controls (n = 55, Kellgren-Lawrence (KL) 0, 1) or having mild-moderate ROA (n = 30, KL 2, 3). T2 weighted MRI images at 3-T were graded for presence of cartilage lesions, labral tears, BMELs and subchondral cysts. Posterior wall sign, cross-over sign, center-edge angle and alpha angle were also recorded. Function was assessed using Hip dysfunction and Osteoarthritis Outcome Score (HOOS), Timed-Up and Go (TUG) test and Y-Balance Test (YBT). Analysis compared function between subjects with and without ROA and those with and without femoral or acetabular cartilage lesions, adjusted for age. Non-parametric correlations were used to assess the relationship between radiographic scores, MRI scores and function.ResultsSubjects with acetabular cartilage lesions had worse HOOS (Difference = 5-10%, P = 0.036-0.004), but not TUG or YBT, scores. Acetabular cartilage lesions, BMELs and subchondral cysts were associated with worse HOOS scores (ρ = 0.23-0.37, P = 0.041-0.001). Differences in function between subjects with and without ROA or femoral cartilage lesions were not significant. Other radiologic findings were not associated with function.ConclusionsAcetabular cartilage defects, but not femoral cartilage defects or ROA, were associated with greater self-reported pain and disability. BMELs and subchondral cysts were related to greater hip related self-reported pain and disability. None of the radiographic or MRI features was related to physical function.

PurposeTo prospectively evaluate changes in T1ρ and T2 relaxation times in the meniscal body with acute loading using MRI in osteoarthritic knees and to compare these findings with those of age-matched healthy controls.Materials and methodsFemale subjects above 40 years of age with (N1  = 20) and without osteoarthritis (OA) (N2  = 10) were imaged on a 3 Tesla MR scanner using a custom made loading device. MR images were acquired, with the knee flexed at 20°, with and without a compressive load of 50% of the subject's bodyweight. The subjects were categorized based on the radiographic evidence of OA. Three different zones (outer, middle, and inner) of meniscus body were defined (each occupying 1/3rd the width). After adjusting for age and body mass index in the general linear regression model, repeated measures analysis of variance was used to detect significant differences in T1ρ and T2 with and without loading.ResultsIn the unloaded condition, the average T1ρ and T2 times were elevated in the outer and middle zones of the medial meniscus in OA subjects compared with the controls. In the loaded condition, T1ρ and T2 times of the outer zone of the medial meniscus was significantly elevated in OA subjects compared with controls. Finally the change (from unloaded to loaded) was significantly higher in controls than OA subjects (15.1% versus 8.3%; P = 0.039 for ΔT1ρ , and 11.5% versus 6.9%, P = 0.049 for ΔT2 ).ConclusionThese findings suggest that while the OA process appears to affect the relaxation times of all regions within the meniscus, it may affect some regions sooner or to a greater degree. Furthermore, the differences in the change in relaxation times between unloaded and loaded conditions may reveal evidence about load transmission failure of the outer zone of the medial meniscus in subjects with knee OA. It is possible that these metrics (ΔT1ρ and ΔT2 ) may be valuable as an early biomechanical biomarker, which could be used to predict load transmission to the underlying articular cartilage.

The purpose of the current investigation was to test the hypothesis that subjects with patellar tendinopathy would demonstrate altered sagittal plane joint moment contributions during hopping tasks. Fourteen subjects (7 patellar tendinopathy, 7 controls) participated. Sagittal net joint moments of the lower extremity, total support moment, and joint contributions to the total support moment were calculated while subjects hopped continuously at a self-selected frequency and at 1.67 Hz. Significant differences were observed for contributions to the total support moment (p = .022). When averaged across hopping frequencies, subjects with patellar tendinopathy demonstrated greater hip contribution (p = .030) and lesser knee contribution (p = .006) compared with the control subjects. Shifting the workload away from the knee and toward the hip may result in a detrimental increase in hip demand and potentially harmful long-term effects on the articular cartilage of the hip. [ABSTRACT FROM AUTHOR]

Background: The purpose of this investigation is to evaluate the T(1ρ) relaxation times of articular cartilage surrounding focal defects in the tibiofemoral joint.Methods: Quantitative cartilage assessment was performed using 3T MRI with T(1ρ) mapping in 19 healthy individuals and 44 OA patients. Sagittal T2-weighted fast spin echo (FSE) images were acquired for lesion assessment. Differences were determined using analysis of variance (ANOVA).Results: Cartilage lesions were found in 37% of controls, and 93% of OA patients. Meniscal tears were found in 16% of controls and 57% of OA patients. We observed no difference in T(1ρ) relaxation times when comparing cartilage immediately surrounding a focal defect, and the remaining cartilage within that compartment. The medial femoral condyle (MFC) had the highest incidence of cartilage defects. MFC and medial meniscus posterior horn T(1ρ) were higher in subjects having multiple focal lesions (p = 0.048, pb 0.001 respectively) and extensive full thickness lesions (p = 0.009, pb 0.001 respectively) compared to subjects with no MFC defects. Significant elevations in T(1ρ) of the adjacent compartment (medial tibia) and medial meniscus were observed in subjects with MFC lesions.Conclusion: Increased relaxation times in the involved compartment as well as the adjacent compartment and associated meniscus underscore the interdependence of these structures at bearing load. However, no differences in cartilage composition immediately surrounding a defect were noted. Finally, an association was observed between cartilage defects and meniscal damage in advanced disease.Clinical Relevance: Cartilage defects were not associated with degeneration in the immediately adjacent cartilage. [ABSTRACT FROM AUTHOR]

Objective: To explore and to compare the magnitude and spatial pattern of in vivo femorotibial cartilage deformation in healthy and in osteoarthritic (OA) knees.Methods: One knee each in 30 women (age: 55 ± 6 years; BMI: 28 ± 2.4 kg/m(2); 11 healthy and 19 with radiographic femorotibial OA) was examined at 3Tesla using a coronal fat-suppressed gradient echo SPGR sequence. Regional and subregional femorotibial cartilage thickness was determined under unloaded and loaded conditions, with 50% body weight being applied to the knee in 20° knee flexion during imaging.Results: Cartilage became significantly (p < 0.05) thinner during loading in the medial tibia (-2.7%), the weight-bearing medial femur (-4.1%) and in the lateral tibia (-1.8%), but not in the lateral femur (+0.1%). The magnitude of deformation in the medial tibia and femur tended to be greater in osteoarthritic knees than in healthy knees. The subregional pattern of cartilage deformation was similar for the different stages of radiographic OA.Conclusion: Osteoarthritic cartilage tended to display greater deformation upon loading than healthy cartilage, suggesting that knee OA affects the mechanical properties of cartilage. The pattern of in vivo deformation indicated that cartilage loss in OA progression is mechanically driven. [ABSTRACT FROM AUTHOR]

Background: Effective interventions to improve and maintain strength (force-generating capacity) and endurance are needed for children with cerebral palsy (CP). Objective: This study was performed to examine the effects of a stationary cycling intervention on muscle strength, locomotor endurance, preferred walking speed, and gross motor function in children with spastic diplegic CP. Design: This was a phase I randomized controlled trial with single blinding. Setting: The interventions were performed in community-based outpatient physical therapy clinics. Outcome assessments were performed in university laboratories. Participants: Sixty-two ambulatory children aged 7 to 18 years with spastic diplegic CP and Gross Motor Function Classification System levels I to III participated in this study. Intervention and Measurements: Participants were randomly assigned to cycling or control (no-intervention) groups. Thirty intervention sessions occurred over 12 weeks. Primary outcomes were peak knee extensor and flexor moments, the 600-Yard Walk-Run Test, the Thirty-Second Walk Test, and the Gross Motor Function Measure sections D and E (GMFM-66). Results: Significant baseline-postintervention improvements were found for the 600-Yard Walk-Run Test, the GMFM-66, peak knee extensor moments at 120°/s, and peak knee flexor moments at 30°/s for the cycling group. Improved peak knee flexor moments at 120°/s were found for the control group only, although not all participants could complete this speed of testing. Significant differences between the cycling and control groups based on change scores were not found for any outcomes. Limitations: Heterogeneity of the patient population and intrasubject variability were limitations of the study. Conclusions: Significant improvements in locomotor endurance, gross motor function, and some measures of strength were found for the cycling group but not the control group, providing preliminary support for this intervention. As statistical differences were not found in baseline-postintervention change scores between the 2 groups; the results did not demonstrate that stationary cycling was more effective than no intervention. The results of this phase I study provide guidance for future research. [ABSTRACT FROM AUTHOR]

STUDY DESIGN: Clinical measurement, criterion standard. OBJECTIVES: To determine if the clinical measure of femoral anteversion is comparable to measures obtained from magnetic resonance imaging (MRI). An additional purpose of this study was to assess the intertester and intratester reliability of the clinical test. BACKGROUND: Femoral anteversion is commonly assessed as part of the physical examination; however, limited and inconsistent data exist on the validity and reliability of the clinical test. METHODS: Eighteen healthy adults (9 males, 9 females; mean +/- SD age, 25.4 +/- 3.3 years; body mass index, 22.9 +/- 3.4 kg/m2) participated. Each underwent 3 data collection sessions: (1) MRI to measure femoral anteversion, (2) clinical testing of femoral anteversion, measured independently by 2 physical therapists, and (3) repeated clinical testing. Validity and reliability were assessed using intraclass correlation coefficient (ICC2,3) and standard error of measurement (SEM). RESULTS: Moderate agreement was found between the clinical test and MRI measures of femoral anteversion (ICCs of 0.69 and 0.67 for examiners 1 and 2, respectively). The SEM was similar for both examiners (5.8 degrees and 6.0 degrees ). Both intratester (ICCs of 0.88 and 0.90 for examiners 1 and 2, respectively) and intertester (ICC = 0.83) reliability was found to be substantial. CONCLUSIONS: In persons with a low body mass index, the clinical test to assess femoral anteversion was shown to exhibit substantial reliability, but only moderate agreement with MRI measurements. When performing the clinical test, one can be 95% confident that the true value of femoral anteversion will fall within 11.8 degrees of the clinically measured value. This relatively wide confidence interval calls into question the clinical utility of the clinical test for assessing femoral anteversion. J Orthop Sports Phys Ther 2009;39(8):586-592, Epub 24 June 2009. doi:10.2519/jospt.2009.2996. [ABSTRACT FROM AUTHOR]

STUDY DESIGN: Controlled laboratory study using a cross-sectional design. OBJECTIVES: To determine whether females with patellofemoral pain (PFP) demonstrate differences in hip kinematics, hip muscle strength, and hip muscle activation patterns when compared to pain-free controls. BACKGROUND: It has been proposed that abnormal hip kinematics may contribute to the development of PFP. However, research linking hip function to PFP remains limited. METHODS AND MEASURES: Twenty-one females with PFP and 20 pain-free controls participated in this study. Hip kinematics and activity level of hip musculature were obtained during running, a drop jump, and a step-down maneuver. Isometric hip muscle torque production was quantified using a multimodal dynamometer. Group differences were assessed across tasks using mixed-design 2-way analyses of variance and independent t tests. RESULTS: When averaged across all 3 activities, females with PFP demonstrated greater peak hip internal rotation compared to the control group (mean +/- SD, 7.6 degrees +/- 7.0 degrees versus 1.2 degrees +/- 3.8 degrees ; P<.05). The individuals in the PFP group also exhibited diminished hip torque production compared to the control group (14% less hip abductor strength and 17% less hip extensor strength). Significantly greater gluteus maximus recruitment was observed for individuals in the PFP group during running and the step-down task. CONCLUSION: The increased peak hip internal rotation motion observed for females in the PFP group was accompanied by decreased hip muscle strength. The increased activation of the gluteus maximus in individuals with PFP suggests that these subjects were attempting to recruit a weakened muscle, perhaps in an effort to stabilize the hip joint. Our results support the proposed link between abnormal hip function and PFP. J Orthop Sports Phys Ther 2009;39(1):12-19, Epub 22 August 2008. doi:10.2519/jospt.2009.2885. [ABSTRACT FROM AUTHOR]

STUDY DESIGN: Resident's case problem. BACKGROUND: Recent literature has suggested that acetabular labral pathology secondary to femoroacetabular impingement (FAI) may be a precursor to early-onset hip osteoarthritis. The purpose of this resident's case problem was to explore the extent to which abnormal movement at the hip is a possible contributor to acetabular labral pathology. DIAGNOSIS: The patient was a 25-year-old female with a 4-year history of anterior-medial groin pain. Based on a combination of the clinical examination and magnetic resonance imaging findings, she was given a diagnosis of acetabular labral tear by her orthopaedic surgeon and referred to a physical therapist for assessment. Movement analysis during a single-leg step down, running, and a drop jump maneuver revealed excessive hip adduction and internal rotation on the involved side, which reproduced her symptoms. Application of a hip-strapping device resulted in decreased hip adduction and internal rotation, and an immediate decrease in symptoms. DISCUSSION: The reduction in pain secondary to controlling hip motion suggests that excessive frontal and transverse plane hip motions may contribute to FAI. Accordingly, physical therapy intervention aimed at controlling and reducing hip adduction and internal rotation during activities may be indicated in patients who present with this movement pattern associated with anterior hip/groin pain. LEVEL OF EVIDENCE: Differential diagnosis, level 4.J Orthop Sports Phys Ther. 2008;38(9):558-565, published online 3 June 2008. doi:10.2519/jospt.2008.2790. [ABSTRACT FROM AUTHOR]

STUDY DESIGN: Experimental laboratory study. OBJECTIVES: To examine how a change in trunk position influences the kinematics, kinetics, and muscle activity of the lead lower extremity during the forward lunge exercise. BACKGROUND: Altering the position of the trunk during the forward lunge exercise is thought to affect the muscular actions of the lead lower extremity. However, no studies have compared the biomechanical differences between the traditional forward lunge and its variations. METHODS AND MEASURES: Ten healthy adults (5 males, 5 females; mean age ± SD, 26.7 ± 3.2 years) participated. Lower extremity kinematics, kinetics, and surface electromyographic (EMG) data were obtained while subjects performed 3 lunge exercises: normal lunge with the trunk erect (NL), lunge with the trunk forward (LTF), and lunge with trunk extension (LTE). A 1-way analysis of variance with repeated measures was used to compare lower extremity kinematics, joint impulse (area under the moment-time curve), and normalized EMG (highest 1-second window of activity for selected lower extremity muscles) among the 3 lunge conditions. RESULTS: During the LTF condition, significant increases were noted in peak hip flexion angle, hip extensor and ankle plantar flexor impulse, as well as gluteus maximus and biceps femoris EMG (P<.015) when compared to the NL condition. During the LTE condition, a significant increase was noted in peak ankle dorsiflexion and a significant decrease was noted in peak hip flexion angle (P<.015) compared to the NL condition. CONCLUSIONS: Performing a lunge with the trunk forward increased the hip extensor impulse and the recruitment of the hip extensors. In contrast, performing a forward lunge with the trunk extended did not alter joint impulse or activation of the lower extremity musculature. LEVEL OF EVIDENCE: Therapy, level 5. [ABSTRACT FROM AUTHOR]

Objective: Loading is invariably an important factor of consideration for understanding the causality flow and parallel existence of articular cartilage and subchondral bone changes. The goal of this study was to investigate the patterns of subregional 18 NaF-SUV vs. T 1p -T 2 associations and vertical ground reaction force loading rates; in isolated patellofemoral-joint-osteoarthritis (PFJ-OA) patients., Method: Thirty-five isolated PFJ-OA patients, with no tibiofemoral involvement, underwent simultaneous scans in a 3.0T whole-body hybrid positron emission tomography-magnetic resonance imaging scanner. MRI Whole-Organ Magnetic Resonance Imaging Scoring assessments were performed to identify/confirm isolated PFJ-OA knees from bilateral scans. T 1p -T 2 relaxation and SUV values were automatically computed for both trochlear and patellar cartilage and subchondral bone subregions (deep, superficial, lateral, and medial). Maximum vertical impact loading rates (Loading-Rate Norm ) were calculated from walking trials. Relationships were explored between SUV uptake, T 1p -T 2 values, and Loading-Rate Norm via linear mixed-effects modeling., Results: Significant and complex association patterns were noted between medial and lateral bone 18 NaF-SUV uptakes vs. medial and lateral cartilage sub-regional T 1p and T 2 . SUV Mean and SUV Max were positively associated with deep cartilage subregional T 1p and T 2 values; and negatively associated with superficial cartilage subregional T 1p -T 2 values in both medial and lateral regions. Both medial and lateral bone 18 NaF-SUV Mean and SUV Max uptakes remained positively associated with the individual gait characteristics, i.e., peak vertical impact loading rates (Loading-Rate Norm )., Conclusion: Evidence of simultaneous, complementary, cross-sectional associations between T 1p -T 2 values and peak vertical loading rates with 18 NaF-SUV, have been rare in the isolated PFJ-OA cohort. The clinical implications of such novel associations remain of utmost importance from a gait retraining perspective., Competing Interests: Conflict of interest The authors declare no competing interests., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Objective: To study the longitudinal changes of cartilage T 1 ρ and T 2 relaxation time measurements in hip-OA patients., Methods: A calibration study compared two scanner data, Scanner-1 (GE Discovery MR750 3.0T) with unilateral acquisition protocol and Scanner-2 (GE Signa Premier 3.0T) with bilateral acquisition protocol, using nine subjects(average age ​= ​40.33 ​± ​13.53 years, 5 females), including one hip-OA subject. Quantified parameters from the Scanner-2 were adjusted using voxel-based relaxometry(VBR) and Z-score normalization to reduce the inter-scanner variability. Eighteen hip-OA Subjects (age ​= ​53.11 ​± ​14.96 years, 12 females) were recruited to the longitudinal variability study from 2016, comprising five assessments at 1-year intervals. Baseline to 3rd-year data used unilateral acquisition with Scanner-1, while 4th-year data used bilateral acquisition with Scanner-2. A linear mixed-effects model(LME) assessed trajectory analyses, with acquisition year, age, sex, body mass index(BMI), and Kellgren-Lawrence(KL) score as predictor variables and cartilage mean T 1 ρ and T 2 values as outcomes., Results: VBR analysis after Z-score normalization showed that only a few of the whole cartilage voxels had significant differences in T 1 ρ ( femur-2.36 ​% and acetabular-3.23 ​%) and T 2 (femur-2.30 ​% and acetabular-2.94 ​%) values between the scanners. The LME analysis showed that the BMI predictor variable was significantly correlated with the femur T 1 ρ (p ​< ​0.0001) and T 2 (p ​< ​0.0001) and acetabular T 1 ρ (p ​< ​0.0001) and T 2 (p ​< ​0.0001) cartilage region., Conclusion: The calibration study demonstrated the effectiveness of VBR and Z-score normalization in reducing inter-scanner variability. The longitudinal study revealed a significant correlation between T 1 ρ and T 2 values of the cartilage and BMI; also the T 1 ρ and T 2 values increased over time in some of the cartilage subregions., Competing Interests: The authors have declared that no conflict of interest exists., (© 2024 The Author(s).)

Background: Hip internal rotation has been reported to affect patellofemoral joint mechanics and contribute to patellofemoral pain (PFP). The SERF (Stability through External Rotation of the Femur) strap was designed to provide hip stability by pulling the thigh into external rotation during weight-bearing activities., Research Question: What are the effects of the SERF strap on hip internal rotation and pain response in females with PFP who present with hip internal rotation during weight-bearing activities?, Methods: Nineteen females between the ages of 18 and 45 with a diagnosis of PFP participated. Lower extremity kinematics were obtained during three tasks (drop-jump, unilateral step-down, over-ground running) under strap and no-strap conditions. A 10-cm visual analog scale (VAS) was used to assess pain response during each task and strap condition. Participants who exhibited at least 5 degrees of hip internal rotation during at least one of the 3 tasks were included in the final analysis. Peak hip internal rotation and mean VAS score were compared separately between strap conditions across tasks using 2 ×3 (strap condition x task) repeated-measures ANOVAs., Results: Eighteen of the 19 females with PFP met the criteria for the presence of hip internal rotation. There was a significant reduction in peak hip internal rotation across tasks when wearing the SERF strap (mean ± sd = 7.4 ± 2.3, p<0.001). Additionally, the change in mean VAS pain score was significantly lower across tasks when wearing the SERF strap (1.0 ± 1.0, p=0.03)., Significance: The SERF strap was effective in reducing hip internal rotation and PFP during dynamic weight-bearing activities in symptomatic females. The SERF strap may be a useful treatment adjunct for persons with PFP who present with poor transverse plane control of the hip., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Christopher M. Powers has US & International Patent #20070219478, “Device and method for externally rotating the femur”. License agreement with Don Joy Orthopaedics Inc. through USC Stevens Center for Innovation; with royalties paid to Dr. Powers through DJO. The authors declare that they have no other known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Limited information exists regarding abductor muscle quality variation across its length and which locations are most representative of overall muscle quality. This is exacerbated by time-intensive processes for manual muscle segmentation, which limits feasibility of large cohort analyses. The purpose of this study was to develop an automated and localized analysis pipeline that accurately estimates hip abductor muscle quality and size in individuals with mild-to-moderate hip osteoarthritis (OA) and identifies regions of each muscle which provide best estimates of overall muscle quality. Forty-four participants (age 52.7 ± 16.1 years, BMI 23.7 ± 3.4 kg/m 2 , 14 males) with and without mild-to-moderate radiographic hip OA were recruited for this study. Unilateral hip magnetic resonance (MR) images were acquired on a 3.0 T MR scanner and included axial T 1 -weighted fast spin echo and 3D axial Iterative Decomposition of water and fat with Echo Asymmetry and Least-squares estimation (IDEAL-IQ) spoiled gradient-recalled echo (SPGR) with multi-peak fat spectrum modeling and single T 2 * correction. A three dimensional (3D) V-Net convolutional neural network was trained to automatically segment the gluteus medius (GMED), gluteus minimus (GMIN), and tensor fascia lata (TFL) on axial IDEAL-IQ. Agreement between manual and automatic segmentation and associations between axial fat fraction (FF) estimated from IDEAL-IQ and overall muscle FF were evaluated. Dice scores for automatic segmentation were 0.94, 0.87, and 0.91 for GMED, GMIN, and TFL, respectively. GMED, GMIN, and TFL volumetric and FF measures were strongly correlated (r: 0.92-0.99) between automatic and manual segmentations, where all values fell within the 95% limits of agreement of [-9.79 cm 3 , 17.43 cm 3 ] and [-1.99%, 2.89%], respectively. Axial FF was significantly associated with overall FF with the strongest correlations at 50%, 50%, and 65% the length of the GMED, GMIN, and TFL muscles, respectively (r: 0.93-0.97). An automated and localized analysis can provide efficient and accurate estimates of hip abductor muscle quality and size across muscle length. Specific regions of the muscle may be used to estimate overall muscle quality in an abbreviated evaluation of muscle quality., Competing Interests: Declaration of competing interest None., (Copyright © 2023. Published by Elsevier Inc.)

Objectives: To investigate the association between magnetic resonance imaging (MRI)-based ligamentum teres lesions (LTL) and structural hip degeneration., Methods: Bilateral 3-T hip MRIs of participants (n = 93 [36 men]; mean age ( ± SD) 51 years ± 15.4) recruited from the community and the orthopedic clinic of a single medical center were included. Clinical and imaging data acquired included hip disability and osteoarthritis outcome scores, semi-quantitative scoring of hip osteoarthritis on MRI (SHOMRI) scores on fluid-sensitive sequences, and cartilage T 1ρ /T 2 compositional sequences. An MRI-based LTL scoring system, incorporating continuity, thickening, and signal intensity, ranging from 0 (normal) to 4 (complete tear) was constructed. Hip morphological features associated with LTL, based on functional or anatomical relationships to LT, were defined. Relationships between MRI-LT scores and SHOMRI, global/regional cartilage T 1ρ /T 2 , and proposed morphological abnormalities and LTL were explored by mixed effects linear and logistic regression models., Results: In 82 (46.1%) hips, no pain was documented; 118 (63.4%) and 68 (36.6%) hips were graded as KL-grade ≤ 1 and ≥ 2, respectively. Compared to MRI-LT score = 0 (normal), score = 4 (complete tear) revealed significantly worse subchondral bony degenerative changes for bone marrow lesions (SHOMRI-BML) and subchondral cysts (SHOMRI-sc) (p < 0.001, p = 0.015, respectively). Global acetabular T 1ρ , femoral T 2 were significantly increased for abnormal MRI-LT scores (p-range = 0.005-0.032). Regional analyses revealed significantly increased T 1ρ /T 2 in central acetabular/increased T 2 in off-central femoral regions (p-range = 0.005-0.046). Pulvinar effusion-synovitis, shallow fovea, and foveal osteophytes were significantly associated with abnormal LT MRI findings (p-range = < 0.001-0.044)., Conclusion: MRI abnormalities of LT are associated with worse SHOMRI-sc/BML scores, indicative of hip osteoarthritis and higher T 1ρ and T 2 that differ by region. Pulvinar effusion-synovitis and changes in femoral head morphology are associated with LTL., Clinical Relevance Statement: Abnormal ligamentum teres findings identified via MRI are associated with structural degenerative changes of the hip joint and alterations in acetabular and femoral cartilage compositions show spatial differences in relation to LTL., Key Points: The clinical significance of common ligamentum teres lesions (LTL) on MRI is not well understood. LTL identified by an MRI-based scoring system is associated with worse biomarkers, indicating more advanced degenerative hip changes. Effusion-synovitis signal at pulvinar, shallow fovea capitis, and foveal osteophytes are associated with LTL on imaging., (© 2024. The Author(s), under exclusive licence to European Society of Radiology.)