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Objective: Intra-articular (IA) mineralization may contribute to osteoarthritis (OA) structural progression. We studied the association of IA mineralization on knee computed tomography (CT) with cartilage damage worsening on knee magnetic resonance imaging (MRI), with a focus on location- and tissue-specific effects., Methods: Participants from the Multicenter Osteoarthritis Study with knee CT and MRI scans were included. Presence of IA mineralization on CT was defined as a Boston University Calcium Knee Score >0 anywhere in the knee. Cartilage worsening on MRI was defined as any increase in the MRI OA Knee Score, including incident damage. We evaluated the association of whole-knee, compartment-specific (ie, medial or lateral), and subregion-specific (ie, location-matched) IA mineralization at baseline with cartilage worsening at two years' follow-up in the corresponding locations using binomial regression with generalized estimating equations, adjusting for age, sex, and body mass index (BMI)., Results: We included 1,673 participants (mean age 60 years, 56% female, mean BMI 29). Nine percent had any IA mineralization in the knee, and 47.4% had any cartilage worsening on follow-up. Mineralization of any tissue in the knee, regardless of location, was not associated with MRI cartilage worsening. However, cartilage mineralization was associated with 1.39 (95% confidence interval 1.04-1.88) times higher risk of cartilage worsening in the same compartment, with similar results in subregion-specific analysis., Conclusion: CT-detected IA mineralization in the cartilage was associated with higher risk of MRI cartilage worsening in the same compartment and subregion over two years. These findings suggest potential localized, tissue-specific effects of IA mineralization on cartilage pathology in knee OA., (© 2024 American College of Rheumatology.)

Purpose: Our aim was to introduce a simplified MRI instrument, Rapid OsteoArthritis MRI Eligibility Score (ROAMES), for defining structural eligibility of patients for inclusion in disease-modifying osteoarthritis drug trials using a tri-compartmental anatomic approach that enables stratification of knees into different structural phenotypes and includes diagnoses of exclusion. We also aimed to define overlap between phenotypes and determine reliability., Methods: 50 knees from the Foundation for National Institutes of Health Osteoarthritis Biomarkers study, a nested case-control study within the Osteoarthritis Initiative, were selected within pre-defined definitions of phenotypes as either inflammatory, subchondral bone, meniscus/cartilage, atrophic or hypertrophic. A focused scoring instrument was developed covering cartilage, meniscal damage, inflammation and osteophytes. Diagnoses of exclusion were meniscal root tears, osteonecrosis, subchondral insufficiency fracture, tumors, malignant marrow infiltration and acute traumatic changes. Reliability was determined using weighted kappa statistics. Descriptive statistics were used for determining concordance between the a priori phenotypic definition and ROAMES and overlap between phenotypes., Results: ROAMES identified 43 of 50 (86%) pre-defined phenotypes correctly. Of the 50 participants, 27 (54%) had no additional phenotypes other than the pre-defined phenotype. 18 (36%) had one and 5 (10%) had two additional phenotypes. None had three or four additional phenotypes. All features of ROAMES showed almost perfect agreement. One case with osteonecrosis and one with a tumor were detected., Conclusions: ROAMES is able to screen and stratify potentially eligible knees into different structural phenotypes and record relevant diagnoses of exclusion. Reliability of the instrument showed almost perfect agreement., (Copyright © 2019 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.)

Objectives: Medial meniscal body extrusion ≥ 3 mm on MRI is often considered "pathologic." The aims of this study were to (1) assess the adequacy of 3 mm as cut-off for "pathological" extrusion and (2) find an optimal cut-off for meniscal extrusion cross-sectionally associated with radiographic knee osteoarthritis, bone marrow lesions (BMLs), and cartilage damage., Methods: Nine hundred fifty-eight persons, aged 50-90 years from Framingham, MA, USA, had readable 1.5 T MRI scans of the right knee for meniscal body extrusion (measured in mm). BMLs and cartilage damage were read using the whole organ magnetic resonance imaging score (WORMS). Knee X-rays were read according to the Kellgren and Lawrence (KL) scale. We evaluated the performance of the 3-mm cut-off with respect to the three outcomes and estimated a new cut-off maximizing the sum of sensitivity and specificity., Results: The study persons had mean age of 62.2 years, 57.0% were women and the mean body mass index was 28.5 kg/m 2 . Knees with radiographic osteoarthritis, BMLs, and cartilage damage had overall more meniscal extrusion than knees without. The 3-mm cut-off had moderate sensitivity and low specificity for all three outcomes (sensitivity between 0.68 [95% CI 0.63-0.73] and 0.81 [0.73-0.87], specificity between 0.49 [0.45-0.52] and 0.54 [0.49-0.58]). Using 4 mm maximized the sum of sensitivity and specificity and improved the percentage of correctly classified subjects (from between 54 and 61% to between 64 and 79%)., Conclusions: The 4-mm cut-off may be used as an alternative cut-off for denoting pathological meniscal extrusion., Key Points: • Medial meniscal body extrusion is strongly associated with osteoarthritis. • The 3-mm cut-off for medial meniscal body extrusion has high sensitivity but low specificity with respect to bone marrow lesions, cartilage damage, and radiographic osteoarthritis. • The 4-mm cut-off maximizes the sensitivity and specificity with respect to all three osteoarthritis features.

Objective: To determine the relationship of meniscal damage to magnetic resonance imaging (MRI) features of compartment-specific patellofemoral joint (PFJ) osteoarthritis (OA) at baseline and 2 years later., Method: Individuals from a prospective cohort of individuals aged 50-79 with or at risk of knee OA were included. At the 60-month and 84-month study visit, Whole-Organ MRI Score (WORMS) was used to assess meniscal tears and extrusions as well as cartilage damage and bone marrow lesions (BMLs) in the medial and lateral patella and trochlea. Worsening of structural features was defined as any increase in WORMS score from 60 to 84 months. Logistic regression was used to determine the cross-sectional and longitudinal relation of meniscus damage to features of compartment-specific PFJ OA., Results: Relative to knees without lateral meniscal pathology at baseline, those with grades 3-4 lateral meniscal tear and extrusion had greater risk of worsening of cartilage damage in the lateral PFJ 2 years later (Risk ratio: 1.7 [95% CI: 1.1-2.7) and (1.7 [1.2-2.5]), respectively. Relative to those without medial meniscal pathology at baseline, those with grades 1-2 (0.6 [0.4-0.9]) and 3-4 (0.7 [0.5-1.0]) medial meniscal tears had lower risk of worsening of BMLs in the medial PFJ 2 years later., Conclusion: Meniscal tear and extrusion are associated with increased risk of medial and lateral PFJ OA and more severe meniscal pathology is associated with worsening of PFJ OA 2 years later. Lateral meniscal pathology appears to be more detrimental to the lateral PFJ., (Copyright © 2018 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.)

Objective: To assess whether medial tibiofemoral joint space width (JSW) on 3-dimensional (3-D) standing computed tomography (SCT) correlates more closely with magnetic resonance imaging cartilage morphology (CM) and meniscal scores than does radiographic 2-D JSW., Methods: Participants in the Multicenter Osteoarthritis Study, who had standing fixed-flexion posteroanterior knee radiographs, were recruited. Medial tibiofemoral 3-D JSW on SCT and 2-D JSW on fixed-flexion radiographs were compared with medial tibiofemoral cartilage and meniscal morphology using the Whole-Organ Magnetic Resonance Imaging Score (WORMS). Associations between the area of the articular surface with 3-D JSW <2.5 mm on SCT, radiographic minimal 2-D JSW, and the WORMS-CM and meniscal scores were assessed using Spearman's rho., Results: For the 19 participants included (33 knees), mean ± SD age was 66.9 ± 5.4 years, body mass index was 29.5 ± 4.4 kg/m(2) , 42.1% of participants were female, and the Kellgren/Lawrence grades were 0 (21.2%), 1 (36.4%), 2 (18.2%), and 3 (24.2%). The articular surface area with 3-D JSW <2.5 mm on SCT correlated with WORMS-CM scores for the central medial tibia (rs  = 0.84, P < 0.001), central medial femur (rs  = 0.60, P < 0.007), and posterior medial meniscal tear (rs  = 0.39, P < 0.026), as did other cut points for 3-D JSW. Correlations with radiographic minimal 2-D JSW were -0.66, -0.52, and -0.40, respectively, differing from SCT only for tibial cartilage (P = 0.001)., Conclusion: Greater surface area with a low JSW, measured by SCT, correlates more strongly with the severity of tibial cartilage lesions, while correlating with medial femoral cartilage and meniscal damage to a similar extent as radiographic minimal JSW. SCT may enable valid stratification of participants in clinical trials, through quickly and inexpensively characterizing osteoarthritis features., (© 2016, American College of Rheumatology.)

Objective: To examine the relation of cartilage loss and bone marrow lesions (BMLs) in the medial and lateral patellofemoral joint (PFJ) to knee pain., Methods: We categorized the location of full-thickness cartilage loss and BMLs in the PFJ on knee magnetic resonance imaging (MRIs) from the Multicenter Osteoarthritis (MOST) and Framingham Osteoarthritis (FOA) Studies as no damage, isolated medial, isolated lateral, or both medial and lateral (mixed). We determined the relation of MRI lesions in each PFJ region to prevalent knee pain. Differences in knee pain severity were compared among categories of PFJ full-thickness cartilage loss and BMLs using quantile regression., Results: In MOST (n = 1137 knees), compared with knees without full-thickness cartilage loss, knees with isolated lateral or mixed PFJ full-thickness cartilage loss had 1.9 (1.3, 2.8) and 1.9 (1.2, 2.9) times the odds of knee pain, respectively, while isolated medial cartilage loss had no association with knee pain. BMLs in both the medial and lateral PFJ had 1.5 (1.1, 2.0) times the odds of knee pain compared with knees without BMLs. Knee pain severity was lowest in knees with isolated medial PFJ cartilage loss or BMLs. In FOA (n = 934 knees), neither isolated medial nor lateral cartilage loss was associated with knee pain, whereas isolated BMLs in either region were associated with pain., Conclusions: Results were not completely concordant but suggest that knee pain risk and severity is greatest with cartilage loss isolated to (MOST) or inclusive of (MOST and FOA) the lateral PFJ. While BMLs in either the medial or lateral PFJ are related to pain., (Copyright © 2015 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.)

Objectives: Arthrogenous muscle inhibition (AMI) is thought to contribute to quadriceps weakness in knee osteoarthritis (OA), but its relationship with structural changes of bone marrow lesions (BMLs), capsular distension and pain is unclear. This study's objective was to investigate the factors associated with AMI in subjects with symptomatic patellofemoral joint OA (PFJOA)., Design: 126 Subjects with predominant PFJOA were assessed for pain by the visual analogue scale (VAS) for a nominated aggravating activity. Their more symptomatic knee underwent a magnetic resonance imaging (MRI) scan which was used to assess BMLs and synovitis which were scored using the Whole Organ MRI score (WORMS). Quadriceps AMI was measured by calculating the activation deficit and quadriceps strength assessed by isometric maximum voluntary contraction. Multiple linear regressions were used to assess factors associated with AMI., Results: We studied 124 subjects [mean age 55.5 (SD 7.5); 57.14% female]. In regression analyses, higher levels of AMI were significantly associated with more severe knee pain and with lower BML score., Conclusion: Quadriceps AMI in knee OA is associated with severity of knee pain and surprisingly with lower BML scores., (Copyright © 2014. Published by Elsevier Ltd.)

Purpose: To assess the diagnostic performance of signal changes in Hoffa's fat pad (HFP) assessed on non-contrast-enhanced (CE) magnetic resonance imaging (MRI) in detecting synovitis, and the association of pain with signal changes in HFP on non-CE MRI and peripatellar synovial thickness on CE MRI., Methods: The Multicenter Osteoarthritis (MOST) Study is an observational study of individuals who have or are at high risk for knee OA. All subjects with available non-CE and CE MRIs were included. Signal changes in HFP were scored from 0 to 3 in two regions using non-CE MRI. Synovial thickness was scored from 0 to 2 on CE MRI in five peripatellar regions. Sensitivity, specificity and accuracy of HFP signal changes were calculated considering synovial thickness on CE MRI as the reference standard. We used logistic regression to assess the associations of HFP changes (non-CE MRI) and synovial thickness (CE MRI) with pain from walking up or down stairs, after adjusting for potential confounders., Results: A total of 393 subjects were included. Sensitivity of infrapatellar and intercondylar signal changes in HFP was high (71% and 88%), but specificity was low (55% and 30%). No significant associations were found between HFP changes on non-CE MRI and pain. Grade 2 synovial thickness assessed on CE MRI was significantly associated with pain after adjustments for potential confounders., Conclusion: Signal changes in HFP detected on non-CE MRI are a sensitive but non-specific surrogate for the assessment of synovitis. CE MRI identifies associations with pain better than non-CE MRI., (Copyright © 2013 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.)

Objectives: Knee osteoarthritis (OA) is thought to be a slowly evolving disease with glacial changes in cartilage morphology necessitating trials of potential treatments lasting 1-2 years with evidence that over 6 months change in cartilage is not detectable. In contrast to cartilage, bone has the capacity to adapt rapidly, such as after fracture. We tested whether bone marrow lesions (BMLs) change in volume in 6 and 12 weeks, suggesting they may provide evidence of short term fluctuations of joint damage., Methods: In 62 patients with patellofemoral knee OA (mean age 55.7 years, 59.7% women, mean BMI 31.0), we obtained baseline, 6 and 12 week knee MRIs with contrast enhancement. Of those with BMLs at baseline, we assessed BML volume on the axial proton density fat saturated (FS) images and postcontrast sagittal T1 weighted FS images. We manually segmented BML volumes, testing repeatability of BML volumes in knees remeasured. Using the standard deviation of the difference between repeated measurements to calculate Bland-Altman Limits of Agreement, we determined how much BML volume change represented a change greater than due to chance., Results: Fifty-two patients had BMLs at baseline. Test-retest reliability for BML volume was high (ICC 0.89, 95% CI 0.80-0.97). All knees showed at least some change in BML volume by 6 and 12 weeks. On the axial view at 6 weeks, 20/49 (40.8%) knees showed BML volume changes greater than the limits of agreement with similar results at 12 weeks. BML changes were evenly divided among knees with enlarging and shrinking BMLs. 63.3% of the knees had more than 50% change in BML volume at either 6 or 12 weeks on the axial view and 48.7% on the sagittal view., Conclusions: Knee BML volumes change in several weeks in many persons with knee OA. To the extent that they could be regarded as treatment targets, trials testing BML effects could avoid the usual prolonged structure modification trials., (Copyright © 2012 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.)

Objective: In order to increase sensitivity to detect longitudinal change, recording of within-grade changes was introduced for cartilage morphology and bone marrow lesion (BML) assessment in semiquantitative magnetic resonance imaging (MRI) scoring of knee osteoarthritis (OA). The aim of this study was to examine the validity provided by within-grade scoring., Design: The Multicenter Osteoarthritis (MOST) study is a longitudinal study of subjects with or at risk of knee OA. Baseline and 30 months MRIs were read according to the modified Whole-Organ Magnetic Resonance Imaging Score (WORMS) system including within-grade changes for cartilage and BMLs. We tested the validity of within-grade changes by whether the 30-month changes in cartilage and BML assessment were predicted by baseline ipsi-compartmental meniscal damage and malalignment, factors known to affect cartilage loss and BMLs, using ordinal logistic regression., Results: 1867 Knees (from 1411 participants) were included. Severe medial meniscal damage predicted partial grade (adjusted odds ratio (aOR) 4.4, 95% confidence interval (95% CI) 2.2, 8.7) but not ≥full grade (aOR 1.3, 95% CI 0.8, 2.2) worsening of cartilage loss and predicted both, partial grade (aOR 9.6, 95% CI 3.6, 25.1) and ≥full grade (aOR 5.1, 95% CI 3.2, 8.2) worsening of BMLs. Severe, but not moderate, malalignment predicted ipsi-compartmental within-grade (medial cartilage damage: aOR 5.5, 95% CI 2.6, 11.6; medial worsening of BMLs: aOR 4.9, 95% CI 2.0, 12.3) but not full grade worsening of BMLs and cartilage damage., Conclusions: Within-grade changes in semiquantitative MRI assessment of cartilage and BMLs are valid and their use may increase the sensitivity of semiquantitative readings in detecting longitudinal changes in these structures., (Copyright © 2012 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.)

Objective: To compare two semiquantitative scoring systems for assessing the prevalence and severity of morphologic cartilage lesions, meniscal damage and bone marrow lesions (BMLs) from Magnetic Resonance Imagings (MRIs) of knees with osteoarthritis (OA)., Methods: From participants in the OA Initiative (OAI), a sample of 115 knees with radiographic OA at high risk of cartilage loss, were selected based on risk factors for progression. Knee MRIs were read separately using both Whole Organ MR Scoring (WORMS) and Boston-Leeds OA Knee Scoring (BLOKS), and a subset was fed back to readers for reliability. Baseline readings were used for comparison of the two methods for inter-reader reliability as well as agreement on presence/absence and severity of MRI features at both the compartment level and finer anatomical subregion levels., Results: Both methods had high inter-reader agreement for all features studied (kappa for WORMS 0.69-1.0 and for BLOKS 0.65-1.0). Although the methods agreed well on presence and severity of morphological cartilage lesions (inter-method kappas from 0.66 to 0.95), BLOKS was more sensitive for full thickness defects. The two methods gave equivalent results for extent (kappa 0.74-0.80) and number (Spearman's Rho=0.85) of BMLs, and little extra information was obtained using the more complex BLOKS BML scoring. Similar results were also obtained for the common types of meniscal damage and extrusion (inter-method kappa 0.85-0.94), but the inclusion in BLOKS of meniscal signal abnormality and uncommon types of tear may be an advantage if these prove clinically meaningful., Conclusion: Both WORMS and BLOKS had high reliability. The two methods gave similar results in this sample for prevalence and severity of cartilage loss, BMLs and meniscal damage. Selecting between, or combining, the two methods should be based on factors such as reader effort, appropriateness for the goals of a study, and longitudinal performance., (Copyright © 2010 Osteoarthritis Research Society International. All rights reserved.)

Introduction: There are two widely used scoring systems for knee magnetic resonance imaging (MRI) in osteoarthritis (OA) and the strengths and weaknesses of each system in terms of ease of use and association with known risk factors and outcomes are unknown., Objective: To compare Whole Organ Magnetic Resonance Imaging Score (WORMS) and Boston Leeds Osteoarthritis Knee Score (BLOKS) scales using longitudinal MRI and X-ray data., Methods: In the Osteoarthritis Initiative (OAI), knee radiographs, long limb films for alignment and MRI's were acquired in the interval from 0 to 24 months follow-up. OAI MRI's from baseline and 24 months were read separately using BLOKS and WORMS scales. X-rays were scored semiquantitatively for joint space loss and long limb films were measured for alignment angle. We evaluated which of the WORMS or BLOKS cartilage loss scores best correlated with joint space loss on the X-ray and which was best predicted by varus malalignment on long limb film. To examine the validity of bone marrow lesion (BML) and meniscal scales, we tested which of WORMS or BLOKS baseline scores for BML or meniscus best predicted cartilage loss from baseline to 24 months. We critically evaluated strengths and weaknesses of each scoring system also., Results: Of 113 knees read longitudinally, 33 showed any cartilage loss using BLOKS and 30 using WORMS with high agreement between the scales. In the medial compartment, both BLOKS and WORMS picked up only 42% of the knees with X-ray joint space loss with similar specificity (88 vs 86%). Varus knees were more likely to be a risk factor for medial cartilage loss in BLOKS [adj odds ratio (OR) 5.9 (95% confidence intervals (CIs) 1.5, 24.0)] than in WORMS [adj OR 2.1 (95% CI 0.7, 6.3)]. WORMS BML scores predicted cartilage loss more strongly than any BLOKS BML variables and some BLOKS BML measures did not affect risk of cartilage loss at all. However, across the range of scores, meniscal tear scores in BLOKS predicted cartilage loss better for each abnormality than did WORMS meniscal tear scores and the meniscal signal abnormality scored in BLOKS but not in WORMS, predicted cartilage loss. BLOKS took longer and was more difficult to score longitudinally especially for BML scores., Conclusion: In a comparison of instruments limited by small numbers of knees compared, BLOKS meniscal score was preferable to WORMS meniscal scale in predicting cartilage loss most likely because it includes potentially important pathology missed by WORMS. On the other hand, BML scoring in WORMS was preferable in that it better predicted later cartilage loss, was easier to score and did not include potentially extraneous measures. Neither method was definitively better for cartilage scoring., (Copyright © 2010 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.)

Objective: The aim of the study was (1) to evaluate contrast enhancement patterns of subchondral cysts on magnetic resonance imaging and (2) to discuss possible radiological explanations of cyst enhancement based on existing theories of subchondral cyst formation in osteoarthritis., Materials and Methods: The Multicenter Osteoarthritis Study (MOST) is a NIH-funded longitudinal observational study for individuals who have or are at high risk for knee osteoarthritis. All subjects with available non-enhanced and contrast-enhanced MRI were included. The tibiofemoral and patellofemoral joints were divided in 14 subregions. The presence and size of subchondral cysts and bone marrow edema-like lesions (BMLs) were scored semiquantitatively in each subregion on non-contrast-enhanced MRI from 0 to 3. Enhancement of subchondral cysts was evaluated on contrast-enhanced MRI as grade 0 (absent), grade 1 (partial enhancement), or grade 2 (full enhancement). The adjacent articular cartilage was scored in each subregion on non-enhanced MRI as grade 0 (intact), grade 1 (partial thickness loss), or grade 2 (full thickness loss)., Results: Four hundred knees were included (1 knee per person, 5600 subregions). Subchondral cysts were detected in 260 subregions (4.6%). After intravenous contrast administration, 245 cysts (94.2%) showed full enhancement, 12 (4.6%) showed partial enhancement and 3 (1.2%) showed no enhancement. Enhancing BMLs were found in 237 (91.2%) subregions containing cysts, which were located adjacent or in the middle of BMLs. In 121 subregions (46.5%) having cysts, no adjacent full thickness cartilage loss was detected., Conclusion: Most subchondral cysts demonstrated full or partial contrast enhancement, and were located adjacent or in the midst of enhancing BMLs. As pure cystic lesions are not expected to enhance on MRI, the term "subchondral cyst-like bone marrow lesion" might be appropriate to describe these lesions., (Copyright 2009 Elsevier Ireland Ltd. All rights reserved.)

Objective: To date semiquantitative whole-organ scoring of knee osteoarthritis (OA) relies on 1.5 Tesla (T) Magnetic resonance imaging (MRI) systems. Less costly 1.0 T extremity systems have been introduced that offer superior patient comfort, but may have limitations concerning field-of-view and image quality. The aim of this study was to compare semi-quantitative (SQ) scoring on a 1.0 T system using 1.5 T MRI as the standard of reference., Methods: The Multicenter Osteoarthritis Study (MOST) is a longitudinal study of individuals who have or are at high risk for knee OA. A sample of 53 knees was selected in which MRI was performed on a 1.0 T extremity system as well as on a 1.5 T scanner applying a comparable sequence protocol. MRIs were read according to the Whole Organ Magnetic Resonance Imaging Score (WORMS) score. Agreement was determined using weighted kappa statistics. Sensitivity, specificity and accuracy were assessed using the 1.5 T readings as the reference standard. In addition the number of non-readable features was assessed., Results: Agreement (w-kappa) for seven main WORMS features (cartilage, bone marrow lesions (BMLs), osteophytes, meniscal damage and extrusion, synovitis, effusion) ranged between 0.54 (synovitis) and 0.75 (cartilage). Sensitivity ranged between 68.1% (meniscal damage) and 88.1% (effusion). Specificity ranged between 63.6% (effusion) and 96.4% (BMLs). Although the overall rate of non-readable features was very low, it was higher for the 1.0 T system (1.9% vs 0.2%)., Conclusions: Semiquantitative whole organ scoring can be performed using a 1.0 T peripheral scanner with a moderate to high degree of agreement and accuracy compared to SQ assessment using a 1.5 T whole body scanner. Our results are comparable to the published inter- and intra observer exercises obtained from 1.5 T systems. Sensitivity to change of longitudinal scoring was not evaluated in this cross-sectional design and should be investigated in future validation studies., (Copyright 2009 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.)

Objective: By magnetic resonance imaging (MRI), subchondral bone attrition (SBA) can be seen in early osteoarthritis (OA), but the significance of this is unknown. We therefore evaluated whether SBA was associated with cartilage loss within the same subregion of the knee., Methods: The Multicenter Osteoarthritis Study is a cohort of individuals who have or are at high risk for knee OA. At baseline and 30 months, participants' knee MRIs were graded using the Whole-Organ Magnetic Resonance Imaging Score in the 10 subregions of the tibiofemoral joint for cartilage morphology and SBA. We conducted analyses within a knee to eliminate between-person confounding, using an M:N (cases:controls) matched case-control approach with the 10 subregions of a person's knee forming a matched set. Cases within a knee were defined as subregions with cartilage loss, while controls were subregions in that same knee without cartilage loss. We evaluated the association of cartilage loss over 30 months with the presence of baseline SBA in the same subregion within that knee using conditional logistic regression., Results: SBA was associated with an odds ratio of 7.5 (95% confidence interval 5.6-9.9, P < 0.0001) for cartilage loss in the same subregion compared with subregions without any baseline SBA in our sample of 459 knees from participants, 64% of whom were women, with a mean age of 63 years and a mean body mass index of 30.5 kg/m(2)., Conclusion: SBA is strongly associated with cartilage loss within the same subregion of a knee. SBA may directly influence overlying cartilage loss or serve as a marker of an area undergoing great compressive stress and in which cartilage loss is inevitable.

Objectives: In vivo cartilage contact deformation is instrumental for understanding human joint function and degeneration. This study measured the total deformation of contacting articular cartilage in the human tibiofemoral joint during in vivo weight-bearing flexion., Methods: Eleven healthy knees were magnetic resonance (MR) scanned and imaged with a dual fluoroscopic system while the subject performed a weight-bearing single-leg lunge. The tibia, femur and associated articulating cartilage were constructed from the MR images and combined with the dual fluoroscopic images to determine in vivo cartilage contact deformation from full extension to 120 degrees of flexion., Results: In both compartments, minimum peak compartmental contact deformation occurred at 30 degrees of flexion (24 +/- 6% medial, 17 +/- 7% lateral) and maximum peak compartmental deformation occurred at 120 degrees of flexion (30 +/- 13% medial, 30 +/- 10% lateral) during the weight-bearing flexion from full extension to 120 degrees. Average medial contact areas and peak contact deformations were significantly greater than lateral compartment values (P < 0.05). In addition, cartilage thickness in regions of contact was on average 1.4- and 1.1-times thicker than the average thickness of the tibial and femoral cartilage surfaces, respectively (P < 0.05)., Conclusions: These data may provide base-line knowledge for investigating the effects of various knee injuries on joint contact biomechanics and the aetiology of cartilage degeneration.

Objective: The aim of the study was to examine the association between patellofemoral (PF) alignment (using standard magnetic resonance imaging (MRI) images of extended knees) and knee pain and function., Design: Subjects were recruited to participate in a natural history study of symptomatic knee osteoarthritis, called the Boston Osteoarthritis of the Knee Study (BOKS). The association of predictive variable (patellar alignment in sagittal and transverse planes) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain and function were examined using a linear regression model while adjusting for age, sex, body mass index (BMI), Center for Epidemiologic Studies Depression Scale (CES-D) score and Kellgren and Lawrence score., Results: Increasing trochlear angle (TA) was associated with both WOMAC (P=0.06) pain and WOMAC function subscale (P=0.04). Increasing lateral patellar title angle (LPTA) and decreasing bisect offset (increasing lateral subluxation) appeared to be associated with increasing WOMAC pain. However, no such an association was observed for other predictors., Conclusions: The findings of the present study suggest that increasing TA is associated with increased functional impairment. Other measures of PF malalignment were not significantly associated with either knee pain or functional impairment.

Objective: To examine the effects of smoking on cartilage loss and pain at the knee in individuals with knee osteoarthritis., Methods: 159 men with symptomatic knee osteoarthritis who participated in a 30-month, prospective, natural history study of knee osteoarthritis were examined. The more symptomatic knee was imaged using magnetic resonance imaging (MRI) at baseline, and again at 15 and 30 months of follow-up. Cartilage was scored using the Whole-Organ MRI Score semiquantitative method at the medial and lateral tibiofemoral joints and at the patellofemoral joint. At baseline and follow-up visits, the severity of knee pain was assessed using a Visual Analogue Scale pain score (0-100 mm)., Results: Among the 159 men, 19 (12%) were current smokers at baseline. Current smokers were younger (mean (standard deviation (SD)) age 62 (9) v 69 (9) years) and leaner (mean (SD) body mass index (BMI): 28.9 (3.2) v 31.3 (4.8) kg/m(2)) than men who were not current smokers. When adjusted for age, BMI and baseline cartilage scores, men who were current smokers were found to have an increased risk for cartilage loss at the medial tibiofemoral joint (odds ratio (OR) 2.3, 95% confidence interval (CI) 1.0 to 5.4) and the patellofemoral joint (OR 2.5, 95% CI 1.1 to 5.7). Current smokers also had higher adjusted pain scores at baseline (60.5 v 45.0, p<0.05) and at follow-up (59.4 v 44.3, p<0.05) than men who were not current smokers., Conclusions: Men with knee osteoarthritis who smoke sustain greater cartilage loss and have more severe knee pain than men who do not smoke.

Magnetic resonance imaging (MRI) provides a sensitive tool for examining all the structures involved in the osteoarthritis (OA) process. While much of the MRI literature previously focussed on cartilage, there is increasing research on whole-organ evaluation and including features such as synovitis, bone marrow edema, and meniscal and ligamentous pathology. The aim of this session at the Outcome Measures in Rheumatology Clinical Trials (OMERACT)-Osteoarthritis Research Society International (OARSI) Workshop for Consensus in Osteoarthritis Imaging was to describe the current MRI methods for identifying and quantifying non-cartilaginous structures and review their associations with both OA symptoms and structural progression. Although there is much experience in measuring synovitis (derived from the rheumatoid arthritis literature), only one study has reported an association of MRI-detected synovitis and effusions with OA pain. Bone marrow edema lesions, which may represent areas of trabecular remodelling, have been associated with pain and compartment-specific structural deterioration. MRI studies have confirmed the frequency and importance of meniscal damage in progressive cartilage loss, but not related such damage to symptoms. Osteophytes have been associated with cartilage loss and malalignment to the side of the osteophyte. Ligament damage, including anterior cruciate ligament tears, has been found more commonly than expected in painful OA knees. Improvements in quantitative and semi-quantitative assessments of non-cartilage features will greatly assist understanding of the OA process and its response to therapy.

Objective: The ability to reliably quantify all the structural abnormalities in osteoarthritis (OA) of the knee is a long-standing goal of OA research. On December 5 and 6, 2002, Outcome Measures in Rheumatology Clinical Trials and Osteoarthritis Research Society, International held a Workshop for Consensus on Osteoarthritis Imaging in Bethesda, MD, with the aim of providing a state-of-the-art review of imaging outcome measures for OA of the knee. As part of the Workshop, data from previous clinical trials and epidemiological studies of OA were analysed with respect to the metrological properties of the measurement methods used. The following report outlines the results of analyses aimed at evaluating the internal construct validity of a whole-organ, ordinal (semi-quantitative) magnetic resonance imaging score (WORMS) using Rasch analysis. The fit of data to the Rasch model offers a measure of the validity of summing different items into a subscale score and the degree to which this score behaves as a unidimensional, interval level measurement tool., Methods: The Rasch model was applied in two OA studies. The first was a clinical cohort comprising OA knee subjects entering a clinical trial; study entry criteria included patients with at least moderate pain, radiographic osteophytes and a minimum of 1.5mm tibiofemoral joint-space width. The second cohort was from the Boston Osteoarthritis Knee Study, an observational cohort of subjects with symptomatic knee OA with pain on most days and a definite osteophyte in either the tibiofemoral or patellofemoral joints. Baseline WORMS scores from both studies were used for the Rasch analysis, performed with RUMM 2020 software., Results: There was a substantial proportion of subjects in both study populations with zero scores in several of the subscales of WORMS. Few of the subscales met the requirements of the Rasch measurement model when summated across all sites, and summations of some postulated compartmentally based sites also failed to fit the Rasch model. The existing scoring categories also required rescoring at many sites., Conclusion: There remain important issues in constructing outcome measurements that summate different features across multiple anatomical sites. The whole-organ scoring system evaluated here is no exception. Resolving these issues will improve the ability of imaging studies to assess complex pathological structural change.

ObjectivePopulation-based osteoarthritis (OA) cohorts provide vital data on risk factors and outcomes of OA, however the methods to define OA vary between cohorts. We aimed to provide recommendations for combining knee and hip OA data in extant and future population cohort studies, in order to facilitate informative individual participant level analyses.MethodInternational OA experts met to make recommendations on: 1) defining OA by X-ray and/or pain; 2) compare The National Health and Nutrition Examination Survey (NHANES)-type OA pain questions; 3) the comparability of the Western Ontario & McMaster Universities Osteoarthritis Index (WOMAC) scale to NHANES-type OA pain questions; 4) the best radiographic scoring method; 5) the usefulness of other OA outcome measures. Key issues were explored using new analyses in two population-based OA cohorts (Multicenter Osteoarthritis Study; MOST and Osteoarthritis Initiative OAI).ResultsOA should be defined by both symptoms and radiographs, with symptoms alone as a secondary definition. Kellgren and Lawrence (K/L) grade ≥2 should be used to define radiographic OA (ROA). The variable wording of pain questions can result in varying prevalence between 41.0% and 75.4%, however questions where the time anchor is similar have high sensitivity and specificity (91.2% and 89.9% respectively). A threshold of 3 on a 0-20 scale (95% CI 2.1, 3.9) in the WOMAC pain subscale demonstrated equivalence with the preferred NHANES-type question.ConclusionThis research provides recommendations, based on expert agreement, for harmonising and combining OA data in existing and future population-based cohorts.

ObjectiveStrong associations between radiographic features of knee osteoarthritis (OA) and pain have been demonstrated in persons with unilateral knee symptoms. This study was undertaken to compare radiographic and magnetic resonance imaging (MRI) features of knee OA and assess their ability to discriminate between painful and nonpainful knees in persons with unilateral symptoms.MethodsThe study population included 283 individuals ages 70-79 years with unilateral knee pain who were enrolled in the Health, Aging, and Body Composition Study, a study of weight-related diseases and mobility. Radiographs of both knees were read for Kellgren/Lawrence (K/L) grade and individual radiographic features, and 1.5T MRIs were assessed using the Whole-Organ Magnetic Resonance Imaging Score. The association between structural features and pain was assessed using a within-person case-control design and conditional logistic regression. Receiver operating characteristic (ROC) analysis was then used to test the discriminatory performance of structural features.ResultsIn conditional logistic analyses, knee pain was significantly associated with both radiographic features (any joint space narrowing grade ≥ 1) (odds ratio 3.20 [95% confidence interval 1.79-5.71]) and MRI features (any cartilage defect scored ≥ 2) (odds ratio 3.67 [95% confidence interval 1.49-9.04]). However, in most subjects, MRI revealed osteophytes and cartilage and bone marrow lesions in both knees, and using ROC analysis, no individual structural feature discriminated well between painful and nonpainful knees. The best-performing MRI feature (synovitis/effusion) was not significantly more informative than K/L grade ≥ 2 (P = 0.42).ConclusionIn persons with unilateral knee pain, MRI and radiographic features were associated with knee pain, confirming that structural abnormalities in the knee have an important role in the etiology of pain. However, no single MRI or radiographic finding performed well in discriminating between painful and nonpainful knees. Further work is needed to examine how structural and nonstructural factors influence knee pain.

Objective. The aim of our study was to evaluate the association between patellar alignment (using standard MRI images of extended knees) and MRI indices of patellofemoral (PF) osteoarthritis (OA) features. [ABSTRACT FROM PUBLISHER]

Objective: Magnetic resonance imaging (MRI) of articular cartilage has evolved to be an important tool in research on cartilage (patho)physiology and osteoarthritis (OA). MRI provides a wealth of novel and quantitative information, but there exists no commonly accepted terminology for reporting these metrics. The objective of this initiative was to propose a nomenclature for definitions and names to be used in scientific communications and to give recommendations as to which minimal methodological information should be provided when reporting MRI-based measures of articular cartilage in OA.Methods: An international group of experts with direct experience in MRI measurement of cartilage morphology or composition reviewed the existing literature. Through an iterative process that included a meeting with a larger group of scientists and clinicians (December 2nd, 2004, Chicago, IL, USA), they discussed, refined, and proposed a nomenclature for MRI-based measures of articular cartilage in OA.Results: The group proposes a nomenclature that describes: (1) the anatomical location and (2) the structural feature being measured, each name consisting of a metric variable combined with a tissue label. In addition, the group recommends minimal methodological information that should be described.Conclusions: Utilization of this nomenclature should facilitate communication within the scientific community. Further, the uniform adoption of comprehensive nomenclature to describe quantitative MRI- features of articular cartilage should strengthen epidemiological, clinical, and pharmacological studies in OA. [ABSTRACT FROM AUTHOR]