Objective-Varus and valgus alignment increase, respectively, medial and lateral tibiofemoral load. Alignment was associated with tibiofemoral osteoarthritis progression in previous studies; an effect on risk of incident osteoarthritis is less certain. We tested whether alignment influences the risk of incident and progressive radiographic tibiofemoral osteoarthritis.Methods-In an observational, longitudinal study of the MOST (Multicenter Osteoarthritis Study) cohort, full-limb x-rays to measure alignment were acquired at baseline and knee x-rays were acquired at baseline and 30 months. Varus alignment was defined as ≤ 178° and valgus as ≥ 182°. Using logistic regression and GEE, we examined the association of baseline alignment and incident osteoarthritis at 30 months (in knees without osteoarthritis at baseline), and alignment and osteoarthritis progression (in knees with baseline osteoarthritis). All analyses were adjusted for age, gender, BMI, knee injury, laxity, and extensor strength, with neutral knees as referent.Results-2958 knees (1752 participants) were without osteoarthritis at baseline. Varus (adj. OR 1.49, 95% CI 1.06, 2.10) but not valgus alignment was associated with incident osteoarthritis. 1307 knees (950 participants) had osteoarthritis at baseline. Varus alignment was associated with a greater risk of medial osteoarthritis progression (adj. OR 3.59, 95% CI 2.62, 4.92) and a reduced risk of lateral progression, and valgus with a greater risk of lateral progression (adj. OR 4.85, 95% CI 3.17, 7.42) and a reduced risk of medial progression.Conclusion-Varus but not valgus alignment increased the risk of incident tibiofemoral osteoarthritis. In knees with osteoarthritis, varus and valgus alignment each increased the risk of progression in the biomechanically stressed compartment and reduced the risk of progression in the unloaded compartment.

Fixed-flexion, non-fluoroscopic radiography of the knee can provide reproducible JSW measurement using widely available X-ray equipment. This technique is more feasible for multicenter clinical studies and routine clinical use than are methods that rely on fluoroscopic alignment of the tibial plateau.

Objectives-To describe the natural history of subchondral bone marrow lesions (BMLs) in a sample of subjects with knee osteoarthritis (OA) or at risk of developing it. Additionally, to examine the association of change in BMLs from baseline to 30-month follow-up with the risk of cartilage loss in the same subregion at follow-up.Methods-1.0 T MRI was performed using proton density-weighted, fat-suppressed sequences. BML size and cartilage status were scored in the same subregions according to the WORMS system. Subregions were categorised based on comparison of baseline and follow-up BML status. A logistic regression model was used to assess the association of change in BML status with cartilage loss over 30 months using stable BMLs as the reference group.Results-395 knees were included. 66% of prevalent BMLs changed in size; 50% showed either regression or resolution at follow-up. The adjusted odds ratios (95% confidence intervals) of cartilage loss in the same subregion at follow-up for the different groups were 1.2 (0.5 to 1.6) for regressing BMLs, 0.9 (0.5 to 1.6) for resolving BMLs, 2.8 (1.5 to 5.2) for progressing BMLs, 0.2 (0.1 to 0.3) for subregions with no BMLs at baseline and follow-up and 3.5 (2.1 to 5.9) for newly developing BMLs. BML size at baseline was associated with risk of subsequent cartilage loss.Correspondence to: Dr F Roemer, Department of Radiology, Boston University Medical Center, FGH Building, 3 rd Floor, 820 Harrison Ave, Boston, MA 02118, USA; frank. roemer@bmc.org. Competing interests: AG is president of Boston Imaging Core Lab, LLC (BICL), Boston, Massachusetts, USA, a company providing radiological image assessment services; and shareholder of Synarc Inc. FWR is vice president of BICL. None of the other authors have declared any conflict of interest. Ethics approval:The study was conducted in compliance with the ethical principles derived from the Declaration of Helsinki and in compliance with local institutional review boards, informed consent regulations and International Conference on Harmonization Good Clinical Practices Guidelines. Conclusions-The majority of pre-existing BMLs decreased in size at follow-up. Absence of BMLs was associated with a decreased risk of cartilage loss, while progressing and new BMLs showed a high risk of cartilage loss in the same subregion. NIH Public AccessSubchondral bone marrow lesions (BMLs) are one of the hallmarks of knee osteoarthritis (OA) on magnetic resonance imaging (MRI). Radiologically, BMLs in OA are non-cystic subchondral areas of ill-defined hyperintensity in T2-weighted or proton density-weighted, fast spin echo images on MRI. 1-3 BMLs are observed regularly in conjunction with cartilage alterations in the same region.4 -6 Higher grades of cartilage damage seem to be associated with higher prevalence and greater volume of concomitant BMLs. 7 As the disease progresses, an increase in oedema volume in the same region subchondrally is positively correlated with an increase in cartilage loss and radiographic joint space narrowing....

Objective To evaluate if two different measures of synovial activation, baseline Hoffa-synovitis and effusion-synovitis, assessed by MRI, predict cartilage loss in the tibiofemoral joint at 30 months follow-up in subjects with neither cartilage damage nor tibiofemoral radiographic osteoarthritis (OA) of the knee. Methods Non-contrast enhanced MRI was performed using proton density-weighted fat-suppressed sequences in the axial and sagittal planes and a STIR sequence in the coronal plane. Hoffa-synovitis, effusion-synovitis and cartilage status were assessed semiquantitatively according to the WORMS scoring system. Included were knees that had neither radiographic OA nor MRI-detected tibio-femoral cartilage damage at the baseline visit. Presence of Hoffa-synovitis was defined as any grade ≥2 (range from 0–3) and effusion-synovitis as any grade ≥2 (range from 0–3). We performed logistic regression to examine the relation of presence of either measure to the risk of cartilage loss at 30 months adjusting for other potential confounders of cartilage loss. Results Of 514 knees included in the analysis, prevalence of Hoffa-synovitis and effusion-synovitis at the baseline visit was 8.4% and 10.3%, respectively. In the multivariable analysis, baseline effusion-synovitis was associated with an increased risk for cartilage loss (odds ratio (OR) = 2.7, 95% confidence intervals 1.4–5.1, p=0.002); however, no such an association was observed for baseline Hoffa-synovitis (OR =1.0, 95% confidence intervals 0.5–2.0). Conclusions Baseline effusion-synovitis, but not Hoffa-synovitis, predicted cartilage loss. Our findings suggest that effusion-synovitis, a reflection of inflammatory activity including joint effusion and synovitic thickening, may play a role in future development of cartilage lesions in knees without OA.

In participants with minimal baseline cartilage damage, the presence of high BMI, meniscal damage, synovitis or effusion, or any severe baseline MR-depicted lesions was strongly associated with an increased risk of fast cartilage loss. Patients with these risk factors may be ideal subjects for preventative or treatment trials.

IntroductionThe goals of this study were (i) to compare the prevalence of focal knee abnormalities, the mean cartilage T2 relaxation time, and the spatial distribution of cartilage magnetic resonance (MR) T2 relaxation times between subjects with and without risk factors for Osteoarthritis (OA), (ii) to determine the relationship between MR cartilage T2 parameters, age and cartilage morphology as determined with whole-organ magnetic resonance imaging scores (WORMS) and (iii) to assess the reproducibility of WORMS scoring and T2 relaxation time measurements including the mean and grey level co-occurrence matrix (GLCM) texture parameters.MethodsSubjects with risk factors for OA (n = 92) and healthy controls (n = 53) were randomly selected from the Osteoarthritis Initiative (OAI) incidence and control cohorts, respectively. The specific inclusion criteria for this study were (1) age range 45-55 years, (2) body mass index (BMI) of 19-27 kg/m2, (3) Western Ontario and McMaster University (WOMAC) pain score of zero and (4) Kellgren Lawrence (KL) score of zero at baseline. 3.0 Tesla MR images of the right knee were analyzed using morphological gradings of cartilage, bone marrow and menisci (WORMS) as well as compartment specific cartilage T2 mean and heterogeneity. Regression models adjusted for age, gender, and BMI were used to determine the difference in cartilage parameters between groups.ResultsWhile there was no significant difference in the prevalence of knee abnormalities (cartilage lesions, bone marrow lesions, meniscus lesions) between controls and subjects at risk for OA, T2 parameters (mean T2, GLCM contrast, and GLCM variance) were significantly elevated in those at risk for OA. Additionally, a positive significant association between cartilage WORMS score and cartilage T2 parameters was evident.ConclusionsOverall, this study demonstrated that subjects at risk for OA have both higher and more heterogeneous cartilage T2 values than controls, and that T2 parameters are associated with morphologic degeneration.

Objective To investigate the association of cartilage thickness change by MRI (over 24 months (M)) with knee osteoarthritis (OA) progression at 24–48M. Methods This nested case-control study included 600 knees with baseline Kellgren Lawrence grade (KLG) 1–3 from 600 Osteoarthritis Initiative (OAI) participants. Case knees had both medial tibiofemoral radiographic joint space loss (≥0.7 mm) and a persistent increase in WOMAC pain (≥9 on a 0–100 scale) at 24–48M from baseline (n=194). Control knees (n=406) included 200 with neither radiographic nor pain progression, 103 with radiographic progression only and 103 with pain progression only. Medial and lateral femorotibial cartilages were segmented from sagittal 3Tesla baseline, 12M, and 24M MRIs. We used logistic regression to assess the association of change in cartilage thickness, with a focus on the central medial femorotibial (cMFTC) compartment, and OA progression. Results cMFTC thickness loss was statistically significantly associated with case status (odds ratio (OR) 1.9; 95% confidence interval [CI] 1.6, 2.3), p<0.0001), with both the central femur (OR=1.8; 95% CI 1.5, 2.2) and the central tibia (OR=1.6; 95%CI 1.3, 1.9) reaching p<0.05. Lateral femorotibial compartment cartilage thickness loss, in contrast, was not significantly associated with case status. Reduction in cMFTC cartilage thickness was associated strongly with radiographic progression (OR: 4.0; 95%CI: 2.9, 5.3; p<0.0001) and only weakly with pain progression (OR:1.3; 95% CI: 1.1, 1.6; p<0.01). Conclusions Loss in medial femorotibial cartilage thickness over 24M is associated with the combination of radiographic and pain progression in the knee; this association was stronger for radiographic progression.

SUMMARY Objective The purpose of this study is to determine whether the mean and heterogeneity of magnetic resonance (MR) knee cartilage T2 relaxation time measurements at baseline are associated with morphologic degeneration of cartilage, meniscus, and bone marrow tissues over 3 years in subjects with risk factors for osteoarthritis (OA). Design Subjects with risk factors for OA (n = 289) with an age range of 45–55 years were selected from the Osteoarthritis Initiative (OAI) database. 3.0 Tesla MR images were analyzed using morphological gradings of cartilage, bone marrow and menisci whole-organ magnetic resonance imaging scores (WORMS scoring). A T2 mapping sequence was used to assess the mean and heterogeneity of cartilage T2 (gray level co-occurrence matrix texture analysis). Regression models were used to assess the relationship between baseline T2 parameters and changes in morphologic knee WORMS scores over 3 years. Results The prevalence of knee abnormalities in the cartilage (P < 0.0005), meniscus (P < 0.00001), and bone marrow significantly (P < 0.00001) increased from baseline to 3 years in all compartments combined. The baseline mean and heterogeneity of cartilage T2 were significantly (P < 0.05) associated with morphologic joint degeneration in the cartilage, meniscus and bone marrow over 3 years. Conclusions The prevalence of knee abnormalities significantly increased over 3 years; increased cartilage T2 at baseline predicted longitudinal morphologic degeneration in the cartilage, meniscus, and bone marrow over 3 years in subjects with risk factors for OA.