ObjectiveTo determine whether 3D meniscal measures had similar sensitivity to longitudinal change as cartilage thickness; to what extent these measures are associated with longitudinal joint space width (JSW) change; and whether the latter associations differ between minimum (mJSW) and fixed-location JSW.MethodsTwo-year changes in medial meniscal position and morphology, cartilage thickness (MRI) and minimum and fixed-location JSW (radiography) were determined in 35 Osteoarthritis Initiative knees [12 men, age: 67 (51-77) years; 23 women, age: 65 (54-78) years], progressing from baseline Kellgren-Lawrence grade ≤2 to knee replacement within 3-5 years. Multiple linear regression assessed the features contributing to JSW change.ResultsMeniscal measures, cartilage thickness and JSW displayed similar sensitivity to change (standardised response mean≤|0.76|). Meniscal changes were strongly associated with JSW change (r≤|0.66|), adding ≤20% to its variance in addition to cartilage thickness change. Fixed-location JSW change (multiple r2=72%) was more strongly related to cartilage and meniscal change than mJSW (61%). Meniscal morphology explained more of fixed-location JSW and meniscal position more of mJSW.ConclusionMeniscal measures provide independent information in explaining the variance of radiographic JSW change. Fixed-location JSW appears to be more reflective of structural change than mJSW and, hence, a potentially superior measure of structural progression.Key Points• 3D positional/morphological meniscal measures change in rapidly progressing knees. • Similar sensitivity to 2-year change of quantitative meniscal/cartilage measures in rapid progression. • Changes in meniscal measures are strongly associated with radiographic JSW change. • Meniscal change provides information to explain JSW variance independent of cartilage. • Fixed-location JSW reflects structural disease stage more closely than minimum JSW.

line0.032) and function scores (mean difference 5.3 units (95% CI 0.3e10.3), pThe medial joint line0.037) and ICOAP total scores (score range 0e100, mean difference 9.7 units (95% CI 2.2e17.3), p ¼ 0.012) were significantly higher in the diffuse pattern compared to those with anterior-medial pain. Mean painDETECT scores (score range 0e38) were higher in both the diffuse pain (mean difference 3.7 units (95% CI 1.1e6.4), p ¼ 0.007) and posterior-medial patterns (mean difference 4.2 units (95% CI 0.8e7.6), p ¼ 0.017) relative to anterior-medial patterns. Conclusions: Only 16% of the cohort indicated isolated medial knee pain, whilst a diffuse pain pattern was most common. People with diffuse knee pain reported more severe pain and physical dysfunction than those with anterior-medial pain. Prevalence of possible/ likely neuropathic-like symptoms tended to be more frequent in diffuse and posterior-medial patterns compared to anterior-medial pain.

Objective To explore to what extent three-dimensional measures of the meniscus and femorotibial cartilage explain the variation in medial and lateral femorotibial radiographic joint space width (JSW), in healthy men and women. Methods The right knees of 87 Osteoarthritis Initiative healthy reference participants (no symptoms, radiographic signs or risk factors of osteoarthritis; 37 men, 50 women; age 55.0±7.6; BMI 24.4±3.1) were assessed. Quantitative measures of subregional femorotibial cartilage thickness and meniscal position and morphology were computed from segmented magnetic resonance images. Minimal and medial/lateral fixed-location JSW were determined from fixed-flexion radiographs. Correlation and regression analyses were used to explore the contribution of demographic, cartilage and meniscal parameters to JSW in healthy subjects. Results The correlation with (medial) minimal JSW was somewhat stronger for cartilage thickness (0.54≤r≤0.67) than for meniscal (−0.31≤r≤0.50) or demographic measures (−0.15≤r≤0.48), in particular in men. In women, in contrast, the strength of the correlations of cartilage thickness and meniscal measures with minimal JSW were in the same range. Fixed-location JSW measures showed stronger correlations with cartilage thickness (r≥0.68 medially; r≥0.59 laterally) than with meniscal measures (r≤|0.32| medially; r≤|0.32| laterally). Stepwise regression models revealed that meniscal measures added significant independent information to the total variance explained in minimal JSW (adjusted multiple r2=58%) but not in medial or lateral fixed-location JSW (r2=60/51%, respectively). Conclusions In healthy subjects, minimal JSW was observed to reflect a combination of cartilage and meniscal measures, particularly in women. Fixed-location JSW, in contrast, was found to be dominated by variance in cartilage thickness in both men and women, with somewhat higher correlations between cartilage and JSW in the medial than lateral femorotibial compartment. The significant contribution of the meniscus’ position on minimal JSW reinforces concerns over validity of JSW as an indirect measure of hyaline cartilage.

Objective To assess whether quantitative changes in the meniscus predict progression from early knee osteoarthritis (OA) to knee replacement (KR). Methods A nested case–control study was conducted among Osteoarthritis Initiative participants: all 35 case knees with baseline Kellgren/Lawrence (K/L) grade ≤2 that had KR between 36 and 60 months were matched 1:1 by age, sex, and baseline K/L grade to 35 control knees without subsequent KR. Quantitative 3‐dimensional medial meniscus position and morphologic measures were determined from magnetic resonance imaging at the visit just before KR and 2 years before. Paired t‐tests and case–control odds ratios (ORs, standardized per SD of change in controls) were used to compare changes between groups. Results Cases (52% women, age 65 ± 7 years, body mass index [BMI] 30 ± 4 kg/m2, K/L grades 0/1/2: 5/8/22 participants, respectively) and controls (52% women, age 64 ± 7 years, BMI 30 ± 5 kg/m2, K/L grades 0/1/2: 9/4/22 participants, respectively) were similar. Compared to control knees, KR case knees displayed longitudinal changes, specifically, a decrease in tibial plateau coverage, an increase in meniscal extrusion, and a decrease in meniscal width. The odds for KR increased with greater reduction in the percentage of tibial plateau coverage (OR 2.28 [95% CI confidence interval (95% CI) 1.43, 3.64]), a greater increase in maximal extrusion (OR 1.40 [95% CI 1.12, 1.75]), and a greater reduction of mean meniscal width (OR 2.01 [95% CI 1.23, 3.26]). The odds for KR increased with medial compartment cartilage thickness loss (OR 2.86 [95% CI 1.51, 5.41]) for comparison. Conclusion Quantitative measures of meniscal position and morphology are associated with subsequent KR in knees with rapidly progressing knee OA. These findings show that structural changes of the meniscus are related to an important clinical and economic outcome of knee OA.

Thigh muscle weakness is a risk factor for incident radiographic and symptomatic knee osteoarthritis. The role of thigh muscle weakness in radiographic and/or symptomatic knee osteoarthritis progression remains elusive. 527 knees of 527 Osteoarthritis Initiative participants with baseline Kellgren-Lawrence grade 1–3 were included in this nested case-control study evaluating whether baseline muscle strength predicted symptomatic and/or radiographic knee osteoarthritis progression. Case knees (n=173) displayed both medial tibiofemoral joint space loss (≥0.7mm) and a persistent increase in Western Ontario McMasters (WOMAC) pain (≥9 on a 0–100 scale) over 24–48 months from baseline. Control knees (n=354) included 174 with neither radiographic nor symptomatic progression, 91 with radiographic progression only, and 89 with symptomatic progression only. Isometric knee extensor and flexor strength were recorded at baseline. Using logistic regression models, muscle strength was not associated with case status. However, knee extensor (odds ratio=1.7; 95% confidence interval 1.1, 3.3; p=0.035) and flexor weakness (odds ratio=2.0; 95% confidence interval 1.1, 3.3; p=0.016) predicted isolated symptomatic progression in males, but not in females. The results indicate that thigh muscle strength may affect symptomatic and structural progression differently in males with knee osteoarthritis, and identify an important window for potentially lowering risk of symptomatic osteoarthritis progression in men.