Factors associated with meniscus volume in knees free of degenerative features.

OBJECTIVES: To explore factors that were associated with meniscus volume in knees free of radiographic osteoarthritis (OA) features and symptoms of OA. METHODS: In the third Rotterdam Study cohort, clinical, radiographic, and magnetic resonance data were obtained at baseline (BL) and after 5 years of follow-up. Meniscus volumes and their change over time were calculated after semi-automatic segmentation on Magnetic Resonance Imaging. Knees with radiographic OA features (Kellgren and Lawrence>0) or clinical diagnosis of OA (American College of Rheumatology) at BL were excluded. Ten OA risk factors were adjusted in the multivariable analysis (generalized estimating equations), treating two knees within subjects as repeated measurements. RESULTS: From 1065 knees (570 subjects), the average (standard deviation) age and Body mass index (BMI) of included subjects were 54.3 (3.7) years and 26.5 (4.4) kg/m2. At BL, nine factors (varus alignment, higher BMI, meniscus pathologies, meniscus extrusion, cartilage lesions, injury, greater physical activity level, quadriceps muscle strength, and higher age) were significantly associated with greater meniscus volume. Five factors (injury, meniscus pathologies, meniscus extrusion, higher age, and change of BMI) were significantly associated with meniscus volume loss. CONCLUSIONS: Modifiable factors (varus alignment, BMI, physical activity level, and quadriceps muscle strength) and non-modifiable factors (higher age, injury, meniscus pathologies, meniscus extrusion, and cartilage lesions) were all associated with meniscus volume or meniscus volume loss over time.

Association between meniscal volume and development of knee osteoarthritis.

OBJECTIVE: To assess the association between meniscal volume, its change over time and the development of knee OA after 30 months in overweight/obese women. METHODS: Data from the PRevention of knee Osteoarthritis in Overweight Females study were used. This cohort included 407 women with a BMI ≥ 27 kg/m2, free of OA-related symptoms. The primary outcome measure was incident OA after 30 months, defined by one out of the following criteria: medial or lateral joint space narrowing (JSN) ≥ 1.0 mm, incident radiographic OA [Kellgren and Lawrence (K&L) ≥ 2], or incident clinical OA. The secondary outcomes were either of these items separately. Menisci at both baseline and follow-up were automatically segmented to obtain meniscal volume and delta-volumes. Generalized estimating equations were used to evaluate associations between the volume measures and the outcomes. RESULTS: Medial and lateral baseline and delta-volumes were not significantly associated to the primary outcome. Lateral meniscal baseline volume was significantly associated to lateral JSN [odds ratio (OR) = 0.87; 95% CI: 0.75, 0.99], while other measures were not. Medial and lateral baseline volume were positively associated to K&L incidence (OR = 1.32 and 1.22; 95% CI: 1.15, 1.50 and 1.03, 1.45, respectively), while medial and lateral delta-volume were negatively associated to K&L incidence (OR = 0.998 and 0.997; 95% CI: 0.997, 1.000 and 0.996, 0.999, respectively). None of the meniscal measures were significantly associated to incident clinical OA. CONCLUSION: Larger baseline meniscal volume and the decrease of meniscal volume over time were associated to the development of structural OA after 30 months in overweight and obese women.

Physical Activity and Features of Knee Osteoarthritis on Magnetic Resonance Imaging in Individuals Without Osteoarthritis: A Systematic Review.

OBJECTIVE: To systematically review all studies that have evaluated the association between physical activity (PA) levels and features of knee osteoarthritis (OA) on magnetic resonance imaging (MRI) for subjects without OA. METHODS: The inclusion criteria for prospective studies were as follows: 1) subjects without OA; 2) average age 35-80 years; and 3) any self-reported PA or objective measurement of PA. The eligible MRI outcomes were OA-related measures of intraarticular knee joint structures. Exclusion criteria were evaluations of instant associations with transient structural changes after PA. RESULTS: Two randomized controlled trials and 16 observational studies were included. One of 11 studies found that PA was harmfully related to cartilage volume or thickness, but 4 studies found a significant protective association. Four of 10 studies found that PA was harmfully related to cartilage defects, while others showed no significant associations. Two of 3 studies reported a significantly increased cartilage T2 value in individuals with more PA. All 3 studies reported no significant association between PA and bone marrow lesions. Two studies assessed the association between PA and meniscus pathology, in which only occupational PA involving knee bending was associated with a greater risk of progression. CONCLUSION: Within the sparse and diverse evidence available, no strong evidence was found for the presence or absence of an association between PA and the presence or progression of features of OA on MRI among subjects without OA. Therefore, more research is required before PA in general and also specific forms of PA can be deemed safe for knee joint structures.

Predictive value of early structural changes on radiographs and MRI for incident clinical and radiographic knee osteoarthritis in overweight and obese women.

OBJECTIVE: To determine the predictive value of tibiofemoral (TF), patellofemoral (PF) MRI osteoarthritis (OA), and Kellgren and Lawrence grade 1 (KLG1) for the incidence of knee OA (clinical and/or radiological signs) at 2.5 and 6.5 years follow-up in a high-risk cohort. METHODS: Data of the PROOF study were used, consisting of middle-aged obese women without clinical (ACR-criteria) knee OA and free of radiographic signs (KLG < 2) at baseline. To determine the relation between MRI defined knee OA and KLG1 at baseline with clinical (ACR criteria) or radiographic OA (KLG ≥ 2) at the follow-up points, sensitivity, specificity, likelihood ratios and pre-test and post-test probabilities were calculated. RESULTS: The baseline prevalence of KLG1 (42.9%) was higher than TF MRI OA (14.6%) and PF MRI OA (10.0%). All diagnostic performance statistics indicated better prediction for radiographic OA than for clinical OA. For both outcomes and time points, the absolute difference between pre-test and post-test probabilities was the highest for TF MRI OA. The number needed to screen to obtain a certain number of cases with definite knee OA after a given follow-up period was higher (16-524%) for MRI OA, than for KLG1. CONCLUSIONS: When comparing the associations and post-test probabilities, TF MRI OA was more strongly related to the development of radiographic knee OA than KLG1. However, for the selection of people at high risk for developing knee OA, for instance for preventive trials, radiography seems to be sufficient, due to the high baseline prevalence.