Do Ahlbäck scores identify subgroups with different magnitudes of cartilage thickness loss in patients with moderate to severe radiographic osteoarthritis? One-year follow-up data from the Osteoarthritis Initiative.

Objective: Kellgren-Lawrence grades (KLG) are frequently used for patient selection in clinical trials. The Ahlbäck radiographic grading system has been developed for moderate and severe knee OA. KLG 3 is comparable to Ahlbäck 1 and KLG 4 is subdivided into Ahlbäck 2-5.

The effects of intensive dietary weight loss and exercise on gait in overweight and obese adults with knee osteoarthritis. The Intensive Diet and Exercise for Arthritis (IDEA) trial.

The Intensive Diet and Exercise for Arthritis (IDEA) trial was an 18-month randomized controlled trial that enrolled 454 overweight and obese older adults with symptomatic and radiographic knee osteoarthritis (OA). Participants were randomized to either exercise (E), intensive diet-induced weight loss (D), or intensive diet-induced weight loss plus exercise (D + E) interventions. We previously reported that the clinical benefits of D + E were significantly greater than with either intervention alone (e.

Segmentation of the lateral femoral notch sign with MRI using a new measurement technique.

Background: The goal of this present study was to precisely determine the dimension and location of the impaction fracture on the lateral femoral condyle in patients with an ACL rupture.

Methods: All patients with post-injury bi-plane radiographs and MRI images after sustaining a tear to the anterior cruciate ligament were included. Lateral radiographs of the affected knee were inspected for a lateral femoral notch sign.

Improving bone strength prediction in human proximal femur specimens through geometrical characterization of trabecular bone microarchitecture and support vector regression.

We investigate the use of different trabecular bone descriptors and advanced machine learning tech niques to complement standard bone mineral density (BMD) measures derived from dual-energy x-ray absorptiometry (DXA) for improving clinical assessment of osteoporotic fracture risk. For this purpose, volumes of interest were extracted from the head, neck, and trochanter of 146 proximal femur specimens on multidetector computer tomography. The trabecular bone captured was characterized with (1) statistical moments of the BMD distribution, (2) geometrical features derived from the scaling index method (SIM), and (3) morphometric parameters, such as bone fraction, trabecular thickness, etc.

A novel methodology for generating 3D finite element models of the hip from 2D radiographs.

Finite element (FE) modelling has been proposed as a tool for estimating fracture risk and patient-specific FE models are commonly based on computed tomography (CT). Here, we present a novel method to automatically create personalised 3D models from standard 2D hip radiographs. A set of geometrical parameters of the femur were determined from seven a-p hip radiographs and compared to the 3D femoral shape obtained from CT as training material; the error in reconstructing the 3D model from the 2D radiographs was assessed.

Prediction of bone strength by μCT and MDCT-based finite-element-models: how much spatial resolution is needed?

Objectives: Finite-element-models (FEM) are a promising technology to predict bone strength and fracture risk. Usually, the highest spatial resolution technically available is used, but this requires excessive computation time and memory in numerical simulations of large volumes. Thus, FEM were compared at decreasing resolutions with respect to local strain distribution and prediction of failure load to (1) validate MDCT-based FEM and to (2) optimize spatial resolution to save computation time.

Longitudinal sensitivity to change of MRI-based muscle cross-sectional area versus isometric strength analysis in osteoarthritic knees with and without structural progression: pilot data from the Osteoarthritis Initiative.

Object: Biomechanical measurement of muscle strength represents established technology in evaluating limb function. Yet, analysis of longitudinal change suffers from relatively large between-measurement variability. Here, we determine the sensitivity to change of magnetic resonance imaging (MRI)-based measurement of thigh muscle anatomical cross sectional areas (ACSAs) versus isometric strength in limbs with and without structural progressive knee osteoarthritis (KOA), with focus on the quadriceps.

Lateral and medial joint space narrowing predict subsequent cartilage loss in the narrowed, but not in the non-narrowed femorotibial compartment--data from the Osteoarthritis Initiative.

Objective: To determine the predictive value of unicompartimental joint space narrowing (JSN) for MRI-based cartilage thickness loss in the narrowed and the non-narrowed femorotibial compartment.

Methods: 922 knees from 922 Osteoarthritis Initiative (OAI) participants (62.2 ± 9.

Contribution of regional 3D meniscus and cartilage morphometry by MRI to joint space width in fixed flexion knee radiography--a between-knee comparison in subjects with unilateral joint space narrowing.

Background: Radiographic joint space width (JSW) is considered the reference standard for demonstrating structural therapeutic benefits in knee osteoarthritis. Our objective was to determine the proportion by which 3D (regional) meniscus and cartilage measures explain between-knee differences of JSW in the fixed flexion radiographs.

Methods: Segmentation of the medial meniscus and tibial and femoral cartilage was performed in double echo steady state (DESS) images.

Longitudinal (one-year) change in cartilage thickness in knees with early knee osteoarthritis: A within-person between-knee comparison.

Objective: To test the hypothesis that cartilage displays significant longitudinal thickening in the external subregions of the central medial (ecMF) and lateral (ecLF) femur in knees with early radiographic osteoarthritis (ROA) compared with contralateral knees without ROA, and to explore differences in change in other subregions and in radiographic joint space width (JSW). Methods: 50 participants (50% women; age 61.1±9.

Association of changes in delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) with changes in cartilage thickness in the medial tibiofemoral compartment of the knee: a 2 year follow-up study using 3.0 T MRI.

Objective: To determine the association between changes in the delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) index over 2 years as a measure of cartilage proteoglycan concentration, with changes in cartilage thickness in the medial tibiofemoral compartment of knees in middle-aged women.

Methods: One hundred and forty-eight women (one knee for each subject) aged ≥40 years were included. 3.

Introducing Anisotropic Minkowski Functionals and Quantitative Anisotropy Measures for Local Structure Analysis in Biomedical Imaging.

The ability of Minkowski Functionals to characterize local structure in different biological tissue types has been demonstrated in a variety of medical image processing tasks. We introduce Minkowski Functionals (AMFs) as a novel variant that captures the inherent anisotropy of the underlying gray-level structures. To quantify the anisotropy characterized by our approach, we further introduce a method to compute a quantitative measure motivated by a technique utilized in MR diffusion tensor imaging, namely fractional anisotropy.

Baseline and longitudinal change in isometric muscle strength prior to radiographic progression in osteoarthritic and pre-osteoarthritic knees--data from the Osteoarthritis Initiative.

Objective: To test whether cross-sectional or longitudinal measures of thigh muscle isometric strength differ between knees with and without subsequent radiographic progression of knee osteoarthritis (KOA), with particular focus on pre-osteoarthritic female knees (knees with risk factors but without definite radiographic KOA).

Methods: Of 4,796 Osteoarthritis Initiative participants, 2,835 knees with Kellgren Lawrence grade (KLG) 0-3 had central X-ray readings, annual quantitative joint space width (JSW) and isometric muscle strength measurements (Good strength chair). Separate slope analysis of covariance (ANCOVA) models were used to determine differences in strength between "progressor" and "non-progressor" knees, after adjusting for age, body mass index, and pain.

Predicting the Biomechanical Strength of Proximal Femur Specimens through High Dimensional Geometric Features and Support Vector Regression.

Estimating local trabecular bone quality for purposes of femoral bone strength prediction is important for improving the clinical assessment of osteoporotic hip fracture risk. In this study, we explore the ability of geometric features derived from the Scaling Index Method (SIM) in predicting the biomechanical strength of proximal femur specimens as visualized on multi-detector computed tomography (MDCT) images. MDCT scans were acquired for 50 proximal femur specimens harvested from human cadavers.

Direct comparison of fixed flexion, radiography and MRI in knee osteoarthritis: responsiveness data from the Osteoarthritis Initiative.

Objective: Minimum radiographic joint space width (mJSW) represents the Food and Drug Administration (FDA) standard for demonstrating structural therapeutic benefits for knee osteoarthritis (KOA), but only shows moderate responsiveness (sensitivity to change). We directly compare the responsiveness of magnetic resonance imaging (MRI)-based cartilage thickness and JSW measures from fixed-flexion radiography (FFR) and explore the correlation of region-matched changes between both methods.

Methods: Nine hundred and sixty-seven knees of Osteoarthritis Initiative participants with radiographic KOA were studied: 445 over 1 year with coronal FLASH MRI and FFR, and 375/522 over 1/2 years with sagittal DESS MRI and FFR.

How do short-term rates of femorotibial cartilage change compare to long-term changes? Four year follow-up data from the osteoarthritis initiative.

Objective: To compare unbiased estimates of short- vs long-term cartilage loss in osteoarthritic knees.

Method: 441 knees [216 Kellgren Lawrence (KL) grade 2, 225 KL grade 3] from participants of the Osteoarthritis Initiative were studied over a 4-year period. Femorotibial cartilage thickness was determined using 3 T double echo steady state magnetic resonance imaging, the readers being blinded to time points.

Quantitative MRI measures of cartilage predict knee replacement: a case-control study from the Osteoarthritis Initiative.

Objective: Knee osteoarthritis commonly requires joint replacement, substantially reduces quality of life and increases healthcare utilisation and costs. This study aimed to identify whether quantitative measures of articular cartilage structure predict knee replacement, and to establish their utility as outcomes in clinical trials of disease-modifying therapy.

Methods: A nested case-control study was performed in Osteoarthritis Initiative participants, a multicentre observational cohort of 4796 participants with or at risk of knee osteoarthritis.

Side differences of thigh muscle cross-sectional areas and maximal isometric muscle force in bilateral knees with the same radiographic disease stage, but unilateral frequent pain - data from the osteoarthritis initiative.

Objective: To determine whether anatomical thigh muscle cross-sectional areas (MCSAs) and strength differ between osteoarthritis (OA) knees with frequent pain compared with contra-lateral knees without pain, and to examine the correlation between MCSAs and strength in painful vs painless knees.

Methods: Forty-eight subjects (31 women; 17 men; age 45-78 years) were drawn from 4,796 Osteoarthritis Initiative (OAI) participants, in whom both knees displayed the same radiographic stage (KLG2 or 3), one with frequent pain (most days of the month within the past 12 months) and the contra-lateral one without pain. Axial MR images were used to determine MCSAs of extensors, flexors and adductors at 35% femoral length (distal to proximal) and in two adjacent 5 mm images.

Comparison between different implementations of the 3D FLASH sequence for knee cartilage quantification.

Objective: To compare several sequence implementations of the 3D FLASH sequence in the context of quantitative cartilage imaging.

Materials And Methods: Test-retest coronal fast low angle shot (FLASH) sequences with water excitation were acquired in knees of 12 healthy participants, using two 1.5 T scanners from the same manufacturer.

Quantitative cartilage imaging in knee osteoarthritis.

Quantitative measures of cartilage morphology (i.e., thickness) represent potentially powerful surrogate endpoints in osteoarthritis (OA).

Morphometric differences between the medial and lateral meniscus in healthy men - a three-dimensional analysis using magnetic resonance imaging.

The objective of this work was to characterize tibial plateau coverage and morphometric differences of the medial (MM) and lateral meniscus (LM) in a male reference cohort using three-dimensional imaging. Coronal multiplanar reconstructions of a sagittal double-echo steady state with water excitation magnetic resonance sequence (slice thickness: 1.5 mm, and in-plane resolution: 0.

Greater rates of cartilage loss in painful knees than in pain-free knees after adjustment for radiographic disease stage: data from the osteoarthritis initiative.

Objective: To investigate whether rates of cartilage loss differ in knees with frequent baseline pain versus those without pain, after adjustment for radiographic osteoarthritis (OA) stage.

Methods: One knee in each of 718 Osteoarthritis Initiative participants was examined: 310 with calculated Kellgren/Lawrence (K/L) grade 2, 299 with calculated K/L grade 3, and 109 with calculated K/L grade 4. Twelve-month change in (subregional) cartilage thickness was assessed by magnetic resonance imaging.

Comparison of 1-year vs 2-year change in regional cartilage thickness in osteoarthritis results from 346 participants from the Osteoarthritis Initiative.

Objective: To compare femorotibial cartilage thickness changes over a 2- vs a 1-year observation period in knees with radiographic knee osteoarthritis (OA).

Methods: One knee of 346 Osteoarthritis Initiative (OAI) participants was studied at three time points [baseline (BL), year-1 (Y1), year-2 (Y2) follow-up]: 239 using coronal fast low angle shot (FLASH) and 107 using sagittal double echo at steady state (DESS) MR imaging. Changes in cartilage thickness were assessed in femorotibial cartilage plates and subregions, after manual segmentation with blinding to time-point.

Rates of change and sensitivity to change in cartilage morphology in healthy knees and in knees with mild, moderate, and end-stage radiographic osteoarthritis: results from 831 participants from the Osteoarthritis Initiative.

Objective: To study the longitudinal rate of (and sensitivity to) change of knee cartilage thickness across defined stages of radiographic osteoarthritis (OA), specifically healthy knees and knees with end-stage radiographic OA.

Methods: One knee of 831 Osteoarthritis Initiative participants was examined: 112 healthy knees, without radiographic OA or risk factors for knee OA, and 719 radiographic OA knees (310 calculated Kellgren/Lawrence [K/L] grade 2, 300 calculated K/L grade 3, and 109 calculated K/L grade 4). Subregional change in thickness was assessed after segmentation of weight-bearing femorotibial cartilage at baseline and 1 year from coronal magnetic resonance imaging (MRI).

Effect of exercise intervention on thigh muscle volume and anatomical cross-sectional areas--quantitative assessment using MRI.

The objective of this study was to evaluate the location-specific magnitudes of an exercise intervention on thigh muscle volume and anatomical cross-sectional area, using MRI. Forty one untrained women participated in strength, endurance, or autogenic training for 12 weeks. Axial MR images of the thigh were acquired before and after the intervention, using a T1-weighted turbo-spin-echo sequence (10 mm sections, 0.