The objective of this work was to develop a methodology for measuring cartilage thickness in anatomically based subregions in the tibial and in the central weight-bearing femoral cartilage from ...magnetic resonance (MR) images. The tibial plateau was divided into a central area of the total subchondral bone area (tAB), and anterior, posterior, internal, and external subregions surrounding it. In the weight-bearing femoral condyles, central, internal, and external subregions were determined. The Euclidean distance between the tAB and cartilage surface was used for determining cartilage thickness. The reproducibility of the method was evaluated on test-retest data sets of 12 participants (six healthy, six with osteoarthritis). The subregion size was varied systematically to study the influence on the reproducibility. The size of the subregions was highly consistent under conditions of repositioning (standard deviation 0.0%-0.3%). The precision errors for regional mean cartilage thickness measurements ranged from 19 mum (1.5%) to 84 mum (4.7%). The computation of regional cartilage thickness values from segmented MR images is shown to be highly reproducible and robust under conditions of joint repositioning. In longitudinal studies, this technique may substantially enhance the ability of quantitative MRI to monitor structural changes in osteoarthritis at narrow time intervals.
Summary Objective Test the hypothesis that greater baseline peak external knee adduction moment (KAM), KAM impulse, and peak external knee flexion moment (KFM) during the stance phase of gait are ...associated with baseline-to-2-year medial tibiofemoral cartilage damage and bone marrow lesion progression, and cartilage thickness loss. Methods Participants all had knee OA in at least one knee. Baseline peak KAM, KAM impulse, and peak KFM (normalized to body weight and height) were captured and computed using a motion analysis system and six force plates. Participants underwent MRI of both knees at baseline and 2 years later. To assess the association between baseline moments and baseline-to-2-year semiquantitative cartilage damage and bone marrow lesion progression and quantitative cartilage thickness loss, we used logistic and linear regressions with generalized estimating equations (GEE), adjusting for gait speed, age, gender, disease severity, knee pain severity, and medication use. Results The sample consisted of 391 knees (204 persons): mean age 64.2 years (SD 10.0); BMI 28.4 kg/m2 (5.7); 156 (76.5%) women. Greater baseline peak KAM and KAM impulse were each associated with worsening of medial bone marrow lesions, but not cartilage damage. Higher baseline KAM impulse was associated with 2-year medial cartilage thickness loss assessed both as % loss and as a threshold of loss, whereas peak KAM was related only to % loss. There was no relationship between baseline peak KFM and any medial disease progression outcome measures. Conclusion Findings support targeting KAM parameters in an effort to delay medial OA disease progression.
Osteoarthritis year in review 2020: imaging Eckstein, F.; Wirth, W.; Culvenor, A.G.
Osteoarthritis and cartilage,
February 2021, 2021-02-00, 20210201, Volume:
29, Issue:
2
Journal Article
Peer reviewed
Open access
This narrative “Year in Review” highlights a selection of articles published between January 2019 and April 2020, to be presented at the OARSI World Congress 2020 within the field of osteoarthritis ...(OA) imaging. Articles were obtained from a PubMed search covering the above period, utilizing a variety of relevant search terms. We then selected original and review studies on OA-related imaging in humans, particularly those with direct clinical relevance, with a focus on the knee. Topics selected encompassed clinically relevant models of early OA, particularly imaging applications on cruciate ligament rupture, as these are of direct clinical interest and provide potential opportunity to evaluate preventive therapy. Further, imaging applications on structural modification of articular tissues in patients with established OA, by non-pharmacological, pharmacological and surgical interventions are summarized. Finally, novel deep learning approaches to imaging are reviewed, as these facilitate implementation and scaling of quantitative imaging application in clinical trials and clinical practice. Methodological or observational studies outside these key focus areas were not included. Studies focused on biology, biomechanics, biomarkers, genetics and epigenetics, and clinical studies that did not contain an imaging component are covered in other articles within the OARSI “Year in Review” series. In conclusion, exciting progress has been made in clinically validating human models of early OA, and the field of automated articular tissue segmentation. Most importantly though, it has been shown that structure modification of articular cartilage is possible, and future research should focus on the translation of these structural findings to clinical benefit.
Summary Objective To test the hypothesis that quantitative measures of meniscus extrusion predict incident radiographic knee osteoarthritis (KOA), prior to the advent of radiographic disease. Methods ...206 knees with incident radiographic KOA (Kellgren Lawrence Grade (KLG) 0 or 1 at baseline, developing KLG 2 or greater with a definite osteophyte and joint space narrowing (JSN) grade ≥1 by year 4) were matched to 232 control knees not developing incident KOA. Manual segmentation of the central five slices of the medial and lateral meniscus was performed on coronal 3T DESS MRI and quantitative meniscus position was determined. Cases and controls were compared using conditional logistic regression adjusting for age, sex, BMI, race and clinical site. Sensitivity analyses of early (year Y 1/2) and late (Y3/4) incidence was performed. Results Mean medial extrusion distance was significantly greater for incident compared to non-incident knees (1.56 mean ± 1.12 mm SD vs 1.29 ± 0.99 mm; +21%, P < 0.01), so was the percent extrusion area of the medial meniscus (25.8 ± 15.8% vs 22.0 ± 13.5%; +17%, P < 0.05). This finding was consistent for knees restricted to medial incidence. No significant differences were observed for the lateral meniscus in incident medial KOA, or for the tibial plateau coverage between incident and non-incident knees. Restricting the analysis to medial incident KOA at Y1/2 differences were attenuated, but reached significance for extrusion distance, whereas no significant differences were observed at incident KOA in Y3/4. Conclusion Greater medial meniscus extrusion predicts incident radiographic KOA. Early onset KOA showed greater differences for meniscus position between incident and non-incident knees than late onset KOA.
Summary Background Treatment of severe osteoarthritis (OA) in relatively young patients is challenging. Although successful, total knee prosthesis has a limited lifespan, with the risk of revision ...surgery, especially in active young patients. Knee joint distraction (KJD) provides clinical benefit and tissue structure modification at 1-year follow-up. The present study evaluates whether this benefit is preserved during the second year of follow-up. Methods Patients included in this study presented with end-stage knee OA and an indication for total knee replacement (TKR); they were less than 60 years old with a VAS pain ≥60 mm ( n = 20). KJD was applied for 2 months (range 54–64 days) and clinical parameters assessed using the WOMAC questionnaire and VAS pain score. Changes in cartilage structure were measured using quantitative MRI, radiography, and biochemical analyses of collagen type II turnover (ELISA). Results Average follow-up was 24 (range 23–25) months. Clinical improvement compared with baseline (BL) was observed at 2-year follow-up: WOMAC improved by 74% ( P < 0.001) and VAS pain decreased by 61% ( P < 0.001). Cartilage thickness observed by MRI (2.35 mm (95%CI, 2.06–2.65) at BL) was significantly greater at 2-year follow-up (2.78 mm (2.50–3.09); P = 0.03). Radiographic minimum joint space width (JSW) (1.1 mm (0.5–1.7) at BL) was significantly increased at 2-year follow-up as well (1.7 mm (1.1–2.3); P = 0.03). The denuded area of subchondral bone visualized by MRI (22% (95%CI, 12.5–31.5) at BL) was significantly decreased at 2-year follow-up (8% (3.6–12.2); P = 0.004). The ratio of collagen type II synthesis over breakdown was increased at 2-year follow-up ( P = 0.07). Conclusion Clinical improvement by KJD treatment is sustained for at least 2 years. Cartilage repair is still present after 2 years (MRI) and the newly formed tissue continues to be mechanically resilient as shown by an increased JSW under weight-bearing conditions.
The effects of exercise on articular hyaline articular cartilage have traditionally been examined in animal models, but until recently little information has been available on human cartilage. ...Magnetic resonance imaging now permits cartilage morphology and composition to be analysed quantitatively in vivo. This review briefly describes the methodological background of quantitative cartilage imaging and summarizes work on short‐term (deformational behaviour) and long‐term (functional adaptation) effects of exercise on human articular cartilage. Current findings suggest that human cartilage deforms very little in vivo during physiological activities and recovers from deformation within 90 min after loading. Whereas cartilage deformation appears to become less with increasing age, sex and physical training status do not seem to affect in vivo deformational behaviour. There is now good evidence that cartilage undergoes some type of atrophy (thinning) under reduced loading conditions, such as with postoperative immobilization and paraplegia. However, increased loading (as encountered by elite athletes) does not appear to be associated with increased average cartilage thickness. Findings in twins, however, suggest a strong genetic contribution to cartilage morphology. Potential reasons for the inability of cartilage to adapt to mechanical stimuli include a lack of evolutionary pressure and a decoupling of mechanical competence and tissue mass.
To investigate the predictive and concurrent validity of magnetic resonance imaging (MRI)-based cartilage thickness change between baseline (BL) and year-two (Y2) follow-up (predictive validity) and ...between Y2 and Y4 follow-up (concurrent validity) for symptomatic and radiographic knee osteoarthritis (OA) progression during Y2→Y4.
777 knees from 777 Osteoarthritis Initiative (OAI) participants (age: 61.3 ± 9.0 years, BMI: 30.1 ± 4.8 kg/m2) with Kellgren Lawrence (KL) grade 1–3 at Y2 (visit before progression interval) had cartilage thickness measurements from 3T MRI at BL, Y2 (n = 777), and Y4 (n = 708). Analysis of covariance and logistic regression were used to assess the association of pain progression (≥9 WOMAC units scale 0–100, n = 205/572 with/without progression) and radiographic progression (≥0.7 mm minimum joint space width (mJSW) loss, n = 166/611 with/without progression) between Y2 and Y4 with preceding (BL→Y2) and concurrent (Y2→Y4) change in central medial femorotibial (cMFTC) compartment cartilage thickness.
Symptomatic progression was associated with concurrent (Y2→Y4: −305 ± 470 μm vs −155 ± 346 μm, Odds ratios (OR) = 1.5 1.2, 1.7) but not with preceding cartilage thickness loss in cMFTC (−150 ± 276 μm vs −151 ± 299 μm, OR = 0.9 95% CI: 0.8, 1.1). Radiographic progression, in contrast, was significantly associated with both concurrent (−542 ± 550 μm vs −98 ± 255 μm, OR = 3.4 2.6, 4.3) and preceding cMFTC thickness loss (−229 ± 355 μm vs −130 ± 270 μm, OR = 1.3 1.1, 1.5).
These results extend previous reports that did not discern predictive vs concurrent associations of cartilage thickness loss with OA progression. The observed predictive and concurrent validity of cartilage thickness loss for radiographic progression and observed concurrent validity for symptomatic progression provide an important step in qualifying cartilage thickness loss as a biomarker of knee OA progression.
NCT00080171.
To determine whether loss in thigh muscle strength in women concurrent with knee osteoarthritis progression is associated with reductions of muscle anatomical cross-sectional area (ACSA) or ...specific-strength (i.e., isometric force÷ACSA), and to explore relationships with local adiposity.
Female participants from the Osteoarthritis Initiative with Kellgren–Lawrence grade ≤3, thigh isometric strength measurements, and thigh magnetic resonance images at year-two (Y2) and year-four (Y4) (n = 739, age 62 ± 9 years; body mass index measurements (BMI) 28.8 ± 5.9 kg/m2) were grouped into: (1) those with vs without symptomatic progression (≥9 increase in Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC)-pain scale: 0–100); and (2) those with vs without radiographic progression (≥0.7 mm reduction in minimum joint space width). The change in knee extensor and flexor ACSA and specific-strength, and subcutaneous and intermuscular fat (IMF) ACSAs were compared between progressors and non-progressors using analysis of covariance.
Symptomatic progression was associated with a significantly greater loss (p < 0.001) of knee extensor ACSA (−2.0%, 95%CI −2.5, −1.5) compared to those without progression (−0.7%, 95%CI −1.0, −0.4), and greater loss (p = 0.020) of knee flexor specific-strength (−7.6%, 95%CI −11.5, −3.7; vs −2.4%, 95%CI −4.8, 0.0). Radiographic progression was associated with a significantly greater increase (p = 0.023) in IMF (+1.7%, 95%CI -0.1, +3.6) compared to those without progression (−0.6%, 95%CI −1.6, +0.3).
The significant reduction in thigh muscle strength concurrent with symptomatic progression in women appears to be associated with loss of extensor muscle ACSA and flexor specific-strength. In contrast, radiographic progression appears to be unrelated to muscle properties, but to be associated with local (intermuscular) adiposity gains.
Abstract Objective To cross-sectionally determine the quantitative relationship of age-adjusted, sex-specific isometric knee extensor and flexor strength to patient-reported knee pain. Methods ...Difference of thigh muscle strength by age, and that of age-adjusted strength per unit increase on the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) knee pain scale, was estimated from linear regression analysis of 4553 Osteoarthritis Initiative participants (58% women). Strata encompassing the minimal clinically important difference (MCID) in knee pain were compared to evaluate a potentially non-linear relationship between WOMAC pain levels and muscle strength. Results In Osteoarthritis Initiative participants without pain, the age-related difference in isometric knee extensor strength was -9.0%/-8.2% (women/men) per decade, and that of flexor strength was -11%/-6.9%. Differences in age-adjusted strength values for each unit of WOMAC pain (1/20) amounted to -1.9%/-1.6% for extensor and -2.5%/-1.7% for flexor strength. Differences in torque/weight for each unit of WOMAC pain ranged from -3.3 to -2.1%. There was no indication of a non-linear relationship between pain and strength across the range of observed WOMAC values, and similar results were observed in women and men. Conclusion Each increase by 1/20 units in WOMAC pain was associated with a ∼2% lower age-adjusted isometric extensor and flexor strength in either sex. As a reduction in muscle strength is known to prospectively increase symptoms in knee osteoarthritis and as pain appears to reduce thigh muscle strength, adequate therapy of pain and muscle strength is required in knee osteoarthritis patients to avoid a vicious circle of self-sustaining clinical deterioration.
Summary Objective The Osteoarthritis Initiative (OAI) is aimed at validating (imaging) biomarkers for monitoring progression of knee OA. Here we analyze regional femorotibial (FT) cartilage thickness ...changes over 1 year using 3 Tesla MRI. Specifically, we tested whether changes in central subregions exceed those in the total cartilage plates. Methods The right knees of a subsample of the OAI progression subcohort ( n = 156, age 60.9 ± 9.9 years) were studied. Fifty-four participants had definite radiographic osteoarthritis (OA) (KLG 2 or 3) and a BMI > 30. Mean and minimal cartilage thickness were determined in subregions of the medial/lateral tibia (MT/LT), and of the medial/lateral weight-bearing femoral condyle (cMF/cLF), after paired (baseline, follow up) segmentation of coronal FLASHwe images with blinding to the order of acquisition. Results The central aspect of cMF displayed a 5.8%/2.8% change in mean thickness in the group of 54/156 participants, respectively, with a standardized response mean (SRM) of −0.47/−0.31, whereas cartilage loss in the total cMF was 4.1%/1.9% (SRM −0.49/−0.30). In the central MT, the rate of change was −1.6%/−0.9% and the SRM −0.29/−0.20, whereas for the entire MT the rate was −1.0%/−0.5% and the SRM −0.21/−0.12. Minimal thickness displayed greater rates of change, but lower SRMs than mean thickness. Conclusions This study shows that the rate of cartilage loss is greater in central subregions than in entire FT cartilage plates. The sensitivity to change in central subregions was higher than for the total cartilage plate in the MT and was similar to the total plate in the medial weight-bearing femur.
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