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

Authors

  • Felix Eckstein,

    Corresponding author
    1. Institute of Anatomy and Musculoskeletal Research, Paracelsus Medical University, Salzburg, Austria
    2. Chondrometrics GmbH, Ainring, Germany
    • Institute of Anatomy & Musculoskeletal Research, Paracelsus Medical University, Strubergasse 21, A5020 Salzburg, Austria
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    • Dr. Eckstein has received consultant fees, speaking fees, and/or honoraria (less than $10,000 each) from Merck, Genzyme, GSK, and Pfizer, and (more than $10,000 each) from Merck Sorono, Novartis, and Sanofi-Aventis, and owns stock and/or holds stock options in Chondrometrics GmbH.

  • Michael Nevitt,

    1. University of California, San Francisco
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  • Alberto Gimona,

    1. Novartis Pharma AG, Basel, Switzerland
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    • Dr. Gimona owns stock and/or holds stock options in Novartis Pharma AG.

  • Kristen Picha,

    1. Centocor Research and Development, Inc., Radnor, Pennsylvania
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    • Dr. Picha owns stock and/or holds stock options in Johnson & Johnson and has several patents pending from Centocor R&D.

  • Jennifer H. Lee,

    1. Wyeth Research, Collegeville, Pennsylvania
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    • Dr. Lee owns stock and/or holds stock options in Pfizer and Johnson & Johnson.

  • Richard Y. Davies,

    1. GlaxoSmithKline, Inc., Collegeville, Pennsylvania
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    • Dr. Davies owns stock and/or holds stock options in GSK.

  • Donatus Dreher,

    1. Merck Serono SA, Geneva, Switzerland
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  • Olivier Benichou,

    1. Eli Lilly & Co., Indianapolis, Indiana
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    • Dr. Benichou owns stock and/or holds stock options in Eli Lilly.

  • Marie-Pierre Hellio Le Graverand,

    1. Pfizer, Inc., New London, Connecticut
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  • Martin Hudelmaier,

    1. Institute of Anatomy and Musculoskeletal Research, Paracelsus Medical University, Salzburg, Austria
    2. Chondrometrics GmbH, Ainring, Germany
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  • Susanne Maschek,

    1. Institute of Anatomy and Musculoskeletal Research, Paracelsus Medical University, Salzburg, Austria
    2. Chondrometrics GmbH, Ainring, Germany
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    • Drs. Maschek and Wirth have received honoraria (more than $10,000) from Chondrometrics GmbH and own stock and/or hold stock options in Chondrometrics GmbH.

  • Wolfgang Wirth,

    1. Institute of Anatomy and Musculoskeletal Research, Paracelsus Medical University, Salzburg, Austria
    2. Chondrometrics GmbH, Ainring, Germany
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    • Drs. Maschek and Wirth have received honoraria (more than $10,000) from Chondrometrics GmbH and own stock and/or hold stock options in Chondrometrics GmbH.

  • Osteoarthritis Initiative Investigators Group


Abstract

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). Regional and ordered values (OVs) of change were compared by baseline radiographic OA status.

Results

Healthy knees displayed small changes in plates and subregions (±0.7%; standardized response mean [SRM] ±0.15), with OVs being symmetrically distributed close to zero. In calculated K/L grade 2 knees, changes in cartilage thickness were small (<1%; minimal SRM −0.22) and not significantly different from healthy knees. Knees with calculated K/L grade 3 showed substantial loss of cartilage thickness (up to −2.5%; minimal SRM −0.35), with OV1 changes being significantly (P < 0.05) greater than those in healthy knees. Calculated K/L grade 4 knees displayed the largest rate of loss across radiographic OA grades (up to −3.9%; minimal SRM −0.51), with OV1 changes also significantly (P < 0.05) greater than in healthy knees.

Conclusion

MRI-based cartilage thickness showed high rates of loss in knees with moderate and end-stage radiographic OA, and small rates (indistinguishable from healthy knees) in mild radiographic OA. From the perspective of sensitivity to change, end-stage radiographic OA knees need not be excluded from longitudinal studies using MRI cartilage morphology as an end point.

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