Reference values and Z-scores for subregional femorotibial cartilage thickness – results from a large population-based sample (Framingham) and comparison with the non-exposed Osteoarthritis Initiative reference cohort

Eckstein, F.; Yang, M.; Guermazi, A.; Roemer, F.W.; Hudelmaier, M.; Picha, K.; Baribaud, F.; Wirth, W.; Felson, D.T.

doi:10.1016/j.joca.2010.07.010

« Previous Next »Osteoarthritis and Cartilage
Volume 18, Issue 10 , Pages 1275-1283, October 2010

Reference values and Z-scores for subregional femorotibial cartilage thickness – results from a large population-based sample (Framingham) and comparison with the non-exposed Osteoarthritis Initiative reference cohort

F. Eckstein
- Paracelsus Medical University & Chondrometrics GmbH, Salzburg, Austria
- Address correspondence and reprint requests to: Felix Eckstein, Institute of Anatomy & Musculoskeletal Research, PMU, Strubergasse 21, A5020 Salzburg Austria. Tel: 43-662-44-2002-1240; Fax: 43-662-44-2002-1249.
M. Yang
- Clinical Epidemiology Research & Training Unit, Boston University School of Medicine, MA, USA
A. Guermazi
- Department of Radiology, Boston University School of Medicine, Boston, MA, USA
F.W. Roemer
- Department of Radiology, Boston University School of Medicine, Boston, MA, USA
M. Hudelmaier
- Paracelsus Medical University & Chondrometrics GmbH, Salzburg, Austria
K. Picha
- Centocor Inc., Radnor, PA, USA
F. Baribaud
- Centocor Inc., Radnor, PA, USA
W. Wirth
- Paracelsus Medical University & Chondrometrics GmbH, Salzburg, Austria
D.T. Felson
- Clinical Epidemiology Research & Training Unit, Boston University School of Medicine, MA, USA

Received 14 December 2009; accepted 27 July 2010. published online 06 August 2010.

Summary

Objective

To establish sex-specific (subregional) reference values of cartilage thickness and potential maximal Z-scores in the femorotibial joint.

Methods

The mean cartilage thickness (ThCtAB.Me) in femorotibial compartments, plates and subregions was determined on coronal magnetic resonance imaging (MRI) from a population-based sample (Framingham) and from a healthy reference sample of the Osteoarthritis Initiative (OAI).

Results

686 Framingham participants (309 men, 377 women, age 62±8 years) had no radiographic femorotibial osteoarthritis (OA) (“normals”) and 376 (156 men, 220 women) additionally had no MRI features of cartilage lesions (“supernormals”). The Framingham “normals” had thinner cartilage in the medial (3.59mm) than in the lateral femorotibial compartment (3.86mm). Medially, the femur displayed thicker cartilage (1.86mm) than the tibia (1.73mm), and laterally the tibia thicker cartilage (2.09mm) than the femur (1.77mm). The thickest cartilage was observed in central, and the thinnest in external femorotibial subregions. Potential maximal Z-scores ranged from 5.6 to 9.8 throughout the subregions; men displayed thicker cartilage but similar potential maximal Z-scores as women. Mean values and potential maximal Z-scores in Framingham “supernormals” and non-exposed OAI reference participants (112 participants without symptoms or risk factors of knee OA) were similar to Framingham “normals”.

Conclusions

We provide reference values and potential maximal Z-scores of cartilage thickness in middle aged to elderly non-diseased populations without radiographic OA. Results were similar for “supernormal” participants without MRI features of cartilage lesions, and in a cohort without OA symptoms or risk factors. A cartilage thickness loss of around 27% is required for attaining a Z-score of −2.

Keywords: Normal values, Cartilage thickness, Z-scores, Population-based study, MRI