O3446 THE RELATIONSHIP BETWEEN THREE MEASUREMENTS OF BONE QUALITY AND BONE STRENGTH OF THE TIBIAL PLATEAU

Abstract

Objective: To examine the relationship between three measurements of bone quality and bone strength of the tibial plateau, and the relationships between these measurements. Methods: The bone quality of sixteen cadaveric tibias was assessed for density and architecture using three methods: DXA, pQCT, and spectral analysis of digitised radiographs. These bone quality measurements were correlated with the þxation strength of a bicondylar plateau fracture, obtained by mechanical testing. Results: All three techniques correlate strongly with the mechanical strength of the þxed tibial plateau, with the highest correlation being with DXA (r=0.81, P< 0.001), and pQCT (r=0.79, P< 0.001); followed by spectral analysis (r= 0.5, P,0.01). DXA correlates strongly with pQCT (r=0.95, P< 0.001); Whereas, spectral analysis has a weaker correlation with both DXA (r=0.65, P< 0.01), and pQCT (r=0.69, P< 0.01). Discussion: This is the þrst study of bone quality assessment in the tibial plateau, and as with studies at other sites, DXA showed that BMD has the best correlation with mechanical failure. Both DXA and pQCT are a reßection of density assessment which explains the strong correlation seen. However, the strength of bone is a function of not just quantity and density but also its structure. This was assessed using spectral analysis which involves image processing and pattern recognition algorithm of the trabecular structure. This measures structure only and this may explain the lower correlation with bone strength. Nevertheless we feel that further analysis may demonstrate a speciþc use of this technique to compliment either DXA or PqCT in providing complete assessment of the bone.