DOS Kongressen 2014 ·
87
Equally good methods for determination of bone
quality of the trapezium
Kamille Breddam Mosegaard, Nadja Bouteldja, Maiken Stilling,
Torben Bæk Hansen
Department of Orthopaedics , Regional Hospital Holstebro, Hospital Unit West,
Denmark; Department of Radiology, Regional Hospital Holstebro, Hospital Unit
West, Denmark; Department of Orthopaedics, Regional Hospital Holstebro,
Hospital Unit West, Denmark
Background:
High loosening rates of the trapezium component in total joint
arthroplasty of the trapeziometacarpal joint may be caused by multiple inde-
pendent factors, and one possible cause is poor bone mineral quality of the tra-
pezium. However technical difficulties in measuring the bone mineral density
(BMD) has been described due to the irregular and sclerotic bone contours.
Purpose / Aim of Study:
We wanted to compare the measurements of bone
quality of the trapezium using DXA scan BMD with bone quality measurements
using computed tomography (CT) and Houndsfield units (HU).
Materials and Methods:
We included 71 hands in 60 patients, 13 males and
47 females, mean age 59 years (43-77) diagnosed with Eaton– Glickel stage
II–IV osteoarthritis. In all patients we measured the BMD of the trapezium with
two different methods: DXA including the circumferential/cortical part of the
bone or in the center of the trapezium alone. We also measured the BMD of the
distal radius. All BMD measurements were compared to measurements of the
bone quality using the HU.
Findings / Results:
In the trapezium the CT measured HU in the trapezium
correlated with DXA measured BMD (r=0.49, p=0.000) of the trapezium (pe-
rimeter method) and with DXA measured BMD (r=0.55, p=0.000) in the tra-
pezium (inner-circle method). DXA measured BMD of the trapezium (perimeter
method) correlated (r=0.94, p=0.000) with DXA measured BMD of the trape-
zium (inner-circle method). In the radius the average CT measured HU in distal
radius correlated with DXA measured BMD (r=0.67, p=0.000).
Conclusions:
The correlation between the two DXA measurement methods
was excellent, and the easier inner-circle method may be preferred. We found
a good correlation between measurements made by CT with HU and DXA BMD
in both the distal radius and in the trapezium using the inner circle method, and
both methods may be used.
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