Abstracts Posters SICOT-SOF meeting Gothenburg 2010 _2_

Poster
Topic: General Orthopaedics
Abstract number: 26286
REPEATABILITY OF SHOULDER BONY LANDMARKS LOCATION FROM
BIPLANAR X-RAY, IN A PSEUDO-KINEMATIC CONTEXT
Pierre-Yves LAGACÉ 1 , Xavier OHL 2 , Fabien BILLUART 2 , Wafa SKALLI 2 , Jacques
DE GUISE 1 , Nicola HAGEMEISTER 1
1 Laboratoire De Recherche En Imagerie Et Orthopédie - École De Technologie
Supérieure, Montréal (Québec) (CANADA), 2 Laboratoire de Biomécanique - Arts et
Métiers ParisTech, Paris (FRANCE)
Analysis of shoulder movement requires precise identification of bony landmarks.
Following work by Ohl [1], the purpose of the study is to verify the repeatability of
shoulder bony landmark identification in a pseudo-kinematic context, from biplanar Xrays.
Nine healthy subjects participated in the study. Biplanar X-rays (EOS(TM)) were
acquired at 3 elevations of the arm in the scapular plane. Image analysis consisted in
modelling bones with simple geometric shapes (points and spheres), in a dedicated
virtual 3D environment. These shapes were manually positioned in 3D so that their
projections superimposed to bony landmarks visible on the radiographs. Image
analysis was carried out by 2 observers, 3 times each. Repeatability for identification
of the humeral head center was good with 95% confidence intervals (CI) ranging
from 0.57mm to 2.25mm. The coracoid process was the most repeatable scapular
landmark with 95% CI’s ranging from 0.81mm to 6.55mm. Other scapular landmarks
which were studied are the acromial angle, the inferior angle and the superior and
inferior borders of the glenoid fossa. Repeatability data obtained in this study is
comparable to that reported for palpation [2]. Biplanar X-rays has the advantage of
identifying bones without soft tissue artefacts and directly accessing the humeral
head and glenoid fossa, however at the cost of low radiation doses. This study
clearly demonstrates the potential of biplanar X-ray for shoulder pseudo-kinematics
analysis.[1] Ohl X. et al., (2009) Surgical and Radiologic Anatomy, [2] Lewis J. et
al., (2002) Manual Therapy, 7: 26-30
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