ARUP; ISBN: 978-0-9562121-5-3 - CMBBE 2012 - Cardiff University

model to create an efficient simulation model according to biomechanical constraints
(e.g., nonlinear model, large displacements and deformations of soft tissues and
collisions.).
Finally, resulting data of the mentioned methods are used as inputs to setup the
physically-based simulation model which is used for estimating the joint mechanics.
To evaluate our approach, a clinical analysis of the subject is performed by radiologist.
Standard morphological measurements based on anatomical parameters [4] (e.g., alpha
angle, acetabular version and acetabular depth) (Fig.3) are performed by using subjectspecific
data (MRI and 3D bones models). Moreover, radiological analysis is completed
on the subject’s MRI data to verify potential abnormalities in the subject hip joint [22].
The results of this analysis are compared with the simulation results.
Fig. 2: Left: acetabulum divided into 4 regions. Middle: measurement of acetabular
depth and alpha angle. Right: standard hip joint anatomical axes.
4. RESULTS
Given the mechanical properties (Young modulus) of bones and cartilage [2], our
biomechanical model is simplified by considering the cartilage as deformable models,
and bone as rigid.
This model is used to simulate the subject hip joint mechanics during dancing
movements. These movements are characterized by the leg in air position with extreme
hip flexion and/or abduction. These movements are discretized in several frames and
expressed according to standard hip joint anatomical axes (Fig. 3). For each frame, the
estimated load is applied and the stress along the direction of the maximal compression
is computed. Given the importance of the stress distribution, the location of peak
stresses is detected during the simulation.
For simulated dancing movements, peak stresses are frequently observed in the superior
region of the actabular rim of the subject hip joint (Fig. 4). In parallel, during the
medical analysis, radiologists have detected lesions in the same region (Fig. 4), but they
didn’t find any morphological abnormalities.