In vivo determination of homogenised mechanical characteristics of human tibia: application to the study of tibial torsion in vivo

Objective. The study presents a method allowing the in vivo homogenised characteristics of the tibiae of children to be assessed.Design. Studies have been performed on two groups of children: six normal children, aged from 5 to 16 yr, and on four children, aged from 8 to 11 yr with tibial deformities. We analysed the tibial transverse sections from CT scans performed on the left tibia of each child.Background. Most tibial torsion studies have only been based on geometrical parameters. Our study integrated mechanical and geometrical considerations.Methods. The finite element models and integration of mechanical properties were performed from CT scans. Then homogenised mechanical characteristics (tensile stiffness, flexural stiffness and torsional stiffness) were calculated.Results. The homogenised mechanical characteristics decrease between 20 to 80% of the tibial length. The values increased with age for both groups of children. Children with abnormalities seem to have values of tibial rigidities comparable with those of normal tibiae.Conclusions. By considering the mechanical and geometrical properties of the tibia in our study, we showed that the bone stiffness of children is not altered with torsional deformities

Long-Term Effects on Tibial Growth After Intraosseous Infusion: A Prospective, Radiographic Analysis

International audienc

Long-Term Effects on Tibial Growth After Intraosseous Infusion: A Prospective, Radiographic Analysis

International audienc

Compatible scales for progressive and additive MRI assessments of haemophilic arthropathy.

Summary. The international MRI expert subgroup of the International Prophylaxis Study Group (IPSG) has developed a consensus for magnetic resonance imaging (MRI) scales for assessment of haemophilic arthropathy. A MRI scoring scheme including a 10 step progressive scale and a 20 step additive scale with identical definitions of mutual steps is presented. Using the progressive scale, effusion/haemarthrosis can correspond to progressive scores of 1, 2, or 3, and synovial hypertrophy and/or haemosiderin deposition to 4, 5, or 6. The progressive score can be 7 or 8 if there are subchondral cysts and/or surface erosions, and it is 9 or 10 if there is loss of cartilage. Using the additive scale, synovial hypertrophy contributes 1–3 points to the additive score and haemosiderin deposition contributes 1 point. For osteochondral changes, 16 statements are evaluated as to whether they are true or false, and each true statement contributes 1 point to the additive score. The use of these two compatible scales for progressive and additive MRI assessments can facilitate international comparison of data and enhance the accumulation of experience on MRI scoring of haemophilic arthropathy