Jeannette Østergaard Penny

Jens-Erik Varmarken

Ming Ding

Ole Ovesen

Søren Overgaard

Journal of Orthopaedic Translation

Penny, Jeannette Østergaard

Ding, Ming

Ovesen, Ole

Varmarken, Jens-Erik

Overgaard, Søren

Elsevier - Publisher Connector 

208 Abstractsrelationship to other metabolic parameters in osteoporosis, diabetes,
metabolic syndrome and anorexia nervosa.
Brief CV
Research Area(s): Marrow changes in osteoporosis
Technical Expertise: Imaging (MRI, clinical CT, ultrasound, radiography)
Email: griffith@cuhk.edu.hk
Professor James F Griffith MB, BCh, BAO, MRCP, FRCR, HKFAM (radiology),
MD, studied medicine in University College Cork Ireland, practiced clinical
medicine in the UK and underwent radiological training in the West Midlands
UK. His current clinical practice comprises all aspects of musculoskeletal
imaging. He has published almost 300 peer-reviewed papers with particular
research interests being glenoid bone loss in should dislocation and the
imaging of marrow fat and bone vascularity with a view to the early detect
of osteoporosis.
Some representative papers are:
Griffith JF, Yeung DK, Ma HT et al. Bone marrow fat content in the elderly: a
reversal of sex difference seen in younger subjects. J Magn Reson Imaging.
2012;36(1):225e30.
Griffith JF, Wang YX, Zhou H et al. Reduced bone perfusion in osteopo-
rosis: likely causes in an ovariectomy rat model. Radiology.
2010;254(3):739e46.
Griffith JF, Yeung DK, Chow SK et al. Reproducibility of MR perfusion and (1)H
spectroscopy of bone marrow. J Magn Reson Imaging. 2009 ;29(6):1438e42.
Griffith JF, Yeung DK et al A study of bone marrow and subcutaneous fatty
acid composition in subjects of varying bone mineral density. Bone.
2009;44(6):1092e6.
Griffith JF, Yeung DK, Tsang PH et al. Compromised bone marrow perfusion in
osteoporosis. J Bone Miner Res. 2008 ;23(7):1068e75.
Griffith JF, Yeung DK, Antonio GE et al. Vertebral marrow fat content and
diffusion and perfusion indexes in women with varying bone density: MR
evaluation. Radiology. 2006;241(3):831e8.
Yeung DK, Griffith JF, Antonio GE et al Osteoporosis is associated with
increased marrow fat content and decreased marrow fat unsaturation: a
proton MR spectroscopy study. J Magn Reson Imaging. 2005 ;22(2):
279e85.
RADIO-STEREOMETRIC ANALYSIS IN RESURFACING HIP ARTHROPLASTY
Jeannette Østergaard Penny, Ming Ding, Ole Ovesen, Jens-Erik Varmarken,
Søren Overgaard
Department of Orthopedic Surgery, Odense University Hospital, Odense,
Denmark
Dept. of Orthopedic Surgery, Næstved Hospital, Næstved, Denmark
Clinical Institute, University of Southern Denmark, Odense, Denmark
RSA is a method which can measure small migration of prosthetic compo-
nents in bone and wear of e.g. polyethylene. The radiographic method has
been develop in Sweden during the 1970’ies and is today used as a tool
documenting new implants in order to verify a stable implant in bone.
Studies using the method have shown that early and continuous migration is
one of the most important predictors of implant loosening and is thus a
surrogate indicator for survival of the implant.
RSA requires simultaneous exposure of two X-ray tube creating two images
(fig, 1 and 2.) In addition, a calibration cage, implant and bone markers are
needed. A software program will translate these projections into a 3D
coordinate system, calculation the distance between the rigid bodies of the
cage, bone and implant. Changes, during follow-up between the relative
position of bone and implant, mean that the implant is migrating in one or
more directions.
The RSA method has in the present study been used to evaluate different
types of hip arthroplasties.Resurfacing hip arthroplasty (RHA) versus a standard total hip arthroplasty
(THA) with a large diameter metal on metal heads (LDH-THA) stable.
The primary aim of this study was evaluate the implant stability of the DePuy
ASR Hip Resurfacing by use of RSA, and secondly to compare it to a cup
from a LDH-THA
Fig. 2
Results
Cup:
The mean (sd) micro motion over the first two years of 18 ASR cups was a
lateral movement of -0.115 (0.60) mm (p Z 0.82), proximal migration of
0.075 (0.14)mm (pZ 0.01), and anterior movement of 0.438 (0.88)mm (pZ
0.04). 16 ReCap cups migrated 0.307 (0.53)mm (p Z 0.01) medially, 0.282
(0.36)mm (p < 0.001) proximally and 0.343 (0.63)mm pZ (0.03) posteriorly.
On the z axis, both cups moved in opposite directions at 2 years (p < 0.01).
No difference between the cups was found at 2 years for the X and Y axis.
Fig. 2.
The proximal migration for the ReCap cup places it in an “at risk” group,
whereas RSA failed to identify ASR cup as a problematic implant. We
conclude that early migration is not the mode of failure for the ASR implant.
Stem.
Abstracts 209The mean (sd) micro motion over the first two years of nineteen femoral
Articular Surface Replacement (ASR) components was a lateral movement of
0.107 (0.513) mm, distal migration of 0.055 (0.204) mm, and anterior
movement of 0.150 (0.413) mm. The backward tilt around the x axis was
-0.08(1.088), there was 0.165(0.924) internal rotation and 0.238 (0.420)
varus tilt. The baseline to 2 year varus tilt was statistically significant from
zero movement, but on a group level no significant movement was present
from 1 year onwards.
Conclusion.
We conclude that the ASR femoral implant achieves initial stability, and that
early migration is not the mode of failure for the ASR implant.
Brief CV
Name: Søren Overgaard, Professor, Head of Research, MD, PhD, Chief Surgeon
Affiliation(s): Department of Orthopaedic Surgery and Traumatology, Odense
University Hospital
Institute of Clinical Research, University of Southern Denmark, Denmark
Research Area(s): Clinical, experimental and epidemiological research
within Orthopaedic Surgery
Email: soeren.overgaard@rsyd.dk
Website: www.sdu.dk/ki/ortoIN SILICO MULTISCALE SIMULATIONS OF BONE REMODELLING IN HEALTH,
DISEASE AND TREATMENT
Patrik Christen
Institute for Biomechanics, Department of Health Sciences and Technology,
ETH Zurich, Vladimir-Prelog-Weg 3, 8093 Zurich, Switzerland
Today, the exact spatial relationship between the micromechanical envi-
ronment and consequent bone adaptation in health, disease and treatment
is not well understood. A quantitative understanding of how the mechanical
environment regulates bone remodeling could lead to an improved under-
standing of bone formation and bone quality maintenance as well as an
ability to predict micro-architectural changes in bone geometry. Here a
combined multiscale experimental and computational model is presented
which is able to quantify, for the first time, the relationship between local
events of trabecular bone remodeling and the local micromechanical
environment. The in silico model includes a newly developed strain-
adaptive feedback algorithm for the simulation of trabecular bone remod-
eling in response to loading and pharmaceutical treatment, which has
recently been validated against in vivo reference data of bone adaptation
using time-lapsed micro-computed tomography. For this purpose, the
effects of anabolic, antiresorptive treatment, and mechanical loading on
caudal vertebrae in a mouse model for postmenopausal osteoporosis were
investigated. Simulations of bone remodeling and adaptation in 180
osteopenic mice were performed, and included a permutation of the
conditions for loading of 8N or 0N, and treatments with bisphosphonates,
or parathyroid hormone. Static and dynamic morphometry and local
remodeling sites from in vivo and in silico studies were compared. For
each study, an individual set of four model parameters was selected.
Trabecular bone volume fraction was chosen as an indicator of the accuracy
of the simulations. Overall errors for this parameter were 0.1e4.5%. Other
morphometric indices were simulated with errors of less than 19%. Dynamic
morphometry was more difficult to predict, which resulted in significant
differences from the experimental data although overall patterns of local
adaptation were well represented. In conclusion, a new algorithm for
multiscale simulation of bone remodeling in health, disease and treatment
was rigorously validated against in vivo data using time-lapsed micro-
computed tomography. The results indicate that the simulations accurately
reflect effects of treatment and loading seen in respective in vivo data. In
the future this might help to better understand bone mechanobiology in
humans using the model to stratify patient populations for risk of
osteoporotic fractures in large clinical trials or even as a predictive tool
to plan treatment in individual patients.
BIOMECHANICAL MODELING AND APPLICATION OF MUSCULOSKELETAL
SYSTEM
Yu-bo Fan, Lizhen Wang, Xiaoyu Liu, Jie Yao, Chao Wang, Wenxin Niu
School of Biological Science and Medical Engineering, Beihang University,
ChinaThe numerical simulation has been a critical methodology in the biome-
chanical researches. This paper aims to present the finite element (FE)
studies in the areas of orthopedics, stomatology, and injury prevention.
(1) Structure of woodpecker’s head could protect brain from high impact.
The drumming process was simulated with a FE model of woodpecker head.
The results revealed special functions of beak and hyoid, and provided novel
insight into protective design for human. (2) A FE model of human knee joint
was validated and utilized to evaluate the post-operative mechanical
environment after anterior cruciate ligament reconstruction. Local stress
redistribution predisposing to surgical sequelae was quantified. Optimal
surgical procedure was proposed. (3) Injury process of human eyeball was
also investigated with an eyeball FE model. The simulation quantified
intraocular stress wave during impact injury, and proposed the mechanism
of amotio retinae. (4) A precise FE model of cervical spine was developed.
The model has been used at areas of cervical spinal fusion and artificial
intervertebral discs. The study provided mechanical knowledge of cervical
spondylosis and could help improve the surgical techniques. (5) Bone
remodeling phenomena in osteoporosis and post-operative rehabilitation
were also researched with FE methodology. Particularly in oral implant,
post-operative outcomes were predicted under a variety of implant and
loading conditions.
The present FE studies provided insight from mechanical viewpoint into
orthopedics, stomatology, and injury prevention, and could help advance
theories and technologies in these areas.
Brief CV
Research Area(s): Biomechanics
Technical Expertise: Biomechanical Modeling
Email: yubofan@buaa.edu.cn
Website: http://bme.buaa.edu.cn
Professor Yubo Fan is the Dean of the School, Director of Key Laboratory for
Biomechanics and Mechanobiology of Ministry of Education, Beihang Univer-
sity, China. He is the President of Chinese Biomedical Engineering Society,
Chair elect of World Association for Chinese Biomedical Engineers (WACBE),
Vice president of China Strategic Alliance of Medical Devices Innovation,
AIMBE Fellow and a Council Member of World Congress of Biomechanics.
ACOUSTIC IMAGING FOR BONE DIAGNOSIS USING A HAND-HELD FOCAL
QUANTITATIVE ULTRASOUND
Yi-xian Qin, Jesse Muir, Jiqi Cheng, Liangjun Lin, Wei Lin
SUNY-Stony Brook University, Stony Brook, NY, USA
Introduction: In order to provide a non-ionizing, repeatable method of skel-
etal imaging, a novel hand-held scanning confocal quantitative ultrasound
(QUS) device has been developed. A mobile scanning technology that can
provide advanced risk and injury identification in high-risk areas where


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