Postersession I
Onsdag den 23. oktober
11:00 – 12:00
lokale: Reykjavik
Chairmen: Jeannette Østergaard Penny / Ole Ovesen
139. No increased risk of elevated metal ions and pseudotumour formation when using modular neck-stems bilaterally
Peter Revald, Claus Varnum, Poulsen Thomas K., Per Kjærsgaard-Andersen
Department of orthopaedic surgery, Vejle Hospital
Background: Lately, potential corrosion/fretting and metal
ion release from the neck-stem taper
junction of modular total hip arthroplasty
(THA) has been in focus.
Purpose / Aim of Study: The aim of this study was to compare blood
levels of metal-ion and abnormal soft tissue
reactions in patients having a modular neck-
stem in one or both hips.
Materials and Methods: All patients having implanted a
cementless THA with modular neck-stem
(ABG2 stem and Trident cup) were
examined. The patients underwent
surgery from May 2009 to November
2011. In total, 39 unilateral and 7 bilateral
operated patients were included
corresponding to 53 THAs. All had metal-
on-HXL polyethylene bearings with a
head diameter of 36 mm. At follow-up,
plasma chrome and cobalt ion levels
were measured, and a MRI of the hip
was performed. The Wilcoxon rank-sum
test was used to compare metal ions
levels between uni- and bilaterally
operated patients. Chi-test was used to
compare proportions.
Findings / Results: The mean age at surgery was 65.6
years.70% were males. The overall
mean follow-up was 2.3 years. In the
unilateral group, the median chrome
plasma value was 14.7 nmol/l, and the
median cobalt level was 51.2 nmol/l. In
the bilateral group, the median values
were 16.5 nmol/l for chrome and 54.6
nmol/l for cobalt. There was no difference
in chrome (p=0.26) or cobalt levels
(p=0.60) between the two groups. Five
patients (13.5%) in the unilateral group
and one (14.3%) in the bilateral group
had elevated plasma cobalt values (>119
nmol/l) (p=0.89). There were no elevated
chrome values (>134.5 nmol/l) in either
group. Four (10.3%) cystic type 2
pseudotumours were found on MRI in the
unilateral group, none in the bilateral
group (p=0.32).
Conclusions: No increased risk of elevated metal ions or
pseudotumour formation could be noticed
when operated with modular neck-stems in
THA in both hips.
140. Body composition preoperatively has no impact on clinical outcome after hip arthroplasty - A cohort study of 102 patients 1year after surgery
Anette Liljensøe, Jens Ole Laursen, Kjeld Søballe , Inger Mechlenburg
Orthopaedic Research Unit, Aarhus University Hospital; Department of Orthopaedics, Hospital Southern Jutland
Background: Previous studies indicate that knee
arthroplasty patients preoperative BMI
is a predictor of the clinical effect
postoperatively. A high BMI increases
the risk of quality of life (QoL) and
physical function. However, the
association between obesity and
outcome after THA is controversial.
Purpose / Aim of Study: To investigate whether there is an
association between the preoperative
body composition of patients
undergoing THA and their QoL and
physical function 1 year after surgery.
Materials and Methods: 102 patients scheduled for THA
participated in a 1-year follow-up
study. Body composition (fat and
muscle mass) was measured with Dual
Energy X-ray Absorptiometry (DXA)
preoperatively and 1-year after
surgery. The outcome measures were
patient reported questioners: SF-36
and Hip disability and Osteoarthritis
Outcome Score (HOOS).
Findings / Results: Mean percentage of fat (%fat) for
females were 40(23-53)% and for
males 31(15-46)%. Mean percentage
of muscle mass for females were 58
(46-74)%, males 66(52-82)%. We
found no statistically significant
association between body composition
and any of the SF-36 and HOOS sub-
scales. For %fat and Physical
component score (PCS) odds ratio
(OR)=0,98 (p=0,4), %fat and Mental
component score (MCS) OR=0,99
(p=0,6), muscle mass and PCS
OR=1,03 (p=0,4), muscle mass and
MCS OR=1,02 (p=0,6).
Conclusions: Our findings indicate that overweight
and obesity has no impact on the QoL
and the self-assessed physical
function for THA patients 1year after
surgery.
141. 3 year Follow-up of a Long-term Registry-based Multicenter study on Vitamin E Diffused Polyethylene in Total Hip Replacement
Nanna H. Sillesen, Meridith E. Greene, Audrey K. Nebergall, Anders Troelsen, Peter Gebuhr, Henrik Malchau
Harris Orthopaedic Laboratory, MGH + Department of Orthopedics, Hvidovre Hospital. , Massachusetts General Hospital, Boston, MA, USA. + Copenhagen University Hospital, Hvidovre, Denmark; Harris Orthopaedic Laboratory, MGH, Boston, Massachusetts General Hospital, Boston, MA, USA.; Department of Orthopedics, Hvidovre., Copenhagen University Hospital Hvidovre, Copenhagen, Denmark
Background: Preclinical studies of vitamin E diffused
highly cross-linked polyethylene (VEPE)
have shown improved material and wear
properties due to the antioxidative properties
of the vitamin E.
Purpose / Aim of Study: To document both early and long-term clinical
outcome of VEPE in order to ensure that
there are no detrimental effects of the new
developments and to evaluate the materials
performances from clinical use.
Materials and Methods: 977 patients from 17 centers in USA and
Europe are enrolled into a prospective
10year outcome study. Patients received
either Porous Titanium Coated or Porous
Plasma Sprayed acetabular shells with
either VEPE liners or medium cross-linked
(XLPE) liners. At each follow-up, 3
radiographs were obtained, 5 PROMs
were completed (Harris hip score, case
mix indicator, UCLA, SF-36, EQ-5D).
Radiographs were measured for cup and
stem position, as well as femoral head
penetration into the liner. Postoperative
complications and revisions were also
collected.
Findings / Results: Mean age at surgery was 62±9 years. At
3year follow-up there were 15 dislocations
in 11 patients and 13 revisions (4
periprosthetic fracture, 1 sepsis, 6 instability,
and 2 implant mismatch at surgery). Five
patients died due to causes unrelated to the
operation. Wear analysis of AP pelvis films
with Martell method from post-op to 3year
showed a penetration rate at 0.01 mm/year
for XLPE and a penetration rate of 0.003
mm/year for VEPE with no significant
difference between them (p=0.43).
Improvement was seen in all PROMs pre-op
to 3years postop (p<0.0001).
Conclusions: Early follow-up of VEPE liners provide
encouraging results with few intra- and
postoperative complications. PROMs indicate
improvement after THA in functionality and
quality of life across the centers. We have
not observed any early adverse effects
from diffusing the liners with vitamin E.
142. Effect of early progressive resistance training compared to home based exercise after fast track total hip replacement. -A randomised controlled trial.
Lone Ramer Mikkelsen, Inger Mechlenburg, Kjeld Søballe, Søren Mikkelsen, Thomas Bandholm, Mette Krintel Petersen
Elective Surgery Centre, Silkeborg Regional Hospital ; Department of Orthopaedics, Aarhus University Hospital; (1)Physical Medicine & Rehabilitation Research – Copenhagen (PMR-C), Department of Physiotherapy, (2, Copenhagen University Hospital, Hvidovre; (1)Department of Physiotherapy- and Occupational Therapy, (2)Centre of Research in Rehabilitation (C, (1)Aarhus University Hospital, (2)Institute of Clinical Medicine, Aarhus University
Background: After Total Hip Replacement (THR) deficits in
muscle strength and physical function
persist. There is lack of evidence concerning
which rehabilitation strategy is most
effective and the amount of rehabilitation
needed after fast track THR.
Purpose / Aim of Study: To investigate the effect of supervised
progressive resistance training in the early
rehabilitation phase after fast track THR in
improving muscle strength and functional
performance.
Materials and Methods: 73 THR patients with preoperative self-
assessed disability (HOOS ADL
score≤67) were randomly assigned to a
control group (CG, home based exercise
7 days/week) or intervention group (IG,
home based exercise 5 days/week and
resistance training of hip and thigh
muscles 2 days/week). The IG trained
with loads of 10 repetition max from
week 1 to 10 after THR . Before surgery
and after the intervention, performance
was evaluated by; leg extension power
(primary outcome), isometric strength
(hip abduction + flexion), sit-to-stand test
(STS), stair test and 20 meter walking
speed.
Findings / Results: 62 patients completed the trial (31 in each
group). Leg extension power improved
significantly in both groups, with no between
group difference: IG (difference baseline to
follow up): 0.28 [0.1;0.3] Watt/kg, CG: 0.26
[0.0;0.5] Watt/kg, p=0.91. 20 m walk
performance improved more in IG: 2.98
[1.8;4.2] sec than CG: 1.58 [0.8;2.4] sec,
p=0.05. No significant differences were
found in the other outcomes, yet borderline
significance (p=0.06-0.09) was seen in
favour of IG in STS and isometric muscle
strength.
Conclusions: 7 days/week of home based exercise was
equally effective as 5 days/week of home
based exercise plus 2 days/week of
supervised progressive resistance training
in improving leg extension power after THA.
For some of the secondary outcomes,
trends were in favour of resistance training.
143. 3 months home-training by a standardized program improves walking distance and knee extension strength in old patients 1-7 years after surgery with dual-mobility THA following femoral neck fracture.
Christina Frølich, Inger Mechlenburg, Sara Birch, Lone Lundager, Torben Bæk Hansen, Maiken Stilling
Department of Orthopaedics, Regional Hospital Holstebro; Department of Physiotherapy, Regional Hospital Holstebro
Background: Dual-mobility total hip arthroplasty
(THA) has become the treatment
choice for displaced femoral neck
fracture (FNF) at our institution.
However, ambulatory follow-up has
revealed poor gait function and leg
strength increasing the fall-risk in many
of these patients.
Purpose / Aim of Study: To test the effect of a standardized
home-based resistance training
program.
Materials and Methods: 31 patients (27 women) at mean 82
(60-96) years were included at mean 3
(1-7) years past dual-mobility THA
after FNF. Patients trained daily for 3
months, with 1 weekly physiotherapist
supervision, and kept a training-diary.
Criteria for study participation were:
dementia score > 7, STS10 > 30sek,
TUG > 12sek, and NMS < 8. Patients
were examined at baseline and at 3
months follow-up with spatio-temporal
parameters during 3 functional tests:
timed-up and go(TUG), 10m walk, sit-
to-stand(STS), and block-step test
(BST). Also, 6 minute walk test(6WT)
and sit-to-stand in 30 seconds(STS30)
was performed. Oxford Hip Score
(OHS) was collected. Leg muscle
mass was measured by DXA, and
muscle strength was tested by hand-
held dynamometer(HHD). Activity was
monitored by a 3-axial accelerometer.
Findings / Results: Between baseline and 3 months follow-
up 6WT improved by 19m (p=0.01).
TUG, STS30, and OHS was
unchanged (p>0.20). Knee extension
strength improved in the operated leg
(p=0.03) but not in the contralateral leg
(p=0.74). Muscle mass did not improve
(p>0.06). 92% were satisfied with the
training program and wished to
continue. Analysis of spatiotemporal
parameters and activity are ongoing.
Conclusions: Initial data assessment revealed
improved walking distance and knee
extension strength after a standardized
3 months home-based resistance
training program in old and fragile
patients 1-7 years THA after femoral
neck fracture.
144. Preoperative planning in cementless total hip arthroplasty - Accuracy of digital templating
Mikkel Krüger Jensen, Søren Solgaard
Ortopædkirurgisk afdeling, Gentofte hospital
Background: Choosing the correct implant size and
determining the correct femoral cut is
important for the optimal result after THA.
Purpose / Aim of Study: In the present study we investigated the
accuracy of pre-operative digital templating
in uncemented THA compared to the actual
implanted component size (cup and stem)
and furthermore we evaluated the
discrepancy in leg-length pre-
and post-operatively.
Materials and Methods: 150 patients undergoing uncemented THA
during the period from 1/1-2011 until 31/12-
2012 were retrospectively reviewed. Four
experienced surgeons performed the
operations. Component size and difference
in leg-length data were registered pre-
operative, per-operative and 3 months post-
operative. Leg-length was measured
radiographically. Data was stratified in
relation to gender, age and surgeon.
Findings / Results: Overall the pre-operative templated cup-
size was predicted correctly in 59% of
the cases. If +/- 1 cup-size was included
the precision increased to 95%. The pre-
operative templated stem-size was
correctly predicted in 61% of the cases.
If +/- 1 stem-size was included the
precision increased to 97%.
The mean pre-operative leg-length
difference was -2,1mm(+/- 6,4mm)
compared to a mean leg-length
difference post-operative of 1,7mm(+/-
6,7mm).
18(12%) out of 150 included patients had
a difference in leg-length >10mm pre-
operative. 18 out of 150 patients still had
a difference in leg-length >10mm post-
operative.
Only 2 patients had a discrepancy of
more than 20 mm.
Conclusions: It can be concluded from the present study
that digital preoperative templating is safe
and reliable.
There was an overall trend towards
increased leg-length of the operated leg.
Equal leg-length within 10mm was achieved
in 88% of the patients.
145. Timing of preoperative prophylactic antibiotics for knee arthroplasties. A quality study after the introduction of the WHO checklist with a standard “time-out” before skin incision.
Arne Svensson, Lars Peter Jorn
Department of Orthopaedic Surgery., Regionshospitalet Viborg
Background: A slight increase in revisions for
infected joint arthroplasties has been
observed in the Nordic countries since
2000 and the reasons for this are not
clear. The most commonly used
antibiotics have a short half-life, and it
has been documented that administration
more than 60 min preoperatively is
associated with higher risk of surgical
infection. It has been considered optimal
to start the infusion 45 – 15 min before
inflation of the cuff for the blood less
field.
Purpose / Aim of Study: To evaluate our current routine, where
antibiotic infusion is scheduled to start
when the patient has arrived at the
operation theater, and before further
anesthetic procedures are initiated.
Materials and Methods: 118 consecutive patients operated
during 2011 at our Hospital with primary
knee prosthesis had their anesthetic
journal evaluated retrospective. Time
markings of the start of the antibiotic
infusion, of the inflation of the cuff for
the blood less field (in-BLF) and the
closure of the wound were recorded for
each patient.
Findings / Results: All patients did receive preoperative
prophylactic antibiotic. Mean time of
infusion before in-BLF was 37 min
(range 5min – 230min). 82 (70%) of the
patients received antibiotics at the
optimal time interval. 6 (5%) of the
patients received antibiotic more than 60
min before in-BLF, and 26 (22%)
patients more than 45 min before in-
BLF. 10 (8%) patients received antibiotic
later than 15 min before in-BLF. Mean
time from in-BLF till wound closure was
80 min (range 50min – 145min), and 44
(37%) patients did receive antibiotics
more than 120 min before wound
closure.
Conclusions: Our findings are in accordance with
reports from a national Swedish survey
from 2011, and leave room for
improvements. Detailed instructions as to
when the antibiotics should be given in
relation to the start of the operation might
improve timing.
146. No correlations between radiological angles and self-assessed Quality of Life in patients with Hip Dysplasia at 2-13 years of follow up after periacetabular osteotomy
Sara Birch, Anette Liljensøe, Charlotte Hartig-Andreasen, Kjeld Søballe, Inger Mechlenburg
Department of Physiotherapy and Occupational Therapy, Herning Regional Hospital; Department of Orthopedic Surgery, Aarhus University Hospital
Background: Only few studies have described the
patients' health-related Quality of Life
(QoL) after periacetabular osteotomy
(PAO). Thus, there is a lack of data on
the self-assessed outcome of patients
operated with PAO, and none of the
existing studies correlate the results
from SF-36 with the radiological
parameters.
Purpose / Aim of Study: The aim of this study was to investigate
the health-related QoL for patients with
hip dysplasia operated with PAO and
investigate whether QoL is associated
with the acetabular angles or hyper
mobility.
Materials and Methods: Out of 388 patients, 228 patients (mean
age of 40.5 years, mean follow-up of
7.1 years) returned the SF-36 and
Beighton questionnaires. The patients'
QoL was compared to reference data
from a Danish population. Center-Edge
(CE) and Acetabular Index (AI) angles
were measured before and after PAO
and the association with the patients'
QoL was tested with logistic regression.
Findings / Results: For both males and females the SF-36
score was significantly lower than for
the reference data for a Danish
population, especially for those
dimensions concerning physical health.
No association was found between the
patients' CE- or AI-angles before or after
PAO and their subsequent QoL.
Significant associations were found
between both Physical Component
Score (PCS) and Physical Function (PF)
and follow-up time after the operation.
The adjusted OR for a PCS≥50 was 0.87
(95% CI: 0.76-0.99) and for a PF≥85
0.81 (95% CI: 0.71-0.91). No association
between hyper mobility and PCS, PF or
Bodily Pain (BP) was found.
Conclusions: The results suggest that physical
function after PAO decreases with
longer follow-up time. Neither the
acetabular angles nor hyper mobility is
associated with the physical
components of QoL.
151. Collateral Ligament Reconstruction of the Chronic Thumb Injury with Biotenodesis Screw Fixation
Robert Gvozdenovic, Michel Boeckstyns
Department of Orthopaedic Surgery, Hand Surgery Unit, Gentofte Hospital
Background: Numbers of techniques have been
introduced for the management of
chronic insufficiency of the collateral
ligaments of the thumb. Fixation of the
tendon graft in order to establish good
stability of the reconstruction, avoiding
stiffness of the MCP-joint and loss of
the pinch strength remains a
challenge. The potential advantages of
using interference screws for fixation of
the tendon graft is its ability to stabilize
the reconstruction during the healing,
allowing a short immobilization time.
Purpose / Aim of Study: The purpose of this review was to
analyse short-term results of a
consecutive series of 18 collateral
ligament reconstructions of the thumb
using the 4 x 10 mm Bio-Tenodesis
screw for fixation the tendon graft of
Palmaris Longus.
Materials and Methods: Seven men and 11 women with
posttraumatic instability, pain and
dysfunction of the thumb were
treated.The mean follow-up period was
26 months (range 12-43 months). We
measured active flexion of the MCP-
and IP-joints, abduction of the thumb
as well as the grip and pinch strength
of the injured and contralateral
(control) hand, sick-leave, pain score
(VAS) and Quick DASH score. For
statistical analysis, t-test for paired
data has been used.
Findings / Results: The mean active range of motion in the
MCP-joint of the operated thumbs was
90% of the contralateral side. The
main active range of motion in the IP-
joint was 96% of the contralateral side.
There was no reduction of the
abduction. Neither was there any
difference in grip strength between
operated and non-operated sides.
Pinch strength (pure or tip pinch) of the
operated thumb was the same as of
the contralateral side.
Conclusions: Our procedure had short
immobilization and rehabilitation time,
minimal loss of motion of the MCP-
and IP- joints, no loss of hand and
pinch strength, permitting early return
to work.
154. Erythropoietin elicits a dose-dependent osteogenic effect on human mesenchymal stem cells
Jan Duedal Rölfing, Anette Baatrup, Maik Stiehler, Helle Lysdahl, Cody Bünger
Orthopaedic Research Laboratory, Aarhus University Hospital; Department of Orthopaedics and Centre for Translational Bone, Joint and Soft Tissue Research, University Hospital Carl Gustav Carus at Technische Universität Dresden
Background: Erythropoietin (EPO) is a pleiotropic growth
factor. Of interest for orthopaedics, EPO
increases bone formation and angiogenesis.
However, accommodating safety concerns,
physiological dosing of EPO is a perquisite
before clinical translation can be considered.
Purpose / Aim of Study: The aim of this study was to establish a
dose-response relationship and to determine
the lowest effective osteogenic dose of
continuous EPO stimulation on human
mesenchymal stromal cells (MSCs).
Materials and Methods: MSCs from two donors were cultured at
13500 cells/cm2. A wide range of EPO
concentrations (0–100 IU/ml) was
continuously applied. The primary outcome
measurement was Arsenazo mineralization
assay after 14 and 21 days. Secondary
outcome measurements were an alkaline
phosphatase (ALP) and cell viability assay
after 2 and 7 days. The positive control was
osteogenic medium and proliferation medium
served as negative control. Results were
normalized to cell number. Statistics
consisted of one-way ANOVA and post hoc
testing for linear trend and EPO
concentration against positive control with
Fisher's LSD.
Findings / Results: The observed proportional dose-response
relationship can be adequately described
with the slope of a fitted line. The effect size
corresponds to this slope, which declined
from 0.35 to 0.09 between day 14 and 21
(p<0.001). The lowest effective dose of 20
IU/ml increased mineralization to 146 ±17%
after 14 days relative to positive control
(p=0.002). EPO also increased cell viability
and ALP (p<0.01).
Conclusions: EPO increased osteogenic differentiation of
MSCs in a dose-dependent manner. In vivo,
the lowest effective dose of 20 IU/ml should
be used to prevent adverse effects. Ex vivo,
the highest dose of 100 IU/ml could
overcome the major limitation of cell-based
tissue engineering, namely vascularization
and bony ingrowth into 3D scaffolds.
155. The influence of hemostatic agents on bone healing after sternotomy in a porcine model
Rikke Falsig Vestergaard, Annemarie Brüel, Jesper Skovhus THomsen, Ellen Margrethe Hauge, Kjeld Søballe, John Michael Hasenkam
Dept. of Ortopeadic surgery , Hospitals Enheden Horsens; Department of Biomedicine – Anatomy, Aarhus University; Department of Rheumatology, Aarhus University Hospital, Nørrebrogade; Department of Orthopedic Surgery, Aarhus University Hospital, Tage-Hansens Gade; Department of Cardio-Thoracic and Vascular Surgery and Department of Clinical Medicine, Aarhus University Hospital, Skejby
Background: Sternotomy is the preferred access to
the mediastinum. During sternotomy
trabecular bone is exposed, which
often results in bleeding. Mechanical
hemostatics are used to diminish this
bleeding; however, their influence on
the sternal healing process is relatively
unexplored.
Purpose / Aim of Study: The aim of the present study was to
investigate the influence of two
hemostatics, bone wax (BW) and a
water-soluble polymer wax, Ostene
(WSW), on the mechanical properties
and histological characteristics of
healing sternal bone.
Materials and Methods: Twenty-four pigs underwent
sternotomy and were randomized into
three groups: WSW, BW, or no
hemostatic treatment (control). The
animals were sacrificed 6 weeks after
surgery and bone samples were
obtained. In all, 42 bone samples
underwent mechanical testing and 44
histological sections were evaluated
microscopically.
Findings / Results: Fracture strength in the BW group was
32% lower than in the control group
(p<0.05), and maximum stiffness was
56% lower in the BW group than in
control group (p<0.05). The
mechanical properties did not differ
between the WSW and BW groups.
The fraction of granulomatous tissue
was 379% higher in the BW group than
in the WSW group (p<0.001) and
582% higher than controls (p<0.001).
There was 117% more calcified tissue
in controls than in BW pigs (p<0.05).
Conclusions: In a porcine model, BW was found to
significantly inhibit sternal healing and
was associated with chronic
inflammation and reduced mechanical
integrity. Animals treated with WSW
demonstrated bone healing
characteristics similar to those of the
control group, and WSW is thus a
compelling alternative to BW when a
mechanical hemostatic is needed.