Session 3: Hip Arthroplasty
09:00 - 10:30
Lokale: Vingsal 3
Chair: Ann Ganestam and Thomas Jakobsen
21. Cemented and cementless dual mobility implants show similar cup fixation, low polyethylene wear, and low serum cobalt-chromium in elderly patients with hip osteoarthritis. A randomized controlled radiostereometry study of 60 patients with 6 years FU
Peter Bo Jørgensen¹ ², Steffan Tabori-Jensen³, Inger Mechlenburg³ 4, Morten Humilius¹ , Torben Bæk Hansen¹ 4, Maiken Stilling¹ ² ³ 4
¹ University Clinic for Hand, Hip and Knee Surgery, Department of Orthopaedics,
Gødstrup Hospital, Herning, Denmark.
² AutoRSA Research Group, Orthopeadic Research Unit
Aarhus University Hospital, Denmark.
³ Department of Orthopaedic Surgery
Aarhus University Hospital, Denmark.
4 Department of Clinical Medicine
Aarhus University, Denmark.
Background: Dual mobility (DM) articulation total hip
arthroplasty (THA) is used increasingly due to
Recently, concerns were raised specifically for
PE wear and metal debris of cementless DM
implants due to coating and metal debris
particles found in the instrumentation of
cementless DM implants, which may be left in
the joint during surgery and cause third body
Aim: The aim was to investigate cup fixation,
polyethylene (PE) wear, serum chromium and
cobalt, and their correlation to physical activity
in patients with DM implants at 6-year follow-
Materials and Methods: In a patient-blinded RCT, 60 patients with hip
osteoarthritis at a median age of 74 years (70–
82) were randomly allocated to cemented
(n=29) or cementless hydroxyapatite-coated
(n=30) fixation of Avantage DM THA with a
highly-crosslinked vitamin-E PE liner. Cup
migration and PE wear were measured with
radiostereometry, chromium and cobalt ions
were measured in serum, and physical activity
was measured with accelerometers.
Results: PE liner bedding-in was higher for cementless
than for cemented cups (p=0.046). The PE
wear rate from 1- to 6-year follow-up of 0.06
(CI95% 0.04–0.09) mm/year for cemented
cups was similar to 0.07 (CI95% 0.04–0.11)
mm/year for cementless cups. At 6-year
follow-up, proximal cup migration of 0.14
(CI95% 0.01–0.28) mm for cemented cups
and 0.21 (CI95% 0.02–0.39) mm for
cementless cups was similar. Serum metal ion
levels were undetectable or very low. Physical
activity was mainly low intensity and did not
correlate to PE wear rate or cup migration.
Interpretation / Conclusion: The findings support that cemented and
cementless DM implants with highly
crosslinked vitamin E infused liners have
similar performance when used for primary
THA surgery in elderly patients.
22. Polyethylene liner motion in dual mobility hip prostheses: static and dynamic radiostereometry in 16 cases 1 year after operation
Peter Bo Jørgensen¹, Bart L. Kaptein², Kjeld Søballe¹ ³, Stig S. Jakobsen³ , Maiken Stilling¹ ³
¹ AutoRSA Research Group, Orthopeadic Research Unit
Aarhus University Hospital, Aarhus, Denmark.
² Biomechanics and Imaging Group, Department of Orthopaedics, Leiden
University Medical Center, Leiden, The Netherlands
³ Department of Orthopaedic Surgery
Aarhus University Hospital, Aarhus, Denmark.
Background: Dual mobility hip arthroplasty utilizes a freely
rotating polyethylene liner to protect against
dislocation. As liner motion has not been
confirmed in vivo, we investigated the liner
kinematics in vivo using dynamic
Aim: The aims of the study were; (1) to evaluate if
liner movement occurred in DM cups 1 year
after primary operation and (2) to describe the
movement pattern and range of such
Materials and Methods: 16 patients with Anatomical Dual Mobility
acetabular components were included.
Markers were implanted in the liners using a
drill guide. Static RSA recordings and
patient reported outcome measures were
obtained at post-op and 1-year follow-up.
Dynamic RSA recordings were obtained at 1-
year follow-up during a passive hip
movement: abduction/external rotation,
adduction/internal rotation (modified FABER-
FADIR), to end-range and at 45° hip flexion.
Liner- and neck movements were described
as anteversion, inclination and rotation.
Results: Liner movement during modified FABER-
FADIR was detected in 12 of 16 patients.
Median (range) absolute liner movements
were: anteversion 10° (5–20), inclination 6°
(2–12), and rotation 11° (5–48) relative to the
cup. Median absolute changes in the
resulting liner/neck angle (small articulation)
was 28° (12–46) and liner/cup angle (larger
articulation) was 6° (4–21). Static RSA
showed changes in median (range) liner
anteversion from 7° (-12–23) postoperatively
to 10° (-3–16) at 1-year follow-up and
inclination from 42 (35–66) postoperatively to
59 (46–80) at 1-year follow-up. Liner/neck
contact was associated with high initial liner
Interpretation / Conclusion: The polyethylene liner moves over time. One
year after surgery the liner can move with or
without liner/neck contact. The majority of
movement is in the smaller articulation
between head and liner.
23. Time trends in use of Non-Steroidal Anti-Inflammatory Drugs and opioids one year after total hip arthroplasty due to osteoarthritis during 1996-2018: A population-based cohort study of 103,209 patients
André Nis Klenø, Henrik Toft Sørensen, Alma Becic Pedersen
Department of Clinical Epidemiology, Department of Clinical Medicine, Aarhus
University and Aarhus University Hospital, Aarhus, Denmark.
Background: Non-steroidal anti-inflammatory drugs (NSAIDs)
and opioids are commonly used to treat acute
pain after total hip arthroplasty (THA). Towards
combating the global opioid epidemic, changes
in opioid recommendations in general has
occurred. However, it is unclear how these
changes have affected analgesic prescription
pattern in relation to THA.
Aim: To examine time trends in the use of NSAIDs
and opioids for patients with osteoarthritis
undergoing total hip arthroplasty (THA) over a
Materials and Methods: Using Danish population-based medical
databases, we identified 103,209 THA patients.
Proportions of NSAID and opioid use among
preoperative users and non-users were
calculated in four quarters (Q1-Q4) after THA by
calendar periods (1996-2000, 2001-2006, 2007-
2012 and 2013-2018). Prevalence rate ratios
(PRR) were adjusted for age and gender.
Results: Among preoperative NSAID users and non-users,
NSAID use in Q1 increased from 32.6% in 1996-
2000 to 48.0% in 2013-2018 (PRR=1.49, 95% CI:
1.42-1.55) and from 12.9% to 32.0% (PRR=2.49,
CI: 2.32-2.67), respectively. Among preoperative
opioid users and non-users, opioid use in Q1
increased from 42.7% in 1996-2000 to 76.9% in
2013-2018 (PRR=1.81, CI: 1.73-1.89) and from
15.2% to 58.2% (PRR=3.85, CI: 3.65-4.05),
NSAID use in Q4 decreased from 24.5% in 1996-
2000 to 21.4% in 2013-2018 (PRR= 0.88, CI:
0.83-0.93) and from 6.9% to 5.6% (PRR=0.81, CI:
0.73-0.91) in preoperative NSAIDs users and
non-users, respectively. Opioid use in Q4
increased from 26.6% in 1996-2000 to 28.6%
(PRR=1.08, CI: 1.02-1.15) in 2013-2018 and from
4.1% to 5.0% (PRR=1.25, CI: 1.11-1.40) in
preoperative opioid users and non-users,
Interpretation / Conclusion: Although we observed up to a 4-fold increase in
NSAID and opioid use in Q1 after THA during
1996-2018, use of NSAIDs and opioids in Q4
did not change substantially since 1996.
However, 5-6% of the preoperative non-users of
NSAIDs and opioids were users in Q4 after
THA, which might relate to inaccurate indication
for or timing of THA and the post-surgical
phasing out of analgesics use.
24. Vitamin E-Diffused Liners Showed Less Head Penetration Compared With XLPE In Primary Total Hip Arthroplasty: 10 Years Results Of A Multi-Arm Randomized Trial
Joseph El-Sahoury, Kristian Kjærgaard, Ole Ovesen, Christian Hofbauer, Søren Overgaard, Ming Ding
Joseph A. N. El-Sahoury1, Kristian Kjærgaard1, Ole Ovesen1, Christian
Hofbauer2, Søren Overgaard*3, Ming Ding*1
1. Orthopaedic Research Laboratory, Department of Orthopaedic Surgery and
Traumatology, Odense University Hospital, Department of Clinical Research,
University of Southern Denmark, Odense, Denmark, Odense C, Denmark
2. Department of Orthopaedic Surgery, Vejle Hospital, Vejle, Denmark, Vejle,
3. Department of Orthopaedic Surgery & Traumatology, Copenhagen University
Hospital, Bispebjerg, And Department of Clinical Medicine, University of
Copenhagen, 2400, Copenhagen, NV, Denmark, Copenhagen, Denmark
*Equal senior authors
Background: Wear of the acetabular polyethylene liner in total
hip arthroplasty (THA) may lead to bone
osteolysis, aseptic loosening and subsequently
revision surgery. Wear may be reduced by using
oxidatively stabilized, vitamin E-doped, cross-
linked polyethylene (vE-PE) liners instead of
annealed or remelted cross-linked polyethylene
Aim: The primary aim was to investigate differences
in Head penetration between vE-PE and XLPE
liners and between 32- and 36-mm head size.
Secondary outcomes included cup migration
and PROMs (EQ-5D, SF-36, HHS, UCLA
Materials and Methods: This study(NCT02196792) was comprised of
4 combined intervention groups in a 2X2
setup. Moreover the study was randomized,
as patients were randomly assigned to
receive a liner material (vE-PE or XLPE) and
head size component ( 32 mm or 36 mm).
The outcome of the study includes Head
penetration and cup migration, both of these
were obtained and measured by
radiostereometric analysis (RSA). RSA was
performed postoperatively at baseline, 3, 12,
24, 60, 84 and 120 months. Patient-reported
outcome measures (UCLA Activity Score,
Harris Hip Score, and EQ-5D) were acquired
at baseline, 3, 12, 24, 36, 60, 84 and 120
months. The Outcomes were calculated by
linear mixed-effect analysis. We aimed to
include 100 patients in our study powered as
a parallel-group design.
Results: A total of 220 patients were assessed for
eligibility for this study, but 93 of the patients
were excluded. Four patients received screws,
26 patients received cups smaller than 54 mm, 5
patients received other components, 1 patient
underwent surgical complications, and 57
patients due to other reasons. 127 patients who
underwent randomization into 4 groups and 116
patients received their allocated intervention.
Ten years later, 34 patients were lost to follow-
up and 82 patients were followed-up. Baseline
data was similar between groups in. The
following results will be intention-to-treat (ITT)
Interpretation / Conclusion: There was significantly lower head penetration
in vE-PE compared to XLPE liners at 10 years,
and No difference was found between 32 and 36
mm heads. The findings is of clinical importance
and may reduce the risk of revision in the long
25. Time trends - Increasing risk of revision due to infection after total hip arthroplasty: a study on 575,502 primary THAs in the Nordic Arthroplasty Register Association’s dataset from 2004 to 2018
Håvard Dale 1,2, Anne Marie Fenstad 1, Geir Hallan 1,2, Sören Overgaard 3,4,5, Alma B Pedersen 5,6, Nils P Hailer 7,8, Johan Kärrholm 8,9, Ola Rolfson 8,9, Antti Eskelinen 10,11, Keijo T Mäkelä 11,12, Ove Furnes 1,2
1 The Norwegian Arthroplasty Register, Department of Orthopaedic Surgery,
Haukeland University Hospital, Bergen, Norway
2 Department of Clinical Medicine, University of Bergen, Bergen, Norway
3 Department of Clinical Medicine, Faculty of Health and Medical Sciences, University
of Copenhagen, Copenhagen, Denmark.
4 Department of Orthopaedic Surgery and Traumatology, Copenhagen University
Hospital, Bispebjerg, Denmark
5 The Danish Hip Arthroplasty Register, Århus, Denmark
6 Department of Clinical Epidemiology, Aarhus University Hospital and Department of
Clinical Medicine, Aarhus University, Aarhus, Denmark.
7 Section of Orthopaedics, Department of Surgical Sciences, Uppsala University
8 The Swedish Arthroplasty Register, Gothenburg, Sweden
9 Department of Orthopaedics, Institute of Clinical Sciences, The Sahlgrenska
Academy, University of Gothenburg, Sweden
10 Coxa Hospital for Joint Replacement, Tampere; Faculty of Medicine and Health
Technologies, University of Tampere, Tampere, Finland
11 The Finnish Hip Arthroplasty Register, Helsinki, Finland
12 Department of Orthopaedics and Traumatology, Turku University Hospital, and
University of Turku, Turku, Finland
Background: Previous publications have suggested that the
incidence of revisions due to infection after THA.
Aim: We explored trends of risk and timing of revision
due to infection after primary THAs in the Nordic
countries during the period 2004-2018.
Materials and Methods: Primary THAs reported to the Nordic arthroplasy
registers (NARA) from 2004 to 2018 were included.
Adjusted Cox regression survival analyses with the
first revision due to deep infection after primary THA
was performed. The risk of revision as a function of
time was investigated. In addition, we explored
changes in the time span from primary THA to
revision due to infection.
Results: Of 575,502 primary THAs that met the inclusion
criteria, 5,703 (1.0%) were revised due to deep
infection. The risk of revision due to infection
increased through the period studied. Compared
to THAs implanted in 2004-2008, the risk of
revision due to infection was 1.4 (95%CI 1.3-1.5)
for 2009-2013, and 1.8 (1.7-2.0) for 2014-2018.
We found an increased risk for all four nations.
Compared to 2004-2008, for all THAs, the
adjusted risk of revision due to infection 0-30
days postoperatively was 2.5 (1.8-2.8) for 2009-
2013 and 3.3 (2.9-3.8) for 2013-2018. The
adjusted risk of revision due to infection 31-90
days postoperatively was 1.5 (1.2-1.9) for 2009-
2013 and 2.4 (2.0-2.9) for 2013-2018, compared
to 2004-2008. Beyond 91 days postoperatively,
the risk of revision due to infection was similar to
2004-2008 for all 3 time periods.
Interpretation / Conclusion: The risk of revision due to deep infection after THA
increased 80% throughout the period 2004-2018.
This increase was mainly due to an increased risk of
early revisions. The cause for these changes may
be multifactorial (patient selection, diagnostics,
revision strategy, completeness of reporting, etc.),
and are not possible to disclose in the present study.
26. Association between duration of anticoagulant thromboprophylaxis and revision rate in primary total hip arthroplasty: A Danish and Norwegian nationwide cohort study.
Dennis Vinther¹ ², Aurelie Mailhac¹, Ina Trolle Andersen¹, Søren Overgaard³ 4, Anne Marie Fenstad5, Stein Atle Lie5 6, Jan-Erik Gjertsen5 7, Alma B Pedersen¹ ²
Department of Clinical Epidemiology, Aarhus University Hospital, Denmark¹; Department
of Clinical Medicine, Aarhus University, Aarhus, Denmark²; Department of Orthopaedic
Surgery and Traumatology, Copenhagen University Hospital, Bispebjerg, and The Danish
Hip Arthroplasty Register, Denmark³; Department of Clinical Medicine, Faculty of Health
and Medical Sciences Register, Denmark4; The Norwegian Arthroplasty Register,
Department of Orthopaedic Surgery, Haukeland University Hospital, Bergen, Norway5;
Department of Clinical Dentistry, University of Bergen, Bergen, Norway6; Department of
Clinical Medicine, University of Bergen, Bergen, Norway7.
Background: There are concerns that bleeding following primary
total hip arthroplasty (THA) contributes to prolonged
wound drainage and prosthetic joint infection (PJI)
and inferior fixation.
Aim: We examined whether short (1-5 days), medium (6-
14 days), and extended (= 14 days) duration of
thromboprophylaxis is associated with the 5 year
revision rate after THA due to osteoarthritis.
Materials and Methods: Cohort study based on data from hip arthroplasty
and administrative registries in Denmark and
Norway (2008-2013). The outcome was revision
surgery; due to PJI, aseptic loosening, any cause
and death. Adjusted cause-specific hazard ratios
(HRs) were analyzed with Cox regression analyses.
Results: Among 50,482 THA patients, 8,333 received short,
17,009 received medium, and 25,140 received
extended thromboprophylaxis. The HRs for any
revision were 1.0 (95% CI 0.9-1.2) and 1.0 (0.9-1.1)
for short and extended vs medium
thromboprophylaxis. The HRs for revision due to PJI
were 0.9 (0.7-1.2) and 1.04 (0.9-1.3) for short and
extended vs. medium thromboprophylaxis. The HRs
for revision due to aseptic loosening were 1.1 (0.8-
1.5) and 1.3 (1.0-1.6) for short and extended vs.
medium thromboprophylaxis. The absolute
differences in cumulative incidences at 5 years were
Interpretation / Conclusion: Our data suggest no association between duration
of anticoagulant thromboprophylaxis and revision
rate within 5 years of THA. There is an indication
that the extended thromboprophylaxis might be
associated with increased revision rate due to
aseptic loosening, but the mechanism of this
association is not entirely clear and is a topic that
requires further research.
27. Risk of total hip arthroplasty revision depending on different acetabular component fixation in patients 65 years of age and older operated with total hip arthroplasty due to primary hip osteoarthritis. A study of 203,301 primary total hip arthroplasties from the Nordic Arthroplasty Register Association (NARA).
Roshan Latifi¹, Maziar Mohaddes², Nils Hailer³, Anne Marie Fenstad4 5, Geir Hallan4, Antti Eskelinen6, Keijo Mäkelä7, Claus Varnum8, Søren Overgaard?
1. Department of Orthopedic Surgery, Aalborg University Hospital.
2. Department of Orthopedics, Institute of Clinical Science, Sahlgrenska
Academy, University of Gothenburg, Gothenburg; The Swedish
Arthroplasty Register, Gothenburg, Sweden; Department of
Orthopedics, Sahlgrenska University Hospital, Region Västra Götaland,
3. Department of Surgical Sciences-Orthopedics, Uppsala University,
4. The Norwegian Arthroplasty Register; Department of Orthopedic
Surgery, Haukeland University Hospital, Bergen, Norway.
5. Department of Clinical Medicine, University of Bergen, Norway.
6. Coxa Hospital for Joint Replacement, and Faculty of Medicine and
Health Technologies, University of Tampere, Tampere, Finland.
7. Turku University Hospital and University of Turku, Finland, and the
Finnish Arthroplasty Register.
8. Department of Orthopedic Surgery, Lillebaelt Hospital - Vejle,
University Hospital of Southern Denmark, Denmark; Department of
Regional Health Research, Faculty of Health Science, University of
Southern Denmark; The Danish Hip Arthroplasty Register.
9. Department of Orthopaedic Surgery and Traumatology, Copenhagen
University Hospital, Bispebjerg, Denmark; University of Copenhagen,
Department of Clinical Medicine, Faculty of Health and Medical
Sciences, Denmark; The Danish Hip Arthroplasty Register
Background: Use of uncemented fixation of total hip
arthroplasty (THA) components are
increasing worldwide. Cemented femoral
component fixation in THA has shown
better results in older patients, but less is
known about the result when focusing on
Aim: To compare the risk of THA revision due to
any reason in patients with cemented or
uncemented acetabular cups.
Materials and Methods: We used data from the NARA database;
and included in total 174,536 patients
divided into 107,320 cemented and
95,981 uncemented cups operated
between 1995-2018. Only patients with
primary osteoarthritis and 65 years of
age or older were included. Metal-on-
metal and ceramic-on-ceramic bearings
were excluded. We used Cox regression
analyses adjusted for period of primary
surgery, type of stem fixation, femoral
head size and type of bearing to
estimate the hazard ratio (HR) of THA
revision due to any reason. Data was
stratified for sex and age groups of 65-
69,70-74,75-79 and 80+ years and is
presented with hazard ratios (HR) and
95% confidence intervals (CI).
Results: Totally 10,427(5.1%) THAs were revised
distributed in 4.5% of THAs with
uncemented cups and 5.7% with cemented
cups. Aseptic loosening was the most
frequent cause of revision for cemented
cups (45%) and dislocation was for
uncemented cups (29%). The risks of
revision for women between 65-69, 70-74,
75-79 and 80+ were HR=0.9 (0.7-1.0),
HR=0.8 (0.7-1.0), HR=1.2 (1.0-1.3) and
HR=1.3 (1.1-1.5) respectively. Risk of
revision for male group in corresponding
age groups were HR=0.9 (0.7-1.0), HR=0.8
(0.7-1.0), HR=0.9 (0.8-1.1) and HR=1.0
Interpretation / Conclusion: There is a slightly increased risk of THA
revision for any reason when uncemented
cups are used in women over the age of 75
years. Uncemented cups in elderly women
should be used with care.
28. Occurrence of pseudotumors, metal ion levels and patient reported outcome in patients treated with resurfacing and stemmed metal-on-metal total hip arthroplasty compared to metal-on-polyethylene total hip arthroplasty a long-term follow-up study
Rasmus Tyrsted Mikkelsen¹ ² ³, Claus Varnum¹ ², Trine Torfing4, Ole Graumann4 5 , Henrik Schrøder6, Søren Overgaard³ 5 7 8
Department of Orthopedic Surgery, Lillebaelt Hospital - Vejle¹; Department of
Regional Health Research, Faculty of Health Science, University of Southern
Denmark²; Department of Orthopedic Surgery and Traumatology, Odense
University Hospital, Odense³; Department of Radiology, Odense University
Hospital, Odense4; Department of Clinical Research, University of Southern
Denmark5; Department of Orthopedic Surgery, Naestved Hospital6; Department of
Orthopaedic Surgery and Traumatology, Copenhagen University Hospital,
Bispebjerg7; University of Copenhagen, Department of Clinical Medicine, Faculty
of Health and Medical Sciences8
Background: Metal-on-metal (MoM) total hip arthroplasty
(THA) and hip resurfacing arthroplasty (HRA)
may cause adverse reaction to metal debris
such as pseudotumors (PT), but PTs can also
form around metal-on-polyethylene (MoP) THA.
Little is known about the long-term natural
history of PT in different types of hip arthroplasty
which is important for postoperative follow-up.
Aim: We aimed to investigate how occurrence of PT,
metal ion blood levels and patient reported
outcome changed over time in HRA, MoM and
MoP THA at 4 and 13 years after primary
Materials and Methods: We conducted a prospective cohort study based
on a cohort consisting of 127 HRA, 38 MoM
THA and 62 MoP THA who underwent primary
surgery between 2005-2010. We included 58
HRA, 16 MoM and 24 MoP THA who twice
underwent magnetic resonance imaging (MRI)
and had their blood levels of cobalt and
chromium and patient reported outcome
measure (PROM) scores evaluated at a median
of 4 and 13 years after surgery.
Results: There were no differences in PT prevalence
between the types of hip arthroplasty at first
(p=0.348) or second (p=0.272) MRI. Most
PTs were Hauptfleisch type I (11) followed by
type III (4) and type II (3) at second
examination. 14 out of 26 PTs could not be
diagnosed at the latest follow-up. Six new
PTs were diagnosed between first and
second MRI, 4 of these in MoP THA and 2 in
HRA. Median PT volume were 48 cm3
(range 2-126) in HRA, 28 cm3 (range 24-32)
in MoM THA and 16 cm3 (range 2-60) in
MoP THA (p=0.554) at second examination.
HRA had the highest median levels of cobalt
and chromium (1.8 ug/L, range 0.24-83 and
1.6 ug/L, range 0.21-47), followed by MoM
(1.3 ug/L, range 0.59-3.8 and 1.1 ug/L, range
0.52-2.8) and MoP THA (0.29 ug/L, range
0.12-5.8 and 0.52 ug/L, range 0.21-1.7)
(p<0.001 and p<0.001) at second
examination. We found no differences in the
Interpretation / Conclusion: PTs were just as common in HRA and MoM THA
as in MoP THA. More new PTs were diagnosed
in MoP THA. Blood levels of cobalt and
chromium was higher in HRA and MoM THA
compared to MoP THA, but type of hip
arthroplasty and PT had no influence on
PROMs. In perspective, we showed a clear
change in PT incidence which is important to
know when following these patients.
29. The presence of bacteria and their resistance pattern following revision of total hip or knee arthroplasty
Rasmus Linnebjerg Knudsen² ¹ , Søren Overgaard² ³, Marc Stegger4, Henrik Calum5, Krassimir Kostadinov²
1. University of Copenhagen, Faculty of Health and Medical Sciences.
2. Copenhagen University Hospital, Bispebjerg, Department of Orthopedic
Surgery and Traumatology.
3. University of Copenhagen, Faculty of Health and Medical Sciences,
Department of Clinical Medicine
4.Department of Bacteria, Parasites and Fungi, Statens Serum Institut,
5. Copenhagen University Hospital, Hvidovre, Department of Clinical Microbiology
Background: ostoperative joint infections are a major complication that occur in
1-2% of all total hip arthroplasty and total knee arthroplasty (THA
and TKA) leading to increased morbidity and mortality. The
knowledge of these infective organisms and their resistance
patterns is of great importance for the treatment of the patient and
for future prophylactic strategy.
Aim: The main purpose of this study is to investigate the presence
of bacteria cultured from revision surgery after THA and TKA.
Additionally, we will investigate the phenotypic resistance
patterns and describe multidrug-resistance of the different
Materials and Methods: The study is a retrospective review of the patient reports on all
revisions of THA and TKA undertaken at Bispebjerg Hospital,
Copenhagen, in 2018 and 2019. We noted the organism(s) in
cultured biopsies in all cases and their antibiotic resistance
patterns. We also investigated the difference in cultures between
first-time and all later revisions.
Results: A total of 170 revisions were performed. Here 88 cases had positive
culture from biopsies, of which 11% had polymicrobial findings.
Staphylococcus aureus was identified in 31% of the cases with 79% of
these resistant to Penicillin G. Staphylococcus epidermidis was identified
in 11% of cases with high levels of resistance towards Dicloxacillin (75%),
Cefuroxime (75%), and Gentamicin (73%). The percentages of S.
epidermidis in the study increased from 5% at first-time revision to 16%
at later revisions. Only four cases with positive cultures of
Corynebacterium striatum (n=1), Enterococcus faecium (n=2) and
Enterococcus casseliflavus (n=1) showed resistance to Vancomycin.
Interpretation / Conclusion: In conclusion, we showed that S. aureus and S. epidermidis were the most
frequent species cultured from revision THA and TKA. However,
importantly the proportion of S. epidermidis increasing when comparing
first-time revision with second time and more. Also, the resistance patterns
of S. epidermidis showed resistance to several antibiotics, including drugs
used in common practice prophylaxis.
30. KKR: The use of dual mobility bearings in primary total hip arthroplasty
Morten Bøgehøj, Martin Lamm , Thomas Jakobsen
Danish Society for Hip and Knee Arthroplasty
Background: Operation with a total hip arthroplasty (THA) is a well-documented treatment, with a high probability for a good outcome and low risk of serious complications. Dislocation is one of the most frequent complications. Several conditions increase the risk of dislocation of a THA, femoral neck fracture, high age, lumbar fusion and neuromuscular disease. To reduce the risk of dislocation in these high-risk patients the dual mobility cups are often used as an anti-dislocation cup.
Studies have reported the use of dual mobility designs as a standard component for patients the gets treated with a THA, in these cases the dislocation rate is reported to be low.
A dual mobility cup is designed with two articulations and hence a big surface that is subject to wear. Furthermore, there have been described release of metal debris when the cup is inserted.
Aim: The aim of this short clinical guideline was to answer to PICO-question:” Does patients above the age of 70 years of age, with osteoarthrosis and indication for a THA have better effect when operated with a dualmobility cup than patients operated with a unipolar cup, regarding dislocation, reoperation and function?”
Materials and Methods: A systematic literature search based upon the PICO-question was conducted in Pubmed and Embase. 1283 records were screened. 22 full-text articles were assessed for eligibility. Three systematic reviews and four registry studies were included. Quality assessment of included studies was conducted using AMSTAR for systematic reviews and ROBINS-I for registry studies.
Results: In the literature the comparison of unipolar and dualmobility cup are with different sizes of unipolar heads from 22.2 to 36 mm, many studies compare with 22.2- and 28-mm heads. From the Danish hip registry, we know that the most common head sizes today is 36- and 32-mm and very few 28 mm.
On reoperation after 1 and 5 years we find the same risk of revision, but for different reasons.
Interpretation / Conclusion: Dual mobility cups are only to be used after thorough evaluation of the individual patient case, as the benefit for the standard patient with osteoarthrosis is uncertain compared with the unipolar cup.
The use of dual mobility cups can be relevant in patients with osteoarthrosis with low level of function and high risk of dislocation (risk of falling, neuromuscular disease or reduced spinopelvin mobility due to lumbar fusion).