Session 12: Knee II
Fredag d. 26. oktober
09:00-10:30
Lokale: Reykjavik
Chairmen: Anders Troelsen og Svend Erik Østgaard
86. Postoperative phone calls (Coaching to Self-Care model) after total knee arthroplasty surgery do not alter patient-reported outcome measures
Robin Bawer, Anne Mørup-Petersen, Anne-Katrine Mathiassen, Britta Hørdam, Anders Odgaard
Department of Orthopaedics, Copenhagen University Hospital Herlev-Gentofte; Department of Orthopaedics, Copenhagen University Hospital Herlev-Gentofte; Department of Orthopaedics, Copenhagen University Hospital Herlev-Gentofte; Department of Orthopaedics, Copenhagen University Hospital Herlev-Gentofte; Department of Orthopaedics, Copenhagen University Hospital Herlev-Gentofte
Background: Follow-up regimes after total knee
arthroplasty (TKA) are in constant change.
Coaching to Self-Care (CtSC) is a
telephonic follow-up model for counselling
patients, and it has shown beneficial effects
on patient-reported outcome measures
(PROMs) during rehabilitation after total hip
arthroplasty. We hypothesized that similar
effects could be seen after TKA. Such
effects could herald a change from clinical
follow-up to CtSC.
Purpose / Aim of Study: To evaluate the effect of CtSC on knee-
specific and generic PROMs in TKA patients
by comparing with a control group.
Materials and Methods: CtSC is based on questions regarding
general and knee-specific well-being, and
individualized counseling for patients.
Patients operated on Mondays and
Tuesdays in the period from 25/10/16 to
31/1/17 received telephone calls by a nurse
1, 3 and 7 weeks after TKA and thus
followed using the CtSC principles
(intervention group, n = 98). Patients
operated on Wednesdays and Thursdays
during the same period did not receive any
calls (control group, n = 77). Both groups
were evaluated at baseline, at 6 weeks and
3, 6 and 12 months postoperatively with
patient-reported parameters: Oxford Knee
Score (OKS, 0-48), patient satisfaction,
range of motion, consumption of analgetics
and EQ-5D-5L.
Findings / Results: PROMs were available for 62 and 77
patients in the intervention and control
group, respectively. Mean OKS values at
baseline were 23.2 (SD 5.9) and 22.7 (SD
6.7), P = 0.62. At 6 weeks, the OKS values
were 27.5 (SD 6.4) and 26.2 (SD 7.0), P =
0.40. On all aforementioned parameters we
found no significant difference between the
groups during the 1-year follow-up period.
Conclusions: Based on this study CtSC has no effect on
knee specific and generic PROMs after
TKA. Further studies may determine if there
are subgroups of patients who could benefit
from the intervention.
87. Can regional differences in revision rates after knee arthroplasty surgery be explained by differences in symptom states prior to primary surgery? Preoperative results from the "SPARK" study.
Anne Mørup-Petersen, Mogens Berg Laursen, Frank Madsen, Michael Rindom Krogsgaard, Anders Odgaard
Department of Orthopaedic Surgery, Copenhagen University Hospital, Herlev-Gentofte; Department of Orthopaedic Surgery, Aalborg University Hospital Farsø; Department of Orthopaedic Surgery, Århus University Hospital; Department of Orthopaedic Surgery, Copenhagen University Hospital Bispebjerg; Department of Orthopaedic Surgery, Copenhagen University Hospital, Herlev-Gentofte
Background: The risk of revision after knee arthroplasty
(KA) varies greatly between Danish regions.
We are not sure what this means to
patients. Though revision is an important
outcome, surgical quality might also be
evaluated by viewing data on all KA patients
instead of only those undergoing
subsequent revision. The prospective
observational “SPARK” study was
performed to compare KA patients across
regions using uniform PROM sets pre- and
postoperatively.
Purpose / Aim of Study: This part of the study aims to describe
whether patients awaiting primary KA differ
between large hospitals in each of three
regions that are traditionally known to differ
in revision rates (1.0 to 5.0% per 2 y., 2015).
Materials and Methods: From 1 Sept 2016 and 14-16 months ahead
all patients scheduled for medial
unicompartmental (mUKA) or total knee
arthroplasty (TKA) in three hospitals were
invited to answer a set of PROMs, either
electronically or on paper. Knee specific
PROMs such as Oxford Knee Score (OKS
0-48) and Copenhagen Knee ROM Scale
were obtained along with generic and
qualitative questions.
Findings / Results: Preoperative PROMs were completed by
1329 patients (Farsø 207, Århus 304 and
Gentofte 818 patients). OKS was higher,
indicating less severe symptoms, prior to
mUKA compared to TKA (24.3 vs. 22.9,
P=0.0016). No difference in OKS was found
between patients scheduled for the same
procedure in different regions. The same
pattern applies for patient-reported range of
motion (P < 0.001).
Conclusions: Based on PROMs from three hospitals, we
find no reason to believe that patients differ
in symptom states prior to primary KA
between Danish regions. However, works
continue to explore demographic, lifestyle
and qualitative data, and a comparison of
radiographic signs of knee osteoarthritis
may uncover whether perception of
symptoms varies between regions.
88. Discriminating between mild and severe radiographic knee osteoarthritis using a performance test and gait summary measures – A cross-sectional study
Josefine Eriksson Naili, Eva Weidenhielm Broström, Ewa M. Roos, Brian Clausen, Anders Holsgaard-Larsen
Department of Women's and Children's Health, Karolinska Institutet, Stockholm, Sweden; Department of Women's and Children's Health, Karolinska Institutet, Stockholm, Sweden; Research Unit for Musculoskeletal Function and Physiotherapy, Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark; Research Unit for Musculoskeletal Function and Physiotherapy, Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark; Orthopaedic Research Unit, Department of Clinical Research, University of Southern Denmark, Odense, Denmark
Background: Little is known about which tests of knee function
that may discriminate between mild and severe knee
osteoarthritis (OA).
Purpose / Aim of Study: This cross-sectional study evaluated whether a
physical performance-based test and summary
measures of overall gait function by 3D gait analysis
could discriminate between patients with mild and
severe radiographic OA in a case-mix of individuals
with knee OA.
Materials and Methods: The study sample (n=115) consisted of 60%
women, with a mean age of 61 years (SD 8) and
mean BMI of 27 (SD 5). All participants
performed the maximal 30-second Single Limb
Mini Squat test (SLMS), and underwent 3D gait
analysis. Radiographic severity was classified
using Kellgren and Lawrence (KL) classification
ranging between grades 0-4. The Gait Deviation
Index (the pathologic deviation from a healthy
reference group) for kinematics (GDI) and
kinetics (GDI-kinetic) were subsequently
calculated and used to summarize ‘gait quality’
into a single score. Area under receiver
operating characteristic curves (AUC) and 95%
confidence intervals (CI) were used to evaluate
whether SLMS and GDI-scores could
discriminate between patients with mild (KL
grade 1 and 2) and severe (KL grade 3 and 4)
knee OA.
Findings / Results: Performance on the SLMS test displayed a good
ability to classify individuals into either mild or
severe knee OA (AUC 0.83, CI 0.76 – 0.91). The
ability of GDI to discriminate OA severity was
moderate (AUC 0.62, CI 0.52 – 0.73), and GDI-
kinetics poor (AUC 0.36, CI 0.26 – 0.47).
Conclusions: The SLMS test is able to discriminate between
patients with mild and severe radiographic knee OA,
and is a useful physical performance-based test
easily used in clinical practice. Gait summary
measures are not able to discriminate radiographic
severity in the present case-mix of individuals with
knee OA.
89. Is the postoperative Forgotten Joint Score associated with the preoperative score in patients undergoing total knee arthroplasty?
Sofie Ryaa, Lina H. Ingelsrud, Håkon Sandholdt, Kirill Gromov, Henrik Husted, Anders Troelsen
Department of Orthopaedic surgery, Copenhagen University Hospital Hvidovre; Department of Orthopaedic surgery, Copenhagen University Hospital Hvidovre; Department of Orthopaedic surgery, Copenhagen University Hospital Hvidovre; Department of Orthopaedic surgery, Copenhagen University Hospital Hvidovre; Department of Orthopaedic surgery, Copenhagen University Hospital Hvidovre; Department of Orthopaedic surgery, Copenhagen University Hospital Hvidovre
Background: It is not clear whether the preoperative level
of knee awareness as measured with the
Forgotten Joint Score (FJS) impacts on the
likelihood of gaining low knee awareness
after total knee arthroplasty (TKA).
Purpose / Aim of Study: To evaluate the association between
preoperative FJS and the postoperative FJS
at one-year follow-up in patients receiving
primary TKA.
Materials and Methods: All patients undergoing primary TKA
registered in a local TKA registry from
01.01.2015 to 01.03.2017 were included.
Age, gender and Body Mass Index (BMI)
were recorded preoperatively. The FJS pre-
and one year postoperatively was used for
analysis (0-100, worst-best). Oxford Knee
Score (OKS) was used to describe the
patients’ pain- and functional level (0-48,
worst-best). Multiple linear regression
analysis was used to study the association
between post- (dependent variable) and
preoperative FJS as well as the possible
confounding effect of age, gender and BMI
(independent variables).
Findings / Results: Out of 735 eligible patients, 574 (78%)
patients responded to the FJS and OKS at
one year follow-up. Responders had a
median (25;75 quantile) age of 68.8
(61.5;74.1) years and 60.1% were female.
Median (25;75 quantile) preoperative FJS
and OKS were 12.5 (5.0;25.0) and 22.0
(17.0;27.0), respectively. Multiple regression
analysis showed significant association
between pre- and postoperative FJS, with
an estimate of 0.4 (p<0.001) and adjusted
R2 of 0.097, when adjusting for age, gender
and BMI.
Conclusions: The study found a clinical small, but
significant association between preoperative
FJS and one year postoperative FJS,
suggesting that patients with low levels of
knee awareness preoperatively are more
likely to be less aware of their knee joint one
year after TKA. Ensuring the predictive
ability of the preoperative FJS requires
external validation in another cohort.
90. Take good care of your menisci; once build, they don’t renew
Christoffer Våben, Katja Heinemeier, Peter Schjerling, Michael Mørk Petersen, Michael Kjær, Michael Krogsgaard
Section for Sports Traumatology M51, Department of Orthopaedic Surgery M, Bispebjerg-Frederiksberg Hospital; Institute of Sports Medicine, Department of Orthopaedic Surgery M,, Bispebjerg Hospital, Center for Healthy Aging, Faculty of Health and Medical Sciences, University of Copenhagen; Institute of Sports Medicine, Department of Orthopaedic Surgery M,, Bispebjerg Hospital, Center for Healthy Aging, Faculty of Health and Medical Sciences, University of Copenhagen; Musculoskeletal Tumor Section, Department of Orthopaedic Surgery, Rigshospitalet, Faculty of Health and Medical Sciences, University of Copenhagen; Institute of Sports Medicine, Department of Orthopaedic Surgery M,, Bispebjerg Hospital, Center for Healthy Aging, Faculty of Health and Medical Sciences, University of Copenhagen; Section for Sports Traumatology M51, Department of Orthopaedic Surgery M, Bispebjerg-Frederiksberg Hospital
Background: The meniscus is essential for weight distribution in
the knee joint and preservation of joint cartilage. The
architectural structure of meniscal collagen is the
basis for its weight absorbing properties. Injury and
degeneration of menisci are the most common
symptomatic conditions of the knee, and their
treatment has been subject to debate during the
recent years. The content of water and
glycosaminoglycans (GAG) in menisci adapts
through life, but can collagen renew to reduce
meniscal degeneration and support repair after
meniscal injury?
Purpose / Aim of Study: This study explores the collagen turnover in both
healthy and osteoarthritis (OA) menisci by the “14C
bomb-pulse method”. Secondarily, water-, GAG-,
and collagen content was measured.
Materials and Methods: Menisci from 18 patients with osteoarthritis (OA) and
7 patients with normal knees born before, during
and after the bomb-pulse peak, went through a
collagen purification process and were analyzed for
14C-content. Furthermore, the water-, GAG-, and
collagen content was analyzed in raw menisci.
Findings / Results: We demonstrated a very low turnover of the
collagen in menisci after they had matured during
teen-age in knees with osteoarthritis as well as in
and healthy knees. There was no difference
between medial and lateral meniscus or between
the central and the capsular part of the menisci.
There was no difference in water content between
menisci from healthy and OA knees, but a higher
GAG content in OA menisci and an insignificant
trend of lower collagen content in OA menisci.
Conclusions: We conclude that human menisci have practically no
potential to repair or renew the natural collagen
meshwork once the menisci have matured at teen-
age. Prevention of degeneration and injury is
therefore essential in research on how to reduce the
burden of meniscal disease.
91. Increased TTTG measured on axial MRI is not due to lateralization of the tibial tubercle but medialization of the trochlear groove. A cross sectional study of dysplastic and non-dysplastic knees.
Mathias Paiva, Lars Blønd, Kristoffer Weisskirchner Barfod
Sports Orthopedic Research Center Copenhagen (SORC-C), Department of Orthopedic Surgery, Copenhagen University Hospital Hvidovre.; Department of Orthopedic Surgery, Zealand University Hospital, Køge and Aleris-Hamlet Parken; Sports Orthopedic Research Center Copenhagen (SORC-C), Department of Orthopedic Surgery, Copenhagen University Hospital Hvidovre.
Background: .
Purpose / Aim of Study: To investigate if increased Tibial
tubercle – Trochlear Groove distance
(TT-TG) measured on axial MRI is due to
lateralization of the tibial tubercle or
medialization of the trochlear groove.
Materials and Methods: The study was performed as a cross
sectional study of 67 knees (29 normal,
26 with trochlear dysplasia (TD) and 12
with patellar dislocation without TD).
MRI data was gathered from October 2010
to December 2017 at Køge Hospital and
Parken Private hospital. The medial
border of the posterior cruciate
ligament (PCL) was chosen as the central
anatomical landmark. The distance from
the tibial tubercle (TT) to PCL (TT-PCL)
was measured to examine the
lateralization of the tibial tubercle.
The distance from the trochlear groove
to PCL (TG-PCL) was measured to examine
the medialization of the trochlear
groove. Between group differences was
investigated by use of one-way ANOVA.
Findings / Results: The mean (SD) values for TT-TG were 8.5
mm (3.6) in the normal group, 11.4 mm
(6.2) in the group with patellar
dislocation without TD and 17.1 mm (4.8)
in the TD group (p<0.01). The mean (SD)
values for TT-PCL were 19.5 mm (4.2) in
the normal group, 17.0 mm (5.0) in the
group with patellar dislocation without
TD and 20.2 mm (5.0) in the TD group (p=
0.10). The mean (SD) values for TG-PCL
were 10.5 mm (3.7) in the normal group,
5.8 mm (4.9) in the patellar dislocation
group without TD and 3.9 mm (3.9) in the
dysplastic group (p<0.01).
Conclusions: TD knees had increased TT-TG compared to
normal knees and knees with patellar
dislocation without TD. The TT-PCL
distance did not differ significantly
between groups, whereas the TG-PCL
distance declined with increased TT-TG.
The present results indicate that
increased TT-TG is due to medialization
of the trochlear groove and not
lateralization of the tibial tubercle.
92. RELIABILITY OF STRESS RADIOGRAPHY IN QUANTIFICATION OF CORONAL LAXITY FOLLOWING TOTAL KNEE ARTHROPLASTY.
Andreas Kappel, Nielsen Poul Torben, Odgaard Anders, Laursen Mogens
Aalborg/Farsø, Aalborg University Hospital; Aalborg/Farsø, Aalborg University Hospital; Gentofte, Copenhagen University; Aalborg/Farsø, Aalborg University Hospital
Background: Instability is one of the main causes for
early failure following total knee
arthroplasty (TKA), and the frequency
of revisions due to instability is rising in
both national and international
registries. The reliability of clinical soft
tissue laxity examination is proven
unsatisfactory and may be biased by
patient complaints. Soft tissue laxity
can be quantified with stress
radiography, where the degree of
stability between the components is
measured as an angulation.
Purpose / Aim of Study: To examine the reliability of coronal
stress radiography following TKA.
Materials and Methods: 17 cases with uncomplicated TKA
were examined with coronal stress
radiograph under both varus- and
valgus-stress. In extension, the Telos
device was applied. In flexion, the
epicondylar view with a horizontal
stress was used. All procedures were
repeated (test/re-test).
Findings / Results: Mean laxity and SD were comparable
to values published earlier. Pearson
correlation coefficient, mean and SD
for the differences in angulation
between the repeated radiographs
were as follows. Extension and valgus
stress, cc=.97, mean .140, SD .620.
Extension and varus stress, cc=.97,
mean .180, SD .530. Flexion and
valgus stress, cc=.95, mean .20,
SD .820. Flexion and varus stress,
cc=.77, mean .340, SD 2.90. In flexion
and varus stress the angulations
measured was larger and both rotation
and translation between the
components became evident on the
stress radiographs.
Conclusions: Coronal stress radiography is a reliable
method to judge soft tissue laxity
following TKA. The method is clinically
applicable and may be a useful tool in
both postoperative evaluation and in
research.
93. Debridement and exchange of tibial insert of the infected knee arthroplasty
Morten Torrild Schmiegelow, Frederik Taylor Pitter, Jens Bagger, Anders Odgaard, Martin Lindberg-Larsen
Department of Orthopedic surgery, Copenhagen University Hospital Bispebjerg; Department of Orthopedic surgery, Copenhagen University Hospital Rigshospitalet; Department of Orthopedic surgery, Copenhagen University Hospital Bispebjerg; Department of Orthopedic surgery, Copenhagen University Hospital Gentofte; Department of Orthopedic surgery, Odense University Hospital
Background: Surgical treatment of periprosthetic knee
infection is debridement with exchange of
the tibial insert or a one- or two-stage
exchange arthroplasty procedure. Implant
salvage using the less comprehensive
debridement procedure is appealing, but
high failure rates have been reported.
Purpose / Aim of Study: To study the re-revision rate due to
infection after first-time debridements and
debridements of previously revised knee
arthroplasties (KA). And, to investigate the
association between time-course from
previous KA to the debridement and risk
of re-revision due to infection.
Materials and Methods: Data on all debridements performed under
the indication periprosthetic knee infection
and later re-revisions due to infection from
2007-2017 were collected from The
Danish Knee Arthroplasty Register.
Findings / Results: A total of 416 debridements; 297 first-
time revisions and 119 revisions of
previously revised KAs were registered.
The re-revision rate after first-time
debridements was 31% (95% CI
23.2-38.8). 48.8% of these were
performed within 0-30 days, 19.5%
within 31-90 days, 7.7% within 91-365
days and 23.9% >365 days after the
previous primary KA and re-revision
rates were 34.5%, 31.0%, 30.4% and
23.9% respectively (p=0.5). The re-
revision rate of partial revisions of
previously revised knee arthroplasties
was 51.3% (95% CI 42.5-60.1). 42% of
these were performed within 0-30
days, 10.9% within 31-90 days, 19.3%
within 91-365 days and 27.7% >365
days after the previous KA and re-
revision rates were 44.0%, 53.8%,
73.9% and 45.5% respectively (p=0.1).
Conclusions: We found a re-revison rate of 31% after
the first-time debridements and 51% after
debridement of previously revised KA.
Surprisingly more than half of the
debridements were performed >30 days
after previous KA and we found no
association between time from previous
KA and risk of re-revision.
94. Safe Performance of Vitamin E-Infused Polyethylene in TKA at Three Year Follow-up Evaluated in a Prospective, Multicenter Study
Christian Nielsen, James W. Connelly, Vincent P. Galea,, Mina A. Botros, James I. Huddleston , Henrik Malchau, Anders Troelsen
Department of Orthopedics , Copenhagen University Hospital, Hvidovre, Denmark ; The Harris Orthopaedic Laboratory, Orthopaedic Department,, Massachusetts General Hospital, Boston, USA; The Harris Orthopaedic Laboratory, Orthopaedic Department,, Massachusetts General Hospital, Boston, USA; The Harris Orthopaedic Laboratory, Orthopaedic Department,, Massachusetts General Hospital, Boston, USA; Department of Orthopaedic Surgery, Stanford University Medical Center, Stanford, California, USA; Department of Orthopaedics, Sahlgrenska University Hospital, Gothenburg, Sweden; Department of Orthopaedic surgery, , Copenhagen University Hospital Hvidovre, Copenhagen, Denmark
Background: Vitamin E-infused polyethylene has shown low wear
for THA but literature confirming the safety and
efficacy of vitamin E-infused polyethylene in Total
Knee Arthroplasty (TKA) in a clinical setting is
extremely limited
Purpose / Aim of Study: The aim of this prospective multicenter study was to
investigate the safety and efficacy of vitamin E-
infused polyethylene in TKA after 3 years as
assessed by 1) rate of revision (2) risk of developing
osteolytic lesions 3) functionality (PROMs)
Materials and Methods: A total of 391 TKA patients from 8 centers in 4
continents (Europa, North America, Asia and
Australia) received were included in the study and
operated fra 2011 to 2014. All TKA devices in the
study were cemented and utilized vitamin E liners.
The present analysis reports on patient
demographic data, as well as radiographic
assessment and PROMs collected at the 3-year
interval (2.5 - 4.5 years).
Findings / Results: Three patients were revised, 2 due to acute sepsis
and 1 due to aseptic loosening 1,5 y
postoperatively, with a cumulative survival rate of
99.2%. Of those eligible for follow-up, 299 (80.8%)
reported 3-year PROMs and 302 (81.6%) received
3-year postoperative radiographs. Radiographic
analysis showed that 264 (87.4%) patients had no
signs of radiolucent lines. There were no cases of
osteolysis at 3-years.
PROM values: KOOS (Pain, Symptoms, Activities in
Daily Life, Sports/Recreation, Quality of Life), UCLA
and EQ-5D all showed significant improvements
from the preoperative baseline. (p < 0.001)
Conclusions: In this multicenter study, vitamin E-infused
polyethylene was associated with a low rate of
postoperative complications and low osteolytic
potential at 3-year follow-up based on low revision
rates and radiographic findings. Functionality,
symptoms and quality of life PROMs were excellent
at three years across the study cohort
95. Day of surgery discharge in patients undergoing unicompartmental knee replacement. A prospective cohort-study in an unselected patient group
Søren Rytter, Bjørn Gottlieb Jensen, Stig Munk, Susanne Jung, Torben Bæk Hansen
University Clinic for Hand, Hip and Knee Surgery, Regional Hospital Holstebro, Denmark; Department of Orthopedic Surgery, Lillebælt Hospital, Regional Hospital of Vejle, Denmark ; University Clinic for Hand, Hip and Knee Surgery, Regional Hospital Holstebro, Denmark; Department of Orthopedic Surgery, Lillebælt Hospital, Regional Hospital of Vejle, Denmark ; University Clinic for Hand, Hip and Knee Surgery and The Lundbeck Foundation Centre for Fast-Track Hip and Knee arthroplasty Denmark, Regional Hospital of Hostebro, Denmark
Background: With an improved multimodal pain
treatment there have been an increased
focus on fast track programmes and the
potential to convert unicompartmental
knee replacement (UKR) surgery from
short-admission surgery to ambulatory
surgery with same-day discharge.
Purpose / Aim of Study: The purpose of this study was to describe
patient selection and completion rates in
an unselected patient group undergoing
UKR at two different high volume
hospitals.
Materials and Methods: All consecutive patients (n = 368) referred
to and selected for a medial UKR at two
participating clinics were screened for
eligibility for outpatient surgery with
discharge to their own home on the day of
surgery (DOS). Reasons for not being
discharged on the DOS were recorded in
patients not fulfilling the outpatient
pathway and complications (infection and
reoperation) and readmission were
recorded until 4 months postoperatively.
Findings / Results: 96% (n = 255) of all referred and
screened patients in this unselected
healthcare population for UKR were
eligible for outpatient surgery. DOS
discharge occurred in 59 % of the
operated patients and 36 % of all
referred and screened patients. Main
reasons for not being discharged were
active wound drainage, postoperative
nausea and vomiting and dizziness or
malaise. Two patients were readmitted
during the first 24 hours due to
bleeding. There were no infections.
One patient had a lung embolus and
one patient an AMI in the period 0-90
days after surgery. 93% of the patients
would undergo outpatient surgery
again.
Conclusions: This study illustrates that not all patients in
an unselected healthcare population for
UKR were suitable for outpatient surgery
as only 36 % of all referred and screened
patients were discharged on the DOS.
Further studies should focus on optimizing
pain treatment and especially reducing
postoperative nausea.