Session 7: Knee I
Torsdag den 25. oktober
09:30-10:30
Lokale: Sweden
Chairmen: Andreas Kappel og Christian Skovgaard
42. What is the Outcome of Bi-cruciate Versus Cruciate Retaining Total Knee Arthroplasty at 2-year Follow-up Assessed in a Randomized Controlled Trial?
Anders Troelsen, Lina Holm Ingelsrud, Morten Grove Thomsen, Omar Muharemovic, Kristian Otte, Henrik Husted
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 Radiology, Copenhagen University Hospital Hvidovre; Department of orthopaedic surgery, Copenhagen University Hospital Hvidovre; Department of orthopaedic surgery, Copenhagen University Hospital Hvidovre
Background: Bi-cruciate retaining (Bi-CR) total knee
arthroplasty (TKA) intend to improve
outcome by maintaining intrinsic ACL
functions.
Purpose / Aim of Study: The aim was to compare tibial implant
migration and clinical outcomes of Bi-
CR and CR TKA.
Materials and Methods: This single-blinded parallel-group trial
randomized 50 patients eligible for a
CR TKA with intact ACL during surgery
to receive a Bi-CR or CR TKA.
Patients suspected to have ACL
rupture were excluded. The primary
outcome was the maximum total point
motion (MTPM) measured with
radiostereometric analyses at 2 years
postoperatively. Patient-reported
outcomes were assessed by the
Oxford Knee Score (OKS; 0-48) and
the Forgotten Joint Score (FJS; 0-100).
Findings / Results: At 2 years postoperatively, RSA
images were available for 45 patients
and PROMs for 48 patients. The mean
MTPM was 0.59 and 0.62 mm in the Bi-
CR and CR groups, respectively
(p=0.82). Two patients (2-year OKS:
41 and 43) receiving Bi-CR TKA were
classified as migration outliers. The
improvement in median OKS from
preoperative to 2 years was 20.5 to
41.0 and 25.0 to 44.0 in the Bi-CR and
CR groups, respectively. The mean
FJS improved from 16.1 to 62.0 and
21.8 to 69.6 in the Bi-CR and CR
groups, respectively. Neither absolute
values at 2 years nor improvements
showed statistically significant
differences between the groups
(p=0.07 and 0.96 for OKS; p=0.28 and
0.80 for FJS, respectively). Three
patients (Bi-CR group) underwent
arthroscopically assisted manipulation
between 3 and 4 months
postoperatively. One patient sustained
a tibial island fracture during primary
surgery and was revised after 6
months.
Conclusions: Stable fixation and excellent clinical
outcomes of a Bi-CR TKA at 2 year
follow-up, similar to a gold standard
CR TKA, can be achieved, although a
unique learning curve was identified.
43. 6-year Radiosteriometric Follow-up on a RCT with Comparison of the Vanguard Tibial Component with either Regenerex® or Porous Plasma Spray Coating in Total knee Arthroplasty
Karen Dyreborg, Nikolaj Winther, Thomas Lind, Gunnar Flivik, Michael Mørk Petersen
Department of Orthopaedic Surgery, Rigshospitalet; Department of Orthopaedic Surgery, Rigshospitalet; Department of Orthopaedic Surgery, Gentofte, Herlev Gentofte Hospital; Department of Orthopaedics, Skåne University Hospital, Lund; Department of Orthopaedic Surgery, Rigshospitalet
Background: Regenerex® is a porous titanium
construct with a 3D interconnecting
pore structure and biomechanical
characteristics close to that of normal
trabecular bone.
Purpose / Aim of Study: The aim of this study was to compare
this structure to the Porous Plasma
Sprayed (PPS) tibial implant, with non-
interconnecting pore structure, after
uncemented total knee arthroplasty
(TKA).
Materials and Methods: 61 patients (mean age=63(49-71),
F/M=35/26) planned for an
uncemented Vanguard TKA (Biomet,
Warsaw, Indiana, USA) at Hørsholm
Hospital (n=41) or at Gentofte Hospital
(n=20) were randomized to receive
either a Regenerex® or a PPS tibial
component (31/30). RadioSteriometric
Analysis (RSA) using the tibial
components, marker-based technique,
was performed postoperatively, at 3
months, 6 months and at 1, 2 and 6
years with measurement of migration
(segment motion and maximum total
point motion (MTPM)). All patients had
the clinical results monitored with the
Knee Society knee and function
scores. 55 patients attended the 6-year
follow-up. Statistics: Mann-Whitney U
test. Results are presented as mean
(range).
Findings / Results: One patient had died and 4 was re-
operated (infection=2, mechanical
reasons=2) during the 6-year period.
All reoperations were in the
Regenerex®-group. The total 6-year
MTPM was 1.40mm (0.51-3.71) for the
PPS-group and 2.67mm (0.37-15.42)
for the Regenerex®-group (p=0.43).
The 2 to 6-year MTPM was 0.40mm
(0.10-3.01) in the PPS-group and
0.56mm (0.11-4.48) in the
Regenerex®-group (p=0.61).
Conclusions: We did not find any significant
differences between the PPS- and
Regenerex®-group with regards to
total long-term migration or migration
beyond 2 years. Since no patient was
revised due to aseptic loosening both
implants are considered to work well
with regards to tibial component
fixation and biocompatibility.
44. Mismatch Never Events in Hip and Knee Arthroplasty: A Cohort and Intervention Study
Anders Odgaard, Mogens Berg Laursen, Kirill Gromov, Anders Troelsen, Frank Madsen, Overgaard Overgaard
Dept. of Orthopaedics, Copenhagen University Hospital Herlev-Gentofte; Dept. of Orthopaedics, Aalborg University Hospital; Dept. of Orthopaedics, Copenhagen University Hospital Hvidovre; Dept. of Orthopaedics, Copenhagen University Hospital Hvidovre; Dept. of Orthopaedics, Aarhus University Hospital; Dept. of Orthopaedics, Odense University Hospital
Background: Incompatible components in hip or
knee arthroplasty may lead to a risk of
malfunction and early failure. These
mismatch never events are known to
happen, but the frequency is largely
unknown.
Purpose / Aim of Study: We aimed to 1) calculate frequencies
of implant incompatibility in
sequentially registered implants and 2)
assess whether an online warning
system can reduce the frequency of
mismatch never events.
Materials and Methods: Barcode implant registration was
introduced in 11 hospitals from 2013.
We developed a compatibility
database covering all implant families
used, and from May 2017,
compatibility checking became part of
the registration process, immediately
warning theatre staff, if incompatible
implants were registered. Hospitals
were contacted to verify every case of
recorded mismatch, that had occurred
both before and after the introduction
of real-time checking. We defined four
classes (A-I, A-II, B-I and B-II) of
component mismatch depending on an
assessment of patient risk (A/B) and
on whether the mismatch was
knowingly accepted (I/II).
Findings / Results: Implants from a total of 22,564 hip or
knee arthroplasty procedures were
analyzed. Implant information from
12,306 arthroplasty procedures was
collected before the introduction of the
compatibility checking, and from 5,691
hip and 6,615 knee arthroplasty
procedures, we found a class A-I
mismatch rate of 0.14% (95% CI:
0.06%-0.28%) and 0.17% (95% CI:
0.08%-0.30%), respectively. After the
introduction of compatibility checking,
implants from a total of 10,258
procedures were analyzed, and we
identified no class A-I mismatches for
hips (p=0.008) or knees (p=0.003).
Conclusions: Our data presents validated estimates
of the frequency of mismatch never
events for hip and knee arthroplasty
procedures, and it demonstrates that a
significant reduction in class A-I
mismatches is possible.
45. Does preoperative Pain Catastrophizing predict physical function after Knee Arthroplasty?
Sara Birch, Maiken Stilling, Inger Mechlenburg, Torben Bæk Hansen
Department of Physiotherapy and Occupational therapy, Holstebro Regional Hospital; University Clinic for Hand, Hip and Knee surgery, Holstebro Regional Hospital; Department of Orthopaedic Surgery, Aarhus University Hospital; University Clinic for Hand, Hip and Knee surgery, Holstebro Regional Hospital
Background: Pain catastrophizing might contribute to acute
and long-term pain after Knee Arthroplasty
(KA), but the association between pain
catastrophizing and physical function is not
well studied.
Purpose / Aim of Study: 1) to examine the association between
preoperative pain catastrophizing and
physical function one year after surgery and
2) to investigate possible differences in pain,
general health and physical function among
two groups of patients with high and low
preoperative pain catastrophizing score.
Materials and Methods: A total of 651 patients scheduled for KA were
included in this study between marts 2011
and December 2013. The Pain
Catastrophizing Scale (PCS) was completed
prior to surgery and Oxford Knee Score
(OKS), Short Form-36 (SF-36) and EuroQol-
5D (EQ-5D) were completed prior to surgery,
and 4 and 12 months after the surgery.
Findings / Results: Of the 651 patients, 466 underwent Total
Knee Arthroplasty and 185 received
Unicompartmental Knee Arthroplasty. Mean
age was 67.3 and 53.2% were females.
Regression analysis showed no association
between preoperative pain catastrophizing
and change in OKS 12 months after surgery.
Patients with preoperative PCS>21 had
significantly lower OKS, SF-36 and EQ-5D
and higher pain score than patients with
PCS<11 both preoperative and 4 and 12
months postoperative.
Conclusions: The present findings did not support our
hypothesis about an association between
preoperative pain catastrophizing and
change in OKS after the operation, but the
findings suggest that patients with high
levels of preoperative pain catastrophizing
have lower physical function, poorer
general health, and more pain both before
and after KA, which indicate that
interventions designed to reduce pain
catastrophizing might have the potential to
further improve outcome after KA.
46. Pain, sports participation, and physical function in 10-14 years olds with Patellofemoral Pain and Osgood Schlatter: A matched cross-sectional study of 252 adolescents
Rathleff Michael, Winiarski Lukasz, Krommes Kasper, Graven-Nielsen Thomas, Hölmich Per, Olesen Jens, Holden Sinead, Thorborg Kristian
SMI, Department of Health Science and Technology, Faculty of Medicine, Aalborg University; Department of Physiotherapy and Occupational Therapy, Aalborg University Hospital; Sports Orthopedic Research Center-Copenhagen (SORC-C), Department of Orthopaedic Surgery, Copenhagen University Hospital, Amager-Hvidovre; Center for Neuroplasticity and Pain (CNAP), SMI, Department of Health Science and Technology, Aalborg University; Sports Orthopedic Research Center-Copenhagen (SORC-C), Department of Orthopaedic Surgery, Copenhagen University Hospital, Amager-Hvidovre; Research Unit for General Practice in Aalborg, Department of Clinical Medicine, Aalborg University; SMI, Department of Health Science and Technology, Aalborg University; Sports Orthopedic Research Center-Copenhagen (SORC-C), Department of Orthopaedic Surgery, Copenhagen University Hospital, Amager-Hvidovre
Background: Patellofemoral pain (PFP) and Osgood
Schlatter disease (OSD) are common
knee complaints in adolescents, but
knowledge on their relative impact is
lacking.
Purpose / Aim of Study: To compare pain, physical activity and
knee function between pain-free
controls and adolescents diagnosed
with PFP or OSD.
Materials and Methods: This age and sex matched cross-
sectional study included 252
adolescents (aged 10-14 years): 151
with PFP, 51 with OSD, and 50
controls. Pain, physical activity, knee
function, and quality of life were
collected using self-reported
questionnaires. Hip and knee strength
were measured with handheld
dynamometry. Objective measure of
physical activity was collected using
ActiGraphs.
Findings / Results: Over 98% of adolescents with PFP or
OSD participated regularly in sports
prior to their knee pain, and 50% had
reduced sports participation due to
knee pain. Adolescents with PFP or
OSD scored 23-57 points lower
(P<0.001) in the Knee injury and
Osteoarthritis Outcome Score
subscales compared with controls, with
the lowest scores in the ‘sport &
recreation’ and ‘quality of life’. Girls
and boys with OSD had significantly
lower isometric knee strength
compared to controls (26-37%,
P<0.001), whereas only girls with PFP
displayed lower hip extension strength
compared to controls (15%, P<0.05).
Adolescents with PFP or OSD
accumulated more than 2 hours of
vigorous physical activity per day.
Conclusions: Adolescents with PFP or OSD are
characterised by impaired sports
participation and knee function, relative
to pain-free controls, suggesting that
future interventions for this group need
to focus on restoring sports-related
function and sports participation. As
both boys and girls with OSD showed
substantially decreased knee
extension strength, interventions
aimed at this deficit need to be
considered in the future.
47. Pharmacokinetics of high-dose Ropivacaine for local infiltration anesthesia in unilateral and simultaneous bilateral total knee arthroplasty
Kirill Gromov, Stanislas Delyle, Nicolai Bang Foss, Lars Møller Pedersen, Christian Skovgaard Nielsen, Elodie Lamy, Anders Troelsen, Saik Urien, Henrik Husted
Department of Orthopaedic Surgery, Hvidovre Hospital; Plateforme de Spectrométrie, Université de Versailles Saint-Quentin-en-Yvelines; Department of Anaesthesiology , Hvidovre Hospital; Department of Anaesthesiology , Hvidovre Hospital; Department of Orthopaedic Surgery, Hvidovre Hospital; Plateforme de Spectrométrie, Université de Versailles Saint-Quentin-en-Yvelines; Department of Orthopaedic Surgery, Hvidovre Hospital; Plateforme de Spectrométrie, Université de Versailles Saint-Quentin-en-Yvelines; Department of Orthopaedic Surgery, Hvidovre Hospital
Background: Ropivacaine is commonly used in local infiltration
anesthesia (LIA) as pain management following total
knee arthroplasty (TKA). Systemic toxic thresholds
of 4300 ng/mL and 560 ng/mL for total and free
plasma Ropivacaine, respectively, have been
suggested. Although considered safe, no studies
evaluate pharmacokinetic properties and serum
concentration of high dose Ropivacaine infiltration in
unilateral TKA (uTKA) and bilateral simultaneous
TKA (SBTKA).
Purpose / Aim of Study: The purpose of this study was to describe
Ropivacaine concentrations in patients undergoing
uTKA and SBTKA receiving LIA with high dose
Ropivacain.
Materials and Methods: 16 unilateral and 15 SBTKA patients were included.
All patients were operated in a fast-track setup
without use of drains or tourniquet. Standard LIA
technique was used with 200mL 0.2% Ropivacaine
(400mg) injected periarticular in each knee. Free
and bound serum concentrations of Ropivacaine
was measured at 9 and 12 time points within 24
hours after first injection for uTKA and SBTKA,
respectively, using liquid chronomatography mass
spectrometry.
Findings / Results: Mean peak free Ropivacaine concentration was 30
ng/mL and 95ng /mL for uTKA and SBTKA,
respectively. Mean peak bound Ropivacaine
concentration was 756 ng/mL and 1695 ng/mL for
uTKA and SBTKA, respectively. Peak concentration
for both free and bound Ropivacaine was reached
between 2 and 4 hours after first injection both for
uTKA and SBTKA. There was no difference in the
proportion of free Ropivacaine between unilateral
TKA and BSTKA at any time points.
Conclusions: Peak free and peak bound Ropivacaine
concentrations stayed way below previously
proposed toxic thresholds in patients undergoing
uTKA as well as SBTKA receiving LIA with high
dose Ropivacaine
48. The survival of TKAs converted from medial UKA resembles the survival of revision TKAs and not primary TKAs – Results from the Danish Knee Arthroplasty Registry
Anders El-Galaly, Andreas Kappel, Poul Torben Nielsen, Steen Lund Jensen
Department of Orthopaedic Surgery, Aalborg University Hospital; Department of Orthopaedic Surgery, Aalborg University Hospital; Department of Orthopaedic Surgery, Aalborg University Hospital; Department of Orthopaedic Surgery, Aalborg University Hospital
Background: Medial UKA is increasingly popular but may
subsequently be converted to a TKA. It is debated
whether the survival of these conversion TKAs
(uTKA) resembles the survival of primary TKAs
(pTKA) or TKA to TKA revisions (rTKA).
Purpose / Aim of Study: To evaluate the survival of uTKA and compare it with
pTKA and rTKA.
Materials and Methods: 1.005 uTKAs conducted between 1997 and 2017
were retrieved from the Danish Knee Arthroplasty
Registry and compared to 88.713 pTKAs and 3.535
rTKAs. Patients and surgery details were analyzed.
Implant survival was estimated by Kaplan Meier
analysis and Cox Regression was used to estimate
the association between survival and clinical
features.
Findings / Results: Median time from UKA to TKA was 2.3 years and
the most frequent indications for conversion were
aseptic loosening (27%), pain (26%) and
progressive osteoarthritis (14%). Mean age of
uTKA was lower (66 years) than both rTKA (69
years) and pTKA (69 years) (p<0.001). 5- and
10-year implant survival were comparable
between uTKA and rTKA (0.90 vs 0.91 and 0.86
vs 0.88, p=0.31) and both were lower than pTKA
(0.97 and 0.96, p<0.001). Correspondingly, uTKA
and rTKA had a similar adjusted hazard ratio
(HR) for revision when compared to pTKA (2.82
vs 2.86, p<0.001). Early conversion of UKA (<2.3
years) was associated with an increased risk of
revision (HR=1.72, p=0.02). Conversion due to
aseptic loosening or pain did not influence the
risk of revision, while conversion due to
progressive osteoarthritis lowered the risk
(HR=0.23, p<0.01).
Conclusions: Regarding survival, a TKA converted from a medial
UKA behaves like a revision TKA but is inferior to a
primary TKA. Early conversion increased the risk of
revision whereas conversion due to progressive
osteoarthritis lowered the risk.