Session 13:
Foredragskonkurrence
Fredag den 24. oktober
13:30 – 15:00
Lokale: Reykjavik/Stockholm/Copenhagen/Helsinki/Oslo
Chairmen: Casper Foldager / Søren Overgaard
132. Preparation of the femoral bone cavity for cementless stems: Broaching versus Compaction. A 5 year randomized RSA and DXA study of 40 bilateral 1-stage operations
Mette Holm Hjorth , Maiken Stilling , Kjeld Søballe , Poul Torben Nielsen, Poul Hedevang Christensen, Søren Kold
Department of Orthopaedics , Aarhus University Hospital
Background: Experimental studies have shown superior
implant fixation after bone compaction (C)
compared to conventional broaching (B).
Purpose / Aim of Study: To investigate potential advantages and
disadvantages of C compared to B in a
randomized clinical trial (RCT)
Materials and Methods: 1-stage bilateral cementless THA (Bi-Metric,
Biomet) was performed in 20 patients (13 M),
mean age 58 (36-70) years. Patients were
randomized to bone preparation with C on
one side and B on the other side. Patients
were followed with RSA and DXA at
baseline, 6 and 12 weeks, 1, 2 and 5 years.
The subjective part of Harris Hip Score (HHS)
and complications/revisions throughout the
observation period were obtained at mean
6.3 (3-9.5) years after surgery.
Findings / Results: At 6 weeks, mean absolute mean
medio/lateral translations of 0.22 (CI: 0.12
to 0.32) mm in the C group was higher
(p=0.04) than 0.11 (CI: 0.07 to 0.16) mm
in the B group. At 5 years, the difference
was more pronounced (p=0.01) with
mean absolute medio/lateral translations
in the C group of 0.34 (CI: 0.18 to 0.39)
mm versus 0.13 (CI; 0.05 to 0.28) mm in
the B group. At 2 years, mean values of
percentage change in periprosthetic
bone since baseline in Gruen zone 3
was inferior in the C group of 92.6 (CI:
88.1 to 97.1) % versus 100.7 (CI: 93.6 to
107.8) % in the B group (p=0.04).
Intraoperative fractures occurred in 2/20
in the C group and in 0/20 in the B group
(p=0.02). Clinical outcomes of HHS and
dislocations (1 C, 2B) were similar
between groups (p>0.59). No stems
were revised at 5 years after surgery.
Conclusions: Bone compaction as compared to broaching
prior to insertion of the cementless Bi-Metric
femoral stem results in more absolute
medio/lateral translation, starting already 6
weeks and continuing until 5 years follow-up.
In this RCT intraoperative femoral fractures
only occurred with bone compaction.
133. Bone autograft versus recombinant human BMP-2 (rhBMP-2) at bone docking-site in tibial bone transport. A randomized clinical trial (RCT).
Søren Kold, Martin Lind, Susanne Jølck, Knud Christensen
Department of Orthopaedics, Aalborg University Hospital
Background: Bone autograft is applied at the bone-
docking site to increase the union-rate and
decrease the time to union after bone
transport. However, harvesting of the bone
autograft results in donor-site morbidity.
rhBMP-2 might replace the need for bone
autograft.
Purpose / Aim of Study: We investigated the union-rate and the risk
of refracture of the bone docking site
treated with open debridement and
application of either bone autograft or
rhBMP-2.
Materials and Methods: 41 patients treated for segmental defects of
the tibia with bone transport in a circular
frame were randomized to either bone
autograft (n=21) or rhBMP-2 (n=20) at the
docking site. Patients were followed with
monthly radiographs. Union was defined as
presence of bone callus in 3 out of 4
cortices as well as bony bridge in 3 out of 4
cortices. The minimum follow-up after
frame removal was 12 months.
Findings / Results: Radiographic union occurred in 21 out of
21 treated with autograft and in 20 out 20
treated with rhBMP-2. Mean time to union in
months was 7 (range: 4 – 9) with autograft
and 7 (range: 4 – 9) with rhBMP-2. Mean
time in hospital stay in days was 6 (range:
2 – 12) with autograft and 5 (range 1 – 16)
with rhBMP-2. There were no clinical signs
of infection at the docking site in either
group. Refracture at the docking site after
frame removal occurred in one patient in
the autograft group compared with 2
patients in the rhBMP-2 group (p=0.5). The
risk of refracture was higher when the
docking site was located at the mid-
diaphyseal tibia (3 out of 15) compared to
the metaphyseal tibia (0 out of 26)
(p=0.02).
Conclusions: No differences in radiographic union rate or
time to union were found between autograft
and rhBMP-2. Refracture at the docking
site occurred in 3 out of 41 cases, and mid-
diaphyseal docking might carry a higher
risk of refracture compared with
metaphyseal docking.
134. Pharmacokinetics of Cefuroxime in Bone, Subcutaneous Tissue and Plasma – Comparison of Continuous versus Short-term Infusion
Mikkel Tøttrup, Mats Bue , Kurt Fuursted, Tore Forsingdal Hardlei, Kjeld Søballe, Hanne Birke-Sørensen
Department of Orthopaedic Surgery and Orthopaedic Research Unit in Aarhus, Hospitalunit Horsens and Aarhus University Hospital; Department of Orthopaedic Surgery Orthopaedic Research Unit in Aarhus, Hospitalunit Horsens and Aarhus University Hospital; , Statens Serum Institute; Department of Clinical Biochemistry, Aarhus University Hospital; Department of Orthopaedic Surgery, Aarhus University Hospital; Orthopaedic Research Unit, Aarhus University Hospital
Background: The relatively short half-lives of most beta-lactams suggest that continuous
infusion (CI) of these time-dependent antibiotics may be favourable compared to
short-term infusion (STI). Nevertheless, only limited pharmacokinetic (PK) data is
available to support this theory, particularly in solid tissues like bone.
Purpose / Aim of Study: To obtain PK parameters of cefuroxime in plasma, subcutaneous tissue (SCT) and
bone in pigs receiving 1500 mg of cefuroxime administered either as STI or as CI,
and to compare time above minimal inhibitory concentrations (T > MIC) between
the two groups.
Materials and Methods: Twelve pigs were included. Each animal was randomly assigned to receive 1500 mg of
cefuroxime either as STI or CI. Measurements of cefuroxime were conducted in plasma, SCT,
cancellous and cortical bone every 30 min. The measurements in solid tissues were conducted
using microdialysis. A two-compartment population model was fitted to the drug concentration
data separately for the different tissues using a non-linear mixed effects regression model. Key
pharmacokinetic parameters and T > MIC were estimated using Monte Carlo simulations.
Findings / Results: Except for SCT in the STI group, tissue penetration was impaired for all tissues. The
poorest tissue penetration was found in bone. Both tissue area under the curves and tissue
penetration ratios generally appeared to be lower in the CI group. Nevertheless, significantly
longer T > MIC was found for CI up until MICs of 4, 2, 2 and 0.5 μg/mL for plasma, SCT,
cancellous and cortical bone respectively.
Conclusions: CI of beta-lactams with short half-lives may be favourable compared to STI if
dosed appropriately. The poorest tissue penetration was found in bone. The high
rate of treatment failure for osteomyelitis may therefore partly be attributable to
impaired target site penetration of antibiotics.
135. Methylprednisolone reduce pain and decrease knee swelling in the first 24 hours after fast-track Oxford unicompartmental knee arthroplasty
Søren Rytter, Maiken Stilling, Stig Munk, Torben Bæk Hansen
Department of Orthopedics , Holstebro Regional Hospital, Hospital Unit West, Denmark
Background: Unicompartmental knee arthroplasty
(UKA) operated with minimal invasive
surgery (MIS) results in less operative
trauma and faster patient recovery
than after a conventional total knee
arthroplasty. Despite an increased
focus on multimodal analgesic
strategies there is still a substantial
level of patient-reported pain in the
early post-surgical period after MIS
UKA.
Purpose / Aim of Study: The purpose of the study was to
evaluate the effect of a single
preoperative dose of systemic
methylprednisolone (MP) on acute
post-surgical pain after fast-track MIS
Oxford UKA.
Materials and Methods: 72 patients in 2 consecutive series
undergoing unilateral UKA were
included in a prospective cohort study.
Patients (n=35) in the treatment group
received a single preoperative dose of
systemic MP 125 mg whereas the
control group (n=37) did not. Otherwise
there was no difference in the
operative and postoperative treatment.
Outcome measures were post-surgical
pain at rest and during walking,
consumption of opioids for pain
rescue, knee swelling and knee range
of motion. Complications were
monitored until 4 months after surgery.
Findings / Results: In the first 24 hours after surgery the
MP group had less pain at rest
(p=0.000) and during walking
(p=0.000), and less consumption of
opioids (p=0.01) in comparison with
the control group. Furthermore, the MP
group had 2.2 cm less knee swelling
(p=0.02) in the 1st postoperative day,
and also better (p=0.004) knee
extension, whereas flexion was similar
(p>0.68) between groups. No serious
complications were associated with the
treatment.
Conclusions: A single preoperative dose of 125 mg
systemic MP significantly reduce post-
surgical pain and opioid consumption
and decrease knee swelling in the first
24 hours after fast-track MIS Oxford
UKA.
136. Physical activity and return to work after fast-track total hip replacement with or without supervised rehabilitation. Results from a randomized controlled trial.
Lone Ramer Mikkelsen, Inger Mechlenburg, Kjeld Søballe, Lene Bastrup Jørgensen, Thomas Bandholm, Annemette Krintel Petersen
Interdisciplinary Research Unit, Elective Surgery Centre, Silkeborg Regional Hospital ; Department of Orthopaedic Surgery, 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)Aarhus University
Background: Total hip replacement (THR) results in pain
reduction and functional improvements.
However, it is suggested that these
improvements are not followed by increases
in physical activity level and return to usual
activities postoperatively. Furthermore, it is
unknown whether supervised rehabilitation
affects the activity level as well as return to
work after THR.
Purpose / Aim of Study: To investigate whether supervised
progressive resistance training during the
first 10 weeks after THR affects the change
in physical activity level from baseline to 6
months after THR and early return to work.
Materials and Methods: 73 THR patients were randomly assigned to
a control group (CG, home based exercise)
or intervention group (IG, supervised
resistance training in addition to home based
exercise). Preoperative, 6 and 12 months
postoperative self-reported physical activity
was measured in metabolic equivalents
(METS) with the Physical Activity Scale
(PAS) and days until return to work.
Findings / Results: Follow up was completed by 62 patients
(85%). Changes in PAS scores from
baseline to 6 months follow up were, mean
[95% CI]: IG: 6.32 [3.5;9.1] METS and CG:
0.85 [-2.8;4.5] METS (p=0.02). Sick leave
duration in the working population of the
sample (n=25) were, median [range]: IG: 46
[6;161] days and CG: 57 [7;146] days
(p=0.49).
Conclusions: Patients performing supervised resistance
training in addition to home-based exercise
increased their self-reported physical
activity level more than patients performing
home-based exercise only, during 6 months
after THR however, the difference was
eliminated at 1 year follow up. No significant
difference was found concerning return to
work.
137. Preoperative embolization in surgical treatment of spinal metastases: single-blind, randomized controlled clinical trial of efficacy in decreasing intraoperative blood loss
Caroline Clausen, Benny Dahl, Susanne C Frevert, Lars Valentin, Michael B Nielsen, Lars Lönn
Department of Radiology, Rigshospitalet and University of Copenhagen ; Department of Orthopaedic Surgery, Rigshospitalet and University of Copenhagen
Background: An increasing number of patients undergo
surgical treatment for symptomatic spinal
metastasis. No randomized study has
evaluated the effect of preoperative
embolization.
Purpose / Aim of Study: To assess whether preoperative arterial
embolization reduce blood loss, blood
transfusion, and duration of surgery in
surgical treatment of metastatic spinal cord
compression.
Materials and Methods: This single-blind, randomized (1:1),
controlled, parallel-group, single-center
trial was approved by the national
committee on biomedical research ethics
and preregistered. Informed consent
was obtained and the study period was
from May 2011 until March 2013.
All participants were scheduled for
decompression and posterior
thoracic/lumbar spinal instrumentation.
They were randomly assigned to either
1) preoperative arteriography and
embolization – the embolization group or
2) preoperative arteriography – the
control group.
Primary outcome: intraoperative blood
loss. Secondary outcomes: perioperative
blood loss, allogenic RBC transfusion and
duration of surgery. Analyses were by
intention-to-treat (ITT).
Findings / Results: Forty-five randomized patients were
available for the ITT. Mean intraoperative
blood loss did not differ significantly (P =
.270) between the embolization group (618
ml [SD, 282 ml]) and the control group (735
ml [SD, 415 ml]). Neither did perioperative
blood loss and allogenic RBC transfusion.
The duration of surgery, however, was
significantly shorter in the embolization
group (P = .031): median 90 minutes (range,
54-252) vs. 124 minutes (range, 80-183).
Thirty-four of 45 metastases (76%) were
hypervascular.
Conclusions: Preoperative embolization does not result in
a reduction of intraoperative blood loss,
perioperative blood loss and blood
transfusion, but reduces the duration of
surgery for symptomatic metastatic spinal
cord compression.
138. HA-coating may decrease screw migration in the femoral head following hip fracture surgery – a double blinded RSA study
Henrik Palm, Kim Holck, Steffen Jacobsen, Søren Bøvling, Torben Bæk-Hansen, Maiken Stilling
Dept. of Orthopedics, Copenhagen University Hospital Hvidovre
Background: Sliding hip screw (SHS) migration in the
femoral head after hip fracture surgery may
lead to fracture collapse and/or screw cut-
out necessitating a reoperation.
Purpose / Aim of Study: To investigate if a hydroxyapatite (HA)
coated thread could reduce SHS migration.
Materials and Methods: 37 patients (31 female) at mean age 79
(range 56-96) years with stable trochanteric
fractures were operated in two centers with
a 4-hole 135-degrees SHS (HipLoc, Biomet)
and randomly allocated to sliding screws
with either a non-coated (n=19) or an HA-
coated (Bonemaster, Biomet) screw-thread
(n=18). Patients and assessors were
blinded for choice of screw. Patients were
followed after 1.5, 3 and 6 months with
marker-based RSA comparing migration
between 1) The sliding screw marked with 4
beads and 2) The femoral head marked with
3-5 beads inserted through the drilled SHS
canal. Demographic, surgical and
radiological parameters (TAD, fracture
reduction sum and screw placement in the
femoral head) were prospectively collected.
Findings / Results: Mean TAD of 2.1 (sd 0.66) mm, fracture
reduction sum in AP and LA of mean 0.66
(sd 0.87) mm and screw position in the
femoral head were similar between groups
(p>0.28). Screws with HA-coated thread had
less varus rotation (4.1 vs. 0.3 degrees,
p=0.03) after 1.5 months and a reduced
lateral translation (0.6 vs. 0.01 mm, p=0.046)
after 6 months, with a tendency after 1.5
months (0.4 vs. 0.2 mm, p=0.08). Other
translations and rotations were not different
and there were no correlation to radiological
parameters. No cut-outs or revisions.
Conclusions: Coating the SHS thread with HA reduced
screw migration in the femoral head at short-
term follow-up. Missed late follow-ups might
underpower statistics at 3 and 6 months.
Migrations were small and larger clinical
studies are warranted for evaluation of long-
term benefits.