Session 9: Hip I
Torsdag den 24. oktober
09:30 - 10:30
Lokale: Vingsal 3
Chairmen: Claus Varnum og Alma Pedersen
Julie Sandell Jacobsen, Stig Storgaard Jakobsen, Kjeld Søballe, Per Hölmich, Kristian Thorborg
Department of Physiotherapy and Research Centre in Health and Welfare Technology, VIA University College; Department of Orthopaedic Surgery, Aarhus University Hospital; Department of Orthopaedic Surgery, Aarhus University Hospital; Sports Orthopaedic Research Center-Copenhagen (SORC-C), Department of Orthopaedic Surgery, Copenhagen University Hospital, Amager-Hvidovre; Sports Orthopaedic Research Center-Copenhagen (SORC-C), Department of Orthopaedic Surgery, Copenhagen University Hospital, Amager-Hvidovre
Background: Hip dysplasia is a pathological development of the hip joint with reduced acetabular weight-bearing area. The clinical presentation of hip dysplasia is groin pain,
low patient-reported function and impaired hip muscle strength. Patient-reported pain and function improve after periacetabular osteotomy (PAO). However, little is
known about hip muscle strength after PAO.
Purpose / Aim of Study: We aimed to investigate changes in isometric
hip muscle strength from before to 1 year after
PAO in patients with hip dysplasia and to
compare the muscle strength values of the
patients to the values of a reference group with
no hip problems.
Materials and Methods: Muscle strength was assessed before and after
PAO in 100 patients with a mean age of 30
years (SD 9); while the muscle strength of 50
references with a mean age of 31 (SD 9) was
assessed at one time point. Isometric hip muscle
strength was assessed in flexion, extension,
abduction and adduction with a hand-held
dynamometer using a standardised procedure.
Changes in muscle strength from before to 1
year after PAO and differences between patients
and references were analysed with a univariate
repeated measurement model.
Findings / Results: From before to 1 year after PAO, patients improved their isometric hip muscle strength in flexion and abduction, 0.13
Nm/kg (CI 0.06 - 0.20) and 0.10 Nm/kg (CI 0.02 - 0.18). Hip muscle strength in adduction did not change and muscle
strength in hip extension failed to reach statistical significance (0.09 Nm/kg (CI -0.05 - 0.23), p=0.188). However,
despite improvements in hip flexion and abduction, the hip muscle strength values of the patients were 13-34% lower
than the hip muscle strength values of the healthy references at both time points (p<0.01).
Conclusions: One year after PAO, patients improved their maximal isometric hip muscle strength in flexion and abduction.
However, patients’ pre- and postoperative hip muscle strength values were low compared to the hip muscle strength
values of the healthy references. Consequently, future studies should focus on the measured strength deficits and
investigate if strength training can improve hip muscle strength in patients with hip dysplasia.
Anna Bohman, Sören Overgaard, Carl-Johan Tiderius, Cecilia Rogmark
Dept of Orthop Surg, Skane University Hospital Malmö-Lund; Ortopædkirurgisk afd.O/Klinisk Institut, Odense Universitetshospital/Syddansk Universitet; Dept of Orthop Surg, Skane University Hospital Malmö-Lund/Lund University; Dept of Orthop Surg, Skane University Hospital Malmö-Lund/Lund University
Background: Hip dysplasia (HD) is commonly defined as a
center-edge angle (CE) ≤20 degrees on
pelvic radiographs. A 5% prevalence is
suggested by a Danish population study.
Patients with HD may develop symptoms
which can be treated non-surgically, by joint
preserving surgery, or total hip replacement.
Thus, early diagnosis is important for the
Purpose / Aim of Study: To describe a) prevalence of HD in our
catchment area; b) concordance between
original assessment and dedicated
measurement of dysplasia angles c)
association of pain and HD.
Materials and Methods: Retrospective study of individuals 20-70
years; 1501 hip/pelvis radiographs taken
2007 in Malmö. 808 of these permitted both
hips to be measured. CE was measured
according to Wiberg and acetabular index
angle (AIA) according to Tönnis. Radiological
dysplasia was defined as CE ≤20 degrees.
One researcher performed all measurements,
read x-ray referrals and assessments.
Patients had either planned or acute x-ray. T-
test and chi2-test.
Findings / Results: In the 245 acute cases, 10 had uni- or
bilateral dysplasia (4.1%). In 563 planned
cases, the result was 29 (5.2%). The AIA
angles were significantly higher in HD cases,
right side 18 versus 7 degrees (SD 6 and 5),
left 17 vs 6 (SD 5 and 4). According to the
referral, 22 of the 39 HD cases had pain. Men
had dysplasia in 5.5% of the acute cases, and
in 5.7% of the planned cases, women 3.0 and
4.8%. The radiologists’ assessments
mentioned dysplasia (or similar) in 4 of the 39
Conclusions: The hip dysplasia prevalence was 5% in a
adult population with no gender difference. A
majority of the patients with radiological
dysplasia did actually have pain, but the
radiology assessment described acetabular
dysplasia just in a few cases. If patients are
not detected in routine health care, individuals
with symptoms may miss out on treatment.
Bjarke Viberg, Kate Andersen, Ole Ovesen, Morten F. Bøgehøj, Søren Overgaard
Orthopaedic Surgery and Traumatology / Regional Health Research, Kolding Hospital / University of Southern Denmark; Health Science and Technology, Aalborg University; Orthopaedic Surgery and Traumatology, Odense University Hospital; Orthopaedic Surgery and Traumatology, Odense University Hospital; Orthopaedic Surgery and Traumatology / Orthopaedic Research Unit, Department of Clinical Research, Odense University Hospital / University of Southern Denmark
Background: Periacetabular osteotomy (PAO) is a treatment
option in symptomatic acetabular retroversion (AR)
where non-surgical treatment has failed. Very few
studies have been published on patient reported
outcome measure (PROM). The present study
reports on the largest series of patients until today.
Purpose / Aim of Study: Assess PROMs and complications after PAO
surgery in adult patients with AR.
Materials and Methods: From June 2007 to May 2018, 214 patients with
AR were retrieved from a prospective local
database. Patients were followed at baseline, 1,
2, and 5 years after surgery and answered
Oxford Hip Score (OHS), EuroQol-5 dimensions
index (EQ-5D), University of California at Los
Angeles Activity score (UCLA), pain Verbal
Rating Scale (pVRS), and Harris Hip Score
(HHS). Complications are entered into the
database but were also retrieved from the
Danish National Patient Registry. Two follow-up
periods were defined as 2 years (1-2.2 years
postoperatively) and 5 years (2.3-6 years).
STROBE guidelines were followed.
Findings / Results: The 214 patients had a mean (SD) age of 23.7
(24) years, 165 (77%) were female, and the
mean (SD) BMI was 24.7 (16.9). From baseline
to 2 and 5 years after surgery, there was
statistical significant improvement in all PROMs.
Preoperatively and median (InterQuartileRange)
delta value improvements:
pVRS was 8 (7-9) preoperatively and was
reduced with 7 (5-8) points after 2 years and 7
(5-8) after 5 years.
EQ5D was preoperatively 0.72 (0.56-0.72) and
increased with 0.21 (0.05-0.32) points after 2
years and 0.12 (0-0.28) after 5 years.
UCLA was preoperatively 5 (4-7) and increased
with 2 (0-4) points after 2 years and 1 (0-4) after
5 years (non-significant after 5 years).
OHS was preoperatively 30 (24-35) and
increased with 10 (4.5-17) points after 2 years
and 7 (4-15) after 5 years.
HHS was preoperatively 69 (63-74) and
increased with 27 (22-34) points after 2 years
and 26 (24-30) after 5 years.
Apart from screw removal of fixation material in
20.1% of the patients 2 hips (0.9%) were
converted to total hip arthroplasty.
Conclusions: PAO for AR surgery leads to favorable outcomes in
all PROMs suggesting PAO as an effective
treatment of acetabular retroversion with a low
frequency of severe complications.
Christina Nielsen Bræmer, Sarah Ankjær Langberg, Stig Storgaard Jakobsen, Søren Reinhold Jakobsen, Hugo Aleixo, Kjeld Søballe, Inger Mechlenburg
Department of Ortopaedics, Aarhus University Hospital ; Department of Ortopaedics, Aarhus University Hospital ; Department of Ortopaedics, Aarhus University Hospital; Department of Ortopaedics, Aarhus University Hospital; , Hospital Pedro Hispano, Matosinhos, Portugal; Department of Ortopaedics, Aarhus University Hospital; Department of Ortopaedics, Aarhus University Hospital
Background: Outcome in patients with acetabular retroversion
(AR) treated with reverse periacetabular osteotomy
(reverse PAO) is sparsely reported.
Purpose / Aim of Study: The aim of this study was to investigate changes in
pain and hip function among patients with AR two
years after reverse PAO and to examine whether
‘changes in pain’ is associated with ‘changes in hip
function’. In addition, to evaluate patient satisfaction
and changes in quality of life (QoL).
Materials and Methods: This was a follow-up study with patient reported
outcome data from Aarhus University Hospital
Denmark. Pain at rest and during activity was
measured with Visual Analogue Scale (VAS), hip
function with Hip disability and Osteoarthritis
Outcome Score (HOOS) and QoL with Short-Form
36 (SF-36) both preoperatively and two years after
reverse PAO in 74 patients. Changes were analyzed
using paired t-test. Multiple linear regressions were
Findings / Results: Significant (P < 0.05) and clinically relevant mean
improvements in pain and hip function were found.
Proportion of responders achieving a minimal
detectable important change varied from 51-73%.
Positive significant association between ‘changes in
pain’ and ‘changes in hip function’ were found (P <
0.05). Significant mean improvement in QoL were
found (P < 0.05). The study had a loss to follow-up
Conclusions: Two years after reverse PAO, patients diagnosed
with AR showed significant and clinically relevant
mean improvements in pain and hip function and
decreased pain was significantly associated with
improved hip function. The majority of patients were
satisfied with the results of reverse PAO and QoL
were improved towards mean values for the Danish
Josefine Beck Larsen, Stig Storgaard Jakobsen, Theis Muncholm Thillemann, Inger Mechlenburg, Kjeld Søballe
Orthopaedic Surgery, Aarhus University Hospital; Orthopaedic Surgery, Aarhus University Hospital; Orthopaedic Surgery, Aarhus University Hospital; Orthopaedic Surgery, Aarhus University Hospital; Orthopaedic Surgery, Aarhus University Hospital
Background: Only few studies have evaluated long- and mid-
term outcomes after periacetabular osteotomy
Purpose / Aim of Study: The aim of this study was to investigate: (1) the
long-term hip survival rate after PAO; (2) the risk
of complications after PAO and (3) the hip
function at different follow-up points.
Materials and Methods: We retrospectively reviewed 1385 hips (1126
patients) undergoing PAO between January
2004 and December 2017. Through inquiry to
the Danish National Patient Registry we
identified conversions to total hip arthroplasty
(THA) and complications after PAO. We
evaluated the Hip disability and Osteoarthritis
Outcome Score (HOOS) obtained
preoperatively, and at 6 months, 2, 5, and 10
Findings / Results: The overall Kaplan Meier hip survival rate was
80.2% (CI: 68.0-88.1) at 14 years. There was a
significant difference between age groups.
0.43% had deep vein thrombosis after PAO. The
most common complication was PAO screw
removal (12.5%). 11.1% had additional hip
arthroscopy. At 2-year follow-up, HOOS pain
improved by a mean of 25.7 points (CI 23.6-
27.9) and a HOOS pain score ≤50 was observed
Conclusions: The three outcomes used in this study allows for
a more distinct description of PAO surgery
outcome, which can possibly help surgeons in
the selection of patients and enable them to
inform the patients about the expected PAO
Nissa Khan, Henrik Morville Schrøder, Michael Mørk Petersen, Kim Lyngby Mikkelsen
Department of Orthopaedic Surgery, Holbæk Hospital; Department of Orthopaedic Surgery, Næstved Hospital; Department of Orthopaedic Surgery, Rigshospitalet; The Danish Patient Compensation Association,
Background: In Denmark, 107.837 primary total hip arthroplasties (THA) were performed during 2005-2016. As patient safety
awareness increases, a source of insight is data on health care-related injuries from patient compensation
administration. Studies show a rise in claims due to higher expectations of treatment and outcomes, greater
awareness of medical errors, and hence, lower levels of confidence and trust in the health care system. The majority
of filed orthopaedics claims are from elective surgery, and many successful claims might have a preventable cause.
Purpose / Aim of Study: We examined the Danish Patient Compensation
Association (DPCA) database to outline the
frequency and financial burden of compensation
claims after primary THA in Denmark.
Materials and Methods: This was a retrospective study of closed
compensation claims following THA reported to
DPCA between 1st of January 2005 and 31st of
December 2016. The primary cause for claim was
Findings / Results: There were 29.370 orthopaedic patient claims in the
DPCA from which 9.4% was due to primary THA
(2759 cases i.e. 2.6% of all THAs performed in this
period). The approval rate was 54%. Despite an
increase in the number of THAs being carried out,
the number of claims filed was stagnant, except for
a spike of MoM prosthesis-cases. The total pay-out
was DKK 192,494,484, and 87% of this was due to
nerve damage (DKK 58,137,721), infection (DKK
38,611,026), MoM prosthesis (DKK 31,343,184),
insufficient or incorrect treatment (DKK 25,788,714),
and fracture (DKK 13,707,826). Nerve injury (17%),
insufficient or incorrect treatment (16%) and MoM-
prosthesis (15%) were the three most common
causes for hip claims. However, those most likely to
result in pay-out were nerve damage (84%), tendon
injury (75%) and equipment failure during treatment
Conclusions: 2.6% of all primary THAs resulted in a compensation claim reported to DPCA and 54% of these were
approved. The majority of pay-outs were due to nerve damage, infection, MoM prostheses, insufficient or
incorrect treatment, and fracture. Although DPCA manages claims for patients, the data can also provide
beneficial feedback to arthroplasty surgeons with the aim of improving patient care.