A Quick Pathway for Patients With High pRobability of dislocatEd Hemi- or Total Hip Arthroplasty to Minimize the Time From Hospital aDmission to redUCtion of the prosthEsis
Phase: NA
Conditions: THA, Dislocation, Hip, PROM
Sponsor: University of Southern Denmark

Protocol 
 
“A Quick pathway for patients with high pRobability of 
dislocatEd hemi- or total hip arthroplasty to minimize the 
time from hospital aDmission to redUCtion of the 
prosthEsis” 
 
 
 
the Q-REDUCE study 
- a prospective cohort trial 
 
 
 
Main investigator:  
Lars Lykke Hermansen, MD, PhD, post.doc. 
Dept. of Orthopedics, Esbjerg Hospital 
University Hospital of Southern Denmark 
Dept. of Regional Health Research  
University of Southern Denmark, Odense 
 
Co investigators: 
 
Peter Kuhne-Qvist, MD & Thale Forberg Almås, MD 
Dept. of Anesthesiology, Esbjerg Hospital 
University Hospital of Southern Denmark 
 
Rikke Beese Dalby, MD, PhD, Head of Research 
Dept. of Radiology, Esbjerg Hospital 
University Hospital of Southern Denmark 
 
Peter Biesenbach, MD, Head of Research 
Dept. of Emergency Medicine, Esbjerg Hospital 
University Hospital of Southern Denmark 
 
 
 
 
 
 

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Background: 
 
Most patients undergo elective total hip arthroplasty (THA) due to primary osteoarthritis (OA) 
(80%). The remaining 20% are indicated by secondary arthritis as a consequence to earlier fracture 
surgery, hip dysplasia, rheumatism or tumors (1). Additionally, hip replacements are also 
performed in acute cases such as displaced femoral neck fractures, in which hemiarthroplasties 
(HA) often are preferred as opposed to THAs, depending on the surgeon’s preference and skills. 
The patient categories differ significantly, with the acute fracture patients being older and more 
comorbid, thereby more fragile (2). Annually, 10,500 THAs and 2,100 HAs are implanted 
nationally, while the count is 2,100 THAs and 550 HAs in the Region of Southern Denmark (1, 3). 
 
Despite being a highly successful procedure in terms of both safety and patient satisfaction, 
complications after hip replacements do still occur (4). One of the most common complications 
and reason for hip revisions is hip dislocation. After THA, it occurs in 3,5% of primary OA patients 
within the first two postoperative years, while the incidence is higher in other patient categories, 
e.g. fractures (2, 5, 6). The risk of dislocation after HA is reported between 6% - 11% (7, 8).  
 
The dislocated prosthesis is usually managed by a simple, closed reduction maneuver under 
general anesthesia with or without muscle relaxation, resulting in open surgical reduction rarely 
being needed (9-11). Time from admission to actual reduction often includes various steps (incl. 
several patient transfers between emergency units, radiology departments, operating theaters) 
which causes an unnecessarily long period of pain for the patient. In 2015, a fast-track system was 
introduced at Hvidovre Hospital on a trial basis for patients highly suspected for THA/HA 
dislocation (12). This resulted in a significant decrease in the time from arrival to reduction and 
overall time of hospitalization, without resulting in more complications. The study was 
retrospective and did not measure how patients experienced the change in practice. 
 
A fast-track system must be specially designed for the local departments, due to differences in the 
logistical options from hospital to hospital. The purpose of this study is to design a fast-track 
pathway for patients referred to the University Hospital of Southern Denmark, Esbjerg, with high 
probability of having a dislocated hip prosthesis with the primary aim to reduce the time from 
arrival to reduction and the total hospitalization time. Secondary aims are to  
 
- 
investigate whether quicker prosthesis reduction influences on hip function and quality of 
life afterwards 
- 
reduce the pain experience immediately and in the long term 
- 
increase patient satisfaction 
 
without changing the overall complication rate and readmission/mortality 

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Methods:  
 
Trial design 
 
The study is designed as a prospective observational cohort trial, adhering to the STROBE 
guidelines (13). The present protocol will be registered at clinicaltrials.org and submitted for 
publication in an international journal.  
 
Setting 
 
The study is conducted at the University Hospital of Southern Denmark, Esbjerg, as a collaboration 
between the Department of Orthopedics, Department of Anesthesiology, Department of 
Radiology, and Department of Emergency.  
 
The study is planned to start September 1st, 2024, and will continue for two years. During the first 
year, the admitted patients will follow the current standard treatment pathway. After September 
1st, 2025, a newly developed treatment pathway will be adhered to, and for the rest of the 
protocol, this pathway is described as the Fast-track pathway, as the expectation is that treatment 
strategy will shorten time to reduction.  
 
All patients admitted with a dislocated THA or HA will be included in the study without prior 
informed consent. The patients are – disregard of cognitive status – admitted with a complication 
that requires acute treatment. After the acute treatment (reduction of the dislocated prosthesis), 
the patients are informed about the study and encouraged to participate in the second part of the 
study (see outcome section). 
 
Participants 
 
Inclusion criteria: All adult patients admitted to the Department of Emergency Medicine (Dept. of 
EM), University Hospital of Southern Denmark, Esbjerg, for suspected dislocated hip prosthesis 
who fulfills the following  
o age > 18 years 
o a history of either a THA or a HA in combination with at least one of the following 
terms:  
§ having sustained a sudden, incorrect movement or twist in the hip joint in 
either a bending, sitting or supine position leading to inability to stand or 
walk 
§ misalignment of the concerned lower extremity (typically shortened, with 
inward/outward rotation) 

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4 
 
Exclusion criteria: Patients with 
o recurrent dislocations during the same hospital admission (already “in the house”) 
o anticipated difficult airway by the attending anesthesiologist 
o anticipated need for extended respiratory or hemodynamic monitoring by the 
attending anesthesiologist 
o American Society of Anesthesiologists (ASA) score > 3 
o Body Mass Index (BMI) > 40 
o active drug abuse 
o contraindication for Propofol or Esketamine  
 
 
Intervention 
 
Referred patients will follow either the standard pathway or a newly developed fast-track 
pathway, specifically designed with regard of the local logistics and structure at the Dept. of EM, 
University Hospital of Southern Denmark, Esbjerg.  
 
Patient reported to the coordinating nurse at the Department of Emergency Medicine, fulfilling 
the inclusion criteria’s, without violating exclusion criteria’s 
 
  
 
                   Standard Pathway                                                        Fast-track Pathway 
       (September 2024 - August 2025)                                 (September 2025 - August 2026)              
Patient arrival through the ambulance 
entrance  
Patient arrival through the ambulance 
entrance 
Patient admitted to the Dept. of EM ward 
(Team 1 or 2), and transferred to a regular, 
standard patient bed 
Patient is delivered directly to emergency 
trauma room no. 4 (located in conjunction of 
the ambulance entrance), and transferred to a 
radiolucent trauma bed 
Patient is seen by the delegated nurse; vital 
parameters measured and registered, together 
with patient information 
The orthopedic doctor AND the 
anesthesiologist on duty is notified and will 
arrive to the trauma room at their earliest 
convenience, depending on other acute 
activities 
Patient is examined by one of three doctors on 
duty from the Dept. of Orthopedics, when 
Patient is seen by the delegated nurse; vital 
parameters measured and registered, together 
with patient information, and X-ray is ordered 

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available (varying degree of education), and X-
ray is ordered 
Patient is moved to the X-ray room (same floor 
level), (transfer to a special X-ray bearing is 
required) and will be returned to the bed ward 
The diagnosis is verified by X-ray on site, by 
transportable X-ray machine, carried out by 
the radiology staff, without the need for 
patient transfer  
Diagnosis is verified and the patient’s medical 
files is updated 
Patient’s medical files is updated by the 
orthopedic doctor on duty (a standard 
paragraph will be developed for quick 
documentation in the medical records) 
Patient is booked for a closed reduction 
maneuver in the operating theater during a 
short general anesthesia  
The anesthesiologist on duty prepares for local 
sedation, following the sedation algorithm 
designed for this study, assisted by an 
anesthesiology nurse  
Patient is reported to the anesthesiologists on 
duty for the purpose of planning and 
preparation for the anesthetic procedure 
Closed reduction is completed, and control X-
ray is conducted immediately on site, by 
transportable X-ray machine, carried out by 
the radiology staff, without the need for 
patient transfer 
Patient is transferred to the operating theater, 
depending on other surgical activities and 
fasting time 
Patient is transferred to the Dept. of EM ward 
Closed reduction is completed during a short 
general anesthesia, often with simultaneous 
muscle relaxation. Patient is transferred back 
and forth to a surgical bearing to confirm 
reduction, using a C-arm X-ray (not useful for 
documentation) 
Patient is seen by a physiotherapist and 
mobilized with/without walking aids 
Patient return to the Dept. of EM bed ward 
Patient is discharged with/without a planned 
outpatient follow-up by a hip surgeon, 
depending on the specific patient case 
Patient is moved to the X-ray room for a 
control X-ray (same floor level), (transfer to a 
special X-ray bearing is required) and will be 
returned to the bed ward 
 
Patient is seen by a physiotherapist and 
mobilized with/without walking aids 
 

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Patient is discharged with/without a planned 
outpatient follow-up by a hip surgeon, 
depending on the specific patient case 
 
 
Assumed fast-track advantages includes  
- 
elimination of several patient transfers back and forth from the Dept. of EM bed ward to X-
ray rooms and operating theater (saves time and hospital resources) 
- 
elimination of several patient transfers between different beds (reduces patient pain and 
discomfort) 
- 
hip reduction in sedation rather than general anesthesia disregard of fasting time,- safely 
administered by anesthesiologists rather than by the orthopedic (saves time, increases 
safety) 
 
 
Detailed description of standard anesthetic procedure for patients enrolled for standard pathway 
hip reduction (current practice) 
 
Patients following the standard pathway and local guidelines, will receive a general anesthesia 
with a rapid sequence induction and intubation using Propofol 1-2 mg/kg, Alfentanil 0,2-0,3 mg/kg 
or Fentanyl 2-3 μg/kg and Suxamethonium 1 mg/kg. The patient is as a standard monitored with 
non-invasive blood pressure, saturation, pulse, 3-point ECG and end-tidal CO2. More extensive 
monitoring may be used if considered necessary by the attending anesthesiologist.  
 
 
Detailed description of new fast-track sedation procedure for patients enrolled for fast-track hip 
reduction 
 
The goal for the new fast-track sedation pathway is a short deep sedation, according to the 
definition of level of sedation by ASA (14). This is for optimal patient comfort and success and with 
very low risk of aspiration (15, 16). The patient is sedated with Propofol 0,5-1 mg/kg and/or 
Esketamine 0,1-0,5 mg/kg. If a repeat dose is necessary, it is with Propofol 0,2 mg/kg and/or 
Esketamine 0,1-0,5 mg/kg (17, 18). Before sedation an intravenous line is placed with 1 L Ringer 
Acetate and the patient will receive a nasal cannula with an oxygen flow of 2-5 L/min. During the 
sedation the patient is monitored with a non-invasive blood pressure, saturation, respiratory rate, 
pulse and 3-point ECG and the nurse anesthetist and anesthesiologist will continuously observe 
the depth of sedation and respiratory drive. After the hip reduction, the patient is observed and 
monitored until the sedation has worn of and there is no risk of airway obstruction.  
 
 

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Outcomes 
 
The primary outcome is time from arrival at the emergency entrance to prosthesis reduction. 
 
The secondary outcomes are: 
a) total hospitalization time from arrival to discharge 
b) intra-operative complications (fracture, unsuccessful reduction, aspiration, need for mask 
ventilation and/or intubation, others)  
c) post-operative complications (cardiac, pulmonal, thrombo-embolic events, nerve damage, 
re-dislocation, others) during hospitalization 
d) 30 days re-admission 
e) 30- and 90-days mortality 
f) hip-related pain measured by a 10-digit numeric rating scale (NRS)  
g) patient-reported outcome (PRO) using the Hip disability and Osteoarthritis Outcome Score 
(HOOS), domains 1)PAIN, 2)OTHER SYMPTOMS, 3)FUNCTION IN DAILY LIVING, AND 4)HIP-
RELATED QUALITY OF LIFE (19) 
h) Health-related quality of life using the EQ-5D questionnaire (20) 
i) patient satisfaction 
j) time consumption by the involved staff (orthopedic, anesthetic, radiology staff etc.) 
k) total hospital costs during admission 
 
Every admitted patient will be included for evaluation of the primary and secondary outcomes (a-e 
+ j-k) regardless of the patient’s cognitive status. However, the remaining secondary outcomes (f-i) 
will require that the patient is able to understand the Danish language and cognitively able to 
answer the questions meaningfully. A dedicated project nurse will assist during the hospital 
admission if required. A patient can be included several times due to recurrent dislocations which 
will be accounted for during statistical analysis. 
 
 
 
 
 
 
 
 
 
 
 
 
 

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8 
Outcome/variable time table  
 
Pre-admission 
(recall past 14 
days) 
Hospital ad-
mission (Day 0) 
Day 
1 
Day 
3 
Day 7 
Day 14 
Day 30 
Day 90 
Day 
180 
Day 
365 
 
Patient-reported outcomes 
NRS 
NRS 
NRS 
NRS 
NRS 
NRS 
NRS 
 
 
 
HOOS 
 
 
 
 
HOOS 
 
HOOS 
HOOS 
HOOS 
EQ-5D 
 
 
 
 
EQ-5D 
 
EQ-5D 
EQ-5D 
EQ-5D 
 
Satisfaction 
 
 
 
 
 
 
 
 
 
Registry/Patient file outcomes 
 
Time to 
reduction 
 
 
 
 
 
 
 
 
 
Time to 
discharge 
 
 
 
 
 
 
 
 
 
Per-operative 
Complications 
 
 
 
 
 
 
 
 
 
Post-operative 
complications 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Re-
admissions 
 
 
 
 
 
 
 
 
 
Mortality 
Mortality 
 
 
 
Patient variables 
 
Age 
 
 
 
 
 
 
 
 
 
Sex 
 
 
 
 
 
 
 
 
 
ASA-score 
 
 
 
 
 
 
 
 
 
BMI 
 
 
 
 
 
 
 
 
 
Specific 
comorbidities 
 
 
 
 
 
 
 
 
 
Prosthesis variables 
 
Primary 
operation date 
 
 
 
 
 
 
 
 
 
No. of previous 
dislocations 
 
 
 
 
 
 
 
 
 
Type of 
prosthesis (incl. 
liner type) 
 
 
 
 
 
 
 
 
 
Information acquired from patient files: Information regarding patient-related factors (age, sex, 
ASA-score, BMI, and specific comorbidities) and prosthesis-related factors (primary operation 
date, number of previous dislocations, and type of prosthesis), as well as information regarding 

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30-days readmission and mortality, and 90-days mortality will be acquired from the patient files 
after acquired patient consent.  The patient- and prosthesis-related factors will be used to control 
for potential confounding. The acquired patient file information is dated from admission to 90 
days post-admission. The prosthesis-related information is dated to the primary operation date. 
We will only access patient files from patients who accept to participate, therefore 120 patients.  
 
As the acute treatment has been performed when the patient is asked for consent, we apply for 
the use of the data acquired during the acute treatment of the patient, regardless of whether they 
choose to participate in the secondary part of the study regarding the patient-reported outcomes, 
in order to not prolong the study unnecessary.  This includes the patient- and prosthesis-related 
factors, as this will be used to control for potential residual confounding. 
 
 
Sample size 
 
Study sample size are based on the primary outcome “Time from arrival at the emergency 
entrance to prosthesis reduction”, applying a formula for RCT studies with clinically superiority 
design (21). The null-hypothesis dictates no difference in time from arrival at the emergency 
entrance to prosthesis reduction for patients following the Standard Pathway or the Fast-Track 
Pathway. 
 
N = no. of patients in each group 
Alpha-value = 0,05 (5% risk of type-1 error) 
Beta-value = 0,90 (10% risk of type-2 error) 
Delta-value (estimated true value between the two groups) » 4 hours 
Delta0-value (estimated clinical acceptable difference between the two groups) » 3 hours 
S-value (pooled standard deviation (SD) for both groups) » 2.5 hours 
 
A review of 16 randomly selected patients that was admitted to the University of Southern 
Denmark, Esbjerg, with a dislocated THA from January 2018 to May 2022 revealed a mean time 
from arrival at the emergency entrance to prosthesis reduction at 6 hours (range 2.7 – 9.0 hours) 
with a standard deviation at 1.6 hours.  
 
𝑁= 2 ×  &1,645 × 1,28
4 −3
/
!
× 2,5! ≈53 𝑝𝑎𝑡𝑖𝑒𝑛𝑡𝑠 𝑖𝑛 𝑒𝑎𝑐ℎ 𝑔𝑟𝑜𝑢𝑝 
 

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10 
Based on a review of the surgical procedures performed during the period 01.02 – 31.08.2022, we 
expect to admit 5-6 patients per month with a dislocated THA or HA, and we expect an attendance 
rate of >90% based on the primary outcome. Therefore, we will include 53 patients + 15% » 60 
patients in each group, due to the risk that specific comorbidities will lead to exclusion from the 
Fast-Track pathway by the anesthetic staff. It is thus expected that a total of 120 patients will be 
adhered to one of the two treatment algorithms over the course of 24 months. 
 
Blinding 
 
This study concerns emergency research without the possibility of informed consent prior to 
intervention, and the patients will not be informed regarding their participation in a scientific 
study on arrival. Post-reduction, the patients are encouraged to participate in the second part of 
the study involving patient-reported outcome measures. The patient will not be informed of 
whether they have been adhered to the standard or Fast-track treatment strategy and are 
therefore blinded regard the treatment.  
 
The orthopedic and anesthetic staff are not informed regarding the initiation of the current study 
and are therefore blinded in terms of the aim. The staff will be thoroughly instructed to adhere to 
the Fast-track strategy at the time for pathway shift. 
 
Patient information  
 
After reduction of the prosthesis, the patients are admitted to the ward at the Dept. of EM, 
regardless of the treatment received. During the admission, the patient will be interviewed by a 
dedicated study-nurse and informed about the study, without revealing the allocated treatment 
pathway. The rooms are single-patient only, in order to secure that the information can be given 
undisturbed. The patients will be screened for eligibility (cognitive status, language) for 
participation in the secondary part of the study, and the nurse will deliver patient information 
including a study overview depicting the timepoints for evaluation. When recruiting the patient for 
the secondary part of the project, it is stated that this is a scientific trial and that the patient has 
the right to have a companion present during the information, The patients are encouraged to 
respond before discharge, typically 12-24 hours after arrival. 
Up to 15-20% of patients admitted to the hospital with a dislocated THA/HA is cognitively 
impaired due to dementia in a degree that hinders reasonable questionnaire response. These 
patients require the same acute treatment as any other patient, and there is no reason for not 
including them in this study. Information will be given to the patient’s relatives, and we will ask for 
their permission to include the already obtained journal data in the study.  
 
Patent information folder is found in the appendix (in Danish). 

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11 
 
The patients are informed that consent gives the trial manager, sponsor and sponsor's 
representatives as well as any supervisory authority direct access to obtain information in the 
patient's medical record, etc., including electronic medical records, in order to see information 
about the subject's health, which is necessary as part of the implementation of the research 
project and for control purposes, including self-control, quality control and monitoring, which they 
are obliged to carry out. 
 
Statistics 
 
Mean values with standard deviation (SD) are given for normally distributed data, while median 
values with interquartile range (IQR) are given for skewed data. In case of normally distributed 
data, two-sample t-test is used. Mann-Whitney U-test is used to compare continuous 
nonparametric variables and chi-square test is used to compare categorical variables. STATA 
version 18 will be used for all statistical analyses. 
 
Economy 
 
The main investigator and initiator is Lars L. Hermansen, MD, Ph.D., post.doc. 
 
The study is conducted as a collaboration between the Department of Orthopedics, Department of 
Anesthesiology, Department of Radiology, and Department of Emergency Medicine, University 
Hospital of Southern Denmark, Esbjerg. There are no special economics involved in the study 
between the departments, as the study is carried out as a part of normal daily, acute activity. 
 
Vestjysk Orthopedic Fund will be applied for covering expenses to hardware (computer, Ipad etc.) 
 
The Region of Southern Denmark’s Research Fund will be applied for covering salary to a 
dedicated study nurse. 
Grants are administered via an account that is subject to public audit. 
 
There are no conflicts of interest. 
 
Ethics 
 
Permission to store and handle data is obtained upon application to the Region of Southern 
Denmark’s internal register (24/34681). The Danish Law of data protection is observed.  
 
The regional ethics committee has been applied for permission to conduct the study under special 
circumstances as acute research without the possibility of obtaining informed consent from the 

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12 
patient prior to intervention. The purpose and hypothesis of this study can simply not be 
investigated if the patients are admitted as usual and permitted time for consideration to 
participate or not. This group of patients suffers from a complication (a dislocated hip 
arthroplasty) that requires intervention (reduction of the prosthesis) as quick as possible, 
regardless of the patient’s cognitive status. There is only one treatment to this specific 
complication, and thus they will all receive the same surgical intervention whether they 
participate in the study or not. There is no reason to believe that the patients are exposed to 
greater risk by the Fast-Track pathway than Standard pathway. On the contrary, it is strongly 
expected that the patients will be treated significantly quicker during a smooth concept, thereby 
reducing the period in pain. Reduction in the emergency department (Fast-track pathway) is more 
likely to be even safer than current practice (due to the participation of the anesthesiologists), 
where the emergency staff and orthopedics are responsible for sedation outside the operating 
theater. The regional ethics committee has responded that the study does not require their 
permission, and the study can be conducted as a treatment-quality study, locally approved by the 
Executive Board at the University Hospital of Southern Denmark. 
 
X-ray radiation dose: 
 
The patients will be exposed for two different X-ray systems, depending on randomization. The 
patients following the standard pathway is transferred to a room, where a fixed, stationary X-ray 
system is applied, whereas a smaller, transportable X-ray machine is used for the patients 
randomized to the fast-track pathway. We have made a pre-liminary measurement of the 
radiation dosage to compare the two interventions. The conventional, standard machine exposes 
the patient for 0.1258 milliSievert (mSv), whereas the number is 0.1102 mSv for the mobile device. 
Therefore, our new pathway do not expose the patients for higher radiation doses. The annual 
background radiation in Denmark is 3-5 mSv, so the radiation doses are negligible and the study is 
categorized as IIa and justifiable if it leads to increased knowledge and health advantages. The 
lifetime cancer risk in Denmark is approx. 25%. This risk increases 5% pr. Sievert. Thus, 
participation in the study will increase the cancer risk to 25.0001%. 
 
Patient insurance: 
 
The Danish Patient Insurance Scheme (Patienterstatningsordningen) covers all subjects who 
participate in health science trials in Denmark. The coverage is described in the Legislative Order 
No. 995 of 14 June 2018 and covers all test subjects who are harmed during an experiment in 
Denmark. 
 
 
Presentation of results 
 

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Based on the data, a manuscript will be prepared for publication so that the results can be 
published in an internationally recognized journal. Positive, negative as well as inconclusive results 
are published in relevant national and international journals, and 2-4 publications are expected 
divided into orthopedic surgery and anesthesiologic measurement parameters. The results of the 
study will be presented at professional congresses at home and abroad. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Referencer 
 

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