Hip DysplasiaNCT03941171
Is Periacetabular Osteotomy Superior to Progressive Resistance Training?
A study testing PAO and PRT in people with Hip Dysplasia, run by University of Aarhus at 3 sites in 2 countries.
Trial summary
The primary aim of this study is to examine if Periacetabular Osteotomy (PAO) followed by 4 months of usual care followed by 8 months of progressive resistance training (PRT) is superior to 12 months of a PRT intervention in patients with hip dysplasia eligible for PAO in terms of self-reported pain on the HAGOS… Read more about this study
- Who is it for?
- Ages 18 to 40 yearsHealthy volunteers can take part
- Conditions the study is for
- Hip Dysplasia
- What is being tested?
- PAO and PRT
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 69 participants
- Where
- 3 sitesin 2 countries
- Study dates
- 1 Jul 2019to 15 Sep 2025
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 40 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Patients aged 18-45 years and diagnosed with hip dysplasia referred from primary care to the Department of Orthopaedic Surgery at one of the two participating hospitals.
- Considered eligible for PAO by a surgeon.
- Radiographic verified hip dysplasia (CE-angle <25 degrees and AI-angle >10 degrees) and clinical symptoms.
- Range of motion: internal rotation >15 degrees, external rotation >15 degrees, hip flexion >110 degrees.
- Able to commute to training sessions.
Who cannot join
- OA degree ≥1 on classification of Tönnis'.
- CE-angle <10 degrees.
- Previous pelvic surgery for hip dysplasia (affected side).
- Calvé Legg Perthes or epifysiolysis.
- Simultaneous bilateral PAO.
- Previous surgery for herniated disc, spondylodesis, arthroplasty of hip, knee or ankle.
Show all 10Show fewer
- Previous surgery of the hip (tenotomy of iliopsoas tendon, z-plastic of the iliotibial tract or hip arthroscopy) in index leg.
- Neurological or rheumatoid diseases that affect the hip function.
- Inadequacy in written and spoken Danish or Norwegian.
- Body Mass Index (BMI) >25 in Aarhus and BMI >30 in Oslo and Odense
Trial locations and contacts
3 sites in 2 countries.
3 sites in 2 countries
Denmark2 sites
Lisa Urup Tønning
Aarhus N, Central Jutland, 8200
Odense University Hospital
Odense, Fyn, 5000
About this study
Official title: The Effect of PAO Followed by Progressive Resistance Training Versus Progressive Resistance Training in Patients With Hip Dysplasia. A Randomized Controlled Trial
The primary aim of this study is to examine if Periacetabular Osteotomy (PAO) followed by 4 months of usual care followed by 8 months of progressive resistance training (PRT) is superior to 12 months of a PRT intervention in patients with hip dysplasia eligible for PAO in terms of self-reported pain on the HAGOS questionnaire. Secondary aims are to investigate changes in patient-reported symptoms, physical function in daily living, physical function in sport and recreation, hip and/or groin-related quality of life, generic health status, functional performance, muscle strength, physical activity and adverse events between PAO followed by usual care+PRT compared to PRT only. We hypothesise that in patients with hip dysplasia, PAO followed by usual care+PRT, results in significantly less pain at 12 months follow-up, compared to PRT only.
Read the detailed description
Group 1 (PAO+usual+PRT):
PAO will be performed as the trans-sartorial approach or the anterior pelvic approach. Patients commence post-operative rehabilitation as usual and follow the rehabilitation program guided by a physiotherapist specialized in hip problems until 4 months after the operation. 4 months postoperative the patients complete usual care and continue with the same PRT intervention program as the PRT group, with 4 months of supervised sessions (see description below).
Group 2 (PRT):
The PRT group receives 4 months of supervised PRT 2 times per week. A physiotherapist or students will supervise all training sessions the first 4 weeks. The following 4 weeks, 6 out of 8 training sessions are supervised and from week 9-16, half of the training sessions (8 out of 16) are supervised. After these 4 months (16 weeks), patients receive a free membership to a fitness center near their home address and are encouraged to train on their own 2 times per week until 12 months follow-up with one supervised session per month. The PRT program involves 10-min of warm up followed by 50-min of bilateral resistance exercises including sets of loaded squats, hip extension, hip flexion, and hip abduction. The absolute training load will be individually adjusted on a set-by-set basis, using the plus two principle (if the patient is able to perform two or more repetitions than required, the load is increased). Hip related pain levels up to 5 on the VAS is considered acceptable during exercise.
The study is a multicentre randomised controlled and assessor blinded trial. Primary endpoint will be 12 months after initiation of surgical/non-surgical treatment. Secondary endpoints will be measured at 4 months after the start of the treatment (surgical/non-surgical). In addition, 5-year and 10-year follow-up with questionnaires is planned.
- Conditions
- Hip Dysplasia
- Being tested
- PAO, Usual care after PAO, PRT
- Keywords
- Periacetabular Osteotomy, Progressive resistance training, PAO
- Medical subject headings
- Hip Dislocation
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
PAOProcedure or surgery
PAO will be performed as the trans-sartorial approach or the anterior pelvic approach.
Usual care after PAOOther
Patients commence post-operative rehabilitation as usual and follow the rehabilitation program guided by a physiotherapist specialized in hip problems until 4 months after the operation.
PRTOther
4 months of partly supervised progressive resistance training 2 times per week. After these 4 months (16 weeks), patients receive a free membership to a fitness center near their home address and are encouraged to train on their own 2 times per week until 12 months follow-up with one supervised session per month. The PRT program involves 10-min of warm up followed by 50-min of bilateral resistance exercises including sets of squats, hip extension, hip flexion, and hip abduction.
| Study group | Role | What they receive |
|---|---|---|
| Group 1 | Experimental | PAO+usual+PRT Receives: Procedure: PAO; Other: Usual care after PAO; Other: PRT |
| Group 2 | Active comparator | PRT Receives: Other: PRT |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in pain related to hip function, between baseline and 12 months follow-up
The pain subscale of the patient reported questionnaire Copenhagen Hip and Groin Outcome Score (HAGOS), were the total score ranges from 0 (worst) to 100 (best).
Measured: Measured at baseline, 4 month follow-up and 12 month follow-up
Secondary outcomes (8)
Change in self-reported hip function
The subscales; Symptoms, Physical function in daily living, Physical function in Sport and Recreation, Participation in Physical Activities and hip and/or groin-related Quality of Life of the patient reported questionnaire Copenhagen Hip and Groin Outcome Score (HAGOS), where the total score ranges from 0 (worst) to 100 (best).
Measured: Measured at baseline, 4 month follow-up and 12 month follow-up
Change in hip function
Single leg hop for distance is a test that measure functional performance requiring both strength, power and balance. The distance from start to landing is measured in cm. and height adjusted by dividing the distance of the hop with the height of the patient.
Measured: Measured at baseline, 4 month follow-up and 12 month follow-up
Change in balance function
The Y balance test require strength, flexibility, neuromuscular control, stability, range of movement, balance and proprioception. These elements are tested and the maximal reach distance is recorded for each direction (anterior, posteromedial and posteroladeral). The composite reach is calculated and normalized to limb length for analysis of the overall performance on the test.
Measured: Measured at baseline, 4 month follow-up and 12 month follow-up
Number of patients with adverse events and serious adverse events after PAO
Adverse events:
- Haematoma
- Delayed wound closure
- Dysaethesia of lateral femoral cutaneous nerve
- Malpositioning; retroversion or insufficient reorientation. Insufficient reorientation (coverage) - optimal is CE angle 30-40 degrees. AI angle 0-10 degrees.
- Heterotopic ossifications (Brooker I and II)
- Urinary tract infections
- Infection not requiring surgical revision
Serious adverse events:
- Avascular necrosis of the femoral head or acetabulum
- Nerve palsy
- Major bleeding (administration of more than 5 blood units intra- and postoperatively)
- Peroneal and femoral neurapraxia
- Deep vein thrombosis
- Pulmonary embolism
- Stress fracture of ischial bone and posterior column
- Intraarticular osteotomy
- Heterotopic ossifications (Brooker III and IV)
- Infection requiring surgical revision
- Loss of fixation/loss of reorientation
- Delayed or non-union of pubic, ischial or iliac bone
Measured: Reported within 12 months after surgery
Change in usage of painkillers
Usage of painkillers (yes/no), including type of painkillers (Paracetamol, NSAID, Morfin/opiods and/other type of medicine)
Measured: Measured at baseline, 4 month follow-up and 12 month follow-up
Change in self-reported pain
Pain reported by the Visual Analogue Scale (VAS). A scale where pain is marked from 0-100, and 0 is no pain and 100 is worst imaginable pain.
Measured: Measured at baseline, 4 month follow-up and 12 month follow-up
Change in hip awareness
Hip awareness is measured with the Forgotten Joint Score questionnaire (FJS), where each patient completes the 12 questions regarding awareness of their affected hip. Each question is answered with one of the following options; never, almost never, seldom, sometimes and mostly, corresponding to a score of 1-5. The sum of the scores will be converted into a score between 0-100. A high score will indicate lack of awareness and a low score will indicate great awareness of the affected hip.
Measured: Measured at baseline, 4 month follow-up and 12 month follow-up
Change in muscle strength
Muscle strength in hip-abduction, hip-flexion and hip-extension is measured isometrically, with a dynamometer.
Measured: Measured at baseline, 4 month follow-up and 12 month follow-up
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted7 May 2019
- Study start1 Jul 2019
- Primary completion15 Sep 2025
- Study completion15 Sep 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Hip DysplasiaStudies of the same condition, open and under way.
- More trials run by University of AarhusThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- Randomized controlled trial
- Masking
- Single blind
- Who is masked
- Outcomes assessor
- Enrolment
- 69 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Aarhus
- Sponsor type
- University, hospital or other
- Collaborators
- Aarhus University Hospital, VIA University College
- Responsible party
- Sponsor
- Investigators
- Lisa U Tønning, MSc, Principal investigator, Department of Orthopedic Surgery, Aarhus University Hospital, DenmarkInger Mechlenburg, DMSc, PhD, Study director, Department of Clinical Medicine, Aarhus University, DenmarkUlrik Dalgas, MSc, PhD, Study director, Department of Public Health - Sport, Aarhus University, DenmarkStig S Jakobsen, PhD, Study director, Department of Orthopedic Surgery, Aarhus University Hospital, DenmarkKjeld Søballe, DMSc, Study director, Department of Orthopedic Surgery, Aarhus University Hospital, DenmarkJulie S Jacobsen, MSc, Study director, Department of Physiotherapy & Research Centre in Health and Welfare Technology, VIA University College, DenmarkJan E Madsen, MD, PhD, Study director, Department of Orthopedic Surgery, Oslo University Hospital, NorwayLars Nordsletten, PhD, Study director, Division of Orthopaedic Surgery, Oslo University Hospital, Oslo; Faculty of Medicine, University of Oslo, Norway
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT03941171
- Sponsor's protocol ID
- PreserveHIP
- Status last verified
- Oct 2025
- First submitted
- 29 Apr 2019
- Last updated
- 29 May 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: Aarhus University Hospital is responsible for handling all personal data provided by both sites in accordance to the Clinical Trial Agreement and the EU General Data Protection Regulation (GDPR).
Publications
Reimer LCU, Jakobsen SS, Mortensen L, Dalgas U, Jacobsen JS, Soballe K, Bere T, Madsen JE, Nordsletten L, Risberg MA, Mechlenburg I. Efficacy of periacetabular osteotomy followed by progressive resistance training compared to progressive resistance training as non-surgical treatment in patients with hip dysplasia (PreserveHip) - a protocol for a randomised controlled trial. BMJ Open. 2019 Dec 23;9(12):e032782. doi: 10.1136/bmjopen-2019-032782.
PubMed 31874882
Study at a glance
From the registry record, last updated by the sponsor on 29 May 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Effect of PAO Followed by Progressive Resistance Training Versus Progressive Resistance Training in Patients With Hip Dysplasia. A Randomized Controlled Trial
- ClinicalTrials.gov ID
- NCT03941171
- Acronym / sponsor ID
- PreserveHIP
- Conditions
- Hip Dysplasia
- Keywords
- Periacetabular Osteotomy, Progressive resistance training, PAO
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 69 participants (actual)
- Lead sponsor
- University of AarhusUniversity, hospital or other
- Collaborators
- Aarhus University Hospital, VIA University College
- Study start
- 1 Jul 2019 (actual)
- Primary completion
- 15 Sep 2025 (actual)
- Study completion
- 15 Sep 2025 (actual)
- First posted
- 7 May 2019 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The primary aim of this study is to examine if Periacetabular Osteotomy (PAO) followed by 4 months of usual care followed by 8 months of progressive resistance training (PRT) is superior to 12 months of a PRT intervention in patients with hip dysplasia eligible for PAO in terms of self-reported pain on the HAGOS questionnaire. Secondary aims are to investigate changes in patient-reported symptoms, physical function in daily living, physical function in sport and recreation, hip and/or groin-related quality of life, generic health status, functional performance, muscle strength, physical activity and adverse events between PAO followed by usual care+PRT compared to PRT only. We hypothesise that in patients with hip dysplasia, PAO followed by usual care+PRT, results in significantly less pain at 12 months follow-up, compared to PRT only.
Detailed description
Group 1 (PAO+usual+PRT):
PAO will be performed as the trans-sartorial approach or the anterior pelvic approach. Patients commence post-operative rehabilitation as usual and follow the rehabilitation program guided by a physiotherapist specialized in hip problems until 4 months after the operation. 4 months postoperative the patients complete usual care and continue with the same PRT intervention program as the PRT group, with 4 months of supervised sessions (see description below).
Group 2 (PRT):
The PRT group receives 4 months of supervised PRT 2 times per week. A physiotherapist or students will supervise all training sessions the first 4 weeks. The following 4 weeks, 6 out of 8 training sessions are supervised and from week 9-16, half of the training sessions (8 out of 16) are supervised. After these 4 months (16 weeks), patients receive a free membership to a fitness center near their home address and are encouraged to train on their own 2 times per week until 12 months follow-up with one supervised session per month. The PRT program involves 10-min of warm up followed by 50-min of bilateral resistance exercises including sets of loaded squats, hip extension, hip flexion, and hip abduction. The absolute training load will be individually adjusted on a set-by-set basis, using the plus two principle (if the patient is able to perform two or more repetitions than required, the load is increased). Hip related pain levels up to 5 on the VAS is considered acceptable during exercise.
The study is a multicentre randomised controlled and assessor blinded trial. Primary endpoint will be 12 months after initiation of surgical/non-surgical treatment. Secondary endpoints will be measured at 4 months after the start of the treatment (surgical/non-surgical). In addition, 5-year and 10-year follow-up with questionnaires is planned.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (outcomes assessor)
- Number of arms
- 2
- Model description
- Randomized controlled trial
| Arm | Type | Receives |
|---|---|---|
| Group 1 | Experimental | Procedure: PAO, Other: Usual care after PAO, Other: PRTPAO+usual+PRT |
| Group 2 | Active comparator | Other: PRTPRT |
Who may qualify
- Ages
- 18 to 40 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (5 listed)
- Patients aged 18-45 years and diagnosed with hip dysplasia referred from primary care to the Department of Orthopaedic Surgery at one of the two participating hospitals.
- Considered eligible for PAO by a surgeon.
- Radiographic verified hip dysplasia (CE-angle <25 degrees and AI-angle >10 degrees) and clinical symptoms.
- Range of motion: internal rotation >15 degrees, external rotation >15 degrees, hip flexion >110 degrees.
- Able to commute to training sessions.
Key exclusion criteria (10 listed)
- OA degree ≥1 on classification of Tönnis'.
- CE-angle <10 degrees.
- Previous pelvic surgery for hip dysplasia (affected side).
- Calvé Legg Perthes or epifysiolysis.
- Simultaneous bilateral PAO.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| PAOPAO will be performed as the trans-sartorial approach or the anterior pelvic approach. | Procedure or surgery | Group 1 |
| Usual care after PAOPatients commence post-operative rehabilitation as usual and follow the rehabilitation program guided by a physiotherapist specialized in hip problems until 4 months after the operation. | Other | Group 1 |
| PRT4 months of partly supervised progressive resistance training 2 times per week. After these 4 months (16 weeks), patients receive a free membership to a fitness center near their home address and are encouraged to train on their own 2 times per week until 12 months follow-up with one supervised session per month. The PRT program involves 10-min of warm up followed by 50-min of bilateral resistance exercises including sets of squats, hip extension, hip flexion, and hip abduction. | Other | Group 1, Group 2 |
Primary outcome
Change in pain related to hip function, between baseline and 12 months follow-up
Time frame: Measured at baseline, 4 month follow-up and 12 month follow-up
The pain subscale of the patient reported questionnaire Copenhagen Hip and Groin Outcome Score (HAGOS), were the total score ranges from 0 (worst) to 100 (best).
8 secondary outcomes
Change in self-reported hip function
Time frame: Measured at baseline, 4 month follow-up and 12 month follow-up
Change in hip function
Time frame: Measured at baseline, 4 month follow-up and 12 month follow-up
Change in balance function
Time frame: Measured at baseline, 4 month follow-up and 12 month follow-up
Number of patients with adverse events and serious adverse events after PAO
Time frame: Reported within 12 months after surgery
Change in usage of painkillers
Time frame: Measured at baseline, 4 month follow-up and 12 month follow-up
Change in self-reported pain
Time frame: Measured at baseline, 4 month follow-up and 12 month follow-up
Change in hip awareness
Time frame: Measured at baseline, 4 month follow-up and 12 month follow-up
Change in muscle strength
Time frame: Measured at baseline, 4 month follow-up and 12 month follow-up
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 29 May 2026.
- Derived from this study: PubMed 31874882Reimer LCU, Jakobsen SS, Mortensen L, Dalgas U, Jacobsen JS, Soballe K, Bere T, Madsen JE, Nordsletten L, Risberg MA, Mechlenburg I. Efficacy of periacetabular osteotomy followed by progressive resistance training compared to progressive resistance training as non-surgical treatment in patients with hip dysplasia (PreserveHip) - a protocol for a randomised controlled trial. BMJ Open. 2019 Dec 23;9(12):e032782. doi: 10.1136/bmjopen-2019-032782.
- Individual participant dataSharing planned: Yes. Aarhus University Hospital is responsible for handling all personal data provided by both sites in accordance to the Clinical Trial Agreement and the EU General Data Protection Regulation (GDPR).
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Lisa U Tønning, MSc principal investigator
Department of Orthopedic Surgery, Aarhus University Hospital, Denmark
Inger Mechlenburg, DMSc, PhD study director
Department of Clinical Medicine, Aarhus University, Denmark
Ulrik Dalgas, MSc, PhD study director
Department of Public Health - Sport, Aarhus University, Denmark
3 sites in 2 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing PAO and PRT in people with Hip Dysplasia, run by University of Aarhus at 3 sites in 2 countries.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 10 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 29 May 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 3 sites in Denmark, Norway. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in pain related to hip function, between baseline and 12 months follow-up (time frame: Measured at baseline, 4 month follow-up and 12 month follow-up). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT03941171, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 29 May 2026.