Osteoarthritis, HipNCT07134036
Efficiency and Safety of Navigation Aids in Total Hip Arthroplasty With Direct Anterior Approach
An observational study of Osteoarthritis, Hip and Femur Head Necrosis, run by China Medical University Hospital at 1 site in Taiwan.
Trial summary
This retrospective cohort study aimed to evaluate the effectiveness of an imageless navigation system in total hip arthroplasty (THA) via the direct anterior approach (DAA) on a traction table for reducing functional limb length discrepancy (LLD) compared with conventional techniques. Read more about this study
- Who is it for?
- Ages 20 years and older
- Conditions the study is for
- Osteoarthritis, Hip, Femur Head Necrosis, Developmental Dysplasia of the Hip
- What is being tested?
- Navigation system and Conventional total hip arthroplasty
- Type of treatment
- Medical device, Surgery or procedure
- How many people
- 72 participants
- Where
- 1 siteTaiwan
- Study dates
- 1 Mar 2021to 30 Sep 2021
- Phase
- Observational
- 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 20 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: Participants with a diagnosis of advanced hip osteoarthritis (OA), avascular necrosis (AVN), or developmental dysplasia of the hip (DDH) warranting THA were consecutively enrolled. The exclusion criteria included a documented history of prior hip joint infection, severe limb length discrepancy, significant spinal pathologies, and radiographs in which the lesser trochanters and teardrops were difficult to define. Severe limb length discrepancy was defined as a preoperative limb length discrepancy ≥ 5 cm, as such cases typically require additional lengthening procedures beyond standard total hip arthroplasty20, 21. Significant spinal pathologies were defined as concomitant spine and hip disorders associated with persistent neurological signs and/or spinal instability that could not be adequately managed with conservative treatment and were considered likely to affect spinopelvic balance or functional limb length perception.
Who may be able to join
- Clinical diagnosis of advanced hip osteoarthritis (OA) warranting total hip arthroplasty (THA)
- Clinical diagnosis of avascular necrosis (AVN) of the femoral head warranting total hip arthroplasty (THA)
- Clinical diagnosis of developmental dysplasia of the hip (DDH) warranting total hip arthroplasty (THA)
Who cannot join
- Documented history of prior hip joint infection
- Severe limb length discrepancy requiring supplementary surgical interventions
- Significant spinal pathology affecting spinopelvic balance
- Radiographs in which the lesser trochanters and teardrops cannot be clearly defined
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Optimizing Limb Length Discrepancy in Navigated Total Hip Arthroplasty Through the Direct Anterior Approach on a Traction Table
This retrospective cohort study aimed to evaluate the effectiveness of an imageless navigation system in total hip arthroplasty (THA) via the direct anterior approach (DAA) on a traction table for reducing functional limb length discrepancy (LLD) compared with conventional techniques. Seventy-two patients with advanced hip osteoarthritis, avascular necrosis, or developmental dysplasia of the hip undergoing THA between March 1, 2021 and September 30, 2021 were included. Functional LLD was assessed using a preoperative block test. Participants were assigned to the navigation or conventional group based on patient preference. Outcomes included operative parameters, intraoperative fluoroscopy time, limb length measurements, and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores.
Read the detailed description
This single-center retrospective cohort study was conducted at the Joint Reconstruction Center of China Medical University Hospital between March 1, 2021 and September 30, 2021. Eligible participants were adults diagnosed with advanced hip osteoarthritis, avascular necrosis, or developmental dysplasia of the hip requiring THA. Exclusion criteria included prior hip joint infection, severe LLD requiring additional reconstructive procedures, significant spinal pathology affecting spinopelvic balance, or radiographs inadequate for measurement.
All procedures were performed via the direct anterior approach (DAA) on a traction table by the principal surgeon. Functional LLD was assessed preoperatively using a block test, with wooden blocks (5 mm increments) placed under the heel until the patient reported equal leg lengths.
Patients in the navigation group underwent THA with an imageless navigation system (Stryker OrthoMap Versatile Hip Navigation) to record intraoperative limb length change and acetabular cup positioning; the conventional group underwent standard THA without navigation.
Primary outcome was the patients' expectation gap (PEG), defined as the difference between preoperative functional LLD and postoperative radiographic limb length change. Secondary outcomes included intraoperative fluoroscopy time, WOMAC scores at baseline, 3 weeks, and 3 months postoperatively, and the proportion of outliers (PEG > 10 mm).
The study was approved by the Research Ethics Committee of China Medical University Hospital (CMUH112-REC1-149). Written informed consent was obtained from all participants, and the study adhered to the Declaration of Helsinki.
- Being tested
- Navigation system, Conventional total hip arthroplasty
- Keywords
- Direct Anterior Approach, Limb Length Discrepancy, Arthroplasty, Replacement, Hip, Surgery, Computer-Assisted, Surgical Navigation Systems
- Medical subject headings
- Osteoarthritis, Hip, Femur Head Necrosis, Developmental Dysplasia of the Hip
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Navigation systemDevice
Patients underwent total hip arthroplasty via the direct anterior approach using a computer navigation system to assist in intraoperative limb length measurement.
Conventional total hip arthroplastyProcedure or surgery
Patients underwent total hip arthroplasty via the direct anterior approach conventionally.
| Study group | Role | What they receive |
|---|---|---|
| Conventional THA | Participants in this group underwent total hip arthroplasty (THA) via the direct anterior approach on a traction table without the use of a computer navigation system. This arm represents the conventional surgical technique routinely performed at our institution, where intraoperative limb length assessment was based on standard fluoroscopic guidance and anatomical landmarks. Receives: Procedure: Conventional total hip arthroplasty | |
| Navigation-assisted THA | Participants in this group underwent total hip arthroplasty (THA) via the direct anterior approach on a traction table with the assistance of an imageless computer navigation system (Stryker OrthoMap Versatile Hip Navigation). The navigation system provided real-time intraoperative feedback on limb length change and acetabular cup positioning, aiming to improve accuracy and reduce reliance on fluoroscopy. Receives: Device: Navigation system |
What is being measured
The primary outcome is the main question the study is designed to answer.
Patients' Expectation Gap (PEG)
Difference between preoperative functional leg length discrepancy (measured with block test, mm) and postoperative radiographic leg length change (mm).
Measured: Baseline (preoperative) and 3 months postoperatively
Secondary outcomes (9)
Surgeons' Expectation Gap (SEG)
Difference between intraoperative navigation leg length measurement (mm) and postoperative radiographic leg length change (mm).
Measured: Intraoperative and 3 months postoperatively
Outlier Rate (>10 mm PEG)
Percentage of patients with Patients' Expectation Gap greater than 10 mm.
Measured: 3 months postoperatively
WOMAC Pain Score Change
Change in WOMAC pain subscale score (0-20, lower scores indicate less pain) from baseline.
Measured: Baseline, 3 weeks postoperatively, 3 months postoperatively
WOMAC Stiffness Score Change
Change in WOMAC stiffness subscale score (0-8, lower scores indicate less stiffness) from baseline.
Measured: Baseline, 3 weeks postoperatively, 3 months postoperatively
WOMAC Function Score Change
Change in WOMAC function subscale score (0-68, lower scores indicate better function) from baseline.
Measured: Baseline, 3 weeks postoperatively, 3 months postoperatively
Fluoroscopy Execution Time
Duration of intraoperative fluoroscopy use (seconds).
Measured: Intraoperative
Operative Time
Duration of total surgical procedure (minutes).
Measured: Intraoperative
Blood Loss
Total intraoperative blood loss (milliliters).
Measured: Intraoperative
Length Change
Difference in radiographic leg length pre- and postoperatively (mm).
Measured: Baseline and 3 months postoperatively
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted21 Aug 2025
- Study start1 Mar 2021
- Primary completion30 Sep 2021
- Study completion30 Sep 2021
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Osteoarthritis, HipStudies of the same condition, open and under way.
- More trials run by China Medical University HospitalThe 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
- Observational
- Observational model
- Cohort
- Time perspective
- Retrospective
- Enrolment
- 72 participants (actual)
Sponsor and investigators
- Lead sponsor
- China Medical University Hospital
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Chih-Hung Hung, China Medical University Hospital
- Investigators
- Chih-Hung Hung, MD, Principal investigator, China Medical University Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07134036
- Sponsor's protocol ID
- CMUH112-REC1-149
- Status last verified
- Sep 2026
- First submitted
- 5 Jul 2025
- Last updated
- 5 Oct 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- Yes
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 5 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Optimizing Limb Length Discrepancy in Navigated Total Hip Arthroplasty Through the Direct Anterior Approach on a Traction Table
- ClinicalTrials.gov ID
- NCT07134036
- Acronym / sponsor ID
- CMUH112-REC1-149
- Keywords
- Direct Anterior Approach, Limb Length Discrepancy, Arthroplasty, Replacement, Hip, Surgery, Computer-Assisted, Surgical Navigation Systems
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 72 participants (actual)
- Lead sponsor
- China Medical University HospitalUniversity, hospital or other
- Study start
- 1 Mar 2021 (actual)
- Primary completion
- 30 Sep 2021 (actual)
- Study completion
- 30 Sep 2021 (actual)
- First posted
- 21 Aug 2025 (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.
This retrospective cohort study aimed to evaluate the effectiveness of an imageless navigation system in total hip arthroplasty (THA) via the direct anterior approach (DAA) on a traction table for reducing functional limb length discrepancy (LLD) compared with conventional techniques. Seventy-two patients with advanced hip osteoarthritis, avascular necrosis, or developmental dysplasia of the hip undergoing THA between March 1, 2021 and September 30, 2021 were included. Functional LLD was assessed using a preoperative block test. Participants were assigned to the navigation or conventional group based on patient preference. Outcomes included operative parameters, intraoperative fluoroscopy time, limb length measurements, and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores.
Detailed description
This single-center retrospective cohort study was conducted at the Joint Reconstruction Center of China Medical University Hospital between March 1, 2021 and September 30, 2021. Eligible participants were adults diagnosed with advanced hip osteoarthritis, avascular necrosis, or developmental dysplasia of the hip requiring THA. Exclusion criteria included prior hip joint infection, severe LLD requiring additional reconstructive procedures, significant spinal pathology affecting spinopelvic balance, or radiographs inadequate for measurement.
All procedures were performed via the direct anterior approach (DAA) on a traction table by the principal surgeon. Functional LLD was assessed preoperatively using a block test, with wooden blocks (5 mm increments) placed under the heel until the patient reported equal leg lengths.
Patients in the navigation group underwent THA with an imageless navigation system (Stryker OrthoMap Versatile Hip Navigation) to record intraoperative limb length change and acetabular cup positioning; the conventional group underwent standard THA without navigation.
Primary outcome was the patients' expectation gap (PEG), defined as the difference between preoperative functional LLD and postoperative radiographic limb length change. Secondary outcomes included intraoperative fluoroscopy time, WOMAC scores at baseline, 3 weeks, and 3 months postoperatively, and the proportion of outliers (PEG > 10 mm).
The study was approved by the Research Ethics Committee of China Medical University Hospital (CMUH112-REC1-149). Written informed consent was obtained from all participants, and the study adhered to the Declaration of Helsinki.
Study design
- Observational model
- Cohort
- Time perspective
- Retrospective
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Conventional THA | – | Procedure: Conventional total hip arthroplastyParticipants in this group underwent total hip arthroplasty (THA) via the direct anterior approach on a traction table without the use of a computer navigation system. This arm represents the conventional surgical technique routinely performed at our institution, where intraoperative limb length assessment was based on standard fluoroscopic guidance and anatomical landmarks. |
| Navigation-assisted THA | – | Device: Navigation systemParticipants in this group underwent total hip arthroplasty (THA) via the direct anterior approach on a traction table with the assistance of an imageless computer navigation system (Stryker OrthoMap Versatile Hip Navigation). The navigation system provided real-time intraoperative feedback on limb length change and acetabular cup positioning, aiming to improve accuracy and reduce reliance on fluoroscopy. |
Who may qualify
- Ages
- 20 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Participants with a diagnosis of advanced hip osteoarthritis (OA), avascular necrosis (AVN), or developmental dysplasia of the hip (DDH) warranting THA were consecutively enrolled. The exclusion criteria included a documented history of prior hip joint infection, severe limb length discrepancy, significant spinal pathologies, and radiographs in which the lesser trochanters and teardrops were difficult to define. Severe limb length discrepancy was defined as a preoperative limb length discrepancy ≥ 5 cm, as such cases typically require additional lengthening procedures beyond standard total hip arthroplasty20, 21. Significant spinal pathologies were defined as concomitant spine and hip disorders associated with persistent neurological signs and/or spinal instability that could not be adequately managed with conservative treatment and were considered likely to affect spinopelvic balance or functional limb length perception.
Key inclusion criteria (3 listed)
- Clinical diagnosis of advanced hip osteoarthritis (OA) warranting total hip arthroplasty (THA)
- Clinical diagnosis of avascular necrosis (AVN) of the femoral head warranting total hip arthroplasty (THA)
- Clinical diagnosis of developmental dysplasia of the hip (DDH) warranting total hip arthroplasty (THA)
Key exclusion criteria (4 listed)
- Documented history of prior hip joint infection
- Severe limb length discrepancy requiring supplementary surgical interventions
- Significant spinal pathology affecting spinopelvic balance
- Radiographs in which the lesser trochanters and teardrops cannot be clearly defined
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 |
|---|---|---|
| Navigation systemPatients underwent total hip arthroplasty via the direct anterior approach using a computer navigation system to assist in intraoperative limb length measurement. | Device | Navigation-assisted THA |
| Conventional total hip arthroplastyPatients underwent total hip arthroplasty via the direct anterior approach conventionally. | Procedure or surgery | Conventional THA |
Primary outcome
Patients' Expectation Gap (PEG)
Time frame: Baseline (preoperative) and 3 months postoperatively
Difference between preoperative functional leg length discrepancy (measured with block test, mm) and postoperative radiographic leg length change (mm).
9 secondary outcomes
Surgeons' Expectation Gap (SEG)
Time frame: Intraoperative and 3 months postoperatively
Outlier Rate (>10 mm PEG)
Time frame: 3 months postoperatively
WOMAC Pain Score Change
Time frame: Baseline, 3 weeks postoperatively, 3 months postoperatively
WOMAC Stiffness Score Change
Time frame: Baseline, 3 weeks postoperatively, 3 months postoperatively
WOMAC Function Score Change
Time frame: Baseline, 3 weeks postoperatively, 3 months postoperatively
Fluoroscopy Execution Time
Time frame: Intraoperative
Operative Time
Time frame: Intraoperative
Blood Loss
Time frame: Intraoperative
Length Change
Time frame: Baseline and 3 months postoperatively
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 5 Oct 2026.
- Individual participant dataSharing planned: No
Related trials for Osteoarthritis, Hip
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Effects of EDUcation and EXercise Compared to Education Alone on Clinical and Physiological Outcomes in Patients With Hip Osteoarthritis
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Comparison of Spinal Anesthesia With Intrathecal Morphine Versus PENG Block With or Without Dexamethasone in Hip Arthroplasty
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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.
Chih-Hung Hung, MD principal investigator
China Medical University Hospital
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Osteoarthritis, Hip and Femur Head Necrosis, run by China Medical University Hospital at 1 site in Taiwan.
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 3 inclusion and 4 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 5 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Taiwan. 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?
Patients' Expectation Gap (PEG) (time frame: Baseline (preoperative) and 3 months postoperatively). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
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 5 Oct 2026.