ArthroplastyCAR-NAV-ALNCT07574775
Is It Possible to Obtain Reliable MPTA and LDFA Values Using Imageless Navigation in Total Knee Arthroplasty? Comparison Between Preoperative CT Scan Measurements and Intraoperative Bone Morphing Before and After Articular Cartilage Removal
A study testing Non-image-based Computer-Assisted Navigation with Bone Morphing in people with Arthroplasty and Bone Morphing, run by Groupe Hospitalier Diaconesses Croix Saint-Simon at 1 site in France.
Trial summary
Title: Evaluation of Image-less Navigation Accuracy in Total Knee Arthroplasty (CARNAVAL) Summary: The purpose of this study is to evaluate the accuracy of an imageless navigation system in measuring key anatomical angles (MPTA and LDFA) during Total Knee Arthroplasty (TKA). Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Arthroplasty, Bone Morphing, Knee Osteoarthritis
- What is being tested?
- Non-image-based Computer-Assisted Navigation with Bone Morphing
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 50 participants
- Where
- 1 siteFrance
- Study dates
- 7 Jul 2025to 30 Oct 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 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Patients aged 18 years or older.
- Patients with primary or secondary knee osteoarthritis requiring a Total Knee Arthroplasty (TKA).
- Patients for whom the surgical planning requires a pre-operative 3D CT scan.
- Patients who have been informed about the study and have signed the written informed consent.
- Patients affiliated with or beneficiaries of a social security scheme.
Who cannot join
- Revision Total Knee Arthroplasty (re-operation).
- Major bone loss or significant bone deformity that prevents reliable anatomical landmarking.
- History of prior knee surgery that could interfere with the navigation system trackers (e.g., retained hardware in the femur or tibia).
- Pregnant or breastfeeding women.
- Persons deprived of liberty or under legal guardianship.
- Patients with a known allergy to any component used during the standard surgical procedure.
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Is It Possible to Obtain Reliable MPTA and LDFA Values Using Imageless Navigation in Total Knee Arthroplasty? Comparison Between Preoperative CT Scan Measurements and Intraoperative Bone Morphing Before and After Articular Cartilage Removal.
Title: Evaluation of Image-less Navigation Accuracy in Total Knee Arthroplasty (CARNAVAL)
Summary:
Read more
The purpose of this study is to evaluate the accuracy of an imageless navigation system in measuring key anatomical angles (MPTA and LDFA) during Total Knee Arthroplasty (TKA). While preoperative CT scans are currently the gold standard for bone planning, imageless navigation uses a "bone morphing" technique during surgery to create a digital model of the knee.
The study aims to determine if the measurements obtained via bone morphing, both before and after cartilage removal, are consistent with the measurements obtained from preoperative CT scans. The investigators seek to confirm if imageless navigation can provide reliable anatomical data, potentially reducing the need for preoperative radiation and costs associated with CT imaging.
Read the detailed description
Background:
Accurate alignment is critical for the long-term success of Total Knee Arthroplasty (TKA). Newer robotic and navigated systems rely on bone morphing to define the patient's anatomy per-operatively. However, the impact of cartilage thickness and the intrinsic accuracy of these systems compared to 3D CT-based planning remain subjects of clinical interest.
Objectives:
The primary objective is to compare the Medial Proximal Tibial Angle (MPTA) and the Lateral Distal Femoral Angle (LDFA) measured by:
Preoperative CT scan (Reference standard).
Peroperative image-less navigation (bone morphing) with intact cartilage.
Peroperative image-less navigation (bone morphing) after cartilage removal.
Methodology:
This is a prospective, monocentric, interventional study. All included patients will undergo a standard preoperative 3D CT scan as part of the surgical planning. During the TKA procedure, the surgeon will use the navigation system to perform bone morphing at two specific stages:
Initial stage: On the joint surface with the cartilage still present.
Secondary stage: After the surgical removal of the articular cartilage.
Comparison:
The data collected peroperatively will be compared to the CT scan measurements. The study will evaluate the "fidelity" (accuracy) of the navigation system and analyze whether the presence or absence of cartilage significantly alters the reliability of the digital bone model created by the system.
Expected Outcomes:
The results will help determine the degree of confidence surgeons can place in imageless navigation for achieving precise anatomical alignment without the systematic use of preoperative 3D imaging.
- Conditions
- Arthroplasty, Bone Morphing, Knee Osteoarthritis
- Being tested
- Non-image-based Computer-Assisted Navigation with Bone Morphing
- Keywords
- Lateral Distal Femur Angle (LDFA), Medial Proximal Tibial Angle (MPTA), Imageless navigation, Total Knee arthroplasty
- Medical subject headings
- Osteoarthritis, Knee
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Non-image-based Computer-Assisted Navigation with Bone MorphingProcedure or surgery
Intraoperative surface morphing of the joint surfaces is performed to obtain LDFA and MPTA values. The procedure compares measurements taken on the residual cartilage versus measurements taken directly on the osseous surface after cartilage debridement. These values are then validated against preoperative 3D CT scan data.
| Study group | Role | What they receive |
|---|---|---|
| Navigation and CT-scan Comparison Group) | Experimental | All participants undergo Total Knee Arthroplasty (TKA) using an imageless navigation system. Anatomical measurements (MPTA and LDFA) are recorded via bone morphing at two stages: 1) on intact articular cartilage and 2) after cartilage removal. Receives: Procedure: Non-image-based Computer-Assisted Navigation with Bone Morphing |
What is being measured
The primary outcome is the main question the study is designed to answer.
Mean Difference in Medial Proximal Tibial Angle (MPTA) between CT scan and Imageless Navigation.
The mean difference (measured in degrees) between the MPTA calculated from the preoperative 3D CT scan and the MPTA measured intraoperatively via bone morphing after cartilage removal.
Measured: At the time of surgery (intra-operative).
Secondary outcomes (2)
Mean Difference in Lateral Distal Femoral Angle (LDFA) between CT scan and Imageless Navigation.
The mean difference (measured in degrees) between the LDFA calculated from the preoperative 3D CT scan and the LDFA measured intraoperatively via bone morphing after cartilage removal.
Measured: At the time of surgery (intraoperative)
Correlation of MPTA and LDFA measurements before and after cartilage removal.
Evaluation of the measurement shift (in degrees) caused by the presence of articular cartilage during the bone morphing process. This assesses the system's ability to extrapolate the subchondral bone surface.
Measured: At the time of surgery (intra-operative).
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted8 May 2026
- Study start7 Jul 2025
- Primary completion30 Oct 2025
- Study completion30 Oct 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (3)Papers the sponsor has linked to this study.
- Other trials for ArthroplastyStudies of the same condition, open and under way.
- 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
- Health services research
- Allocation
- Not applicable
- Intervention model
- Single group
- Model description
- This is a prospective, single-group diagnostic accuracy study where each participant serves as their own control. For every patient, anatomical measurements (MPTA and LDFA) are obtained and compared using three different methods: Reference Standard: Preoperative 3D CT scan. Index Test A: Peroperative image-less navigation (bone morphing) performed on intact articular cartilage. Index Test B: Peroperative image-less navigation (bone morphing) performed after complete surgical removal of the cartilage. This intra-subject design allows for a direct comparison of the navigation system's fidelity against the gold-standard CT scan, while specifically isolating the impact of cartilage thickness on measurement accuracy.
- Masking
- None (open label)
- Enrolment
- 50 participants (actual)
Sponsor and investigators
- Lead sponsor
- Groupe Hospitalier Diaconesses Croix Saint-Simon
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Antoine MOUTON, Orthopedic surgeon, Principal investigator, Diaconesses Croix Saint Simon Hospital Group
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07574775
- Sponsor's protocol ID
- 2025-A00825-44
- Acronym
- CAR-NAV-AL
- Status last verified
- May 2026
- First submitted
- 28 Apr 2026
- Last updated
- 14 May 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Blakeney WG, Khan RJ, Wall SJ. Computer-assisted techniques versus conventional guides for component alignment in total knee arthroplasty: a randomized controlled trial. J Bone Joint Surg Am. 2011 Aug 3;93(15):1377-84. doi: 10.2106/JBJS.I.01321.
PubMed 21915542MacDessi SJ, Griffiths-Jones W, Harris IA, Bellemans J, Chen DB. Coronal Plane Alignment of the Knee (CPAK) classification. Bone Joint J. 2021 Feb;103-B(2):329-337. doi: 10.1302/0301-620X.103B2.BJJ-2020-1050.R1.
PubMed 33517740Rossi SMP, Sangaletti R, Perticarini L, Terragnoli F, Benazzo F. High accuracy of a new robotically assisted technique for total knee arthroplasty: an in vivo study. Knee Surg Sports Traumatol Arthrosc. 2023 Mar;31(3):1153-1161. doi: 10.1007/s00167-021-06800-8. Epub 2022 Jan 4.
PubMed 34981162
Study at a glance
From the registry record, last updated by the sponsor on 14 May 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Is It Possible to Obtain Reliable MPTA and LDFA Values Using Imageless Navigation in Total Knee Arthroplasty? Comparison Between Preoperative CT Scan Measurements and Intraoperative Bone Morphing Before and After Articular Cartilage Removal.
- ClinicalTrials.gov ID
- NCT07574775
- Acronym / sponsor ID
- CAR-NAV-AL / 2025-A00825-44
- Conditions
- Arthroplasty, Bone Morphing, Knee Osteoarthritis
- Keywords
- Lateral Distal Femur Angle (LDFA), Medial Proximal Tibial Angle (MPTA), Imageless navigation, Total Knee arthroplasty
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 50 participants (actual)
- Lead sponsor
- Groupe Hospitalier Diaconesses Croix Saint-SimonUniversity, hospital or other
- Study start
- 7 Jul 2025 (actual)
- Primary completion
- 30 Oct 2025 (actual)
- Study completion
- 30 Oct 2025 (actual)
- First posted
- 8 May 2026 (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.
Title: Evaluation of Image-less Navigation Accuracy in Total Knee Arthroplasty (CARNAVAL)
Summary:
The purpose of this study is to evaluate the accuracy of an imageless navigation system in measuring key anatomical angles (MPTA and LDFA) during Total Knee Arthroplasty (TKA). While preoperative CT scans are currently the gold standard for bone planning, imageless navigation uses a "bone morphing" technique during surgery to create a digital model of the knee.
The study aims to determine if the measurements obtained via bone morphing, both before and after cartilage removal, are consistent with the measurements obtained from preoperative CT scans. The investigators seek to confirm if imageless navigation can provide reliable anatomical data, potentially reducing the need for preoperative radiation and costs associated with CT imaging.
Detailed description
Background:
Accurate alignment is critical for the long-term success of Total Knee Arthroplasty (TKA). Newer robotic and navigated systems rely on bone morphing to define the patient's anatomy per-operatively. However, the impact of cartilage thickness and the intrinsic accuracy of these systems compared to 3D CT-based planning remain subjects of clinical interest.
Objectives:
The primary objective is to compare the Medial Proximal Tibial Angle (MPTA) and the Lateral Distal Femoral Angle (LDFA) measured by:
Preoperative CT scan (Reference standard).
Peroperative image-less navigation (bone morphing) with intact cartilage.
Peroperative image-less navigation (bone morphing) after cartilage removal.
Methodology:
This is a prospective, monocentric, interventional study. All included patients will undergo a standard preoperative 3D CT scan as part of the surgical planning. During the TKA procedure, the surgeon will use the navigation system to perform bone morphing at two specific stages:
Initial stage: On the joint surface with the cartilage still present.
Secondary stage: After the surgical removal of the articular cartilage.
Comparison:
The data collected peroperatively will be compared to the CT scan measurements. The study will evaluate the "fidelity" (accuracy) of the navigation system and analyze whether the presence or absence of cartilage significantly alters the reliability of the digital bone model created by the system.
Expected Outcomes:
The results will help determine the degree of confidence surgeons can place in imageless navigation for achieving precise anatomical alignment without the systematic use of preoperative 3D imaging.
Study design
- Primary purpose
- Health services research
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
- Model description
- This is a prospective, single-group diagnostic accuracy study where each participant serves as their own control. For every patient, anatomical measurements (MPTA and LDFA) are obtained and compared using three different methods: Reference Standard: Preoperative 3D CT scan. Index Test A: Peroperative image-less navigation (bone morphing) performed on intact articular cartilage. Index Test B: Peroperative image-less navigation (bone morphing) performed after complete surgical removal of the cartilage. This intra-subject design allows for a direct comparison of the navigation system's fidelity against the gold-standard CT scan, while specifically isolating the impact of cartilage thickness on measurement accuracy.
| Arm | Type | Receives |
|---|---|---|
| Navigation and CT-scan Comparison Group) | Experimental | Procedure: Non-image-based Computer-Assisted Navigation with Bone MorphingAll participants undergo Total Knee Arthroplasty (TKA) using an imageless navigation system. Anatomical measurements (MPTA and LDFA) are recorded via bone morphing at two stages: 1) on intact articular cartilage and 2) after cartilage removal. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (5 listed)
- Patients aged 18 years or older.
- Patients with primary or secondary knee osteoarthritis requiring a Total Knee Arthroplasty (TKA).
- Patients for whom the surgical planning requires a pre-operative 3D CT scan.
- Patients who have been informed about the study and have signed the written informed consent.
- Patients affiliated with or beneficiaries of a social security scheme.
Key exclusion criteria (6 listed)
- Revision Total Knee Arthroplasty (re-operation).
- Major bone loss or significant bone deformity that prevents reliable anatomical landmarking.
- History of prior knee surgery that could interfere with the navigation system trackers (e.g., retained hardware in the femur or tibia).
- Pregnant or breastfeeding women.
- Persons deprived of liberty or under legal guardianship.
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 |
|---|---|---|
| Non-image-based Computer-Assisted Navigation with Bone MorphingIntraoperative surface morphing of the joint surfaces is performed to obtain LDFA and MPTA values. The procedure compares measurements taken on the residual cartilage versus measurements taken directly on the osseous surface after cartilage debridement. These values are then validated against preoperative 3D CT scan data. | Procedure or surgery | Navigation and CT-scan Comparison Group) |
Primary outcome
Mean Difference in Medial Proximal Tibial Angle (MPTA) between CT scan and Imageless Navigation.
Time frame: At the time of surgery (intra-operative).
The mean difference (measured in degrees) between the MPTA calculated from the preoperative 3D CT scan and the MPTA measured intraoperatively via bone morphing after cartilage removal.
2 secondary outcomes
Mean Difference in Lateral Distal Femoral Angle (LDFA) between CT scan and Imageless Navigation.
Time frame: At the time of surgery (intraoperative)
Correlation of MPTA and LDFA measurements before and after cartilage removal.
Time frame: At the time of surgery (intra-operative).
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 14 May 2026.
- Background: PubMed 21915542Blakeney WG, Khan RJ, Wall SJ. Computer-assisted techniques versus conventional guides for component alignment in total knee arthroplasty: a randomized controlled trial. J Bone Joint Surg Am. 2011 Aug 3;93(15):1377-84. doi: 10.2106/JBJS.I.01321.
- Background: PubMed 33517740MacDessi SJ, Griffiths-Jones W, Harris IA, Bellemans J, Chen DB. Coronal Plane Alignment of the Knee (CPAK) classification. Bone Joint J. 2021 Feb;103-B(2):329-337. doi: 10.1302/0301-620X.103B2.BJJ-2020-1050.R1.
- Background: PubMed 34981162Rossi SMP, Sangaletti R, Perticarini L, Terragnoli F, Benazzo F. High accuracy of a new robotically assisted technique for total knee arthroplasty: an in vivo study. Knee Surg Sports Traumatol Arthrosc. 2023 Mar;31(3):1153-1161. doi: 10.1007/s00167-021-06800-8. Epub 2022 Jan 4.
- Individual participant dataSharing planned: No
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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.
Antoine MOUTON, Orthopedic surgeon principal investigator
Diaconesses Croix Saint Simon Hospital Group
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Non-image-based Computer-Assisted Navigation with Bone Morphing in people with Arthroplasty and Bone Morphing, run by Groupe Hospitalier Diaconesses Croix Saint-Simon at 1 site in France.
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 6 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 14 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 1 site in France. 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?
Mean Difference in Medial Proximal Tibial Angle (MPTA) between CT scan and Imageless Navigation. (time frame: At the time of surgery (intra-operative).). 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 NCT07574775, which also lists 3 linked publications.
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 14 May 2026.