Ankle Arthrodesis or ArthroplastyASTRANCT07225751
A Prospective, Randomized, Single-blind, Controlled, Multi-center Study to Assess the Safety and Performance of MagnetOsTM Compared to Autogenous Bone Graft in Patients Undergoing Hindfoot or Ankle Fusions.
A study testing MagnetOs and Autograft in people with Ankle Arthrodesis or Arthroplasty and Hindfoot Fusion, run by Kuros Biosurgery AG at 7 sites in United States.
Trial summary
This is a phase IV post-marketing study for MagnetOs Putty and MagnetOs Easypack Putty. MagnetOs is a synthetic bone graft extender product that is routinely used by surgeon as treatment for hindfoot and ankle disorders. Read more about this study
- Who is it for?
- Ages 18 to 75 years
- Conditions the study is for
- Ankle Arthrodesis or Arthroplasty, Hindfoot Fusion, Ankle Deformity
- What is being tested?
- MagnetOs and Autograft
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 126 participants
- Where
- 7 sitesUnited States
- Study dates
- 25 Nov 2025to Dec 2028
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
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 75 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Patient is able to read/be read, understand, and provide written informed consent and has signed the IRB approved informed consent.
- Male or female patient ≥ 18 (considered skeletally mature) up to and including 75 years old
- Patients requiring one of the following hindfoot fusion procedures, using surgical technique, necessitating rigid hardware fixation and supplemental bone graft/ substitute: ankle fusion (tibiotalar) subtalar fusion (talocalcaneal), calcaneocuboid fusion, talonavicular fusion, OR double fusion (any combination of any two of the following: subtalar, talonavicular and calcaneocuboid joints).
- Hardware parameters - rigid fixation using screws, plates, staples, nails or a combination.
Who cannot join
- Expected to need secondary intervention within one year following surgery.
- Had prior fusion or attempted fusion of the joints to be fused.
- Patient is not ambulatory.
- Surgical technique where bone graft is not expected to be used.
- Conditions at the surgeon's discretion in which general bone grafting is not advisable.
- Radiographic evidence of fractures or pathologies around the fusion that could negatively impact the fusion process (e.g., growth plate fracture around the fusion or bone cysts).
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- Significant vascular impairment proximal to the graft site.
- Acute and/or chronic infections in the operated area (soft tissue infections; bacterial bone diseases; osteomyelitis)
- Pre-existing sensory impairment (e.g. diabetes, Charcot). Diabetics patients with HbA1c greater than 7.0 OR that were not sensitive to the 5.07 monofilament will be excluded.
- Metabolic disorders know to adversely affect the skeleton (e.g., renal osteodystrophy or hypercalcemia).
- If intraoperative soft tissue coverage is not planned or possible.
- Receiving treatment with medication interfering with calcium metabolism (chronic use of glucocorticoid and use high dose NSAIDs 800 mg TID for > the first 6 weeks post-op).
- Has benign or malignant tumor at the surgical site.
- Has history or presence of active malignancy (non-invasive skin cancer is allowed).
- Has known substance abuse, psychiatric disorder, or a condition which, in the opinion of the investigator, may influence the healing or ability to comply with protocol requirements (e.g. prisoners, physically or mentally compromised, etc.).
- Is involved in active litigation relating to his/her foot and ankle condition.
- Participation in an investigational study within 30 days prior to surgery for study devices.
- Patient with body mass index (BMI) > 50.
- Patient cannot comply with all post-operative evaluation and visits .
- Any pre-existing condition that the surgeon determines could interfere with the patient's ability to perform objective functional measurements.
- Women who are or intend to become pregnant within the next 12 months.
Trial locations and contacts
7 sites in 1 country. Contact the study team or a site near you to ask about taking part.
7 sites in 1 country
United States7 sites, 7 recruiting
- Recruiting
OrthoCarolina Research Institute, Inc
Charlotte, North Carolina, 28207
Samual Ford, MD, samuel.ford@orthocarolina.com
- Recruiting
Integrity Orthopedics and Sports Medicine
Chattanooga, Tennessee, 37404
Principal Investigator, Jesse Doty, MD
- Recruiting
Hughston Foundation Inc
Columbus, Georgia, 31909
Collier Watson, MD, b.collier.watson@gmail.com
- Recruiting
Centers for Advanced Orthopaedics
Falls Church, Virginia, 22042
Steve Neufeld, MD, sneufeld@cfaortho.com
- Recruiting
Reconstructive Orthopaedic Associates II dba Rothman Orthopaedic Institute
Philadelphia, Pennsylvania, 19107
Selene Parekh, MD, selene.parekh@rothmanortho.com
- Recruiting
University California Davis
Sacramento, California, 95816
Eric Giza, MD
- Recruiting
Steadman Philippon Research Institute
Vail, Colorado, 81657
Jonathon Backus, MD, jbackus@thesteadmanclinic.com
About this study
Official title: A Prospective, Randomized, Single-blind, Controlled, Multi-center Study to Assess the Safety and Performance of MagnetOsTM Compared to Autogenous Bone Graft in Patients Undergoing Hindfoot or Ankle Fusions
This is a phase IV post-marketing study for MagnetOs Putty and MagnetOs Easypack Putty. MagnetOs is a synthetic bone graft extender product that is routinely used by surgeon as treatment for hindfoot and ankle disorders.
In this study, MagnetOs Putty and MagnetOs Easypack Putty will be use according to the latest Instructions For Use, standalone in the foot and ankle.
Read the detailed description
In this study, following a screening period of a maximum of 45 days, approximately 126 patients will receive either MagnetOs Putty/Easypack Putty or autograft in conjunction with rigid hardware (arthrodesis) to treat hindfoot and ankle disorders. They will be randomized (1:1) into one of two treatment groups: standard rigid fixation with MagnetOs Putty/Easypack Putty or local autograft from the calcaneus, distal tibia, or proximal tibia.
They will be followed up at discharge at weeks 2, 6, 12, 24 and 52 post-surgery. The primary endpoint will be analyzed at 24 weeks post-op using CT-scan, and patients will continue follow-up for safety and efficacy for one year post operatively.
In this study, MagnetOs will be applied according to the IFU (Putty) approved in the US, Europe, Middle- East and Australia and Easypack Putty (approved in the US).
The surgical procedures studied in this clinical trial will include rigid hardware fixation and supplemental bone graft/substitute in the following procedures: ankle fusion (tibiotalar), subtalar fusion (talocalcaneal), calcaneocuboid fusion, talonavicular fusion, OR double fusion (any combination of any two of the following: subtalar, talonavicular and calcaneocuboid joints. These procedures will be left to the investigator's discretion.
Radiographs images will be taken at screening, weeks 6, 12, 24 and 52; CT-scans will be taken at weeks 24 and 52 post-op If the patient has a secondary surgical intervention (procedure that adjusts or in any way modifies or removes part of the original implant configuration) at any time after the 6 month visit, the next CT scan will not be necessary. Starting at week 12, all XR images will be weight bearing.
- Conditions
- Ankle Arthrodesis or Arthroplasty, Hindfoot Fusion, Ankle Deformity, Ankle Disease, Hindfoot Arthrodesis, Hindfoot Pathologies
- Being tested
- MagnetOs, Autograft
- Keywords
- ankle arthrodesis, hindfoot fusion
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
MagnetOsDevice
MagnetOs will be used at a volume of approximately 1-5 cc's for the TN, CC and ST joints, and up to 10 cc's for the tibiotalar joint.
AutograftOther
In this study, the comparator is autograft and will be used at a volume of approximately 1-5 cc's for the TN, CC and ST joints, and up to 10 cc's for the tibiotalar joint.
| Study group | Role | What they receive |
|---|---|---|
| MagnetOs | Experimental | Interventions
* Procedure: Instrumented hindfoot or ankle fusion
* Device: MagnetOs Putty or MagnetOs Easypack Putty Receives: Device: MagnetOs |
| Autograft | Active comparator | Interventions
* Procedure: Instrumented hindfoot or ankle fusion
* Device: Autograft Receives: Other: Autograft |
What is being measured
The primary outcome is the main question the study is designed to answer.
Radiographic fusion by CT scan
The primary endpoint is the incidence of fusion at each side by CT analysis as assessed by the independent radiological expert at 24 weeks post-op
Measured: Week 24 post-op
Secondary outcomes (5)
Radiographic fusion by CT scan
Joint fusion at Week 52 post-surgery assessed by CT-scans determined by an independent radiological expert panel (IREP) in patients undergoing hindfoot or ankle fusions
Measured: Week 52
Radiographic Fusion by plain radiographs
Joint fusion at Week 12, Week 24 and Week 52 post-surgery assessed by plain radiographs determined by an independent radiological expert panel (IREP) in patients undergoing hindfoot or ankle fusions
Measured: week 12, week 24, week 52 post-surgery
Functional
Change in Foot Function Index (FFI) from Screening to Week 2, Week 6, Week 12, Week 24 and Week 52 post-surgery. The score ranging from 0% to 100% indicates the severity of a person's foot issues. A score of 100% indicates worst possible pain, while 0% indicates no pain.
Measured: Screening to Week 2, Week 6, Week 12, Week 24 and Week 52 post-surgery.
Functional
Change in Visual Analog Score (VAS) from Screening to Week 2, Week 6, Week 12, Week 24 and Week 52 post-surgery. 0 no pain and 10 worst pain possible
Measured: Screening, Week 2, Week 6, Week 12, Week 24 and Week 52 post-surgery.
Functional
Change in SF-12 from Screening to Week 2, Week 6, Week 12, Week 24 and Week 52 post-surgery. Where 50 is the average health status for general U.S population. A score above 50 indicates better than average, while a score below 50 suggests below average health.
Measured: Screening, Week 2, Week 6, Week 12, Week 24 and Week 52 post-surgery.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted10 Nov 2025
- Study start25 Nov 2025
- Primary completionOct 2028 (estimated)
- Study completionDec 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Ankle Arthrodesis or 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
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 126 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Kuros Biosurgery AG
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07225751
- Sponsor's protocol ID
- FA-2025-001
- Acronym
- ASTRA
- Status last verified
- Aug 2026
- First submitted
- 3 Nov 2025
- Last updated
- 1 Sep 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- Yes
Study at a glance
From the registry record, last updated by the sponsor on 1 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Prospective, Randomized, Single-blind, Controlled, Multi-center Study to Assess the Safety and Performance of MagnetOsTM Compared to Autogenous Bone Graft in Patients Undergoing Hindfoot or Ankle Fusions
- ClinicalTrials.gov ID
- NCT07225751
- Acronym / sponsor ID
- ASTRA / FA-2025-001
- Conditions
- Ankle Arthrodesis or Arthroplasty, Hindfoot Fusion, Ankle Deformity, Ankle Disease, Hindfoot Arthrodesis, Hindfoot Pathologies
- Keywords
- ankle arthrodesis, hindfoot fusion
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 126 participants (estimated)
- Lead sponsor
- Kuros Biosurgery AGIndustry (pharma, biotech, devices)
- Study start
- 25 Nov 2025 (actual)
- Primary completion
- Oct 2028 (estimated)
- Study completion
- Dec 2028 (estimated)
- First posted
- 10 Nov 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 is a phase IV post-marketing study for MagnetOs Putty and MagnetOs Easypack Putty. MagnetOs is a synthetic bone graft extender product that is routinely used by surgeon as treatment for hindfoot and ankle disorders.
In this study, MagnetOs Putty and MagnetOs Easypack Putty will be use according to the latest Instructions For Use, standalone in the foot and ankle.
Detailed description
In this study, following a screening period of a maximum of 45 days, approximately 126 patients will receive either MagnetOs Putty/Easypack Putty or autograft in conjunction with rigid hardware (arthrodesis) to treat hindfoot and ankle disorders. They will be randomized (1:1) into one of two treatment groups: standard rigid fixation with MagnetOs Putty/Easypack Putty or local autograft from the calcaneus, distal tibia, or proximal tibia.
They will be followed up at discharge at weeks 2, 6, 12, 24 and 52 post-surgery. The primary endpoint will be analyzed at 24 weeks post-op using CT-scan, and patients will continue follow-up for safety and efficacy for one year post operatively.
In this study, MagnetOs will be applied according to the IFU (Putty) approved in the US, Europe, Middle- East and Australia and Easypack Putty (approved in the US).
The surgical procedures studied in this clinical trial will include rigid hardware fixation and supplemental bone graft/substitute in the following procedures: ankle fusion (tibiotalar), subtalar fusion (talocalcaneal), calcaneocuboid fusion, talonavicular fusion, OR double fusion (any combination of any two of the following: subtalar, talonavicular and calcaneocuboid joints. These procedures will be left to the investigator's discretion.
Radiographs images will be taken at screening, weeks 6, 12, 24 and 52; CT-scans will be taken at weeks 24 and 52 post-op If the patient has a secondary surgical intervention (procedure that adjusts or in any way modifies or removes part of the original implant configuration) at any time after the 6 month visit, the next CT scan will not be necessary. Starting at week 12, all XR images will be weight bearing.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (participant)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| MagnetOs | Experimental | Device: MagnetOsInterventions * Procedure: Instrumented hindfoot or ankle fusion * Device: MagnetOs Putty or MagnetOs Easypack Putty |
| Autograft | Active comparator | Other: AutograftInterventions * Procedure: Instrumented hindfoot or ankle fusion * Device: Autograft |
Who may qualify
- Ages
- 18 to 75 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- Patient is able to read/be read, understand, and provide written informed consent and has signed the IRB approved informed consent.
- Male or female patient ≥ 18 (considered skeletally mature) up to and including 75 years old
- Patients requiring one of the following hindfoot fusion procedures, using surgical technique, necessitating rigid hardware fixation and supplemental bone graft/ substitute: ankle fusion (tibiotalar) subtalar fusion (talocalcaneal), calcaneocuboid fusion, talonavicular fusion, OR double fusion (any combination of any two of the following: subtalar, talonavicular and calcaneocuboid joints).
- Hardware parameters - rigid fixation using screws, plates, staples, nails or a combination.
Key exclusion criteria (21 listed)
- Expected to need secondary intervention within one year following surgery.
- Had prior fusion or attempted fusion of the joints to be fused.
- Patient is not ambulatory.
- Surgical technique where bone graft is not expected to be used.
- Conditions at the surgeon's discretion in which general bone grafting is not advisable.
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 |
|---|---|---|
| MagnetOsMagnetOs will be used at a volume of approximately 1-5 cc's for the TN, CC and ST joints, and up to 10 cc's for the tibiotalar joint. | Device | MagnetOs |
| AutograftIn this study, the comparator is autograft and will be used at a volume of approximately 1-5 cc's for the TN, CC and ST joints, and up to 10 cc's for the tibiotalar joint. | Other | Autograft |
Primary outcome
Radiographic fusion by CT scan
Time frame: Week 24 post-op
The primary endpoint is the incidence of fusion at each side by CT analysis as assessed by the independent radiological expert at 24 weeks post-op
5 secondary outcomes
Radiographic fusion by CT scan
Time frame: Week 52
Radiographic Fusion by plain radiographs
Time frame: week 12, week 24, week 52 post-surgery
Functional
Time frame: Screening to Week 2, Week 6, Week 12, Week 24 and Week 52 post-surgery.
Functional
Time frame: Screening, Week 2, Week 6, Week 12, Week 24 and Week 52 post-surgery.
Functional
Time frame: Screening, Week 2, Week 6, Week 12, Week 24 and Week 52 post-surgery.
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 1 Sep 2026.
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.
7 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing MagnetOs and Autograft in people with Ankle Arthrodesis or Arthroplasty and Hindfoot Fusion, run by Kuros Biosurgery AG at 7 sites in United States.
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 4 inclusion and 21 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: looking for participants now, as of the sponsor's last update on 1 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 7 sites in United States. 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?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Cesar Silva, MD (9702156793, cesar.silva@kurosbio.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Radiographic fusion by CT scan (time frame: Week 24 post-op). 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 1 Sep 2026.