Distal Femur FracturepDIFFIRNCT05805774
pDIFFIR: Geriatric Periprosthetic DIstal Femur: FIxation Versus Replacement
A study testing Distal Femur Replacement and Surgical fixation in people with Distal Femur Fracture and Periprosthetic Fracture Around Prosthetic Joint Implant Knee, run by Unity Health Toronto at 1 site in Canada.
Trial summary
Periprosthetic distal femur fractures are a significant source of morbidity and mortality for elderly patients. One treatment option involved a surgical fixation with plates or nails, screws and cables/wires along the side of your fractured bone. Read more about this study
- Who is it for?
- Ages 65 years and older
- Conditions the study is for
- Distal Femur Fracture, Periprosthetic Fracture Around Prosthetic Joint Implant Knee, Knee Fracture
- What is being tested?
- Distal Femur Replacement and Surgical fixation
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 148 participants
- Where
- 1 siteCanada
- Study dates
- 17 Oct 2025to 10 Dec 2032
- 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 65 years and older
- All sexes
- No healthy volunteers
- Older adult
Who may be able to join
- • 65 years and older
- Isolated periprosthetic fracture of the distal femur around a stable primary total knee arthroplasty (Lewis and Rorabeck Type 1-2)
- Fracture is acute (within 1 week from time of injury)
- Patient was ambulatory (with or without walking aids) in the community and at home prior to the injury
- Independent or moderately frail with score of 3 to 6 on the validated Clinical Frailty Scale
- Patient is able to read and understand the consent form document, or an interpreter is available to the patient at the time of consent and follow-up
- Patient or substitute decision maker is able to provide written informed consent to participate in the study
Who cannot join
- • Active infection around the fracture (soft tissue or bone)
- Open fracture
- Bilateral femur fractures
- Major neuro-vascular injury requiring intervention, compartment syndrome and major neurologic injuries
- Pathological fracture excluding osteoporosis
- Ipsilateral total knee arthroplasty using revision components (varus/valgus constraint, stemmed femoral components)
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- Periprosthetic distal femur fracture around a loose or failing primary total knee arthroplasty (Lewis and Rorabeck Type III)
- Ipsilateral primary partial knee or patellofemoral arthroplasty
- Previous ORIF of the distal femur or proximal tibia or patella
- Current or previous extensor mechanism (patellar tendon, quadriceps tendon, or patella fracture) disruption or repair
- Poly-trauma status (Injury Severity Score>15) or any associated major injuries of the lower extremities that may hinder post-operative ambulation
- Medical contraindication to surgery
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Canada1 site, 1 recruiting
- Recruiting
St. Michael's Hospital
Toronto, Ontario, M5B 1W8
Cassandra Tardif-Theriault, 416-864-6060 ext. 77117, cassandra.tardif-theriault@unityhealth.to
Amir Khoshbin, MD
About this study
Official title: pDIFFIR: Geriatric Periprosthetic DIstal Femur: FIxation Versus Replacement - A Randomized Controlled Trial of Acute Open Reduction Internal Fixation (ORIF) Versus Distal Femur Replacement (DFR)
Periprosthetic distal femur fractures are a significant source of morbidity and mortality for elderly patients. One treatment option involved a surgical fixation with plates or nails, screws and cables/wires along the side of your fractured bone. The second method consists in replacing your knee joint with an artificial knee prosthesis (artificial knee joint).
The primary objective is to determine if acute distal femur replacement improves knee pain and functional outcomes compared to surgical fixation. Secondary outcomes are mortality, reoperation, complications, post-operative pain and quality of life. A health economic analysis will be conducted to assess the cost-effectiveness of both treatments.
A total of 148 patients (74/group) will be enrolled in the study.
- Conditions
- Distal Femur Fracture, Periprosthetic Fracture Around Prosthetic Joint Implant Knee, Knee Fracture
- Being tested
- Distal Femur Replacement, Surgical fixation
- Keywords
- Periprosthetic Distal Femur fracture, Knee replacement, Surgical fixation, Geriatric patients
- Medical subject headings
- Femoral Fractures, Distal, Knee Fractures
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Distal Femur ReplacementProcedure or surgery
Knee surgery to remove the lower part of the femur and knee joint (where the broken bones are) and will replace them with an artificial knee joint (prosthesis).
Surgical fixationProcedure or surgery
Knee surgery to fix the fracture, that can use wires, nails, screws, pins or plates to health and fix the bones together.
| Study group | Role | What they receive |
|---|---|---|
| Group A - DFR | Active comparator | Not described Receives: Procedure: Distal Femur Replacement |
| Group B - ORIF | Active comparator | Not described Receives: Procedure: Surgical fixation |
What is being measured
The primary outcome is the main question the study is designed to answer.
Knee function
Compare knee pain between the two groups using the Oxford Knee Score - which is a patient reported outcome measure. It assess knee function and gives a rating from 0 to 48 - being 0 bad knee function and 48 - excellent knee function.
Measured: 12 months
Secondary outcomes (1)
Mortality
Track patient's death.
Measured: 24 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted10 Apr 2023
- Study start17 Oct 2025
- Primary completion10 Dec 2030 (estimated)
- Study completion10 Dec 2032 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Distal Femur FractureStudies of the same condition, open and under way.
- More trials run by Unity Health TorontoThe 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
- Masking
- None (open label)
- Enrolment
- 148 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Unity Health Toronto
- Sponsor type
- University, hospital or other
- Collaborators
- Mount Sinai Hospital, Canada
- Responsible party
- Sponsor
- Investigators
- Amir Khoshbin, MD, Principal investigator, Unity Health Toronto - St Michael's HospitalJesse Wolfstadt, MD, Principal investigator, Mount Sinai Health Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05805774
- Sponsor's protocol ID
- 23-001
- Acronym
- pDIFFIR
- Status last verified
- Dec 2025
- First submitted
- 28 Mar 2023
- Last updated
- 18 Dec 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Study at a glance
From the registry record, last updated by the sponsor on 18 Dec 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- pDIFFIR: Geriatric Periprosthetic DIstal Femur: FIxation Versus Replacement - A Randomized Controlled Trial of Acute Open Reduction Internal Fixation (ORIF) Versus Distal Femur Replacement (DFR)
- ClinicalTrials.gov ID
- NCT05805774
- Acronym / sponsor ID
- pDIFFIR / 23-001
- Conditions
- Distal Femur Fracture, Periprosthetic Fracture Around Prosthetic Joint Implant Knee, Knee Fracture
- Keywords
- Periprosthetic Distal Femur fracture, Knee replacement, Surgical fixation, Geriatric patients
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 148 participants (estimated)
- Lead sponsor
- Unity Health TorontoUniversity, hospital or other
- Collaborators
- Mount Sinai Hospital, Canada
- Study start
- 17 Oct 2025 (actual)
- Primary completion
- 10 Dec 2030 (estimated)
- Study completion
- 10 Dec 2032 (estimated)
- First posted
- 10 Apr 2023 (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.
Periprosthetic distal femur fractures are a significant source of morbidity and mortality for elderly patients. One treatment option involved a surgical fixation with plates or nails, screws and cables/wires along the side of your fractured bone. The second method consists in replacing your knee joint with an artificial knee prosthesis (artificial knee joint).
The primary objective is to determine if acute distal femur replacement improves knee pain and functional outcomes compared to surgical fixation. Secondary outcomes are mortality, reoperation, complications, post-operative pain and quality of life. A health economic analysis will be conducted to assess the cost-effectiveness of both treatments.
A total of 148 patients (74/group) will be enrolled in the study.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Group A - DFR | Active comparator | Procedure: Distal Femur Replacement |
| Group B - ORIF | Active comparator | Procedure: Surgical fixation |
Who may qualify
- Ages
- 65 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Older adult
Key inclusion criteria (7 listed)
- • 65 years and older
Key exclusion criteria (12 listed)
- • Active infection around the fracture (soft tissue or bone)
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 |
|---|---|---|
| Distal Femur ReplacementKnee surgery to remove the lower part of the femur and knee joint (where the broken bones are) and will replace them with an artificial knee joint (prosthesis). | Procedure or surgery | Group A - DFR |
| Surgical fixationKnee surgery to fix the fracture, that can use wires, nails, screws, pins or plates to health and fix the bones together. | Procedure or surgery | Group B - ORIF |
Primary outcome
Knee function
Time frame: 12 months
Compare knee pain between the two groups using the Oxford Knee Score - which is a patient reported outcome measure. It assess knee function and gives a rating from 0 to 48 - being 0 bad knee function and 48 - excellent knee function.
1 secondary outcome
Mortality
Time frame: 24 months
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 18 Dec 2025.
- Individual participant dataSharing planned: Undecided
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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.
Amir Khoshbin, MD principal investigator
Unity Health Toronto - St Michael's Hospital
Jesse Wolfstadt, MD principal investigator
Mount Sinai Health Hospital
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Distal Femur Replacement and Surgical fixation in people with Distal Femur Fracture and Periprosthetic Fracture Around Prosthetic Joint Implant Knee, run by Unity Health Toronto at 1 site in Canada.
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 7 inclusion and 12 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 18 Dec 2025. 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 Canada. 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 Cassandra Tardif-Theriault (416-864-6060 ext. 77117, cassandra.tardif-theriault@unityhealth.to), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Knee function (time frame: 12 months). 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 18 Dec 2025.