Replacement vs Fixation for Distal Femur Fractures

(pDIFFIR Trial)

Overseen By Cassandra Tardif-Theriault

Age: 65+

Sex: Any

Trial Phase: Academic

Sponsor: Unity Health Toronto

Disqualifiers: Active infection, Open fracture, Major neuro-vascular injury, Pathological fracture, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: Unknown

Duration: 12 months

148 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial aims to find the best treatment for certain fractures in the thigh bone near the knee, specifically around an artificial knee joint. Researchers are comparing two methods: surgically fixing the bone with hardware like plates and screws (surgical fixation) or replacing the knee joint entirely with an artificial one (distal femur replacement). The goal is to determine which method more effectively reduces pain and improves movement. The trial seeks participants who have recently fractured near a stable artificial knee, can walk at home or in their community, and are not dealing with infections or serious injuries elsewhere. As an unphased trial, it offers participants the chance to contribute to valuable research that could enhance future treatment options for knee-related fractures.

Will I have to stop taking my current medications?

The trial information does not specify whether you need to stop taking your current medications. It's best to discuss this with the trial coordinators or your doctor.

Is there any evidence suggesting that this trial's treatments are likely to be safe?

Research has shown that replacing the end of the thigh bone, known as distal femur replacement (DFR), often results in good movement and function. Although the risk of infection is generally low, some cases of infection around the artificial joint have been reported. Studies indicate that DFR can improve mobility, but there is a small risk of complications such as infections.

In contrast, open reduction and internal fixation (ORIF) involves using plates, screws, and nails to stabilize the bone. Most individuals recover well after ORIF, though there is a small chance of infection. Both treatments have their advantages and disadvantages, so it is important to consider these factors when deciding to join a clinical trial. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Researchers are excited about the treatments for distal femur fractures because they offer different approaches compared to traditional methods like plate and screw fixation. Distal Femur Replacement (DFR) provides a potential alternative by replacing the broken bone with an artificial implant, which might result in faster recovery times and improved stability, especially in severe fractures. On the other hand, Surgical Fixation, specifically Open Reduction and Internal Fixation (ORIF), aims to realign and stabilize the bone using hardware, which is a tried-and-true method but may involve longer healing periods. By comparing these two strategies, researchers hope to determine which method offers better outcomes in terms of recovery speed and overall effectiveness for patients.

What evidence suggests that this trial's treatments could be effective for distal femur fractures?

This trial will compare two treatments for distal femur fractures: distal femur replacement and surgical fixation. Research has shown that replacing the end of the thigh bone (distal femur replacement), which participants in Group A may receive, helps many patients walk again, with 87% achieving this outcome. After this surgery, patients scored an average of 80 out of 100 on a knee health test. In contrast, fixing the bone with surgery (surgical fixation), which participants in Group B may receive, has demonstrated good results in maintaining proper bone alignment and stability. Studies suggest that surgical fixation might be more cost-effective for older patients. Both treatments can be effective, but they offer different benefits. ^{1 3 6 7 8}

Who Is on the Research Team?

Jesse I Wolfstadt, MD

Principal Investigator

Mount Sinai Health Hospital

Amir Khoshbin, MD

Principal Investigator

Unity Health Toronto - St Michael's Hospital

Are You a Good Fit for This Trial?

This trial is for individuals aged 65 or older who have a specific type of knee fracture (periprosthetic distal femur fracture) around a stable knee replacement. Candidates must have been able to walk before the injury, even if they needed help, and not be severely frail. They should understand the consent form or have an interpreter available.

Inclusion Criteria

I can read and understand the consent form, or I have an interpreter who can help me.

I have a fracture near my knee replacement but the implant is stable.

I was able to walk on my own or with help before my injury.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants undergo either surgical fixation or distal femur replacement

12 months

Follow-up

Participants are monitored for knee function, mortality, and other outcomes

24 months

What Are the Treatments Tested in This Trial?

Interventions

• Distal Femur Replacement
• Surgical fixation

Trial Overview The pDIFFIR study compares two treatments for elderly patients with certain knee fractures: surgical fixation using hardware like plates or nails versus replacing the damaged bone with an artificial joint. The goal is to see which method better improves pain and function.

How Is the Trial Designed?

Group I: Group A - DFR Active Control 1 Intervention

Group II: Group B - ORIF Active Control 1 Intervention

Distal Femur Replacement is already approved in European Union, United States, Canada for the following indications:

Approved in European Union as Distal Femoral Replacement for:

• Periprosthetic distal femur fractures
• Geriatric distal femur fractures

Approved in United States as Distal Femoral Replacement for:

• Periprosthetic distal femur fractures
• Geriatric distal femur fractures

Approved in Canada as Distal Femoral Replacement for:

• Periprosthetic distal femur fractures
• Geriatric distal femur fractures

Who Is Running the Clinical Trial?

Unity Health Toronto

Lead Sponsor

Trials

572

Recruited

470,000+

Mount Sinai Hospital, Canada

Collaborator

Trials

210

Recruited

70,700+

Published Research Related to This Trial

A meta-analysis of 58 studies involving 1484 patients found no significant differences in complications or reoperation rates between primary distal femoral replacement (DFR) and open reduction and internal fixation (ORIF) for treating periprosthetic distal femur fractures.

However, patients treated with ORIF had a greater mean knee range of motion compared to those treated with DFR, suggesting that while both treatments are similarly safe, ORIF may offer better functional outcomes in terms of mobility.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Distal Femur Replacement Versus Open Reduction and Internal Fixation for Treatment of Periprosthetic Distal Femur Fractures: A Systematic Review and Meta-Analysis. Wadhwa, H., Salazar, BP., Goodnough, LH., et al.[2022]

A systematic review of 32 studies involving 1,258 periprosthetic distal femur fractures found that open reduction and internal fixation (ORIF) and distal femoral replacement (DFR) have similar rates of surgical complications and reoperations, indicating both methods are comparably safe.

However, patients treated with DFR experienced significantly higher medical complication rates (23.1% for DFR vs. 8.5% for ORIF), suggesting that while DFR can be effective, it may carry additional health risks that need to be considered.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Distal Femoral Replacement versus Operative Fixation for Periprosthetic Distal Femur Fractures: A Systematic Review and Meta-Analysis. Bundschuh, KE., Grommersch, BM., Tipton, SC., et al.[2023]

In a study of 115 patients over 64 years old with periprosthetic distal femur fractures, both open reduction and internal fixation (ORIF) and distal femoral replacement (DFR) showed no significant differences in 1-year mortality, ambulatory status, reoperations, or hospital readmissions after treatment.

However, DFR was associated with longer hospital stays and a higher rate of blood transfusions compared to ORIF, indicating that while both treatments are equally effective in the short term, DFR may involve more immediate complications.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Outcomes of Geriatric Periprosthetic Distal Femur Fractures: Comparison of Fixation Versus Reconstruction. Joseph, NM., Zuke, W., Sharpe, M., et al.[2023]

In a study comparing distal femoral replacement (DFR) and open reduction and internal fixation (ORIF) for comminuted distal femur fractures, DFR showed a trend towards lower rates of revision and reoperation at 2 years (90% vs. 50% for ORIF), although this was not statistically significant.

Patients treated with DFR experienced significantly higher estimated blood loss (592 mL vs. 364 mL) and longer hospital stays (13 days vs. 6.5 days) compared to those treated with ORIF, indicating a trade-off between potential benefits and increased surgical risks.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Distal femoral replacement versus ORIF for severely comminuted distal femur fractures. Tibbo, ME., Parry, JA., Hevesi, M., et al.[2022]

In a study of 58 patients with periprosthetic distal femur fractures, the type of surgical treatment (open reduction internal fixation or distal femoral replacement) did not significantly affect mortality, complications, or functional recovery after one year.

Age was a critical factor, as older patients (especially those over 85) were more likely to lose their ability to walk and require skilled nursing care, highlighting that age at injury is a stronger predictor of outcomes than the surgical method used.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Predictors of Functional Recovery Following Periprosthetic Distal Femur Fractures. Ruder, JA., Hart, GP., Kneisl, JS., et al.[2022]

In a study of 72 patients with displaced periprosthetic distal femur fractures, those treated with open reduction and internal fixation (ORIF) had better Knee Society Functional Scores compared to those treated with distal femoral replacement (DFR).

However, the ORIF group experienced a significantly higher total incidence of revision surgeries, indicating that while ORIF may offer better functional outcomes, it also carries a greater risk of needing additional operations.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Periprosthetic Fractures of the Distal Femur: Is Open Reduction and Internal Fixation or Distal Femoral Replacement Superior? Darrith, B., Bohl, DD., Karadsheh, MS., et al.[2021]

In a study of 38 patients aged 70 and older with distal femur fractures, those who underwent distal femoral replacement (DFR) had better outcomes in terms of mobility, with all DFR patients being ambulatory at one year compared to 25% of those who had open reduction internal fixation (ORIF).

The ORIF group had a significant nonunion rate of 18% and an average time to fracture union of 24 weeks, highlighting potential challenges in recovery compared to DFR, although overall reoperation rates and other outcomes did not show statistically significant differences between the two groups.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Open Reduction vs Distal Femoral Replacement Arthroplasty for Comminuted Distal Femur Fractures in the Patients 70 Years and Older. Hart, GP., Kneisl, JS., Springer, BD., et al.[2018]

Citations

1. pubmed.ncbi.nlm.nih.gov pubmed.ncbi.nlm.nih.gov/35093546/

Clinical Outcomes Following Distal Femur Replacement for ... Following DFR, 87% (95% confidence interval [CI] 71-95) of patients were able to ambulate. The mean postoperative Knee Society Score was 80 (95% CI 77-84). The ...

2. sciencedirect.com sciencedirect.com/science/article/pii/S0020138323001705

Periprosthetic distal femur fractures around total knee ... Pour et al. reported that in their case series of 42 patients treated with a distal femoral replacement had a prosthesis survival rate of 79.6% at one year and ...

3. boneandjoint.org.uk boneandjoint.org.uk/Article/10.1302/2633-1462.33.BJO-2021-0202.R1

Survivorship, complications, and outcomes following distal ... Overall one- and five-year implant survivorship was 87% and 76%, respectively. By indication for DFA, mechanical failure had one- and five-year ...

4. clinicaltrials.gov clinicaltrials.gov/study/NCT04076735

DIFFIR - Geriatric Distal Femur Fixation Versus Replacement There is a lack of guideline and evidence to suggest which surgical technique is best to provide superior function outcomes, lower complications and reduced ...

5. arthroplastyjournal.org arthroplastyjournal.org/article/S0883-5403(25)00528-5/abstract

Comparison of Survivorship of Distal Femoral ... Outcomes of interest included revision rates, revision causes, and DFR survival by fixation method. We identified 243 DFRs for study inclusion: 187 cemented, 30 ...

6. orthopedicreviews.openmedicalpublishing.org orthopedicreviews.openmedicalpublishing.org/article/94574

Distal femoral replacement for the treatment of periprosthetic ... Distal femoral replacement for the treatment of periprosthetic distal femoral fractures around a total knee arthroplasty: a meta-analysis.

7. arthroplastyjournal.org arthroplastyjournal.org/article/S0883-5403(24)01019-2/abstract

Fix or Replace? Comparable Outcomes With Internal ... The purpose of this study was to compare the outcomes of distal femoral replacement (DFR) and open reduction and internal fixation open ...

8. sciencedirect.com sciencedirect.com/science/article/abs/pii/S0972978X24000746

Outcomes of operatively managed periprosthetic distal ... The purpose of this study was to compare outcomes and fixation techniques of distal femur fractures between patients with native knees and those with an ...