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RecruitingNCT05805774pDIFFIRUpdated Dec 18, 2025

pDIFFIR: Geriatric Periprosthetic DIstal Femur: FIxation Versus Replacement

An interventional study of Distal Femur Replacement and Surgical fixation in Distal Femur Fracture, Periprosthetic Fracture Around Prosthetic Joint Implant Knee and Knee Fracture, sponsored by Unity Health Toronto. Recruiting at 1 site in Canada. Open to participants aged 65 Years and older. Per ClinicalTrials.gov, last updated 2025-12-18.

Sponsored by Unity Health Toronto · Not applicable, Interventional, and Treatment

Phase
Not applicable
Study type
Interventional
Enrollment
148
Allocation
Randomized
Ages
65 Years and older
Sex
All
01

Study 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. 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.

02

Conditions studied

  • Distal Femur Fracture
  • Periprosthetic Fracture Around Prosthetic Joint Implant Knee
  • Knee Fracture

Keywords

  • Periprosthetic Distal Femur fracture
  • Knee replacement
  • Surgical fixation
  • Geriatric patients
03

Who can participate

Ages eligible
65 Years and older
Sexes eligible
All
Accepts healthy volunteers
No

Inclusion criteria

    • 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

Exclusion criteria

Exclusion Criteria:

    • 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)
      • 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
04

Study design

Phase
Not applicable
Primary purpose
Treatment
Allocation
Randomized
Intervention model
Parallel assignment
Masking
None (open label)
Enrollment
148 participants (estimated)

Study arms

  • Active comparator
    Group A - DFR

    Procedure: Distal Femur Replacement

  • Active comparator
    Group B - ORIF

    Procedure: Surgical fixation

Interventions

  • ProcedureDistal Femur Replacement

    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).

  • ProcedureSurgical fixation

    Knee surgery to fix the fracture, that can use wires, nails, screws, pins or plates to health and fix the bones together.

05

What researchers measure

Primary outcomes

  1. 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.

    Time frame: 12 months

Secondary outcomes

  1. Mortality

    Track patient's death.

    Time frame: 24 months

06

Study locations

1 of 1 sites recruiting
  • St. Michael's Hospital
    Toronto, Ontario M5B 1W8, Canada
    Recruiting
07

References and documents

Individual participant data

Plan to share: Undecided

No publications or documents are linked to this record.

08

Registry details

Key details

Study ID
NCT05805774
Lead sponsor
Unity Health Toronto
Collaborators
Mount Sinai Hospital, Canada
Responsible party
Sponsor
First posted
Apr 10, 2023
Start date
Oct 17, 2025
Primary completion
Dec 10, 2030 (estimated)
Completion
Dec 10, 2032 (estimated)
Last update
Dec 18, 2025

Study contacts

Cassandra Tardif-Theriault
Contact
cassandra.tardif-theriault@unityhealth.to
416-864-6060 ext. 77117
Amir Khoshbin, MD
principal investigator · Unity Health Toronto - St Michael's Hospital
Jesse Wolfstadt, MD
principal investigator · Mount Sinai Health Hospital

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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