Comparing knee joint replacement to surgical fixation for elderly patients with distal femur fractures

pDIFFIR: Geriatric Periprosthetic DIstal Femur: FIxation Versus Replacement - A Randomized Controlled Trial of Acute Open Reduction Internal Fixation (ORIF) Versus Distal Femur Replacement (DFR)

Not applicable Interventional Unity Health Toronto · NCT05805774

This study is testing whether total knee joint replacement or surgical fixation works better for older patients with broken thigh bones near their knee to help them feel less pain and improve their daily activities.

Quick facts

PhaseNot applicable
Study typeInterventional
Enrollment148 (estimated)
Ages65 Years and up
SexAll
SponsorUnity Health Toronto Academic / other
Locations1 site (Toronto, Ontario)
Trial IDNCT05805774 on ClinicalTrials.gov

What this trial studies

This clinical trial investigates two treatment options for elderly patients suffering from periprosthetic distal femur fractures: surgical fixation using plates or nails versus total knee joint replacement. The primary goal is to assess whether knee replacement leads to better pain relief and functional outcomes compared to fixation. Secondary objectives include evaluating mortality rates, reoperation needs, complications, post-operative pain, and overall quality of life. A total of 148 patients will be enrolled, with a focus on cost-effectiveness of both interventions.

Who should consider this trial

Good fit: Ideal candidates are individuals aged 65 and older with isolated acute periprosthetic fractures around a stable knee prosthesis.

Not a fit: Patients with active infections, open fractures, or significant neurovascular injuries may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could provide clearer guidance on the most effective treatment for improving outcomes in elderly patients with distal femur fractures.

How similar studies have performed: Previous studies have shown varying success with similar surgical approaches, but this specific comparison of fixation versus replacement in this demographic is relatively novel.

Eligibility criteria

Show full inclusion / exclusion criteria
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:

* • 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

Where this trial is running

Toronto, Ontario

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Distal Femur FracturePeriprosthetic Fracture Around Prosthetic Joint Implant KneeKnee FracturePeriprosthetic Distal Femur fractureKnee replacementSurgical fixationGeriatric patients
Last reviewed 2026-06-15 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.