pDIFFIR: Geriatric Periprosthetic DIstal Femur: FIxation Versus Replacement

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.

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