Question
A 73 year old woman with a total knee arthroplasty falls and has a painful deformed thigh.
- Describe the radiographs and classify the injury.
- What determines treatment?
- Outline fixation options.
Answer
Radiographs
- Fracture of the distal femur just above the femoral component of a TKA
- Periprosthetic supracondylar fracture
- Look for anterior notching and component loosening
Classification
| Lewis and Rorabeck type | Description |
|---|---|
| I | Undisplaced, prosthesis intact |
| II | Displaced, prosthesis intact |
| III | Prosthesis loose or failing, any displacement |
- Su classification relates the fracture to the femoral component
Treatment
- Fixation if the implant is well fixed, revision if loose
- Retrograde nail if the femoral component has an open box and enough distal bone
- Distal femoral locking plate
- Nail plate combination allows immediate weight bearing
- Distal femoral replacement for very distal or comminuted fractures and loose implants in the elderly
- Treat like a hip fracture, early surgery and orthogeriatric care
- One year mortality about 20 to 25%
Related pages
Author Contributions
Orthofracs team
Reviewed by Professor Phong Tran, Head of Orthopaedic Surgery, Western Health. Last updated 10 October 2026.