arthroplasty
Periprosthetic Fracture - Total Knee Arthroplasty
advanced
6 min
18 marks
5 questions
Clinical Scenario
An 80-year-old female with TKA performed 5 years ago presents after a fall at home. She is unable to weight bear with gross deformity of the distal thigh. She is hemodynamically stable. On examination, there is obvious varus angulation of the distal thigh. Neurovascular status is intact. Radiographs show a displaced supracondylar femur fracture above the well-fixed TKA.
AP and lateral radiographs showing displaced supracondylar femur fracture above total knee arthroplasty. TKA components appear well-fixed without radiolucent lines. Fracture is displaced with varus angulation. Osteoporotic bone quality evident.
Image source: Open Access medical literature (NIH/PubMed Central) • CC-BY License
Questions
Question 1 (3 marks)
Describe the Lewis-Rorabeck classification for periprosthetic fractures around TKA and its treatment implications.
Question 2 (3 marks)
What preoperative assessment and planning is required?
Question 3 (4 marks)
This is a Type II fracture with stable prosthesis. What are your fixation options?
Question 4 (4 marks)
Describe your lateral locking plate technique for this fracture.
Question 5 (4 marks)
What are the challenges, outcomes, and complications of treating these fractures?
Exam Day Cheat Sheet
Must Mention
- •Lewis-Rorabeck (NOT Vancouver) classification for TKA
- •Type I = non-op possible, Type II = ORIF, Type III = revision
- •Check TKA design: open box (nail OK) vs closed box (plate only)
- •Locking plate with unicortical screws distally
- •High 1-year mortality in elderly (up to 20%)
- •Full-length femur X-rays essential
Common Pitfalls
- •Using Vancouver classification (that's for hip!)
- •Bicortical screws through TKA implant
- •Retrograde nail in closed-box TKA
- •Short plate (risk of proximal fracture)
- •Not checking prosthesis stability
- •Excessive stripping (non-union risk)