Periprosthetic Fracture — ABOS Oral Boards Preparation
What examiners expect and how to prepare
Clinical Scenario
A 72-year-old right-hand-dominant woman presents to the emergency department after a fall from standing at home. She has a history of a left cemented total hip arthroplasty performed 8 years ago for osteoarthritis. Prior to the fall, she was ambulatory without assistive devices and had an excellent result from her hip replacement with no pain. She reports acute left thigh pain and inability to bear weight. On exam, the left thigh is swollen and tender in the mid-diaphyseal region. There is no deformity at the hip, and the prior posterolateral incision is well-healed. Distal neurovascular exam is intact.
AP and lateral radiographs of the left femur reveal a spiral fracture of the femoral shaft at the tip of a well-fixed cemented femoral stem. There are no lucent lines around the proximal cement mantle, and the stem appears well-fixed without subsidence compared to a post-operative film from 6 years ago in the chart. The fracture extends approximately 2 cm distal to the stem tip. There is no acetabular loosening.
You performed open reduction and internal fixation using cerclage cables proximally and a locking plate spanning the fracture distally, with cortical strut allografts applied to the deficient lateral cortex. The stem was confirmed to be well-fixed intraoperatively. Post-operatively, the patient was made toe-touch weight-bearing for 12 weeks with a progressive rehabilitation protocol.
What Examiners Look For
- Data gathering: Pre-injury function, the primary implant details (cemented vs. cementless, approach, vintage), and prior radiographs are critical — present them before the fracture.
- Diagnosis: Vancouver classification — you must determine stem stability, fracture location, and bone quality. Each combination dictates a different treatment.
- Treatment plan: Why did you fix around the stem rather than revise? What findings would have made you revise the femoral component?
- Technical skill: Describe your fixation construct — cable plate, locking plate, strut grafts — and how each element contributes to stability.
- Indications: When is revision arthroplasty indicated in periprosthetic fractures? What about a Vancouver B2 versus B1?
- Complications: What if the fracture goes on to nonunion? What if the stem loosens during follow-up? How do you distinguish from infection?
- Applied knowledge: How does cemented versus cementless primary fixation affect your treatment algorithm for periprosthetic fracture?
Common Pitfalls
- Failing to classify the fracture using the Vancouver system — this is the framework examiners expect and every treatment decision flows from it.
- Not assessing stem stability — this is the single most important factor in deciding between fixation and revision.
- Treating all periprosthetic fractures the same way — B1 (stable stem) and B2 (loose stem) require fundamentally different treatments.
- Forgetting to rule out infection as a cause of implant loosening — always send intraoperative cultures.
- Not knowing your strut graft or cable plating techniques — this is a hands-on technical question examiners love.
Key Classifications
Related Scenarios
Free — takes 3 minutes