What is an atypical femoral fracture ?
- Also known as Bisphosphonate-related proximal femoral fractures.
- Type of insufficiency fracture.
- Usually in patients on long term bisphosphonates (>3-5 years).
- Can be bilateral in up to 60% of cases, always screen the opposite femur.
- Changes first occur on the lateral femoral cortex.
- Subtrochanteric , transverse orientation, lack of comminution cortical beak; occur with low velocity trauma.
- Associated with poor healing.
What are the diagnostic criteria for an atypical femoral fracture (AFF)?
According to the American Society for Bone and Mineral Research Taskforce, 4 of the 5 major criteria are necessary for the diagnosis of AFF.
|Major Criteria (4 out of 5 necessary)||Minor Criteria (not necessary for diagnosis)|
|Minima trauma||Increased cortical thickness of the femoral diaphysis|
|Fracture originating at the lateral cortex and being substantially transverse||Bilaterality|
|Complete fractures extending through both cortices||Delayed fracture healing.|
|Localized periosteal or endosteal cortical thickening||A prodrome of thigh or groin pain.|
|Minimal comminution at most|
What is the management for atypical femoral fractures?
Conservative management: It is reasonable to discontinue bisphosphonates, adequate calcium and vitamin D intake should be ensured, and teriparatide should be considered for those who appear not to heal with conservative therapy . Results are poor and patient may eventually need surgical management.
Femoral subtrochanteric and shaft fractures are usually treated with intramedullary (IM) nailing or plating
Detailed discussion with video:
- Managing Osteoporosis Patients after Long-Term Bisphosphonate Treatment.
- Grainger & Allison’s Diagnostic Radiology