Dorr Classification (Proximal Femoral Morphology)
The Dorr classification of proximal femoral bone morphology on a plain radiograph, from the cortical thickness and the canal-to-calcar ratio, types A / B / C.
Open the calculator → Runs in your browser. Data leaves only if you deliberately send a problem report from the interactive tool.
Example
- Dorr type
- B - intermediate
Result: Dorr type B: intermediate cortical loss with a wider canal, canal-to-calcar ratio 0.5 to 0.75.
The tool opens with these values already filled in. Replace them with your own.
What the result means
- Type A
- Champagne flute: thick cortices, narrow canal; ratio below 0.5.
- Type B
- Intermediate cortical loss, wider canal; ratio 0.5 to 0.75.
- Type C
- Stovepipe: extensive cortical loss, wide canal; ratio above 0.75.
What you enter
- Dorr type
How this is calculated
Dorr LD, Faugere MC, Mackel AM, Gruen TA, Bognar B, Malluche HH. Structural and cellular assessment of bone quality of proximal femur. Bone. 1993;14(3):231-242. Read the source ↗
A reference and educational tool. Not medical, legal, or financial advice, and not a substitute for clinician judgment.