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
Citation
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.