Dejour Classification (Trochlear Dysplasia)
The Dejour classification of trochlear dysplasia, by the radiographic / CT appearance of the femoral trochlea, types A/B/C/D.
Open the calculator → Runs in your browser. Data leaves only if you deliberately send a problem report from the interactive tool.
Example
- Dejour type
- B - flat/convex with a spur (high-grade)
Result: Dejour type B: a flat or convex trochlea with a supratrochlear spur (high-grade dysplasia).
The tool opens with these values already filled in. Replace them with your own.
What the result means
- Type A
- Shallow but symmetric, concave trochlea (crossing sign); low-grade.
- Type B
- Flat or convex trochlea with a supratrochlear spur; high-grade.
- Type C
- Facet asymmetry (double contour) without a spur; high-grade.
- Type D
- Facet asymmetry plus a supratrochlear spur, with a facet cliff; high-grade.
What you enter
- Dejour type
How this is calculated
Dejour D, Le Coultre B. Osteotomies in patello-femoral instabilities. Sports Med Arthrosc Rev. 2007;15(1):39-46. Read the source ↗
A reference and educational tool. Not medical, legal, or financial advice, and not a substitute for clinician judgment.