Ahlback Grade (Knee Osteoarthritis)
The Ahlback classification of knee osteoarthritis, by radiographic joint-space loss and bone attrition, grades I/II/III/IV/V.
Open the calculator → Runs in your browser. Data leaves only if you deliberately send a problem report from the interactive tool.
Example
- Ahlback grade
- III - minor bone attrition (0-5 mm)
Result: Ahlback grade III: minor bone attrition, 0 to 5 mm of bone loss.
The tool opens with these values already filled in. Replace them with your own.
What the result means
- Grade I
- Joint-space narrowing (< 3 mm or < half of the opposite compartment).
- Grade II
- Joint-space obliteration (bone-to-bone contact).
- Grade III
- Minor bone attrition (0 to 5 mm of bone loss).
- Grade IV
- Moderate bone attrition (5 to 10 mm of bone loss).
- Grade V
- Severe bone attrition (> 10 mm), often with subluxation.
What you enter
- Ahlback grade
How this is calculated
Ahlback S. Osteoarthrosis of the knee. A radiographic investigation. Acta Radiol Diagn (Stockh). 1968;Suppl 277:7-72. Read the source ↗
A reference and educational tool. Not medical, legal, or financial advice, and not a substitute for clinician judgment.