Classification of rhizarthrosis according to Eaton/Little.
| Stage | Native radiological pathologies |
| 1 | Joint splitter extension if necessary |
| 2 | Joint space narrowing, osteophytes (bone neoplasms), free joint bodies <2 mm. |
| 3 | Progressive joint narrowing, osteophytes, free joint bodies > 2 mm. |
| 4 | Additional osteoarthritis of the scaphoid (scaphoid trapezoid) joint (STT joint; joint between the scaphoid (scaphoid bone), trapezium (large polygonal bone), and the trapezoideum (small polygonal bone))/carpal arthrosis |