To illustrate different Larsen grades for CMC I.
In the Heinola Follow-up Survey of Arthritis 103 seropositive patients with rheumatoid arthritis (RA) were followed prospectively over 20 years. Hand radiographs were taken at onset and at 1, 3, 8, 15, and 20 years from entry. One female patient was selected to demonstrate Larsen grades for CMC I, as she presented all the different grades of destruction during the progression of RA. Interobserver and intraobserver errors in grading of CMC I were tested.
Radiographs of the different grades with schematic presentation are illustrated. Interobserver and intraobserver errors were in the Weighted Kappa test 0.75 and 0.82, respectively.
We emphasise the importance of following the destruction of CMC I separate from the entire carpus during the course of RA.