The rank order and frequency of joint involvement for increasing grades of radiographic osteoarthritis and erosive osteoarthritis
| Right hand | Left hand | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| Rank | K&L≥2 | K&L≥3 | K&L=4 | Erosive osteoarthritis | Rank | K&L≥2 | K&L≥3 | K&L=4 | Erosive osteoarthritis |
| 1 | DIP2 (30.3%) | DIP2 (15.1%) | DIP2 (6.3%) | DIP2 (3.6%) | 1 | DIP2 (21.9%) | DIP2 (10.0%) | DIP2 (4.1%) | DIP2 (3.2%) |
| 2 | DIP5 (27.2%) | DIP3 (9.1%) | DIP3 (3.6%) | DIP3 (2.5%) | 2 | DIP5 (19.9%) | DIP5 (8.2%) | DIP3 (3.7%) | DIP3 (1.9%) |
| 3 | DIP3 (22.7%) | DIP5 (8.2%) | DIP5 (3.3%) | DIP5 (2.0%) | 3 | DIP3 (15.1%) | DIP3 (7.5%) | DIP5 (3.5%) | DIP5 (1.5%) |
| 4 | PIP5 (12.0%) | DIP4 (4.9%) | DIP4 (1.6%) | DIP4 & PIP3 (0.7%) | 4 | PIP2 (9.7%) | DIP4 (4.0%) | DIP4 (2.1%) | DIP4 (1.0%) |
| 5 | PIP2 (11.8%) | PIP3 (3.2%) | PIP3 (1.4%) | 5 | PIP5 (9.0%) | PIP4 (2.5%) | PIP3 (1.1%) | PIP4 (0.7%) | |
| 6 | PIP3 (11.3%) | PIP4 (2.2%) | PIP4 (1.0%) | PIP4 (0.6%) | 6 | PIP3 (8.7%) | PIP3 (2.0%) | PIP4 (0.8%) | PIP5 & PIP3 (0.3%) |
| 7 | DIP4 (10.8%) | PIP2 (2.0%) | PIP2 & PIP5 (0.5%) | PIP5 (0.3%) | 7 | DIP4 (8.3%) | PIP5 & PIP2 (1.9%) | PIP5 (0.5%) | |
| 8 | PIP4 (6.8%) | PIP5 (1.7%) | PIP2 (0.1%) | 8 | PIP4 (6.3%) | PIP2 (0.4%) | PIP2 (0.1%) | ||
| Spearman rank correlations | 0.611, p=0.108 | 0.970, p<0.001 | 0.988, p<0.001 | Reference | Spearman rank correlations | 0.539, p=0.168 | 0.958, p<0.001 | 0.958, p<0.001 | Reference |
Percentages represent the proportion of joints affected with increasing grades of non-erosive radiographic osteoarthritis and erosive osteoarthritis out of the total number of joints examined.
DIP, distal interphalangeal joint; K&L, Kellgren and Lawrence; PIP, proximal interphalangeal joint.