Frequency of joint space narrowing scored using the van der Heijde-modified Sharp scoring system on conventional radiographs (n = 80 joints from 43 participants).
| MCP | 0 (Normal) | 1 (Focal or Doubtful) | 2 (> 50% of Original JS) | 3 (< 50% of Original JS or Subluxation) | 4 (Bony Ankylosis or Complete Luxation) |
|---|---|---|---|---|---|
| 2nd MCP | 34 | 0 | 1 | 5 | 0 |
| 3rd MCP | 33 | 1 | 3 | 2 | 1 |
MCP: metacarpophalangeal; JS: joint space.