A patient comes in with pain, tenderness, and swelling of his thumb, mostly along the ulnar aspect of the metacarpophalangeal joint. He says the thumb feels slightly unstable. You have him pinch his thumb and forefinger, and compared to the other hand, the affected one has less strength. The history is notable for a recent ski trip to Tahoe. Here's an X-ray:
Challenge: What's the diagnosis?
1. What's seen on the X-ray?
2. What is the historic name for this disease and why is it called that?
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