What s the difference between a thumb sprain or fracture?

Thumb: A sprain effects the ligaments around the thumb joint while a fracture involves the bones of the thumb.

Ligament vs. bone: A sprain is a torn or partially-torn ligament. A fracture is a break of the actual bone. There are some kinds of sprains that are actually more problematic than a fracture. For instance, a sprain of the inner side of the thumb (gamekeeper's thumb) may need surgery if it is neglected. Usually fractures will heal but can become problems if the thumb is angled or the fracture goes into the joint.