A Jones fracture is a fracture of the diaphysis at the base of the fifth metatarsal. It is named after a British Orthopaedic surgeon Sir Robert Jones who described the fracture in 1902 after sustaining one himself.

Resources:

http://www.foot-health-forum.com/forum/showthread.php?t=682

http://www.foot-health-forum.com/forum/showthread.php?t=10606