Boxer's Knuckle

Boxer’s Knuckle is an injury to the structures around the first knuckle of a finger, also known as the metacarpophalangeal joint (MPJ). The skin, extensor tendon, ligaments, joint cartilage, and the bone of the metacarpal head may all be involved. Repeated impacts to the extensor tendon over the knuckle causes Hypertrophic Interstitial Tendonosis, or HIT Syndrome. This is a thickening, weakening, inflammation, and scarring of the extensor tendon.