Innervation of the interphalangeal joint of the thumb: anatomical study.

We dissected 30 cadaveric thumb interphalangeal joints to delineate the sensory nerve anatomy of its capsule. Four articular branches supplying the interphalangeal joint capsule of the thumb were found in all specimens. Ulnar and radial proper digital nerves provide one palmar capsular nerve branch on their respective sides. Of the two dorsal branches of the radial nerve at the dorsum of the thumb, we observed that each nerve provided one branch to the interphalangeal dorsal capsule. Our findings demonstrate a consistent pattern of innervation and may provide the anatomical basis to the treating surgeon for an effective and safe denervation of the interphalangeal joint of the thumb.