A cone-shaped appearance of the epiphysis of the middle phalanx of the 3rd finger of the hand, producing a 'ball-in-a-socket' appearance. This epiphysis is located at the proximal end of the phalanx and is normally nearly flat. The related entity 'angel-shaped' epiphysis refers to a pronounced cone-shaped epiphysis in combination with a pseudoepiphysis at the distal end of the phalanx. [from
HPO]