[TA] the fibrocartilaginous plates, one located on the anterior aspect of each metacarpophalangeal and interphalangeal joint of the hand, which are firmly attached to the bases of the phalanges and the heads of the next proximal bones; they are grooved to accommodate the long flexor tendons.palmar ligaments of interphalangeal joints of hand, palmar ligaments of metacarpophalangeal joints. SYN: ligamenta palmaria [TA], accessory volar ligaments.