Base Of The Distal Phalanx, Anterior View

Description

Distal phalanx base (basis phalangis distalis) occupies the center of this anterior, palmar-facing view of the terminal finger bone. A broad, concave articular surface sits proximally to receive the head of the middle phalanx, forming the distal interphalangeal (DIP) joint, while the nonarticular margins flare slightly medial and lateral toward the collateral ligament attachments. Just distal to the joint line, the palmar surface thickens into the flexor tuberosity, the insertion footprint for flexor digitorum profundus; the dorsal extensor insertion is implied at the opposite rim but remains out of direct view from this anterior perspective. Bone landmarks read cleanly. Teaching the DIP joint often stalls on what is actually “joint surface” versus what is tendon insertion, and the base of the distal phalanx is where those discussions become concrete. A small avulsion fracture at the dorsal base explains classic mallet finger after forced flexion, while palmar-sided pain and loss of active flexion can reflect flexor digitorum profundus avulsion (jersey finger) at its distal insertion on the base. The single, orthogonal viewpoint makes the concavity of the articular surface and the thickness of the palmar base easy to compare against the adjacent margins where the volar plate and collateral ligaments stabilize the joint, a relationship that underlies DIP osteoarthritis osteophytes and post-traumatic stiffness. Hand and upper limb anatomy courses, orthopedic and hand-surgery atlases, and radiology teaching files (correlating with AP finger radiographs) benefit from this focused illustration when labeling DIP joint anatomy, tendon insertions, and avulsion fracture locations. Anatomical accuracy verified by SciePro's Medical Advisory Board.