Let’s begin our journey exploring the anatomy and radiographic images of the hand.
This radiographic projection is called a PA Hand view (the P stands for Posterior; the A stands for Anterior; it denotes the direction the x-rays entered and exited the body part).
There are five distal phalanges (digits 1 through 5). RED
There are four intermediate (aka middle) phalanges (digits 2 through 5). YELLOW
There are five proximal phalanges (digits 1 through 5). BLUE
There are five metacarpals that articulate with the proximal phalanges. GREEN
The proximal metacarpals articulate with the distal row of the carpus (aka wrist).
This radiographic projection is called a Medial Oblique Hand view.
The same structures are visualized in a different orientation.
Sesamoid bones are demonstrated in all 3 views. PURPLE
Sesamoid bones are ossicles imbedded in tendons to enhance the mechanical function and decrease stress on the tendon.
The sesamoid bones in the thumb at the metacarpophalangeal joint are imbedded in the ADDUCTOR POLLICIS (ulnar side) and the FLEXOR POLLICIS BREVIS (radial side).
One sesamoid bone is noted at the interphalangeal joint.
This radiographic projection is called a Lateral Hand view.
The same structures are visualized in a lateral orientation.
Notice: digits 2 – 5 are laying ontop of one another – they are superimposed, one upon the other, making it difficult to visualize independently.
The thumb, however, is readily visualized separately.
The joints (also called articulations) of the hand are SYNOVIAL UNIAXIAL HINGE joints.
The joints are soft tissue structures and appear as black spaces between bones.
Distal interphalangeal joints (DIP) are between the intermediate and distal phalanges of digits 2 – 5. ORANGE
Proxial interphalangeal joints (PIP) are between the intermediate and proximal phalanges of digits 2-5. BLUE
The interphalangeal joint (IP) is between the proximal and distal phalanges onthe first digit (thumb). GREEN
Metacarpophalangeal joints (MCP) are between the proximal phalangeals and distal metacarpals. YELLOW