John P. Cunha, DO, is a U.S. board-certified Emergency Medicine Physician. Dr. Cunha's educational background includes a BS in Biology from Rutgers, the State University of New Jersey, and a DO from the Kansas City University of Medicine and Biosciences in Kansas City, MO. He completed residency training in Emergency Medicine at Newark Beth Israel Medical Center in Newark, New Jersey.
Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.
Fingers are easily injured from everyday activities, and
finger injuries are some of the most common traumatic injuries seen in an emergency room. Injuries may range from simple bruises or contusions to broken bones and
dislocations of the
joints. Understanding the basic anatomy of the hand and fingers is useful in
understanding different types of finger injuries, broken fingers, and how some treatments differ from others.
The hand is divided into three sections: wrist, palm,
and fingers. There are eight bones in the wrist, which move together to allow
the vast ranges of motion of the wrist. The palm, or mid-hand, is made up of
the metacarpal bones. The metacarpal bones have muscular attachments and
bridge the wrist to the individual fingers. These bones frequently are injured
with direct trauma such as a crush from an object or most commonly from a
The fingers are the most frequently injured part of
the hand. Fingers are constructed of ligaments (strong supportive tissue
connecting bone to bone), tendons (attachment tissue from muscle to bone), and
three bones called phalanges. There are no muscles in the fingers. Fingers
move by the pull of forearm muscles on the tendons.
The three bones in each finger are arranged in the
same manner. The finger bones are named in their relation to the hand. The first bone is the proximal phalanx. The second bone is the
middle phalanx. The smallest and farthest from the hand is the distal
phalanx. The thumb is the shortest finger and does not have the middle phalanx.
Knuckles on the back of the hand are joints formed
by the bones of the fingers. They are commonly injured or dislocated with
trauma to the hand. Each joint has a specific name depending on its location and the bones involved.
The first and largest knuckle is the junction
between the palmar bones and the fingers. Medically, it is the joint of
the metacarpals and phalanges or the metacarpophalangeal joint (MCP). This joint commonly is injured in closed fist activities, and a fracture of this area is commonly known as a boxer's fracture.
The next knuckle out toward the fingertip is the joint closest to the hand and between the finger bones. It is termed the proximal inter-phalangeal joint (PIP). This joint may be dislocated in sporting events when a ball or object directly strikes the finger.
The farthest joint of the finger is the distal
inter-phalangeal joint (DIP). Injuries to this joint usually involve a
fracture (a break) or tendon tearing (avulsion) injury.