Phalanx fractures are among the most common injuries of the skeletal system, accounting for 10% of all sustained fractures. Phalanx fractures are twice as common in men than women, and both the right and left hand are affected equally.

Middle phalanx fractures are less common than distal and proximal phalangeal fractures. They are usually caused by a blunt or crush force to the dorsum of the hand. These forces are often perpendicular to the long axis of the phalanx. The patient will present with pain and swelling along the middle phalanx with a history of a direct blow or crush injury to the dorsum of the hand.

Although pathologic causes like tumor and infection can occur, middle phalanx fractures are usually due to traumatic injury. The mechanism of injury is dependent on age group.

• Toddlers and young children: crush injuries.
• Ages 10-29 years: sports and falls are the most common cause.
• Ages 40-69 years: machinery use is the most common cause.
• Age 70 and older: falls are the most common cause.

Risk factors include:

• Poor nutrition, ball sports, and bone / joint disease such as osteoporosis.
• Older adults are more likely to sustain middle phalanx fractures than other age groups because of a higher likelihood of falls.

Middle phalanx fractures can be classified based on various categories such as:

• Open or closed fracture
• Displaced or nondisplaced fracture
• Growth plate involvement (Salter-Harris classification)
• Which part of the phalanx is affected (head, neck, shaft, or base fracture)
• Whether there is an associated artery or tendon injury