Interphalangeal joint

Interphalangeal joints are the hinge joints between the phalanges of the hand and foot. There are two types: the proximal interphalangeal joints (PIP) and the distal interphalangeal joints (DIP). These joints are integral to the flexibility and function of the digits.

Anatomy

The interphalangeal joints are all hinge joints, a type of synovial joint that allows for bending and straightening motions. They are formed by the connection of the phalanges, the bones in the fingers and toes. Each finger and toe, with the exception of the thumb and big toe, have both a PIP and a DIP. The thumb and big toe only have a single interphalangeal joint, equivalent to a DIP.

Function

The primary function of the interphalangeal joints is to allow for movement of the fingers and toes. This includes bending (flexion) and straightening (extension), as well as a small amount of rotation and sideways bending (abduction and adduction).

Clinical significance

Conditions that can affect the interphalangeal joints include osteoarthritis, rheumatoid arthritis, and gout. These can cause pain, swelling, and reduced function of the joints. Treatment may involve medication, physical therapy, or in severe cases, surgery.

See also

• Phalanges
• Hinge joint
• Synovial joint
• Osteoarthritis
• Rheumatoid arthritis
• Gout