How Many Distal Phalanges Are There in a Hand?

The human hand comprises the bones, numerous muscles, sheaths (tubular structures that surround the fingers), tendons (the connection between the muscles and bone), and ligaments (fibrous tissues responsible for binding the joints together), all of which integrate to provide the mobility and flexibility required for day-to-day activities.

Additionally, the hand has arteries and veins that carry blood to and fro and provide sensation to the hands and fingers.

Three types of bones in the hand include:

1. Phalanges:
   • Comprise 14 tubular bones found in the fingers of each hand and toes of each foot
   • Each finger is subdivided to have three phalanges except the thumb which has only two phalanges (proximal and distal):
     • Proximal phalanges (located below the knuckle; largest of the three)
     • Middle phalanges (located above the knuckle)
     • Distal phalanges (also called fingertips or terminal phalanges)
2. Metacarpals: Composed of five bones that form the middle part of the hand
3. Carpals: Composed of the eight bones (aligned in two rows) that create the wrist through a connection with the bones of the arm (ulna and radius)

Five digits of the hand include:

1. Index finger or forefinger
2. Middle finger
3. Ring finger
4. Little finger
5. Thumb

Ligaments of the hand include:

• Digital fascial complex: An attachment between the surrounding subcutaneous tissue and neurovasculature to the bony phalanges
• Metacarpophalangeal ligaments: An attachment to the bases of the proximal phalanges that provides strength to the metacarpophalangeal joints
• Collateral interphalangeal ligaments: An attachment to the heads, supporting the proximal interphalangeal joints

Distal phalanges are one of three types of finger bones with the following characteristics:

• Shorten than other phalanges
• Slightly thicker than the other two (proximal and middle) phalanges
• Each has three parts, namely, a base, body (shaft), and head
• Have a smooth and round dorsal surface
• Has a concave base that tapers distally and expands into a tuberosity

A tuberosity (protuberance) is roughened on the flexor surface of the hand for attachment of a digital fibro-fatty pad (at the pulps of fingers).

The phalanges (considered long bones due to their structural characteristics) are interconnected by interphalangeal joints and vascularized (blood supply) through the nutrient rami to phalanges, which stem from the palmar digital arteries.

The complex human hand articulations consist of the following:

• Metacarpophalangeal joints: Connection between the metacarpal bones and proximal phalanges
• Proximal interphalangeal joints: Connection between the proximal and middle phalanges
• Distal interphalangeal joints: Connection between the middle and distal phalanges
• The interphalangeal joint of the thumb: Connection between the proximal and distal phalanges of the thumb

The phalanges of the hand can be visualized on several series of the distal upper limb including:

• Radiograph or X-rays:
  • Hand X-ray or radiograph
  • Thumb X-ray radiograph
• Cross-sectional imaging tests:
  • Computed tomography scan of the hand
  • Magnetic resonance imaging (MRI) of the finger
  • MRI of the thumb

Pain, swelling, and tenderness of the distal phalanges could be due to conditions such as:

• Overuse
• Trauma (especially vibratory trauma at the workplace)
• Arthritis
• Psoriatic arthritis
• Distal phalanx fracture
• Infected bursas
• Nail bed infections
• Stiffness
• Acro-osteolysis (a rare disease characterized by bone resorption)
• Congenital abnormalities