Bones Of Hand
- The hand consists of carpal bones at wrist, metacarpal bones in the palm, and phalangeal bones in the digits.
- Carpal bones are short bones, eight in number, and arranged in two rows proximal and distal, each row presenting four bones. From lateral to medial side, bones of proximal row arescaphoid lunate triquetraland pisiform; bones of distal row are trapezium, trapezoid, capitate and hamate. Ossification of carpal bones appears after birth in a spiral manner as follows:
Ossification (in years)
- Capitate is the largest carpal, first carpal bone to ossify and articulates with maximum number of bones.
- Lunate is the most commonly dislocated carpal bone.
- Scaphoid is the most commonly fractured carpal bone.
- Metacarpal bones are miniature long bones, five in number and are numbered from lateral to medial side. Each metacarpal possesses a diaphysis and a single epiphysis (unique property among the long bones as most of the long bones have two epiphysis). The epiphysis 0f all metacarpals are directed towards the head, except in the first where it is located towards the base. Heads of metacarpals articulate with proximal phalanges forming MP joints (Knuckles).
- Bennett's fracture dislocation is an oblique intra-articular fracture of base of 1st metacarpal with dislocation of carpometacarpal joint.
- Rolando's fracture is extra-articular fracture of the base of 1st metacarpal.
- Boxer'sfracture is the fracture through the neck of 5th metacarpal.
- Phalangeal bones are 14 in number, 3 for each medial four fingers and 2 for the thumb. These bones are referred to as proximal, middle and distal phalanges. Phalanges are miniature long bones and possess a diaphysis and a single epiphysis directed towards the base (like the first metacarpal bone).