BONES OF THE HAND AND WRIST

AND SELECTED LANDMARKS

BONES OF HAND & WRIST

• FOREARM – RADIUS (LATERAL SIDE), ULNA (MEDIAL SIDE)

• CARPALS – 8 SMALL BONES IN THE WRIST

• METACARPALS – 5 BONES IN THE PALM

• PHALANGES (FINGERS) – 5 PHALANGES, 14 PHALANGEAL BONES

FOREARM (RADIUS & ULNA)

• RADIUS --

• THUMB SIDE

• LATERAL SIDE

• BIGGER AT WRIST THAN ELBOW

• ULNA –

• PINKY SIDE

• MEDIAL SIDE

• SMALLER AT WRIST THAN ELBOW

• (DISTAL HEAD

Dorsal (Posterior) View

CARPALS

• 8 CARPAL BONES

• 2 “ROWS” OF 4 BONES

• PROXIMAL (INTERACT WITH RADIUS & ULNA)

• SCAPHOID (AKA NAVICULAR), LUNATE,

TRIQUETRUM (TRIQUETRAL), PISIFORM

• DISTAL (INTERACT WITH METACARPALS)

• TRAPEZIUM, TRAPEZOID, CAPITATE, HAMATE

SCAPHOID (AKA NAVICULAR)

• PART OF THE FIRST ROW OF WRIST BONES, BUT IT HELPS

TO LINK THE TWO ROWS OF WRIST BONES TOGETHER.

• COVERED WITH CARTILAGE WHICH CONTACTS FIVE

OTHER BONES IN THE WRIST AND FOREARM.

• PART WITHOUT CARTILAGE IS ATTACHED TO LIGAMENTS

HAS & BLOOD VESSELS THAT COME FROM THE RADIAL

ARTERY.

• LONG BOAT-SHAPED BONE UNDER YOUR THUMB

• A BROKEN OR FRACTURED SCAPHOID CAN HAVE

DIFFICULTY HEALING, OR MAY NEVER HEAL, BECAUSE OF

A DISRUPTION OF BLOOD FLOW THROUGH THE

SCAPHOID.

• AN INTACT SCAPHOID IS IMPORTANT AND NECESSARY

FOR PROPER WRIST FUNCTION BECAUSE OF HOW IT

INTERACTS WITH THE OTHER WRIST BONES.

LUNATE

• A CRESCENT-SHAPED BONE MEDIAL TO THE

SCAPHOID

• MIDDLE OF THE WRIST IN THE FIRST ROW OF WRIST

BONES.

• IT IS ALMOST ENTIRELY COVERED IN CARTILAGE.

• SHAPE ALLOWS FOR SIGNIFICANT WRIST MOTION.

• UNCOMMON TO BREAK, BUT CAN BE INVOLVED

WITH DISLOCATIONS OF THE WRIST AND CAN RUB

AGAINST THE ULNA, IF IT IS TOO LONG COMPARED

TO THE RADIUS BONE.

TRIQUETRUM (TRIQUETRAL)

• BONE ON THE LITTLE FINGER SIDE OF THE WRIST IN

THE FIRST ROW OF WRIST BONES.

• ADDS STABILITY TO THE WRIST

• GIVES THE WRIST A LARGER SURFACE TO BEAR

WEIGHT TRANSMITTED FROM THE HAND

• MAKES A JOINT WITH OTHER CARPAL BONES

INCLUDING THE PISIFORM.

PISIFORM

• SMALL SESAMOID BONE THAT IS PART OF

THE CARPALS.

• LOCATED WITHIN THE FLEXOR CARPI

ULNARIS TENDON.

• LIKE OTHER SESAMOID BONES, IT CHANGES

THE DIRECTION OF PULL OF THE TENDON TO

WHICH IT IS ATTACHED.

• OCCASIONALLY, IT CAN BREAK OR CAN

HAVE ARTHRITIS IN THE JOINT WITH THE

TRIQUETRUM.

TRAPEZIUM

• SADDLE-SHAPED BONE IN THE SECOND

ROW OF WRIST BONES

• IT IS THE MAIN PLACE WHERE THE 1ST

METACARPAL CONNECTS TO THE “WRIST”.

• IRREGULAR SHAPE THAT ALLOWS THE

THUMB TO MOVE IN MULTIPLE DIRECTIONS,

YET IT STABILIZES THUMB AS WELL.

• THERE ARE TWO MAIN INJURIES SEEN:

• FRACTURE WITH DIRECT BLOW/ FALL

• ARTHRITIS DEVELOPING BETWEEN THE

TRAPEZIUM AND REST OF THE CARPALS IT

INTERACTS WITH.

TRAPEZOID

• ROUGHLY TRAPEZOIDAL-SHAPED BONE IN

THE SECOND ROW OF WRIST BONES

• PRIMARILY HOLDS THE INDEX 2ND

METACARPAL IN PLACE.

• THIS BONE IS UNCOMMONLY INJURED.

CAPITATE

• LARGE BONE IN THE CENTER OF THE

SECOND ROW OF WRIST BONES.

• FORMS JOINTS WITH MULTIPLE BONES IN

THE WRIST AND HAND.

• IT SITS PRIMARILY UNDER THE 3RD

METACARPAL BONE.

• THIS BONE MAKES AN IMPORTANT

CONTRIBUTION TO WRIST MOTION.

HAMATE

• IS A LARGE, IRREGULARLY SHAPED BONE THAT HAS AN

ALMOST TRIANGULAR SHAPE WHEN SEEN FROM THE TOP

AND IS LOCATED IN THE SECOND ROW OF WRIST BONES.

• IT SERVES AS ATTACHMENT POINTS FOR MULTIPLE LIGAMENTS

AND WORKS WITH MULTIPLE OTHER BONES.

• IT IS ONE OF THE ATTACHMENT POINTS FOR THE LIGAMENT

INVOLVED IN CARPAL TUNNEL SYNDROME.

• IT HOLDS UP THE 4TH & 5TH METACARPALS

• CAN BE INJURED IN MORE THAN ONE WAY.

• FREQUENTLY, IT CAN BREAK WHEN PEOPLE USE THE HAND FOR

PUNCHING.

• THE HOOK OF THE HAMATE CAN FRACTURE DURING A FALL

OR IF STRUCK DIRECTLY, SUCH AS WHEN A BASEBALL PLAYER

SWINGS A BAT OR GOLFER SWINGS A GOLF CLUB.