Bones of the Hand and Wrist · 2020-03-30 · the wrist and hand. •it sits primarily under the...
Transcript of Bones of the Hand and Wrist · 2020-03-30 · the wrist and hand. •it sits primarily under the...
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.