Carpal Bones Flashcards
Distal end of radius articulates with which 2 carpal bones?
- Scaphoid
- Lunate
Wrist joint is a type of?
Condyloid synovial joint between radius and scaphoid + lunate
Scpahoid is on which side?
Lateral (towards thumb)
Trapezium is on which side?
Lateral (towards thumb)
Below scaphoid
The biggest bone in hand?
Capitate
Why is it called hamate?
Because has a hook (hamus in latin)
How many phalanges in thumb?
Only proximal and distal phalanges while all other fingers have proximal, middle and distal
Joints between
1.Carpals and metacarpal?
2.Metacarpal and phalanges?
3.Between phalanges?
1.Carpometacarpal joint
2.Metacarpophalangeal joint
3. Interphalangeal joint (proximal and distal)
Joint between the 1st metacarpal and the proximal phalanx of thumb?
Saddle joint
In rheumatoid arthritis which joints are affected?
- Metacarpophalnageal (MCP)
- Proximal interphalangeal (PIP)
In osteoarthritis which joints are affected?
Distal Interphalangeal joints (DIP)
A fall on the outstretched hand damages which carpal bone? And why? And what happens?
Scaphoid bone because its blood supply enters is distally so the proximal fragment can die in avascular necrosis
What is avascular necrosis?
Avascular necrosis is a condition where bone tissue dies due to a lack of blood supply.
Where is the radial artery?
On the lateral side of wrist just under the thumb
Radius and ulna are on which side?
Radius- lateral
Ulna- medial
Middle phalanx is absent in?
Thumb
Which part of scaphoid can be felt?
Scaphoid tubercle
What is flexor retinaculum?
The flexor retinaculum is a band of connective tissue that runs across the front of the wrist and helps to hold the tendons of the hand and wrist in place.
What structure runs over flexor retinaculum?
Tendon of palmaris longus
Tendon of palmaris longus originates from? What is it function? What is it innervated by?
-Medial epicondyl
-flexion of wrist
-by Median nerve
Flexor retinaculum is also called?
Carpal ligament
Name the structures that run under flexor retinaculum?
- Median nerve
- Tendon of flexor pollicis longus
- Tendon of flexor digitorum superficialis
4.Tendon of flexor digitorum profundus
Median nerve is sensory and motor for which fingers of hands?
Middle, Index and Thumb
What is carpal Tunnel syndrome?
Compression of Median Nerve at flexor retinaculum causing numbness, parasthesia, pain of median nerve distribution
What structures make up carpal tunnel?
Carpal bones on the bottom and sides, and a ligament on the top called the transverse carpal ligament (flexor retinaculum).
The median nerve and tendons that control the fingers pass through this narrow passageway.
The branches of tendon of palmaris longus form?
Palmar aponeurosis
Difference between aponeurosis and tendon?
The main difference between tendons and aponeuroses is that tendons are cord-like and round, while aponeuroses are broad and flat sheet-like tendon.
What is Dupytren’s Contracture?
Dupuytren’s contracture is a condition that causes the fingers (little and ring) to be pulled towards the palm and being unable to straighten due to thickening and tightening of the connective tissue in the palm of the hand.
Proximal and middle phalanx flex
Distal is unaffected
Flexor digitorium superficialis attach to which phalanx?
Middle phalanx
Flexor digitorum profundus attach to which phalanx?
Runs deep (below) to flexor digitorum superficialis and attaches to distal phalanx
What kind of bone is pisiform?
A sesamoid bone
- formed within the tendon of flexor carpi ulnaris
What’s a sesamoid bone?
A sesamoid bone is a small, round bone that is embedded within a tendon or muscle,
typically found in areas of the body where tendons are subjected to a lot of pressure or friction, such as the hands (pisiform) (base of thumb- within tendon of flexor pollicis brevis) , feet, and knees (patella)
Wrist joint is also called?
Radiocarpal joint
Most commonly fractured carpal bone?
Scaphoid
What is the characterisitic clinical feature of scaphoid fracture?
Pain and tenderness in anatomical snuff box
Leads to avascular necrosis
Which artery supplies scaphoid?
The scaphoid bone is primarily supplied by branches of the radial artery, which enter the bone at its distal end.
What is anatomical snuff box?
Triangular depression on lateral side of wrist
Lateral border by
Tendon of:
1. Abductor pollicis longus
2. Extensor pollicis brevis
Medial border by
3. Extensor pollicis longus
.
Which artery passes through anatomical snuff box?
Radial artery
Can be palpated
Scaphoid bone is also called?
Navicular bone
What passes through the carpal tunnel?
Conveys Into the hand:
1. Median nerve
2. Flexor tendons
When does capitate negin to ossify? And when do others?
- Capitate during 1st year
- Others untill 12th year when all the bones are ossified
Trapezium forms which joint with 1st metacarpal bone?
A saddle joint
- allowing great mobility of thumb
Attachment point for flexor retinaculum on hamate?
Hook of hamate
In dislocation of lunate bone, which nerve is commonly involved?
Median
