Wrist Joint Flashcards
What is a sesamoid bone?
A bone in a tendon
What is the function of sesamoid bones?
reduces friction and creates a tunnel to transmit other structures
What are the carpal bones of the hand?
scaphoid, lunate, triquetrum, pisiform, trapezium, trapezoid, capitate, hamate
Which carpal bones have a tubercle?
scaphoid and trapezium
Which carpal bone has a hook?
hamate
Which is the biggest carpal bone?
capitate
Which carpal bone is a sesamoid bone and which tendon is it in?
pisiform - in the tendon of flexor carpi ulnaris
Which carpal bones articulate with the radius?
scaphoid, lunate and triquetrum in ulnar deviation
What nerve is compressed in carpal tunnel syndrome?
the median nerve
Which tendon doesn’t go under the flexor retinaculum?
palmaris longus
What are the tendons that border the anatomical snuff box?
extensor pollicus longus and extensor pollicis brevis and abductor pollicis longus together
Which carpal bone makes up the floor of the anatomical snuff box?
scaphoid
When do carpal bones begin ossification?
Not until 2 years after birth
In what order do carpal bones ossify?
Clockwise from capitate
At what age does pisiform ossify?
11 years old
What are the attachments of the flexor retinaculum?
no answer given in Evernote
What are the two joints of the wrist complex?
radiocarpal and intercarpal
Is flexion or extension greater at the radiocarpal joint?
flexion
Is ulnar deviation or radial deviation greater at the radiocarpal joint?
ulnar deviation
Is flexion or extension greater at the intercarpal joints?
extension
Is ulnar deviation or radial deviation greater at the intercarpal joint?
radial deviation
What is the function of the radiocarpal ligaments?
to resist the sliding movement of carpal bones and stop them going medially
Which are more extensive - palmar or dorsal radiocarpal ligaments?
palmar
Which carpal bone is most commonly dislocated?
lunate - due to the damage of the radioscapholunate ligament
What is a secondary function of the radiocarpal ligaments?
They transmit blood vessels to the bones
Which is the only muscle which has a tendon attaching to carpal bones?
flexor carpi ulnaris
What is a Colles fracture?
a fracture of the distal radius
What is the clinical significance of a fracture to scaphoid?
fracture across the waist will damage blood supply and cause avascular necrosis at the proximal pole
What movements can occur at the first carpometacarpal joint?
flexion/extension, abduction/adduction and opposition - because it is a saddle joint
What movements can occur at the second and third carpometacarpal joints?
none - they are immobile
What movements can occur at metacarpophalangeal joints?
flexion/extension and abduction/adduction
What movements can occur at interphalangeal joints?
flexion and extension only
What links metacarpals II to V?
deep transverse metacarpal ligament
What is the volar plate and dorsal plate and what are their functions?
They are layers of fibrocartilage above and below the metacarpophalangeal joints to increase the surface area for movement at the joint
What structure prevents abduction at the interphalangeal joints in flexion?
collateral ligaments
What is a swan neck deformity?
injury on volar aspect of IP joint that forces it into hyperextension with compensatory flexion at the next joint
What is a boutonniere deformity?
injury on dorsal aspect of IP joint that forces it into flexion
