Wrist Flashcards
bones of the wrist proximal to distal and lateral to medial
scaphoid, lunate, triquetral, pisiform, trapezium, trapezoid, capitate, hamate
(some lovers try positions that they cant handle)
is the ulnar medial or lateral?
medial
what is a sesamoid bone?
bone within a tendon
what is the function of a sesamoid bone
help reduce friction and produce a tunnel for proximal structures to pass to the distal region of the bone within a tendon
what is the key forearm bone that is involved in flexion at the wrist
radius - ulnar not involved at all - no articulation (opposite to the elbow)
what bone does the radius articulate onto at the wrist
scaphoid and lunate
bones of the hand (general)
carpals (wrist)
metacarpals
phalanges (proximal, middle and distal)
what is the largest bone in the wrist
the capitate bone
what forms the floor of the anatomical snuffbox
scaphoid
what is the function of the flexor retinaculum of the wrist
holds down the tendons and median nerve - stopping them from bowing upwards
what is carpel tunnel syndrom
compression of the median nerve of the wrist
what is the retinaculum of the wrist made up of
deep fascia
what are the first and last wrist bones to ossify
first = capitate) last = pisiform
which bone of the wrist is a sesamoid bone? and which tendon is it within
pisiform - within the tendon of the flexor carpi ulnaris
at what age do the bones of the wrist start to ossify
first one around 2nd year of birth
2 joints of the wrist
radiocarpal (between radius and scaphoid and lunate)
intercarpal/midcarpal
what are the 2 movements at the radiocarpal and which dominates over the other
flexion/extension - more flexion
radial/ulnar deviation - more ulnar
which bone of the wrist is not involved in the intercarpal joints
pisiform
which movements of the intercarpal joints dominate over the other?
extension>flexion
radial deviation>ulnar
what is the main articulation of the intercarpal joints
between capitate and scaphoid+lunate
which bone of the wrist takes the majority of the force taken in a fall
capitate
function of the radiocarpal ligaments
- transmit vessels to carpal bones
- prevent the carpal bones from sliding medially
are there more palmar or dorsal radiocarpal ligaments
palmar
what is the arching ligament of the palmar side of the wrist called
radio-scapho-lunate ligament
what is the only tendon that attaches to the carpals
flexor carpi ulnaris
where do the tendons that provide flexion and extension bind to
the distal bones of the hand (only the flexor carpi ulnaris binds to the carpals)
what is the most common fracture of the upper limb
distal radius (with clavicle)
what is the most frequently fractured carpal bone
scaphoid
what is the most commonly subluxed bone of the wrist
lunate
where is the point of fracture usually for the scaphoid bone
across the waist
what is a consequence of fracturing the scaphoid bone
avascular necrosis of the proximal pole of the scaphoid
3 main joints of the hand
carpometacarpal (of thumb) - saddle
metacarpophalangeal
interphalangeal
movements of the metacarpophalangeal joint
flexion/extension
abduction/adduction
movements of the interphalangeal joints
flexion/extension
movement of the carpometacarpal joint
allows opposition of the thumb
function of the deep transverse metacarpal ligament
links metacarpals 2-5
what is the shape of the condyloid joints
convex head of metacarpal with concave base of phalanx
greater articular surface of head of metacarpal compared to phalanx
function of the volar plate
expands surface area for articulation
where are the volar plates
at metacarpophalangeal joints and interphalangeal joints
what is a Palmar interphalangeal joint injury and what is the outcome
site of injury on inferior side of joint - injuring volar plate –> Swan neck deformity
- -> compensatory flexion of distal phalangeal joint
- -> hyperextension of medial phalangeal joint
what is a dorsal interphalangeal joint injury and what is the coucome
injury to dorsal plate (superior side of the joint)
–> compensatory hyperextension of distal phalangeal joint and flexion of medial phalangeal joint
