radioulnar, wrist, and digital joints Flashcards
movements of the wrist joint
flexion, extension, abduction (radil deviation), adduction (ulnar dev.)
proximal row of carpal bones
scaphoid, lunate, triquetrum, pisiform
distal row of carpals
trapezium, trapezoid, capitate, hamate
radiocarpal articulation
distal radius–>scaphoid and lunate. flex/ext
intercarpal articulation
between adjacent carpal bones. little movement
midcarpal articulation
art. btw the proximal and distal rows. lack of ligaments, flex ext movement
carpometacarpal articulation
btw base of metacarpals and the distal row of carpals. little movement because of shape in joints 2-5, but joint 1 (on thumb) is a saddle joint btw the trapezium and the 1st metacarpal (allows for opposable thumbs)
what separates the ulna and the triquetrum?
a triangular fibrocartilagenous disc, allows for greater range of motion in adduction
triangular fibrocartilagenous complex
helps distribute force from the hand to both the radius and ulna. greater range of motion. increases capacity of the wrist to absorb a blow from forces applied to wrist
wrist flexion
ant surface of wrist to toward forearm, occurs at radiocarpal joint
wrist extension
occurs at midcarpal joint
wrist abduction
moving toward radius, radiocarpal joint
wrist adduction
toward ulna, radiocarpal joint
ulnar collateral ligament of the wrist
binds the styloid process of the ulna to the proximal row of carpal bones. very stong, limits abduction
radial collateral ligament of the wrist
attaches radial styloid process to carpal bones. limits adduction
palmar radiocarpal ligament
binds carpals on the palmar wrist, limits extension
dorsal radiocarpal ligament
binds carpals on the dorsal surface of the wrist, limits flexion
flexor retinaculum
continuation of deep fascia of forarm that attaches to scaphoid, trapezium, pisiform, and hamate bones. converts space into carpal tunnel which passes the median nerve and flexor tendons to all digits
sensory to wrist?
median nerve (anterior interosseus branch), radial nerve (post interosseus branch), and the ulnar nerve (carpal branch)
blood supply to wrist
radial and ulnar arteries via dorsal and palmar carpal branches
FOOSH injury
fall on an outstretched hand, fracture most common in scaphoid, pain in anatomical snuffbox
colles fracture
fracture to the distal radius. pain and swelling just above wrist, inability to hold onto things or lift anything. Wrist may be back over the broken bone making it look like a dinner fork
symptoms of radial nerve damage
- drop wrist: injury to any part of the radial nerve will be especially noticable when the hand is pronated.
- gravity will extend the wrist when it is supine. when the hand is supine and extended, the patient will not be able to resist an attempt to flex the hand
- loss of sensation to the radial side of the dorsum of the hand
tenosynovitis
inflammation/irritation within the synovial sheath that surrounds the tendons of the forearm muscles as they cross the wrist.
DeQuervain’s Disease
overuse injury that involves the swelling of the first dorsal extensor pollicis brevis tendons. flexion of the thumb at the MP joint along w/ ulnar deviation of the wrist exacerbates this condition
palmar carpal ligament (plate)
made of fibrocartilage, reinforces the IP and MP joints of the digits
ulnar and radial collateral ligaments of the IP and MP joints
thickenings of the capsule of each joint that strengthens each joint on the medial and lateral side, also attach to palmer carpal plates
MP collateral ligaments: taut during flexion and loose during extension
Game Keepers thumb
results from hyper abduction of the MP joint of the thumb. tears the ulnar collateral ligament and possible fractures from the head of the 1st metaparpal and prox phalanx onf the thumb
digital sheaths
annular and cruciform bands that bind the palmar plates to form longitudinal grooves in which the digital tendon sheath are supported as they cross the joints
deep transverse metacarpal ligament
unity of the palmar plates of digits 2-5. keeps heads of MC’s from being mobile
innervation of IP and MP joints
digital branches of median and ulnar nerves
blood supply of IP and MP joints
digital branches of the superficial palmar arch
power grip
holding an object tightly between the palm and flexed fingers making a tight fist. involves:
- wrist extension (radial direction)
- IP joints flexed by flexor digitorum sup and prof., MP joints flexed by interossei
- thumb adducted at the MP joint by adductor pollicis and IP may or may not be flexed by the flexor pollicis longus
variations of the power grip
hook: only fingers used and they are flexed strongly at IP and MP joints
fist: grasping tightly within a fist, finger flexed, thumb adducted and flexed
precision grip
precision and accuracy, involving thumb and pointer finger
- lumbricals active in 1st finger if MP joint is flexed while IP is extended
- if IP are flexed, interossei flex MP
- thenar mucles oppose thumb
carpal tunnel syndrome
nerve entrapment syndrome of the carpal tunnel. inflammation of tendons causes pressure on median nerve
sensory symptoms: pain and redness to parathesia and anethesia along the cutaneous distribution of the median nerve, pain in palmar surface of first 3.5 digits
motor symptoms: weak opposition of the thumb, inability to oppose it could happen and the wasting of the thenar eminence, ape hand deformity
to fix: they cut open the flexor retinaculum to relieve pressure
pronator teres syndrome
when median nerve is compressed as it passes thru the 2 heads of the pronator teres muscle in the prox forearm. Symptoms:
- weakening of wrist flexion and radial deviation due to loss of function of flexor carpi radialis
- papal hand
- IP joint of digits 1 and 2 are in an extended position
- extensor digitorum and interossei act unopposed to extend the MP and IP joints, ape position - inability to make a closed fist
- difficulty performing a precision grip
guyons tunnel syndrome
compression of the ulnar nerve as it passes through guyons tunnel (between pisiform and the hook of the hamate, covered by palmar carpal ligament).
Symptoms vary, include:
1. parasthesia along ulnar side of hand on the dorsal and palmar surfaces is only sensory branch is affected
2.if only deep motor branch: hyper abducted thumb due to weakness of adductor pollicis, inability to adduct or abduct the MP joints, cant make a fist
cubital tunnel syndrome
proximal ulnar nerve lesion, compression of the nerve as it passes through the origin of the flexor carpi ulnaris muscle posterior to the funny bone. all the symptoms of a distal ulnar nerve lesion plus weakining in movements of flexion and ulnar deviation of the wrist due to weakness in flexor carpi ulnaris
radial nerve entrapment
affects the post branch of the radial nerve
difficulty extending digits, would have already passed through supinator muscle to the wrist would not be affected
tinel sign test
tapping on the entrapped nerve, positive test would be parasthesia when tapping.
- tapping on flexor retinaculum would compress the median nerve and cause tingling along the palmar thumb and fingers 1&2
- tapping the cubital tunnel will compress the ulnar nerve, causing tingling along the ulnar side of the hand and medial 1.5 digits
phalens test
flexing wrist with the forearm prone then pressing the dorsum of the hands together for at least 30 secs. positive sign if there is tingling along the palmar thumb and digits 1 and 2
forment’s sign
indicates ulnar nerve damage, thumb cannot adduct, cant hold tightly to a piece of paper btw the thumb and index finger. instead of adduct the thumb, the patient flexes the IP joint of the thumb
mallet finger
damage to the insertion of the lateral slips of the extensor mechanism on the base of the distal phalanx. DIP cant be extended and stays in a flexed position
boutinniere deformity
PIP is flexed while DIP is extended
swan neck deformity
results from rheumatoid arthritis. MP snf DIP are flexed while PIP is hyper extended
trigger finger
affected finger is in a flexed position bc there is swelling of the sheath surrounding the long common digital flexor tendon sheath as well as the ligaments that bind the sheath. Affected digit is painful.
