Anatomy Flashcards
which combination of carpal bones are the attachment sites of the transverse carpal ligament?
hamate (hook of the hamate)
pisiform
trapezium
scaphoid
what is the role of the transverse carpal ligament?
prevents bowstringing of long flexors of fingers when the wrist flexes and is the attachment site for thenar and hypothenar muscles
what is the scaphoid “ring” sign?
a radiological indicator of ligamentous injury of the wrist. The scaphoid cortical ring sign is produced by the foreshortened appearance of the distal pole of the scaphoid rotated on its axis by scapholunate dissociation, one of the manifestations of carpal instability syndromes
what are the signs of a disrupted SL complex?
widening of scapholunate interval of greater than 4 mm (normal width is <3mm), a scaphoid “ring” sign, and a dorsally facing lunate seen in a true lateral view
compartment syndrome symptoms
pain, paresthesia, paralysis, and pulselessness
(the hand will also usually assume intrinsic minus posture)
Martin-Gruber anastomosis
most common anomalous communication between the median and ulnar nerves. occurs in the FOREARM and typically involves motor fibers of the median nerve or AIN communicating with the ulnar nerve trunk and innervating all instrinsic muscles of the hand
Martin – MEDIAN
grUber – to Ulnar
Riche-Cannieu anastomosis
IN THE HAND, communication between the deep ulnar branch to the recurrent median thenar branch and results in ULNAR INNERVATION OF THE THENAR MUSCLES
Marinacci anastomosis
communication between the ulnar and median nerve in the FOREARM that is a REVERSE Martin-Gruber
Berretini anastomosis
communication between the ulnar 4th common digital nerve and the median 3rd common digital nerve
APB
Innervated by the median nerve and originates from the transverse carpal ligament. strong muscle of opposition (interposition)
supinator
originates from lateral epicondyle and adjacent portion of the ulna and inserts into the upper third of the radius
first volar interosseous
originates from length of second metacarpal and adducts index finger
ECU
innervated by PIN and inserts into base of 5th metacarpal
first dorsal interosseous
strong finger abductor that inserts into the base of the proximal phalanx of the IF
adductor pollicis
innervated by ulnar nerve and inserted into the ulnar side of the proximal phalanx of the thumb and the extensor expansion of the thumb
ECRB
inserts into base of third metacarpal
EPL
innervated by PIN and inserts into first distal phalanx
Bouvier test
used to see if PIPJ capsule and the extensor mechanism is functioning abnormally. Holding MCP in slight flexion to prevent hyperextension allows PIPJ extension. Positive test is when blocking MCPs results in full PIP extension
used to determine if PIP Joint capsule & extensor mechanism are working
TFCC
consists of meniscal disc that spans the head of the ulna; ligamentous support from ECU, UCL, and DRUJ ligaments. Function is DRUJ stabilization and to control force transmission through the ulnar during weight-bearing and gripping activities
arteries of volar UE
subclavian -> axillary -> brachial –> at the atecubital fossa splits into radial and ulnar arteries
how long do vascular repairs need to be protected (via orthosis)?
7-14 days
signs of arterial insufficiency
skin pallor, decreased digital temperatures, increased pain, sluggish capillary refill, cyanosis, and loss of pulse
What is VISI?
Volar Intercalated Segmental Instability – the lunate is tethered to the scaphoid by the SL ligament and to the triquetrum by the LT ligament. Scaphoid naturally wants to move into flexion and triquetrum naturally wants to move into extension. With an injury to the LT ligament, the triquetrum no longer exerts extension force on the lunate, and therefore the scaphoid pulls the lunate VOLARLY into flexion
What is DISI?
Dorsal Intercalated Segmental Instability – the lunate is tethered to the scaphoid by the SL ligament and to the triquetrum by the LT ligament. Scaphoid naturally wants to move into flexion and triquetrum naturally wants to move into extension. With an injury to the scaphoid or SL ligament, the scaphoid no longer exerts flexion force on the lunate, and therefore the triquetrum pulls the lunate DORSALLY into extension
Why does Dart THrower’s Motion (DTM) help with DISI?
with wrist flexion, scaphoid goes into flexion, and when you extend, it goes into extension. When you ulnarly deviate the wrist, the scaphoid goes into extension, and radially deviation causes scaphoid flexion. So if you pair together opposite motion – flexion and ulnar deviation or extension and radially deviation – you can lock the scaphoid into place. In this way, you can get AROM without straining SL ligament.
what do Cleland’s and Grayson’s ligaments do?
Grayson’s run volar to the neuromuscular bundle and insert into skin. Cleland’s pass dorsally to neuromuscular bundle and insert into skin. Together, they prevent rotary movement of the skin around the fingers, thus allowing the ability to grasp objects. Grayson’s contributes to PIPJ contracture in dupuytren’s
vasculature of the hand consists of:
superficial palmar arch, deep palmar arch, and the common palmar arteries. Superficial arch gives rise to the common palmar digital arteries and the proper palmar digital artery typically only to the small finger
palmaris brevis innervation and function
superficial branch of ulnar nerve
fxn: to corrugate the skin at the base of the hypothenar eminence to improve grip
