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
What is Kienbock’s disease?
disruption of nutrients to the lunate that results in progressive necrosis and eventual collapse of the lunate
What is the most common procedure to address Kienbock’s disease?
proximal row carpectomy
What is a SLAC wrist?
Scaphoid Lunate Advanced Collapse (SLAC) describes the specific pattern of degenerative arthritis seen in chronic dissociation between the scaphoid and lunate.
Diagnosis is made clinically with progressive wrist pain and wrist instability with radiographs showing advanced arthritis of the radiocarpal and midcarpal joints (radiolunate joint spared).
The quadrangular space contains which nerve and artery combination?
The quadrangular space is bordered by the teres minor superiorly, terms major inferiorly, humerus laterally, and triceps medially. The axillary nerve and posterior circumflex artery pass through this space.
what veins are part of the superficial venous system of the UE that combines to form an “M” at the volar forearm
**cephalic vein ** on the lateral/radial side, basilic vein on the medial/ulnar aspect, and the median cubital vein that connects between them
Space of Poirier
arrangement of the volar extrinsic ligaments can be thought of as a V within a V formation. The weak area between the V formations is known as the space of Poirier.. This area has a lack of ligamentous support at the lunate/capitate articulation, creating weakness. This allows the lunate to dislocate during high velocity injuries of the wrist
which muscles are implicated in a positive external rotation lag sign
supraspinatus and infraspinatus
how is the shoulder external rotation lag test performed?
externally rotate the humerus just short of full external rotation and then abduct humerus to 20* while supporting the wrist. Examiner releases the wrist and if pt is unable to maintain external rotation and lags into internal rotation, test is positive. lag of 5-10* are indicative of supraspinatus tears and greater than 10* indicative of complete tear of both muscle tendon units
How is drop sign test for the shoulder performed?
bring arm to 90* of abduction in the scapular plane and full external rotation. Release and if the UE lags into internal rotation or the arm drops, it’s indicative of full thickness supraspinatus tears
Pathologies that lead to Swan Neck deformity
- dorsal displacement of lateral bands results in hyper-extension of PIPJ and flexion deformity of DIPJ; 2. intrinsic tightness tightens lateral bands, pulling PIP into hyper extension and the alteration at the PIPJ pulls DIPJ into flexion; 3. mallet deformity initiates the process at the DIPJ – loss of terminal anchor of lateral bands allows them to dorsally sublux; 4. loss of FDS removes a a reinforcing structure for the volar plate, eventually leading to volar plate laxity
Tx of Hook of the Hamate Fx
Minimally displaced: 3 weeks in ulnar gutter cast, followed by ulnar gutter orthosis
Displaced: Excision or ORIF. ORIF is preferred for athletes due to 15% grip strength loss noted after excision
5 common sites of PIN compression
- arcade of Froshe
- fibrous bands lying anterior to the radial head
- radial recurrent vessels
- tendinous margin of the ECRB muscle
- at the deep surface of the supinator muscle
what is the arcade of Froshe?
- the most common site of PIN compression
- fibrous band that arises as a semi-circular structure from the tip and medial aspect of the lateral epicondyle
- a tunnel formed by fibrous bands of the brachialis, brachioradialis, ECRB, and the supinator
what is the arcade of Struthers?
anatomical band of connective tissue in the medial distal arm that crosses the ulnar nerve
what is the ligament of Struthers?
most often arises from a supracondylar process, a bony projection at the anteromedial aspect of the distal humerus approximately 5 cm proximal to the medial epicondyle and extends to the medial epicondyle of the humerus. median nerve and brachial artery pass under the ligament of Struthers and consequently can be compressed, causing supracondylar process syndrome.
mobile wad of Henry (aka mobile wad of three) consists of?
ECRL, ECRB, and brachioradialis
what muscles compose the superficial group of three?
ECU, EDC and EDM
what is the quadrangular space?
an anatomical space in the posterior axilla region. contains the axillary nerve and posterior circumflex humeral artery (and accompanying vein) as they travel into the posterior upper arm.
Top border is teres minor, bottom border is teres major, medial edge is the triceps, and lateral edge is the humerus.
normal monofilament size
2.44
how many trials do the different monofilaments get?
1.65 - 4.08 get 3 trials and 1 correct guess counts. All larger monofilaments only get 1 trial
what are the primary functions of the central slip?
central slip initiates PIP extension as well as the final 15-20 degrees of extension
Weber
static 2 pt discrimination
assesses innervation density and can determine tactile gnosis
Dellon
moving 2pt discrimination (returns before static does in nerve recovery)
What are the Weber Static 2-pt discrimination ranges?
Normal = 0-5mm
Fair = 6-10 mm
Poor = 11-15 mm
Protective sensation intact = can sense at least 1 pt
No sensation = cannot perceive even one point
articular disc shear test
can assess for TFCC central disc lesion
TFCC load test
can assess for either peripheral or central lesion
how to differentiate between TFCC central disc tear and peripheral lesion?
peripheral tear will likely have hx of trauma and/or instability at end range of pronation/supination. If there was no inciting event, no instability with forearm rotation, pos GRIT ratio, and a positive articular disc shear test, then it’s probably a central disc lesion.
How GRIT ratio calculated and what does it indicate?
GRIT ration = supinated grip strength/pronated grip strength. A ration >1 indicates ulnar impaction syndrome or TFCC articular disc tear
How to assess the UB Myotomes?
C2-4: shoulder shrug
C5: shoulder abduction
C6: wrist extension and elbow flexion
C7: wrist flexion, elbow extension
C8: thumb abduction
T1: finger abduction
In reflex testing, what does hypo-reflexia indicate?
lower motor neuron lesion
in reflex test, what does hyper-reflexia indicate?
upper motor neuron lesion
4 sigs of Kanavel?
- flexed posture
- tenderness along the length of the tendon sheath
- severe pain with extension/hyperextension
- uniform swelling
what is pronator syndrome?
compression of the median nerve (MN) by the pronator teres (PT) muscle in the forearm.
Stemmer’s Sign
the only clinical test shown to be valid and reliable in dx of lymphedema. A thickening of the skin over the proximal phalanges of the fingers/toes of the involved extremity and inability to pick up the skin
symptoms of quadrangular space syndrome
shoulder pain and paresthesias down the arm with weakness about the shoulder region
Anterior interosseous nerve (AIN) syndrome
an isolated palsy of flexor pollicus longus, the index and long fingers of the flexor digitorum profundus, and the pronator quadratus muscles of the forearm. It manifests as pain in the forearm accompanied commonly by the weakness of the index and thumb finger pincer movement. occurs most often in the setting of trauma, or comes on slowly with no history of pain. Has no correlation with shoulder pain. Parsonage-Turner syndrome should be considered as a differential diagnosis
What is Parsonage-Turner syndrome and its associated symptoms?
an inflammatory plexopathy that causes a palsy that is rapid and associated with pain, but no trauma. Often presents with a “spotty” pattern of plexus muscle involvement and most often spontaneously resolves. Commonly occurs after viral infection and it affects the AIN, periscapular muscles, shoulder muscles, and long thoracic nerve causing winging.
what are the 3 groups of nociceptors?
mechanical
thermal
polymodal
What does Semmes-Weinstein 3.61 monofilament mean?
diminished light touch
the patient may no even notice the sensory loss at this level and probably has overall good sensory function
What is Ledderhose’s disease?
also called plantar fibromatosis or Dupuytren’s of the foot, is a benign thickening of the connective tissue (fascia) in the sole of your foot. It typically starts as a small lump, called a plantar fibroma, in the arch of your foot
What muscles does the PIN innervate, in order?
- ECRB (only 45% of the time)
- supinator
- EDC
- EDM
- ECU
- APL
- EPL
- EPB
- EIP
Also provides nociceptive and proprioceptive innervation to the dorsal wrist capsule
What is Linburg’s syndrome and what condition is often present with it?
Carpal tunnel syndrome is often present with Lindburg’s
syndrome. Lindburg’s syndrome involves tenosynovitis
in the flexor pollicis longus and usually includes the
flexor digitorum of the index (because of an associated
anomalous interconnection). Patients complain of distal
(radiopalmar) forearm and hand pain that is aggravated
when distal interphalangeal (DIP) flexion of the index is
blocked because the thumb is actively flexed into the
palm
