Low Yield Flashcards
Describe the path of the radial artery?
1) Runs btw the FCR and brachioradialis
2) Passes btw the FCR and ABL/EPB tendons and gives off superficial palmar arch
3) Gives off the deep palmar arch btw the two heads of 1st dorsal interosseous
Describe the path of the ulnar artery?
1) Runs underneath the FCU
2) Artery is radial (lateral) to ulnar nerve; lies on the transverse carpal ligament
3) Joins with the deep and superficial palmar arches
In the majority of patients, the deep palmar arch has a main contribution from what vessel?
Deep (terminal) branch of the radial a.
What is the relationship of the digital artery and nerve?
Nerve is volar to the artery; NV bundle lies btw Grayson’s (volar) and Cleland’s (dorsal) ligament
Where is the princeps pollicis found?
Runs btw the 1st dorsal interossous and the adductor pollicis
Extrinsic imbalance from splinting a crushed hand with metacarpophalangeal joint extension causes what characteristic hand deformity?
MCP extension, PIP and DIP flexion (intrinsic minus hand)
Describe intrinsic minus (claw) hand?
Deficient intrinsic muscles lead to overpull but the EDC and FDP/FDS which in turn leads to:
MCP hyperextension with DIP/PIP flexion
Describe intrinsic plus hand?
MCP flexion, DIP/PIP extension
Ability to passively flex the proximal interphalangeal (PIP) joint when the metacarpophalangeal (MCP) joint is flexed but not when the MCP joint is extended is a sign of?
Intrinsic muscle spasticity; described is a positive Bunnell’s test
Which annular pulleys originate from the volar plate of the fingers?
A1, A3, and A5
Which pulleys prevent bow stringing in the hand?
A2 and A4 in the fingers
Oblique pulley in the thumb
Describe the quadrigia effect?
Flexion lag of adjacent fingers due to early terminal flexion of one digit; from over advancement of FDP by >1cm during repair
What structures are at risk with portal placement during wrist arthroscopy?
1-2: SBRN
6R, 6U: SBUN
What is a potential complication of an amputation at the level of the distal interphalangeal joint?
Lumbrical plus finger; paradoxical extension of the IP joints while attempting to flex the fingers
What is the mechanism of a lumbrical plus finger?
Defined as paradoxical extension of the IP joints while attempting to flex the fingers; d/t lumbricals attaching to phalanx proximal to FDP disruption
What muscles are innervated by AIN?
1) FDP
2) FPL
3) Pronator quadratus
What are signs and symptoms of AIN compressive syndrome?
1) motor deficits only
2) no complaints of pain
3) weak grip pinch
4) cannot make OK sign
Where is the PIN found in the wrist?
Floor of the 4th extensor compartment; innervates the wrist capsule
What are signs and symptoms of PIN compressive syndrome?
1) Pain in the forearm and wrist
2) weakness with wrist extension in neutral or ulnar deviation
What is released in surgical treatment of PIN syndrome?
1) fibrous bands connecting brachialis and brachioradialis
2) leash of Henry
3) fibrous edge of ECRB
4) radial tunnel, including arcade of Frosche and distal supinator
What is the most common cause of ulnar nerve impingement at Guyon’s canal?
Ganglion cyst (80% of non traumatic causes)
What are the Zones of Guyon’s canal
1) Zone 1: proximal to ulnar n bifurcation (mixed)
2) Zone 2: deep motor branch of ulnar n (motor only)
3) Zone 3: Superficial sensory branch of ulnar n (sensory only)
Ganglia and hook of hamate fxs are common causes of compression in Zones 1 and 2; ulnar a. thrombosis is common in zone 3
How is ulnar tunnel syndrome differentiated from cubital tunnel syndrome?
Cubital tunnel demonstrates:
1) less clawing
2) sensory deficit to dorsum of the hand
3) motor deficit to ulnar-innervated extrinsic muscles
4) Tinel sign at the elbow
5) positive elbow flexion test
What is the typical presentation of radial tunnel syndrome?
often presents with insidious onset of pain and tenderness several centimeters distal to the lateral epicondyle, and pain elicited with active extension of the long finger against resistance can help differentiate the condition from lateral epicondylitis
What is the pathoanatomic progression of a Boutonniere deformity?
1) Rupture of the central slip (PIP extension lost)
2) Triangular ligament attenuates
3) Lumbricals (attach on collateral bands via lateral bands) become PIP flexors in addition to normal DIP extension
4) Collateral bands migrate volarly accentuating the deformity
What physical exam test is most specific for central slip rupture?
Elson test; PIP held over corner of table and middle phalanx extended against force
1) If intact DIP remains “floppy”
2) If rupture PIP extension is weak and DIP will extend