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
Chronic injury to what anatomic structure can lead to a boutonnière deformity of the finger?
Central slip of the extensor tendon
What is the treatment of a central slip rupture/tear/laceration?
1) If acute splint PIP in extension for 6 weeks
2) If chronic may have Boutonniere deformity which may need procedure to move lateral bands dorsally
What causes intersection syndrome?
Due to inflammation at crossing point of 1st dorsal compartment (APL and EPB ) and 2nd dorsal compartment (ECRL, ECRB); occurs 5cm proximal to the wrist; common in rowers and weight lifters
What are the contents of the 6 wrist extensor compartments?
1) APL and EPB
2) ECRL, ECRB
3) EPL
4) EDC, EIP
5) EDM
6) ECU
Where are does the sagittal bands of the hand most commonly rupture?
1) Middle finger most common
2) radial side much more common than ulnar (9:1)
3) Common in fighters
4) Rheumatoid
What is the anatomy of the sagittal band of the fingers?
1) Originates on the volar plate and inserts on the side of the extensor tendon
2) Overlies the MCP
3) Prevents ulnar subluxation of the extensor tendon during MCP flexion
What is the treatment for acute sagittal band ruptures?
Extension splinting for 4-6 weeks
What is the treatment for chronic sagittal band ruptures?
Centralization procedure using either the EDC or junctura tendinum
What constitutes a Jersey finger?
FDP avulsion; is a zone 1 injury; FDP to ring finger 75% of the time; may see avulsed fragment on XR
During repair of a Jersey finger injury what must be avoided?
Jersey finger is avulsion of FDP from distal phalanx; cannot advance more than 1cm or will result in quadrigia effect
What is the treatment for a Jersey finger?
Acute (less than 3 months): primary repair
Chronic (>3 months) with FROM: 2 stage tendon graft
Chronic without DIP ROM: DIP arthrodesis
Describe a mallet finger?
Injury to the terminal extensor tendon distal to DIP
What wrist condition is common in new mothers?
DeQuervain’s tenosynovitis; stenosing tenosynovitis of the 1st dorsal compartment (APL, EPB)
What differentiates DeQuervain’s from intersection syndrome?
Pain at radial styloid (DeQuervain’s) vs pain 5cm proximal to wrist (intersection syndrome)
What is a common mistake during 1st dorsal compartment release?
Failure to recognize separate compartments for APL and EPB; APL also has 2-3 slips many times
What is the treatment of an isolated pisiform fracture?
Acute: SAC in 30 deg wrist flexion and ulnar deviation for 8 weeks
Painful nonunion: pisiformectomy
What common eponyms given for a thumb UCL injury?
Gamekeepers- chronic
Skiers- acute
Stener- avulsed and stuck above adductor aponeurosis
How is the thumbs UCL accessed?
Valgus laxity at neutral- injury to accessory collateral
Valgus laxity in 30 deg flexion- injury to proper collateral ligament
>20-35 deg opening requires surgical repair
What three muscles provide deforming forces in fractures of the base of the 1st MC?
1) EPL
2) APL
3) Adductor pollicis
What is the treatment for a Mallet finger?
Acute (less than 12 weeks): extension splint of DIP for 6-8 weeks
If volar subluxation of distal phalanx (absolute) or >2mm gap (relative) or >50% articular involvement (relative) then CRPP vs ORIF
Chronic: arthrodesis vs reconstruction
Describe the tissues around the nail?
1) perionychium- nail, nailbed and surrounding skin
2) paronychium- lateral nail folds
3) hyponychium- skin distal and palmar to the nail
4) eponychium- dorsal nail fold
proximal to nail fold
5) lunula- white part of the proximal nail
6) matrix- sterile soft tissue deep to nail that’s distal to lunula; adheres to nail (germinal matrix is responsible for most of nail development)
insertion of extensor tendon is approximately 1.2 to 1.4 mm proximal to germinal matrix
Repair of a nailbed injury with 2-octylcyanoacrylate (Dermabond) provides what distinct advantage over standard suture repair?
Faster technique; equal cosmetic and functional results
Splint eponychial fold with removed nail, aluminum or non adherent gauze
What is a Seymour fracture?
juxta-epiphyseal fracture of the distal phalanx in pediatric patient
How are most hook of hamate fractures managed?
Acute: immobilization for 6 weeks
Chronic nonunion: hook excision
Which radiographic view best shows a hook of hamate fracture?
Carpal tunnel view
How is frostbite managed?
Initial: rapid rewarming with warm IV fluids and warm water bath (40-44° C)
Clear blisters debride, hemorrhagic drain but leave intact
Delayed: wait for demarcation then debride or amputate (1-3 months)
What are some basic principles of tendon transfer?
1) donor must be expendable and of similar excursion and power
2) one tendon transfer performs one function
3) synergistic transfers rehabilitate more easily
4) it is optimal to have a straight line of pull
5) one grade of motor strength is lost following transfer
Where do ganglion cysts originate?
1) Dorsal (70%)- SL joint
2) Volar (20%)- STT joint or radiocarpal
Remember that ganglion cysts transilluminate
What is the treatment for ganglion cysts?
1) Pediatrics -observation (75% resolve in 1yr)
2) Adults- observe; aspirate (50% recur); surgical excision (volar have higher recurrence 15-20%, than dorsal)
Perform Allen test prior to surgical removal of volar cysts as they tend to involve the radial artery
What is the most important prognostic factor for melanoma?
Depth of lesion
What is the treatment for subungal melanoma of a digit?
Disrtarticulation at the DIP and sentinel node biopsy
What are the four Kanavel signs of flexor tenosynovitis?
1) flexed posturing of the involved digit
2) tenderness to palpation over the tendon sheath
3) marked pain with passive extension of the digit
4) fusiform swelling of the digit
What are common organisms involved with flexor tenosynovitis?
1) Staph (40%)- most common
2) MRSA (25%)- IV drug abusers
3) Eikenella- human bites
4) Pasturella- animal bites
What are risk factors for poor outcomes with flexor tenosynovitis?
1) an age of more than forty-three years
2) the presence of diabetes mellitus, peripheral vascular disease, or renal failure
3) the presence of subcutaneous purulence
4) digital ischemia
5) polymicrobial infection
Pts with subQ purulence amputation rate of 8%
SubQ purulence and ischemic changes amp rate 60%
What is seen in an angiogram in pt with Buerger’s disease?
“Corkscrew” arteries; affects arteries from distal to proximal (PVD is usually proximal to distal); 94% of people who quit smoking avoid amputation
What determines the severity of a high pressure injection injury?
1) time from injury to treatment >6-10hrs
2) force of injection- >1000psi
3) volume injected
4) composition of material; organic solvents cause much more damage than water based
What is hypothenar hammer syndrome?
Post-traumatic digital ischemia from thrombosis of ulnar artery at Guyon’s canal; more common in males than females (9:1); will see ulnar artery thrombosis or aneurysm
Which bone does the ulnar artery pass directly anterior to in the hand?
Hook of the hamate
What is the treatment for digital ischemia a/w hypothenar hammer syndrome?
Ulnar artery reconstruction with a vein or artery graft; non-operative management with activity modification and smoking cessation is appropriate in patients without thrombosis or aneurysm
