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Emergency Medicine Module 3 > Hand and Wrist > Flashcards

Flashcards in Hand and Wrist Deck (60):

the ulnar nerve in the hand

  • -The ulnar nerve enters the palm of the hand through the ulnar canal
  • -Prior to entering the ulnar canal, it gives off:
    • - a palmar cutaneous branch which provides cutaneous innervation to the skin of the ulnar aspect of the palm
    • -A dorsal cutaneous branch which provides cutaneous innervation to the skin of the ulnar aspect of the dorsum of the hand
  • -In the palm of the hand, the ulnar nerve innervates all the intrinsic muscles of the hand not innervated by the median nerve.


epidemiology: hand and finger injuries

  • nMore than 30% of industrial accidents and three-fourths of industrial injuries
  • n5-10% of ED visits
  • nMost frequent body parts injured at work
  • nLacerations most frequent injury
  • nDistal phalanx most commonly fractured
  • nLittle finger most common in US



  • Dominant hand
  • Occupation
  • Tetanus status
  • Traumatized
    • Ascertain hx of trauma
    • Time elapsed since injury
    • Environment of injury
    • Mechanism of injury
  • Nontraumatized
    • When did sx begin
    • What functional impairment
    • What activities worsen sx


initial assessment

  • First, remove any rings, watches, or other jewelry with a ring cutter if necessary.
    • if the finger swells, the metal ring will compromise circulation.
  • Compare both hands for symmetry.
    • Swelling
    • Deformity
    • color changes
    • Sensory deficits



  • location of the injury should be described as radial or ulnar side and on the volar or dorsal (flexor or extensor) surface.
  • skin color; check for capillary refill.
    • Repeat the test on an uninjured digit for comparison.
  • radial and ulnar pulses
  • If swelling of the dorsum of the hand, but otherwise normal, examine volar
    • r/o palmar puncture wound or other injury


excessive bleeding

  • elevation
  • apply a sterile wet-compression dressing.
    •  a blood pressure cuff can be inflated to about 100 mmHg above the patient’s systolic blood pressure.  Never leave this cuff on for more than 30 minutes.
  • Since the nerves follow vessels, never ligate a hand vessel without directly visualizing the bleeding vessel and all surrounding structures.
  • Never blindly clamp a bleeding vessel:
    • trauma to nerve, tendon, or associated vessels.


nerve injury testing

  • Sensory:
    • Radial: dorsum of first web space.
    • Ulnar: 5th finger
    • Median: flexor aspect of index and middle fingers.
  • Motor:
    • Radial: extension at wrist and MP joint
    • Ulnar:  forcible spread of fingers against resistance
    • Median: flexion of wrist and PIP of thumb and index against resistance


range of motion

  • Documentation of presenting motor exam
  • Patients unable to flex one finger together with the others often found to have associated tendon injury.
  • Weak movement of the joint may signal an incomplete tendon injury 
  • Note that pain may also limit functional exam (false positive)


Flexor examination

  • Flexor Digitorum Profundus and Flexor Pollicis Longus
  • Have pt flex DIP while proximal joints are held in extension


test of flexor tendon function

  • Flexor Digitorum Superficialis
  • Test by holding all other fingers in extension and have the pt flex the finger to be tested


testing extension

  • Patient position: hand palm-down on a table and extend the fingers off the table one at a time.
  • Test against resistance for partial lacerations
  • If you suspect an extensor tendon laceration but cannot visualize in the wound, try putting the hand in the position it was in when the injury occurred.
  • Ranging finger increases the chances of seeing a tendon injury in the wound.


foreign bodies

  • Glass, metal, wood—most common
  • Glass, metal detected on xray / ULS
  • Large f.b.’s tend to cause a fibrous rx and become symptomatic


missed foreign bodies

  • 1/3 of legal claims: retained FB
  • Retained glass = most commonly reported in hand
  • XRAYS sensitive for glass > 2mm
  • Rarely  plastic, wood, organic
  • Xray neg but suspicion high = closer examination


foreign bodies identification

  • Ultrasound
    • sensitive 95-100% < 1-4mm
  • CT most sensitive


foreign body management

  • mechanical and inflammatory effects
  • Remove based on size, composition, and location
  • Small FB deeply imbedded – do not attempt
  • Infection common complication
  • Antibiotics? --depends on object and mechanism
  • Ortho Consult ?


hand infections

  • Anatomy : infections extend quickly across the fascial planes of the hand without resistance.
  • Finger infections
    • proceed through the flexor tendon sheath and enter the mid-palmar space.
  • Infections in the mid-palmar space
    • extend rapidly into the thenar space.
  • devastating effects: may resist aggressive treatment with IV antibiotics
  • often require incision and drainage in the operating room.



  • Subcutaneous pyogenic infection of the pulp space of the finger tip (tuft)
  • Presents with severe throbbing pain
  • Most common org =  staph aureus
  • Requires I&D
    • incision 5mm distal to the digital crease and extend to the pulp space
  • tx:
    • Midline incision

    • Avoid neurovascular bundle

    • Consult Ortho if complex

    • Most serious complication is acute tenosynovitis



  • Inflammation involving the lateral and posterior fingernail folds.
  • Predisposing factors:
    • overzealous manicuring
    •  nail biting
    •  thumb  sucking
    •  diabetes mellitus
    • occupations in which the hands are frequently immersed in water
  • also reported in association with antiretroviral therapy for HIV infection
  • TX=I&D: separate the nail plate from the lateral nail fold
    • Packing vs warm soaks


anatomical snuff box

  • The anatomical snuff box:
  • Boundaries:
  • Anterior: Extensor pollicis longus and extensor pollicis brevis


compartments of the palm


blood supply to the hand

  • Blood supply to the palm of the hand is provided by both the radial and ulnar arteries.
  • The ULNAR ARTERY enters the hand anterior to the flexor retinaculum, just lateral to the pisiform bone.  It gives off the deep palmar branch and continues onto the palm as the superficial palmar arterial arch. 
  • At the wrist, the RADIAL ARTERY gives off a superficial palmar branch which completes the superficial palmar arterial arch.  The radial artery then courses posteriorly, traveling in the floor of the anatomical snuffbox.  It pierces the first dorsal interosseus muscle to enter the palm.  When in the palm, the radial artery is the primary source of blood to the deep palmar arterial arch (completed by the the deep palmar branch of the ulnar artery). 


allen test

  • collateral circulation between the two vessels through the palmar arch.
  • forcefully open and close the fist 10-20 times. compress the radial and ulnar arteries
  • When the ulnar artery is released, the patient’s skin pallor should rapidly resolve.


neurologic evaluation

  • examine the patient’s sensation prior to instilling anesthesia.
  • Lacerated nerves are common
  • Median nerve: through carpal tunnel
  • Ulnar nerve: passing between hook of hamate
  • Radial nerve:
  • Superficial branch above radial styloid


radial nerve in the hand

-Superficial radial nerve supplies skin on the lateral side of the dorsum of the hand, and a small portion of the thenar eminence


flexor tenosynovitis

  • VERY SERIOUS - can cause morbidity if not caught
  • The four cardinal signs
    • 1. tenderness over the flexor tendon
    • 2. swelling of the finger
    • 3. pain on passive extension
    • 4. flexed posture of the digit.
  • tendons have scant blood supply ; blood flow easily interrupted by relatively little edema and may cause destruction of underlying tendon.
  • Peri-tendonous scarring = subsequent loss of function of the hand.
  • Tx = prompt drainage in the operating room and admit with appropriate intravenous antibiotic therapy.


pyogenic flexor tenoxynovitis

  • Often begins as benign puncture wound
  • slight digital flexion
  • Uniform volar swelling
  • Flexor tendon sheath tenderness
  • Pain on passive extension
  • Admit : surgical drainage and IV antibiotics


traumatic injuries: wounds

  • Control bleeding
  • Copious irrigation with high pressure NS
  • Consider delayed closure of “dirty” wounds
  • Debridement
  • Foreign body removal


types of wounds

  • Incisional
    • Caused by a sharp object
    • Usually may be closed primarily 
  • Avulsion
    • Full thickness require skin grafting
  • Blast/Crush
    • Considered “dirty”  due to maceration of tissue and microvasculature
    • Often require debridement


degloving and puncture wounds

  • Degloving injuries
    • Require skin grafting
  • Puncture wounds
    • May require “coring”
    • Greater risk of infection
    • Elevate extremity
    • Low threshold for antibiotic tx


crush injuries

  • hand is particularly vulnerable to crush injuries
    • lack of protective muscle mass
  • Unpredictable course/potentially devastating
  • Open wounds, contamination, and thermal injuries often complicate these injuries.
  • Ischemia may result from damage to local microcirculation/damage to major blood vessels
  • Tx: antibiotics, supportive care, watch for compartment syndrome


nail bed injuries

  • Subungal hematoma
  • > 50% = remove nail plate to evaluate for nail bed laceration
  • Repair nail bed w/ absorbable
  • Removed nail may be used as splint
  • Decrease possibility of post traumatic ridged nail or cosmetic deformities



  • 5% of upper extremity injuries and involve about 150,000 people in the United States each year.
  • Re-implantation of amputated digits optimal
  • Survival and function depend on
  • type of injury
  • ischemia of the injured part (particularly if warm)
  • general condition and comorbidities.
  • recommend reimplantation of thumb, the index finger proximal to the PIP joint, multiple digits, and single amputated digits in children.


amputation management: the patient and the part

  • the patient
    • If stable do not delay evaluation for transplant
    • Minimally manipulate/Avoid extensive cleaning
    • Do not inject with local anesthesia
    • Saline gauze, bulky dressing, splint, elevate
    • Ancef 1 gm IV
    • Update Tetanus  and NPO
  • the part
    • Save all parts and rinse with normal saline remove gross contamination only
    • Xray stump and part
    • Wrap in DRY gauze
    • Place in DRY zip lock bag and place bag ON ice
      • Do not use dry ice, do not bury in bag
    • Cooling part to 40° F enhances survival
    • 1 hr of warm ischemia = 6 hrs cold ischemia


amputations and reimplantation: ABSOLUTE INDICATIONS

  • Any amputation in a child
  • Clean amputations of hand, wrist or distal forearm
  • Multiple digit amputations
  • Amputated thumbs


finger tip amputation zones/treatment

  • Zone I = secondary intention  
    • Irrigate/Debridement
    • Antibx dressing
    • Protective splint
  • Zone II = flap reconstruction
  • Zone III = amputation


extrinsic muscle and tendon injuries

  • Extrinsic
  • Tendons responsible for the gross movements of the hand and digits
  • Most commonly involved in hand injuries
  • Abductor pollicis longus and extensor pollicis brevis: ask pt to forcefully spread their fingers
  • Extensor pollicis longus:  ulnar border of the snuff box; ask pt to hyperextend distal phalanx of thumb against resistance


intrinsic muscle and tendon injuries

  • Intrinsic
    • Responsible for fine detailed movement
  • Dorsal interossei: tested by spreading the hand forcibly against resistance
  • Volar interossei tested by placing paper between extended fingers and asking pt to resist its removal.
  • Thenar and hypothenar muscles: pinch and opposition
  • Lumbrical tendons: extend wrist and fingers while examiner presses down on finger tips.


tendon injuries

  • Most common site of injury is dorsum of hand where extensor tendons are superficial and more exposed to injury.
  • Tendon injuries may be partial or complete
    • 70-90% of tendon lacerated and still function
  • *determine the position of the hand at the time of injury
  • DO NOT close bites, crush injury, contaminated wounds
  • DO Start prophylactic antibiotics if dirty
  • DO Consult Ortho in the ED for timing of repair


open flexor and extensor tendon injuries

  • Flexor
    • Lacerations
    • Never repair in ED
    • Assess for vascular injury
    • Surgical consult for timing of repair
    • Irrigate, close skin and flexion splint
    • Consider antibiotics
  • Extensor
    • Most dorsal wounds effect extensor tendons
    • Repair based on:
      • > 50% lacerated
      • Zone of Injury

        • Consider ED repair if Zone VI
    • Severity and contamination


timing of tendon repair

  • Primary repair: within 72 hours of injury
  • Delayed repair:  first week after injury
  • Secondary repair:  after all edema has subsided and the scar has softened
    • (4-6 weeks)
  • Splint in a neutral position


swan neck deformity

  • Untreated Mallet
  • Overactive pull of extensor on middle phalanx
  • PIP hyperextension

  • Flexion of DIP

  • Compensatory Swan neck


Boutonniere deformity

  • Disruption of the tendon at the PIP
  • Flexion of PIP with hyperextension of DIP
  • results from jamming or forced flexion injury that disrupts the extensor tendon insertion into the dorsal base of the middle phalanx
  • Tx: Extension splint to immobilize PIP x 4-6 wks



  • usually etiology =repetitive stress
    • Active and passive movement accentuates pain with well localized tenderness
    • Tenosynovitis:
      •   -hx of excessive stress on the affected tendon
      •   -friction between tendon and sheath causes synovial thickening
    • Tx with NSAIDS and/or local steroid injection


trigger finger

  • Painful blocking of flexion and extension at the involved joint
  • Hypertrophy of the tendon and pulley as a result of  excess repetitive strain
  • Localized tenderness over the proximal flexor pulley
  • Ring and middle fingers most common
  • Tx: steriod injection / surgical release


dislocations and management 

  • “jammed” finger
  • Obtain adequate history of the injury
  • finger forced upward = volar plate rupture or dorsal dislocation.
  • finger compressed more likely fracture or mallet finger injury.
  • Joint stressed sideways = possible collateral ligament injury.
  • management
    • Digital block
    • Closed relocation
    • Post reduction Xrays
    • Access Active ROM and PROM after reduction
    • Unable to reduce = entrapment: volar plate, collateral ligament, or fracture
    • Splinting & Ortho f/u


volar plate - collateral ligaments

  • Main stabilizers of PIP
  • Hyperextension avulses volar plate
  • Dorsal dislocations = most common


PIP joint injuries

  • PIP most commonly injured
  • Often dismissed as a simple sprain and left untreated
  • occult fractures, dislocations, or ligament injury


fracture patterns

  • Nonoperative < 20-40% of articular surface
  • Operative >20-40% of surface, very unstable joint


gamekeeper's/skiers thumb

  • Ulnar collateral ligament rupture
  • Weakened “pinch”
  • Examine thumb in extension; if  > 20 degrees of instability = surgical repair
  • management
    • Xray for underlying avulsion fx
    • With/without fracture full tear = surgical fixation
    • Partial tear = splint and refer


fractures of the distal phalanx

  • Tuft
  • Comminuted
  • Transverse fx
    • often associated with nail bed laceration
  • Mallet
    •  avulsion injury at the attachment of the extensor tendon


mallet finger

  • Flexion deformity at DIP with complete passive but incomplete active extension of  DIP joint
  • Hx sudden flexion force to tip of extended finger
  • Avulsion of extensor tendon at the site of insertion
  • Avulsion fx of distal phalanx with tendon attached.


middle and proximal phalanx fractures

  • Extra-articular fractures
    • ulnar or radial gutter splint
  • Oblique, spiral, displaced, or unstable
    • refer for reduction or surgical fixation
  • Intra-articular fractures
    • reduced anatomically; often require surgical intervention


metacarpal fractures

  • Most commonly at the metacarpal neck
  • 4th or 5th digit = boxer’s fx
  • clenched fist injury
  •  Reduction required: Index or middle finger: angulation  > 15 degrees;  4th or 5th  digit angulation > 30 degrees
  • Look for “fight bite”


Bennett's fracture

  • Fracture at the base of the thumb metacarpal involving the joint
  • Sustained from an axial load with a closed hand
  • Must be reduced and requires surgical intervention


wrist fractures: scaphoid, smith's, and colles

  • Scaphoid fractures:
    • Most common of all carpel fractures
    • anatomic snuff box tenderness
    • more proximal fracture site = more common avascular necrosis
    • Scaphoid views will often demonstrate a fx not seen on plain wrist films.
    • Immobilize in thumb spica splint.
  • Smith’s: fx of distal radius with volar displacement
    • Check for associated median nerve or flexor tendon injury.
  • Colles:  fx of distal radius with dorsal displacement
    • Reduce after traction  and hematoma block



  • AKA: Stenosing tenosynovitis
  • Involves the abductor pollicis longus and extensor pollicis brevis
  • Pts c/o pain at the radial aspect of wrist localized to the radial styloid
  • Finkelstein’s test
    • sharp pain with ulnar deviation of wrist


Carpel Tunnel Syndrome

  • Compression of the median nerve in the carpel canal
  • Etiology = any condition which produces chronic swelling
  • Repetitive motion
  • Paresthesias over median nerve distribution
  • Pain awakens pt from sleep
  • Tinels and Phalen’s sign


ganglion cyst

  • Most common tumor of the hand
  • Synovial cyst from joint or synovial lining of a tendon that has herniated
  • Contains gel-like fluid that forms a cyst or connects with the synovial cavity.
  • Dorsum of the wrist most common
  • Surgical excision is Tx OC


high-pressure injection injuries

  • Grease gun, paint sprayers, or compressed air devices
    •  serious penetrating injuries that require wide debridement.
  •  High-pressure injection devices generate pressures that range from 1500 to 7000 psi
    •  deposit toxins into tendon and synovial sheaths.
  • Most common site of injection = index finger followed by the palm and long finger.
  •  The patient may develop intense throbbing and pain shortly after the injury leading to compartment syndrome.


  • Paint and Grease guns
  • True extent injury hidden behind tiny puncture wound
  • Even with early dx high incidence  of amputation
  • Act aggressively!
  • Management
    • Xrays
    • Pain control
    • No digital blocks = worse outcomes
    • NPO and Tetanus
    • Early extensive surgical debridement and decompression of the wound / fasciotomy.
    •  Prophylactic broad-spectrum antibiotics
    • Corticosteroids ?
  • Prognosis
    • Time since injection critical
    • patients requiring amputation presented 6-48 hours after injury
    • Chemical properties contribute to the severity of the injury.
    • Paint and paint solvents = most irritating to tissue.
    • rapid compromise of circulation to digits.


medical/legal pearls

  • Hand wound complications = highest # medicolegal actions against ED
  • Consider retained foreign bodies or deep tissue injury in all open wounds
  • Inform all patients of possibility of complications: pain, limitation of mobility
  • Carefully document initial neuro exam, procedures and follow-up for all patients
  • When in doubt , refer to ORTHO