Injuries to the Hand and Digits

1
Injuries to the Hand and Digits

• Tintinalli
• Chapter 268

2
Hand/Digit Anatomy
3
Anatomy

• Extensor tendons (9)
• Dorsal side of forearm, wrist and hand
• Pass under extensor retinaculum
• Connected by junctura ? complete tendon lac my
  still result in normal extensor function
• Flexor tendons (9)
• Volar side of forearm, wrist and hand
• Pass under flexor retinaculum
• 4 flexor digitorum superficialis (FDS) ? middle
  phalanx
• 4 (FDP) profundus ? distal phalanx

4
Blood Supply

• Dual
• Radial artery ? deep arch
• Supply palm, thumb, and part of index finger
• Ulnar artery ? superficial arch
• Give rise to common digital arteries
• Supply palm, 2nd through 5th digits

5
Ulnar Nerve

• Runs deep to the carpi ulnaris tendon.
• Sensation
• palm and dorsal aspects of the ulnar side of
  hand, 5th digit and ulnar half of the 4th digit.
• Motor
• Dorsal interosseous, hypothenar muscles, ulnar
  lumbricals
• Test
• abduction of fingers against resistance

6
Median nerve

• Runs through carpal tunnel
• Sensory
• Thumb, palm on the radial side of the hand, the
  palmar aspect of the radial 2 ½ fingers, the
  dorsal aspect of the tips of the index and middle
  fingers and radial half of the ring finger.
• Motor
• Thenar muscles, radial lumbricals
• Test
• opposition of the thumb to each finger vs
  resistance -watch for thenar muscles contractions

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Radial nerve

• Sensory
• dorsum of radial aspect of the hand, dorsum of
  thumb, dorsal aspect of the 2nd and 3rd fingers,
  dorsal radial half of the 4th finger.
• Motor
• Extensors of wrist, no intrinsic muscles in hand
• Test
• extension of the wrist and fingers against
  resistance
• Loss of function wrist drop

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Evaluation

• History
• Time and cause of injury
• Occupation, prior hand injury, handedness
• PE
• Posture, status of skin, devascularization,
  deformity, active bleeding, grip strength
• Compare to other hand
• Clenched fist observe orientation if
  middle/distal phalanxes (should be parallel)

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Evaluation

• Sensory Testing
• Two point discrimination
• gt6mm fingertips abnormal
• Sensory deficit implies digital artery lac (close
  prox)
• Tendon Testing
• Full ROM vs resistance compared to uninjured side
• Pain along course of tendon suggests partial lac
• FDP flex DIP while PIP/MP held extended
• FDS flex PIP while fingers held extended
• Radiographs
• PA, lateral, oblique

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Hand Surgery Consultation

• Immediate
• vascular injury, irreducible dislocations,
  contaminated wounds, crush, compartment syndrome,
  high pressure injection, hand or finger
  amputation
• Delayed
• Extensor/flexor tendon laceration, FDP rupture,
  nerve injury, fractures, dislocations, unstable
  ligament injury

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Anesthesia

• Regional nerve blocks-useful with finger/hand
  injuries.
• Finger injuries-digital block better than local
• Sensation is by the palmar and dorsal digital
  nerves along the lateral aspect of each finger.
• Digital block
• Dorsal approach
• Palmar approach
• Web space approach

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Flexor Tendon Injuries

• Most common laceration
• Zone I Zone V
• Flexor tendon injuries-repaired by hand surgeon
  in 12 hours

13
Extensor Tendon Injury

• Most common site of tendon injury superficial on
  dorsum of hand
• Mallet Finger common injury in athletes
• MOI blunt trauma, sudden forced flexion
• Unable to extend DIP
• Swan-neck deformity develops in chronic/untreated
  
• Tx
• No fx Splint in slight hyperextension
• Fx ortho for pinning

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Extensor Tendon Injury

• Boutonniere Deformity
• Complete disruption of central tendon
• Flexion of PIP and hyperextension of DIP
• MOI direct blow
• Tx
• splint the PIP in extension refer to ortho

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Ligament and Dislocation Injury

• DIP (uncommon)
• Longitudinal traction and hyperextension, direct
  dorsal pressure base of distal phalanx
• PIP (most common)
• Reduce as above plus splint 30 degree flexion
• MP
• Wrist flexed with pressure applied over dorsum of
  the proximal phalanx in a distal and volar
  direction
• Thumb MP Collateral Ligament Rupture
• Game keepers/Skiers Thumb radial deviation of MP
• Hand surgery referral recommended with weak
  pincer

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Fractures

• Distal Phalanx (15-30 of hand fx)
• Splint
• Proximal and Middle Phalanx
• Buddy taping

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Fractures

• Metacarpal MOI - punch clenched fist
• Head
• Direct blow, crush, missile
• Laceration- assume human bite
• Neck
• Direct impaction of force
• Reduce if
• gt15 degree angulation 2nd and 3rd
• gt20 degree angulation 4th
• gt40 degree in 5th (Boxers fx)
• Shaft
• Direct blow
• Rotational deformity/shortening likely
• Tx operative

18
Compartment Syndrome

• Crush injury
• Involved compartments
• Thenar, hypothenar, adductor pollicis, 4
  interossei
• Edema/hemorrhage ? increased pressure ? tissue
  necrosis ? loss of hand fxn/contracture
• Pain (disproportionate and on passive stretch),
  paresthesia, paralysis, pulselessness
• Tx Hand consult for fasciotomy

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High pressure injection injury

• Initially appear benign HISTORY important
• Injection into soft tissue (2000-10,000) psi
• Industrial/operator
• Grease, paint, hydraulic fluid, diesel fuel, etc.
• Causes inflammatory response, tissue
  edema/ischemia
• Compartment syndrome
• Xray
• radio-opaque substance, subQ air
• Tx
• Hand consult, immobilize, elevate, tetanus, atb,
  analgesics
• Surgical decompression/debridement

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High Pressure Injection
21
DeQuervains tenosynovitis

• Inflammed extensor tendons of the thumb-pain on
  radial aspect of wrist-worse with use
• Finkelstein test-pain on ulnar deviation of the
  wrist while thumb is flexed and held in the palm
  by the other finger
• Treatment-NSAIDs-splint position of function

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Infections of the Hand

• Paronychia
• nail fold infection-Staph Strep-Treat with ID
• Felon
• fingertip infection-Staph-Treat with ID
• Incision through the pulp of the finger laterally
  with wick placed though the incision-remove in 72
  hours

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Infections of the Hand

• Herpetic Whitlow-
• viral infection of distal finger-HVS I or
  II-pain, burn, itching and herpetic lesions then
  form.
• Treatment-splint and analgesics-may give oral
  antivirals
• DO NOT DRAIN

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Infections of the Hand

• Human bite or fight bite
• punch to the mouth usually
• DO NOT suture over the MCP-heal by secondary
  intention
• Eikenella corrodens
• Treatment-ortho consult, xrays, wound cultures,
  irrigate, IV antibiotics if necessary

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Infections of the Hand

• Tenosynovitis
• Typically from punture wound-staph or strep
• Diagnose-Kanavel four cardinal signs
• Held in slight flexion
• Symmetric swelling of the finger
• Tender along flexor tendon sheath
• Pain with passive extension of the finger
• Tx IV antibiotics, culture, tetanus
• Penetrating trauma penicillinase-resistant
  antistaphylococcal PCN or 1st gen. cephalosporin
• No history of trauma in a sexually active adult,
  consider GC-treat with ceftriaxone