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OVERVIEW OF HAND ANATOMY

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OVERVIEW OF HAND ANATOMY Powered By Docstoc
					OVERVIEW OF HAND ANATOMY
• The hand is a unique organ that allows humans
  to work and to create.
• The hand can be conveniently divided into the
  palmer (volar) and dorsal parts.
• The volar portion of the hand contains the major
  digital nerves, the flexor tendons, and the
  muscles that allow finger movement.
• The bony architecture is complex: The distal
  surface of the radius (the major portion of the
  wrist); 8 carpal bones; 5 metacarpals; 3
  phalanges for each of the fingers; and a
  proximal and distal phalanx for the thumb.
                                   Skin
• Palmar skin
  – Thick with fibrous septa connecting to underlying
    fascia
  – Attachment limits motion and provides a stable
    platform for grasping and manipulation
  – High concentration of specialized sensory end organs
• Dorsal skin
  – Loose with areolar tissue between skin and tendons
  – Presence of subcutaneous space for lymphatic and
    venous drainage
             Extrinsinc flexors
• Flexor digitorum profundus
• Flexor digitorum superficialis
• Flexor pollicis longus
  ZONES OF FLEXOR TENDONS
• I-distal to sublimus
• II-level of entry of tendons
  in fibrooseous tendon
  sheath to insertion of
  sublimus-no man’s land
• III-area of lumbrical origin
  distal to TCL to level of
  fibrosseous tunnel
• IV-carpal tunnel
• V-forearm
          Extrinsic extensors
• Superficial
  – EDC
  – EDQ
• Deep
  – APL
  – EPL
  – EPB
  – EI
    INTRINSIC MUSCLES OF HAND
•   Dorsal interossei
•   Palmar interossei(3)
•   Lumbricals(4)
•   Thenar muscles(4)
•   Hypothenar
    muscles(4)
                   Blood supply
• Radial artery
• Ulnar artey
• Palmar vessels
  – Superficial
     • Superficial arch and branches
     • Common digital arteries
  – Deep
     • Deep arch and branches
     • Princeps pollicis & arteia radialis indicis
• Dorsal vessels
  – Dorsal arch and dorsal metacarpal branches
              Nerve supply
• Radial nerve
  – From posterior cord
  – Supplies ECRL & ECRB prior to dividing into
    post. Interosseous & superficial sensory
  – Superficial sensory divides in proximal
    forearm becomes superficial at radial side of
    insertion of brachioradialis
  – SUPPLIES RADIAL 2/3rd of dorsal hand &
    dorsal thumb, index, long &1/2 of ring
• Median nerve
  – Forms from lateral &
    medial cords
  – Innervates all thenar
    muscles except deep
    head of FPB & radial 2
    lumbricals
  – Digital branch to radial
    3 ½ digits
  – Palmar cutaneous
    branch – sensation to
    thenar eminence
                     Ulnar nerve
• From medial cord
• Deep branch from
  guyon’s canal
  –   All interossei
  –   Adductor pollicis
  –   Deep head of FPB
  –   Hypothenar muscles
• Sensory
  – Palmar cutaneous branch-
    superficial to carpal tunnel
  – Dorsal cutaneous branch
           Hand infections
• Seen in manual workers and housewives
• Commonest organism is staphylococcus
• Early recognition and early treatment are
  mandatory
• Provision of rest and elevation of limb
• Aftercare and splintage are important
                             FASCIAL SPACES
•   Palmar spaces-
•   Deep to palmar aponeurosis between
    medial and lateral septa is divided by thin
    intermediate septum into
     –   Middle palmar space (medial central space)
           •   Between medial and intermediate septum
           •   Limited dorsally by third to fifth metacarpals,
               fascia over interossei and adductor pollicis
           •   Contains third to fifth digital tendons and
               second to fourth lumbricals,superficial palmar
               arch
     –   Thenar space (lateral central space)
           •   Between lateral and intermediate septum
           •   Deep to flexor tendons, lumbricals and
               neurovscular bundle
           •   Superficial to adductor pollicis
           •   Contains tendons of FPL, FDS to index first
               lumbrical palmar digital vessel and nerve to
               thumb

     –   Posterior adductor space
•   Dorsal spaces
     –   Dorsal subcutaneous space
     –   Dorsal subaponeurotic space
         Types of hand infections
• Acute paronychia
  – Most common hand
    infection
  – Infection under the
    eponychium
• Pulp space infection
  – Second most common
    hand infection
  – Origin is usually a
    prick
• Palmer abscesses
   – Infection in fascial spaces
   – Post traumatic
• Acute suppurative
  tenosynovitis
   – Serious infection
   – Kanavael’s triad for
     diagnosis
       • Symmetrical finger
         swelling
       • Flexion of finger with
         painful extension
       • Tender tendon sheath
         (most important)

				
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