Anatomy Review #1
Brachial Plexus
• See the pdf in google drive on brachial plexus
• *long thoracic
– Injury to this causes winged scapula
– Serratus anterior
• *suprascapular
– Supraspinatus
– infraspinatus
• *thoracodorsal
– Latissimus dorsi
Nerve stems
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Axillary: C5-6
Radial: C5-T1
Musculocutaneous: C5-7
Median: C6-T1 (C5)
Ulnar: C8-T1
Spaces
• Triangular space
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Teres minor
Long head of triceps
Teres major
Circumflex scapular a.
• Triangular interval
• Teres major
• Long head of radius
• Shaft of humerus
• Profunda brachii a.
• Radial n.
• Quadrangular space
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Teres minor
long head of triceps
shaft of humerus
teres major
Axillary n.
Post. circumflex humeral a.
Post. circumflex humeral v.
• pp. 679, 691 text
Joints: Synovial
Synovial
– Capsule (inner synovial membrane, outer fibrous)
– Hyaline covers articulating surfaces
• Sternoclavicular- Modified ball and socket joint (according to the articular surfaces
it is rather a saddle, but because the disk it functions like ball and socket)
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Acromioclavicular- plane joint (gliding)
Glenohumeral- ball and socket
Humeroulnar- compound (hinge-pivot)
Distal radioulnar joint- pivot joint
Radiocarpal- ellipsoid joint (condylar)
Carpal-metacarpal- plane joints (EXCEPT: THUMB =saddle joint)
Metacarpophalangeal- ball and socket
Interphalangeal- hinge joint
p. 20 Gray’s text
Joints: Solid
Fibrous joints: sutures, gomphoses, syndesmoses
• Suture- skull
• Gomphoses- teeth and bone
• Syndesmoses- two adjacent bones linked by ligament
(ligamentum flavum, interosseous membrane)
Cartilaginous joints: synchondroses, symphyses
• Synchondroses- where two ossification centers
separated by cartilage (growth plate)
• Symphyses- two separate bones are interconnected by
cartilage (pubic symphysis, intervertebral discs)
p. 20 Gray’s text
Signs
• Waiter’s tip- “Erb’s palsy” upper trunk injury
– C5-6
• Claw hand- “Klumpke’s” lower trunk injury
– C8-T1
– Ring and little fingers hyperextended at MCP joints, flexed at IP joints
– Can’t open hand with fingers
• Hand of Benediction
– The ability to flex the digits 2–3 at the MCP joints is lost as is the
ability to flex and extend proximal and distal interphalangeal
Dupuytren’s contracture- thick palamar fascia
– Can’t make fist with fingers
• Volkmann’s contracture- flexion deformity caused by ischemic necrosis of
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forearm flexor muscles
Ape hand- flattening of thenar eminence due to injury to median n. (supracondylar fx)
Odds and ends
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Guyon’s canal- formed by pisiform and hamate. Ulnar n. runs through it. “Handlebar
Palsy”
Cubital fossa- TAN lateral to medial
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Fracture of C2 spinous process- obliquous capitis inferior
Trapezius- abd. Of humerus beyond horizontal
Tight ropey muscle C7-T4=splenius capitus
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Biceps brachii tendon
Brachial a. (splits to radial and ulnar)
Median n.
Innervated by C3-6 posterior ramii
What inserts on radial tuberosity and radial neck? Biceps brachii
Midshaft humeral fracture- supinator
Carpal tunnel- lose sensation of skin of middle finger
Subacromial bursitis affects suprascapular nerve
Anatomical position- legs ADDucted
Thoracodorsal- latissimus dorsi
Touch index and middle fingers to thumb= ulnar n.
More odds and ends
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Bennett’s fx- fx of base of metacarpal of thumb
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Boxer’s fx- fx of the necks of 2nd and 3rd metacarpals (5th metacarpal in unskilled boxers)
Colle’s fx- distal radius fx displaced posteriorly (dorsum of wrist) “Dinner fork deformity”
Smith’s fx- opposite of Colle’s
Surgical neck fx- axillary nerve and post humeral circumflex a. affected
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Midshaft of humerus fx- radial n. wrist drop
Supracondylar fx- median n. ape hand
Rotator cuff- SITS (Supraspinatus, Infraspinatus, Teres minor, Subscapularis)
Shoulder most commonly dislocated anteriorly
Scaphoid most commonly fractured
Lunate most commonly dislocated (FOOSH)
Know what makes up anatomical snuff box
Lateral epicondylitis- tennis elbow
Medial epicondylitis- golfer’s elbow
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More
• Mallet finger- permanent flexion of distal phalanx. Avulsion of lateral
bands of extensor tendon
• Boutonniere deformity- flexed middle phalanx, hyperextension
of distal phalanx. Avulsion of the central band of the extensor tendon
• Allen test- test ulnar, radial circulation to hand
Anatomical Snuff Box
• Left hand, palm facing to the right
– Far left= extensor pollicis longus
– Box
– Next= extensor pollicis brevis
– Far right= adductor pollicis longus
– P.759 gray’s text