Anatomy – Upper Limb – Areas
Axilla Pyramidal space between upper arm/side thorax contain neurovascular structures and LNs for upper limb/side wall thorax Floor Axillary fascia Anterior wall pec major/minor , clavipect fascia (ant ax fold) Posterior wall subscap, teres major, Lat dorsi (post ax fold) Medial wall serratus anterior , Ribs 1-4, intercostals Lateral wall Humerus Apex Clavicle, scapula , first rib (cervicoax canal) Contents Ax sheath: ax art/vein , brachial plexus – cords/branches , long thoracic nerve , LNs Openings 1) Cervicoaxillary canal (apex): posterior triangle 2) Clavipectoral triangle: pectoral region 3) Quadrangular space: scapular region
Breast Surface markings Sternal edge to midaxillary line, 2nd to 6th rib Deep - fascia, Pec major, Serratus ant, Rectus sheath, Ext oblique Blood Lat thoracic, Intl thoracic, Post intercostal, Thoracoacromial arteries Lymph 75% axilla (anterior/pectoral group) - Med to parasternal group
Spaces Quadrangular Space Space between subscap/teres major in post axillary wall transmits axillary N Contents: axillary nerve and post. circumflex humeral artery Sup: subscap/teres minor Inf: teres major Med: long head tric Lat: humerus Triangular Space Contents: scap circumfl A Sup: teres minor Inf: teres major Lat: long head tric Triangular Interval Contents: radial nerve, deep artery of arm (Profunda brachii) Borders: triceps long and lat, teres major Clavipectoral fascia Strong fascial sheet between clavicle and pectoralis major Lat: coronoid process, Med: blends with ext intercostals membrane upper 2 spaces, Sup: subclavian groove clavicle, splits to enclose subclavius and pec minor reforms below subclavius Pierced by 4 structures: IN - Lymphatics to ax LNs, Cephalic vein; OUT - Lat pec n, Thoracoacrom A
Antecubital Fossa Triangular intramuscular space ant surface of elbow lateral - brachioradialis medial - pronator teres superior - between 2 epico floor – brachialis, supinator roof – skin, deep fascia, bicipital apon Contents (Lat Med TAN): 1. Radial nerve (Post interosseous n.) 2. Tendon of biceps brachii 3. Brachial artery 4. Median nerve
Flexor Retinaculum Strong fibrous band 2-3cm trans/long across front carpus at prox part hand, extend prox to distal volar skin crease Attachments: lat: scaphoid tubercle, trapezium med: pisiform, hook hamate upper border: deep fascia of forearm lower border: aponeurosis Contents: (M to L) FDL, FDP, FDS, median nerve, FCR ( common flexor sheath: FDS and FDP)
1 Above retinaculum (M to L): FCU own sheath > UN/UA in Canal of Guyon > Palm cut branch UN > PL > Palm cut branch MN > Palm branch RA Origin of: FPB, AbPB, ODM, PDM, AbDM Carpal Tunnel Syndrome: lat 3 1/2 fingers; Weak thenar muscles
Extensor Retinaculum Band fascia 2.5cm obliquely across extensor surface wrist, lat more prox Attachments: prox – radius above styloid process dist – pisiform and triquetral Compartments: fibrous septa from retinaculum = 6 (R →U) 1. APL, EPB (separate synovial sheaths) 2. ECRL and ECRB (separate sheaths) 3. EPL 4. ED, EI (common sheath) 5. EDM 6. ECU All these supplied by radial/post interosseus nerve (C7, 8) except ECRL C6-8
Thumb Thenar eminence 3 short thumb muscles origins largely from flexor retinaculum Flexion - MCP, IPJs → FPL, FPB, OP (median nerve) Extension – MCP, IPJs → EPL, EPB (post interosseous branch radial N) Palmer abduction - away from index finger right angles to palm → AbPB (median nerve) Radial abduction - away index finger in plane of palm → AbPL, EPB (post interos branch radial nerve) Ulnar adduction - AdP, FPB (ulnar and median nerve) Opposition – Add/int rot 1st MC at joint/extension MCPJs and IPJs → OP (median nerve); Assisted by FPB, AdP
Anatomical Snuffbox Concavity formed on radial side of wrist radial side – tendons EPB and AbPL ulnar side – tendon EPL proximal - styloid process radius distal: base 1st MC, trapezium floor - (prox-dist) – radial styloid, scaphoid, trapez, base 1 st MC Contents: radial artery, cephalic vein, ECRL/ECRB, superf branch radial nerve
Palmer aponeurosis Reinforcement deep fascia of hand by superficial layer longitudinal fibres continuous with tendon palmaris longus Prox Continuous w palmer aponeurosis covering thenar/ hypothenar eminences Dist Widens, divides to 4 strips – 1 for each finger Thickening transverse fibres at level MC heads form superficial transverse metacarpal ligament Palmer spaces Septi 2 sides of palmer aponeurosis divide palm into spaces - Ulnar septum attach 5th MC, radial attach mid MC Thenar space – encloses thenar muscles. Midpalmer space – lies underneath palmer aponeurosis
Fibrous flexor sheath Strong fibrous sheath containing long flexor tendons hand, commence at MC heads, end at insertion flexor tendons Form annular pulleys and cruciform pulleys ; FPL own sheath; FDS and FDP share sheath
Web Spaces Spaces in palm between proximal phalanges 4 fingers Fingers Superficial transverse metacarpal ligament Digital vessels and nerves Deep transverse metacarpal ligament Interosseous tendons, Lumbrical tendons Thumb Digital vessels/nerves – radialis indicis and princeps pollicis Tendons transverse head adductor pollicis and 1st dorsal interosseous
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