DOCSLIB.ORG

Upper Limb – Areas

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Upper Limb – Areas 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 2 .
Load more

Recommended publications
  • Gross Anatomy
    www.BookOfLinks.com THE BIG PICTURE GROSS ANATOMY www.BookOfLinks.com Notice Medicine is an ever-changing science. As new research and clinical experience broaden our knowledge, changes in treatment and drug therapy are required. The authors and the publisher of this work have checked with sources believed to be reliable in their efforts to provide information that is complete and generally in accord with the standards accepted at the time of publication. However, in view of the possibility of human error or changes in medical sciences, neither the authors nor the publisher nor any other party who has been involved in the preparation or publication of this work warrants that the information contained herein is in every respect accurate or complete, and they disclaim all responsibility for any errors or omissions or for the results obtained from use of the information contained in this work. Readers are encouraged to confirm the infor- mation contained herein with other sources. For example and in particular, readers are advised to check the product information sheet included in the package of each drug they plan to administer to be certain that the information contained in this work is accurate and that changes have not been made in the recommended dose or in the contraindications for administration. This recommendation is of particular importance in connection with new or infrequently used drugs. www.BookOfLinks.com THE BIG PICTURE GROSS ANATOMY David A. Morton, PhD Associate Professor Anatomy Director Department of Neurobiology and Anatomy University of Utah School of Medicine Salt Lake City, Utah K. Bo Foreman, PhD, PT Assistant Professor Anatomy Director University of Utah College of Health Salt Lake City, Utah Kurt H.
    [Show full text]
  • Infraclavicular Topography of the Brachial Plexus Fascicles in Different Upper Limb Positions
    Int. J. Morphol., 34(3):1063-1068, 2016. Infraclavicular Topography of the Brachial Plexus Fascicles in Different Upper Limb Positions Topografía Infraclavicular de los Fascículos del Plexo Braquial en Diferentes Posiciones del Miembro Superior Daniel Alves dos Santos*; Amilton Iatecola*; Cesar Adriano Dias Vecina*; Eduardo Jose Caldeira**; Ricardo Noboro Isayama**; Erivelto Luis Chacon**; Marianna Carla Alves**; Evanisi Teresa Palomari***; Maria Jose Salete Viotto**** & Marcelo Rodrigues da Cunha*,** ALVES DOS SANTOS, D.; IATECOLA, A.; DIAS VECINA, C. A.; CALDEIRA, E. J.; NOBORO ISAYAMA, R.; CHACON, E. L.; ALVES, M. C.; PALOMARI, E. T.; SALETE VIOTTO, M. J. & RODRIGUES DA CUNHA, M. Infraclavicular topography of the brachial plexus fascicles in different upper limb positions. Int. J. Morphol., 34 (3):1063-1068, 2016. SUMMARY: Brachial plexus neuropathies are common complaints among patients seen at orthopedic clinics. The causes range from traumatic to occupational factors and symptoms include paresthesia, paresis, and functional disability of the upper limb. Treatment can be surgical or conservative, but detailed knowledge of the brachial plexus is required in both cases to avoid iatrogenic injuries and to facilitate anesthetic block, preventing possible vascular punctures. Therefore, the objective of this study was to evaluate the topography of the infraclavicular brachial plexus fascicles in different upper limb positions adopted during some clinical procedures. A formalin- preserved, adult, male cadaver was used. The infraclavicular and axillary regions were dissected and the distance of the brachial plexus fascicles from adjacent bone structures was measured. No anatomical variation in the formation of the brachial plexus was observed. The metric relationships between the brachial plexus and adjacent bone prominences differed depending on the degree of shoulder abduction.
    [Show full text]
  • M1 – Muscled Arm
    M1 – Muscled Arm See diagram on next page 1. tendinous junction 38. brachial artery 2. dorsal interosseous muscles of hand 39. humerus 3. radial nerve 40. lateral epicondyle of humerus 4. radial artery 41. tendon of flexor carpi radialis muscle 5. extensor retinaculum 42. median nerve 6. abductor pollicis brevis muscle 43. flexor retinaculum 7. extensor carpi radialis brevis muscle 44. tendon of palmaris longus muscle 8. extensor carpi radialis longus muscle 45. common palmar digital nerves of 9. brachioradialis muscle median nerve 10. brachialis muscle 46. flexor pollicis brevis muscle 11. deltoid muscle 47. adductor pollicis muscle 12. supraspinatus muscle 48. lumbrical muscles of hand 13. scapular spine 49. tendon of flexor digitorium 14. trapezius muscle superficialis muscle 15. infraspinatus muscle 50. superficial transverse metacarpal 16. latissimus dorsi muscle ligament 17. teres major muscle 51. common palmar digital arteries 18. teres minor muscle 52. digital synovial sheath 19. triangular space 53. tendon of flexor digitorum profundus 20. long head of triceps brachii muscle muscle 21. lateral head of triceps brachii muscle 54. annular part of fibrous tendon 22. tendon of triceps brachii muscle sheaths 23. ulnar nerve 55. proper palmar digital nerves of ulnar 24. anconeus muscle nerve 25. medial epicondyle of humerus 56. cruciform part of fibrous tendon 26. olecranon process of ulna sheaths 27. flexor carpi ulnaris muscle 57. superficial palmar arch 28. extensor digitorum muscle of hand 58. abductor digiti minimi muscle of hand 29. extensor carpi ulnaris muscle 59. opponens digiti minimi muscle of 30. tendon of extensor digitorium muscle hand of hand 60. superficial branch of ulnar nerve 31.
    [Show full text]
  • Section 1 Upper Limb Anatomy 1) with Regard to the Pectoral Girdle
    Section 1 Upper Limb Anatomy 1) With regard to the pectoral girdle: a) contains three joints, the sternoclavicular, the acromioclavicular and the glenohumeral b) serratus anterior, the rhomboids and subclavius attach the scapula to the axial skeleton c) pectoralis major and deltoid are the only muscular attachments between the clavicle and the upper limb d) teres major provides attachment between the axial skeleton and the girdle 2) Choose the odd muscle out as regards insertion/origin: a) supraspinatus b) subscapularis c) biceps d) teres minor e) deltoid 3) Which muscle does not insert in or next to the intertubecular groove of the upper humerus? a) pectoralis major b) pectoralis minor c) latissimus dorsi d) teres major 4) Identify the incorrect pairing for testing muscles: a) latissimus dorsi – abduct to 60° and adduct against resistance b) trapezius – shrug shoulders against resistance c) rhomboids – place hands on hips and draw elbows back and scapulae together d) serratus anterior – push with arms outstretched against a wall 5) Identify the incorrect innervation: a) subclavius – own nerve from the brachial plexus b) serratus anterior – long thoracic nerve c) clavicular head of pectoralis major – medial pectoral nerve d) latissimus dorsi – dorsal scapular nerve e) trapezius – accessory nerve 6) Which muscle does not extend from the posterior surface of the scapula to the greater tubercle of the humerus? a) teres major b) infraspinatus c) supraspinatus d) teres minor 7) With regard to action, which muscle is the odd one out? a) teres
    [Show full text]
  • Quadrilateral Space Syndrome
    FUNCTIONAL REHABILITATION R. Barry Dale, PhD, PT, ATC, CSCS, Report Editor Quadrilateral Space Syndrome Robert C. Manske, PT, DPT, MEd, SCS, ATC, CSCS, Afton Sumler, ATC, and Jodi Runge, ATC • Wichita State University QUADRILATERAL space syndrome (QSS) is a History uncommon condition that has been reported to affect athletes who perform overhead QSS has been reported to have a spontaneous movement patterns, such as baseball play- onset during sport participation or as a result 1,2,7-15 ers,1-4 tennis players,5 and volleyball players.6 of acute trauma. Misdiagnosis may Cahill and Palmer7 described it as a rare be responsible for an underestimate of the 16 7 condition that involves compression of the prevalence of QSS. Cahill described four posterior humeral cir- cardinal features of QSS: (a) poorly localized cumflex artery (PHCA) shoulder pain, (b) nondermatomal distribu- Key PointsPoints and the axillary nerve tion of paresthesia, (c) discrete point ten- within the quadrilat- derness in the quadrilateral space, and (d) a Qaudrilateral space syndrome is an uncom- eral space, which pro- positive arteriogram finding with the affected mon condition. duces pain over the shoulder in a position of abduction and exter- posterior aspect of nal rotation. A high index of suspicion should Symptoms are caused by entrapment of the shoulder that may be maintained for this unusual diagnosis the axillary nerve within the quadrilateral in the overhead athlete who presents with space. radiate into the arm and forearm with a recalcitrant posterior shoulder pain. Conservative treatment should be non-dermatomal dis- attempted prior to surgical intervention. tribution.
    [Show full text]
  • Upper Extremity Venous Ultrasound
    Upper Extremity Venous Ultrasound • Generally sicker patients / bedside / overlying dressings with limited Historically access Upper Extremity DVT Protocols • Extremely difficult studies / senior George L. Berdejo, BA, RVT, FSVU technologists • Most of the examination focuses on the central veins Subclavian/innominate/SVC* Ilio-caval Axillary/brachial Femoro-popliteal Radial/ulnar Tibio-peroneal 2021 Leading Edge in Diagnostic Ultrasound Conference MAY 11-13, 2021 • Anatomic considerations* Upper Extremity Venous Ultrasound Upper Extremity Venous Ultrasound Symptoms / Findings • Incidence of UE DVT low when compared to LE but yield of positive studies is higher ✓Central Vein Thrombosis • Becoming more prevalent with increasing use of UE veins for • Swelling of arm, face and /or neck access • Sometimes asymptomatic http://stroke.ahajournals.org/content/3 • Injury to the vessel wall is most common etiology • Dialysis access dysfunction 2/12/2945/F1.large.jpg ✓Peripheral Vein Thrombosis • Other factors: effort thrombosis, thoracic outlet compression, mass compression, venipuncture, trauma • Local redness • Palpable cord • Tenderness • Asymmetric warmth Upper Extremity Venous Ultrasound Upper Extremity Venous Ultrasound Vessel Wall Injury • Patients with indwelling catheters / pacer wires • Tip of catheter/ wires cause irritation of vein wall 1 Upper Extremity Venous Ultrasound Upper Extremity Venous Ultrasound Anatomy At the shoulder, the cephalic vein travels Deep Veins between the deltoid and pectoralis major • Radial and ulnar veins form
    [Show full text]
  • Surface Anatomy
    BODY ORIENTATION OUTLINE 13.1 A Regional Approach to Surface Anatomy 398 13.2 Head Region 398 13.2a Cranium 399 13 13.2b Face 399 13.3 Neck Region 399 13.4 Trunk Region 401 13.4a Thorax 401 Surface 13.4b Abdominopelvic Region 403 13.4c Back 404 13.5 Shoulder and Upper Limb Region 405 13.5a Shoulder 405 Anatomy 13.5b Axilla 405 13.5c Arm 405 13.5d Forearm 406 13.5e Hand 406 13.6 Lower Limb Region 408 13.6a Gluteal Region 408 13.6b Thigh 408 13.6c Leg 409 13.6d Foot 411 MODULE 1: BODY ORIENTATION mck78097_ch13_397-414.indd 397 2/14/11 3:28 PM 398 Chapter Thirteen Surface Anatomy magine this scenario: An unconscious patient has been brought Health-care professionals rely on four techniques when I to the emergency room. Although the patient cannot tell the ER examining surface anatomy. Using visual inspection, they directly physician what is wrong or “where it hurts,” the doctor can assess observe the structure and markings of surface features. Through some of the injuries by observing surface anatomy, including: palpation (pal-pā sh ́ ŭ n) (feeling with firm pressure or perceiving by the sense of touch), they precisely locate and identify anatomic ■ Locating pulse points to determine the patient’s heart rate and features under the skin. Using percussion (per-kush ̆ ́ŭn), they tap pulse strength firmly on specific body sites to detect resonating vibrations. And ■ Palpating the bones under the skin to determine if a via auscultation (aws-ku ̆l-tā sh ́ un), ̆ they listen to sounds emitted fracture has occurred from organs.
    [Show full text]
  • Shoulder Joint - Upper Limb
    Shoulder Joint - Upper Limb Dr. Brijendra Singh Prof & Head Department of Anatomy AIIMS Rishikesh Learning objectives •Anatomy of shoulder joint •Formation , type & components •Rotator cuff •Relations /nerve & blood supply •Movements & muscles producing them •Dislocations /nerve injuries Articulation - Rounded head of humerus & Shallow , glenoid cavity of scapula. Glenoid cavity • Articular surfaces are covered by articular - hyaline cartilage. • Glenoid cavity is deepened by fibro cartilaginous rim called glenoid labrum. Synovial membrane •lines fibrous capsule & attached to margins of the cartilage covering the articular surfaces. •forms a tubular sheath around the tendon of the long head of biceps brachii. •It extends through anterior wall of capsule to form subscapularis bursa beneath subscapularis muscle. Synovial membrane Musculotendinious/Rotator cuff •Supraspinatus – superiorly •Infraspinatus & Teres minor- posteriorly •Subscapularis – anteriorly •Long head of triceps – inferiorly ( axillary n & post circumflex humeral artery – lax and least supported) – •most common dislocations – Inferiorly axillary n palsy –loss of abduction NERVE SUPPLY of Shoulder joint NERVE SUPPLY of Shoulder joint 1. axillary n 2. suprascapular n & 3. lateral pectoral nerve. Shoulder joint - spaces Quadrangular space Triangular space •Sup - teres minor •Sup – teres major •Inf - teres major •Medially- long head •Medially - long head of of triceps triceps •Laterally – •Laterally – lateral head triceps(humerus) of triceps (humerus) •Contents – in spiral •Contents
    [Show full text]
  • Surface Anatomy and Markings of the Upper Limb Pectoral Region
    INTRODUCTION TO SURFACE ANATOMY OF UPPER & LOWER LIMBS OBJECTIVES By the end of the lecture, students should be able to: •Palpate and feel the bony the important prominences in the upper and the lower limbs. •Palpate and feel the different muscles and muscular groups and tendons. •Perform some movements to see the action of individual muscle or muscular groups in the upper and lower limbs. •Feel the pulsations of most of the arteries of the upper and lower limbs. •Locate the site of most of the superficial veins in the upper and lower limbs Prof. Saeed Abuel 2 Makarem What is Surface Anatomy? • It is a branch of gross anatomy that examines shapes and markings on the surface of the body as they are related to deeper structures. • It is essential in locating and identifying anatomic structures prior to studying internal gross anatomy. • It helps to locate the affected organ / structure / region in disease process. • The clavicle is subcutaneous and can be palpated throughout its length. • Its sternal end projects little above the manubrium. • Between the 2 sternal ends of the 2 clavicles lies the jugular notch (suprasternal notch). • The acromial end of the clavicle can be palpated medial to the lateral border of the acromion, of the scapula. particularly when the shoulder is alternately raised and depressed. • The large vessels and nerves to the upper limb pass posterior to the convexity of the clavicle. 4 • The coracoid process of scapula can be felt deeply below the lateral one third of the clavicle in the Deltopectoral GROOVE or clavipectoral triangle.
    [Show full text]
  • Anatomy Module 3. Muscles. Materials for Colloquium Preparation
    Section 3. Muscles 1 Trapezius muscle functions (m. trapezius): brings the scapula to the vertebral column when the scapulae are stable extends the neck, which is the motion of bending the neck straight back work as auxiliary respiratory muscles extends lumbar spine when unilateral contraction - slightly rotates face in the opposite direction 2 Functions of the latissimus dorsi muscle (m. latissimus dorsi): flexes the shoulder extends the shoulder rotates the shoulder inwards (internal rotation) adducts the arm to the body pulls up the body to the arms 3 Levator scapula functions (m. levator scapulae): takes part in breathing when the spine is fixed, levator scapulae elevates the scapula and rotates its inferior angle medially when the shoulder is fixed, levator scapula flexes to the same side the cervical spine rotates the arm inwards rotates the arm outward 4 Minor and major rhomboid muscles function: (mm. rhomboidei major et minor) take part in breathing retract the scapula, pulling it towards the vertebral column, while moving it upward bend the head to the same side as the acting muscle tilt the head in the opposite direction adducts the arm 5 Serratus posterior superior muscle function (m. serratus posterior superior): brings the ribs closer to the scapula lift the arm depresses the arm tilts the spine column to its' side elevates ribs 6 Serratus posterior inferior muscle function (m. serratus posterior inferior): elevates the ribs depresses the ribs lift the shoulder depresses the shoulder tilts the spine column to its' side 7 Latissimus dorsi muscle functions (m. latissimus dorsi): depresses lifted arm takes part in breathing (auxiliary respiratory muscle) flexes the shoulder rotates the arm outward rotates the arm inwards 8 Sources of muscle development are: sclerotome dermatome truncal myotomes gill arches mesenchyme cephalic myotomes 9 Muscle work can be: addacting overcoming ceding restraining deflecting 10 Intrinsic back muscles (autochthonous) are: minor and major rhomboid muscles (mm.
    [Show full text]
  • Prezentace Aplikace Powerpoint
    Mimsa Dissection 2 Session Konstantinos Choulakis Thorax Borders: • Superiorly: jugular fossa – clavicles – acromion – 7th cervical vertebra • Inferiorly: xiphoid process – ribs – spinous process of 12th thoracic vertebra Superior thoracic aperture: 1st thoracic vertebra – first ribs – superior margin of sternum Inferior thoracic aperture: 12th thoracic vertebra – last ribs – distal costal arches 2 Regions: 1 1. Deltoid 3 3 3 4 2. Inflaclavicular ( =clavipectoral= deltopectoral) 5 3. Pectoral 6 6 4. Presternal 5. Axillary 7 7 6. Mammary 7. Inframammary Muscles: M. Pectoralis Major M. Pectoralis M. Subclavius M. Transversus M. Serratus anterior Minor Thoracis O: I: Inn: F: M. Externus Intercostalis M. Internus Intercostalis M. Innermost Intercostal I Origin I Insertion O O Fasciae • Superficial thoracic fascia: Underneath the skin. • Pectoral fascia: The pectoral fascia is a thin lamina, covering the surface of the pectoralis major, and sending numerous prolongations between its fasciculi: it is attached, in the middle line, to the front of the sternum; above, to the clavicle; laterally and below it is continuous with the fascia of the shoulder, axilla • Clavipectoral fascia: It occupies the interval between the pectoralis minor and Subclavius , and protects the axillary vessels and nerves. Traced upward, it splits to enclose the Subclavius , and its two layers are attached to the clavicle, one in front of and the other behind the muscle; the latter layer fuses with the deep cervical fascia and with the sheath of the axillary vessels. Medially, it blends with the fascia covering the first two intercostal spaces, and is attached also to the first rib medial to the origin of the Subclavius .
    [Show full text]
  • Innervation of the Clavicular Part of the Deltoid Muscle by the Lateral Pectoral Nerve
    Zurich Open Repository and Archive University of Zurich Main Library Strickhofstrasse 39 CH-8057 Zurich www.zora.uzh.ch Year: 2020 Innervation of the clavicular part of the deltoid muscle by the lateral pectoral nerve Larionov, Alexey ; Yotovski, Peter ; Link, Karl ; Filgueira, Luis Abstract: INTRODUCTION: The innervation pattern of the clavicular head of the deltoid muscle and its corresponding topography were investigated via cadaveric dissection in the present study, focusing on the lateral pectoral nerve. MATERIALS AND METHODS: Fifty-eight upper extremities were dissected and the nerve supplies to the deltoid muscle and the variability of the lateral pectoral and axillary nerves, including their topographical patterns, were noted. RESULTS: The clavicular portion of the deltoid muscle received a deltoid branch from the lateral pectoral nerve in 86.2% of cases. Two topographical patterns of the lateral pectoral nerve were observed, depending on the branching level from the brachial plexus: a proximal variant, where the nerve entered the pectoral region undern the clavicle, and a distal variant, where the nerve entered the pectoral region from the axillary fossa around the caudal border of the pectoralis minor. These dissection findings were supported by histological confirmation of peripheral nerve tissue entering the clavicular part of the deltoid muscle. CONCLUSION: The topographical variations of the lateral pectoral nerve are relevant for orthopedic and trauma surgeons and neurologists. These new data could revise the interpretation of deltoid muscle atrophy and of thoracic outlet and pectoralis minor compression syndromes. They could also explain the residual anteversion function of the arm after axillary nerve injury and deficiency, which is often thought to be related to biceps brachii muscle function.
    [Show full text]