Shoulder & Pectoral Region Anatomy PDF

Shoulder & Pectoral Region Madison Barber, MS [email protected]  Learning Objectives List palpable landmarks of the shoulder region utilized for physical exam or clinical procedures. Describe the anatomy of the ste...

Shoulder & Pectoral Region Madison Barber, MS [email protected]  Learning Objectives List palpable landmarks of the shoulder region utilized for physical exam or clinical procedures. Describe the anatomy of the sternoclavicular joint and its role in movements of the shoulder Describe the anatomy of the glenohumeral(shoulder) joint including the surrounding bursae and its movements Name the muscles of the shoulder and describe their general attachments, actions and innervations List the muscles that comprise the rotator cuff and explain their roll in supporting the glenohumeral joint Describe the borders of the quadrangular and triangular spaces and the triangular interval; name the structures that pass through them Describe the blood supply and venous drainage of the shoulder region including the three primary vessels that provide collateral circulation (dorsal scapular, suprascapular, circumflex scapular) Identify features of the scapula, clavicle and humerus on radiographs of the shoulder. Explain position of the breast on the chest wall in relation to the skin, superficial fascia and pectoral muscles Osteology and Joints  Surface Anatomy Anterior Posterior Trapezius m. (superior fibers) Deltoid m. Deltoid m. Clavicle Deltopectoral groove Pectoralis Biceps Brachii m. major m. Triceps Brachii m. Long Lateral head Cephalic vein Tendon Serratus anterior m. Basilic vein **Flexor compartment** **Extensor compartment**  Humerus Clavicle Acromial end Sternal end Anterior Osteology Head of humerus Scapula Anatomical neck Superior angle Superior Border Greater tubercle Acromion Lesser tubercle Suprascapular notch Intertubercular groove Coracoid Process Surgical neck Supraglenoid tubercle Deltoid tuberosity Subscapular Fossa Glenoid fossa Infraglenoid tubercle Medial Border Lateral border Inferior Angle Lateral Medial  Scapula Clavicle Sternal end Acromial end Posterior Osteology Superior angle Humerus Head of humerus Acromion Anatomical neck Suprascapular notch Greater tubercle Supraspinous fossa Surgical neck Spine of Scapula Deltoid tuberosity Infraspinous fossa Medial Border Lateral border Inferior Angle Medial Lateral  Clavicle Fracture Typically, the middle and lateral third of the clavicle Direct fall / indirect force from fall on outstretched hand Presentation: Sternocleidomastoid elevates the medial fragment of bone Shoulder drops Lateral fragment may be pulled medially = overriding bone fragments Shortened clavicle Sling or surgery  Shoulder Joints Acromioclavicular joint (AC Joint) Synovial Joint Anteroposterior & vertical movement Sternoclavicular Joint Between acromial end of clavicle and Synovial joint acromion of scapula Anteroposterior and vertical plane Acromioclavicular movement Joint Capsule Between sternal end of clavicle + clavicular notch of manubrium Rotator cuff Anterior sternoclavicular muscle ligament tendons Subclavius muscle Costoclavicular ligament Glenohumeral Joint Capsule Articular Disc of Glenohumeral Joint Sternocostal sternoclavicular joint Synovial ball and socket joint ligaments Wide range of motion Between glenoid fossa of scapula and head of humerus  Acromioclavicular Joint Coracoclavicular lig. Acromioclavicular lig. Coraco-acromial lig. Acromioclavicular ligament Clavicle Extends from acromion to clavicle Strengthens AC joint superiorly Maintains integrity of the AC joint when separation occurs Humeral head Coracoclavicular ligament Provides most of the strength for the AC Joint Scapular fossa Anchors the clavicle to the coracoid pross of scapula Allows for the scapula and free limb to be suspended from the clavicle Coracoacromial ligament Connects acromion and coracoid process of the scapula Protects the glenohumeral joint from superior dislocations  Shoulder Separations Separation of the acromial end of the clavicle with the acromion process of the scapula Direct blow to the AC joint during contact sports such as football, soccer, hockey, etc. Presentation AC Joint dislocation without coracoclavicular ligament rupture Shoulder still held up AC joint separation with coracoclavicular ligament rupture Shoulder falls – lost connection between clavicle and scapula Surgery  Sub-deltoid bursa AC Joint Glenohumeral Joint Supraspinatus tendon Deltoid muscle AC Joint Coracoid process Humeral Head Ball & socket synovial joint Glenoid Fossa Permits wide range of movement, however this mobility makes the joint unstable Large round Humeral head articulates with the shallow glenoid fossa Glenoid labrum is a fibrocartilaginous ring that helps to deep the glenoid fossa  Glenohumeral Ligaments Coracoacromial ligament Coracohumeral ligament From the base of the coracoid process to the anterior aspect of the greater tubercle Strengthens capsule superiorly Coracohumeral ligament Transverse humeral ligament From greater to the lesser tubercle of the humerus Converts intertubercular sulcus into a canal for the passage of the biceps Transverse humeral brachii long-head tendon ligament Coracoacromial ligament (arch) Prevents superior displacement of the humeral head from shallow glenoid fossa  Glenohumeral Joint Movement Flexion Abduction From resting position, the arm moves superior Humerus moves from resting positon to away from Decreases angle between humerus and acromion midline Extension Adduction Humerus moves posterior from resting position Humerus moves from abducted position back toward midline Increases the angle between humerus and acromion  Glenohumeral Joint Movement Internal (medial) Rotation External (lateral) Rotation Rotation of the of the humerus medially Rotation of the of the humerus laterally Moves greater tubercle closer to glenoid fossa Moves greater tubercle away from glenoid fossa **This movement is best visualized with the elbow bent at 90 degrees**  Shoulder Dislocations Dislocation of the head of the humerus from the shallow glenoid fossa of the scapula Excessive extension and lateral rotation of the humerus Presentation: Anterior dislocation – head of humerus is anterior to infraglenoid tubercle Posterior dislocation – head of humerus lies posterior to infraglenoid tubercle Superior dislocations – very rare due to protection by the coracoacromial arch and surrounding musculature to protect the joint Reset the joint and physical therapy Severe cases may require surgery Axillary nerve injury  Scapulothoracic Joint Not a true synovial joint Between convex surface of posterior thoracic wall and concave surface of anterior scapula Allows for movement of scapula by gliding along the ribs Serratus anterior muscle Facilitates retraction of the scapula Found between anterior surface of scapula and posterior thoracic wall Will discuss in more detail later  Scapulothoracic Joint Movement Elevation Depression Scapula moves superiorly, commonly described as Scapula moves inferiorly “shrugging the shoulders” Abduction Scapula moves laterally away from midline Downward Rotation Inferior angle of scapular moves toward midline Adduction Medial border of scapula moves toward midline Upward Rotation Inferior angle of scapular moves away from midline Adduction Abduction Musculature  Superficial Muscles Trapezius Latissimus Dorsi Attachments: Superior nuchal line, Attachments: Spinous process of occipital protuberance, nuchal T7-L5 vertebrae, thoracolumbar ligament, spinous process of C7-T12 fascia, iliac crest, last three ribs vertebrae Action: Extends, adducts, and Action: Elevates, retracts, and medially rotates humerus at the rotates scapula; lower fibers shoulder depress the scapula Innervation: Thoracodorsal nerve Innervation: Accessory nerve (CN Blood supply: Thoracodorsal artery XI) Blood supply: Transverse cervical artery  Deltoid Deltoid Attachments: Lateral third of the anterior clavicle, lateral acromion, inferior edge of spine of the scapula Action: Clavicular part: flexes and medially rotates arm Acromial part: abducts arm beyond initial 15 degrees done by the supraspinatus Scapular spine part: extends and lateral rotates arm Innervation: Axillary nerve Blood supply: Posterior circumflex humeral artery and deltoid branch of thoracoacromial artery  Donor Images (Anterior) (Posterior)  Posterior Musculature Levator Scapulae Rhomboids Attachments: Transverse processes of Attachments: Nuchal lig., spinous processes C1-C4 to medial superior border of T2-T5 to medial border of scapula scapula Action: Fixes scapula to thoracic wall and Action: Elevates scapula retracts scapula Innervation: Dorsal scapular n. Innervation: Dorsal scapular n. Blood Supply: Dorsal scapular artery Blood Supply: Dorsal scapular a. Supraspinatus* Teres Minor* Attachments: Supraspinatus fossa to Attachments: posterior, lateral border of scapula to greater tubercle of humerus superior greater tubercle of humerus Action: laterally rotates arm Action: Initiates first 15 degrees of Innervation: Axillary n. abduction of humerus at the shoulder Blood Supply: Circumflex scapular a. Innervation: Suprascapular n. Blood supply: Suprascapular a. Teres Major Attachments: Inferior angle to medial lip of Infraspinatus* intertubercular sulcus of humerus Attachments: Infraspinatus fossa to Action: adducts and medially rotates greater tubercle humerus Action: Lateral rotation of humerus Innervation: Lower subscapular n. Innervation: Suprascapular n. Blood Supply: Circumflex scapular a. Blood Supply: Suprascapular a. * Part of rotator cuff muscles  Donor Images Scapulae Levator Infraspinatus Rhomboids  Anterior Musculature Pectoralis Major Pectoralis Minor Attachments: Sternal half of Attachments: Ribs 3-5 to clavicle, sternum to the lateral coracoid process of scapula lip of intertubercular sulcus of Action: Lowers lateral angle of humerus scapula and protracts scapula Action: Flexes, adducts, and Innervation: Medial pectoral medially rotates humerus nerve Innervation: Medial and lateral Blood Supply: Pectoral branch pectoral nn. of thoracoacromial artery Blood Supply: Pectoral branch of thoracoacromial artery  Donor Images Lateral pectoral nerve **You will see medial Pectoralis Pectoralis Major pectoral nerve pierce Medial pectoral Minor pectoralis minor and continue nerve to pectoralis major. Whereas, the lateral pectoral nerve will only go to pectoralis major**  Anterior Musculature Serratus Anterior Subscapularis Attachments: Lateral Attachments: subscapularis surfaces of ribs 8-9 to costal fossa to lesser tubercle of surface of medial border of humerus scapula Action: Medial rotation of Action: protracts & rotates humerus scapula and holds it against Innervation: upper and thoracic wall lower subscapular nerves Innervation: Long thoracic Blood Supply: subscapular nerve Anterior artery Blood Supply: Lateral Lateral thoracic artery  Donor Image With arm in abducted Subscapularis position, you can view both serratus anterior and subscapularis Serratus Anterior  Injury to Long Thoracic n. Paralysis if the serratus anterior muscle due to damage to the long thoracic nerve Radical mastectomy, first rib resection, trauma to the lateral ribs, sports that can stretch the nerve Due to the nerve’s superficial location on the muscle Presentation The medial border of the scapula moves laterally and posteriorly away from the thoracic wall “winged scapula” Treatment = physical therapy  Rotator Cuff Anterior SITS Posterior Supraspinatus Infraspinatus Teres minor Subscapularis What is it? A musculotendinous cuff Muscle Function around the glenohumeral joint All but supraspinatus Blends with and reinforces the rotate the humerus fibrous layer of glenohumeral Supraspinatus initiates joint capsule Tonic contraction of the SITS first 15 degrees of muscles provides stability and Superior abduction protection of the joint  Rotator Cuff Tear Tear in one or multiple of the SITS tendons Supraspinatus is most common Repetitive use of the upper limb above the head Supraspinatus tendon tear presentation: When a patient is asked to lower the arm from 90 degrees abduction slowly, the limb will suddenly drop to the side in an uncontrolled manner Treatment: depends on severity RICE and physical therapy to strengthen surrounding muscles in less severe cases Surgery and physical therapy in more severe cases Vasculature and Lymphatics  Arteries Subclavian artery: Thyrocervical trunk Subclavian artery Axillary artery: 1st Part 1 2 Between the lateral border of 1st rib and the medial border of the pectoralis minor 3 1 branch = Superior thoracic artery 2nd Part Lies posterior to pectoralis minor 2 branches = thoracoacromial and lateral thoracic arteries 3rd Part Extends from the lateral border of pectoralis minor to the inferior border of teres major 3 branches = subscapular artery, anterior circumflex humeral artery, and posterior circumflex humeral artery.  1st Part Artery Branches AC Superior Thoracic artery (1) TC IT 2nd Part 5 Thoracoacromial artery S Clavicular a. (C) Acromial a. (A) C 1 Subclavian Artery A 2 Deltoid a. (D) Pectoral a. (P) ACH D Thyrocervical trunk (5) P Lateral thoracic artery (3) Transverse cervical 3 artery (TC) 4 3rd Part Suprascapular artery (S) PCH Ascending Cervical Subscapular artery (4) CS Artery (AC) Circumflex Scapular (CS) Inferior Thyroid a. (IT) Thoracodorsal a. (T) Anterior circumflex humeral T a. (ACH) Posterior circumflex humeral a. (PCH)  Scapular Anastomosis Suprascapular artery Infraspinatus branch of suprascapular a. Dorsal scapular a. Posterior circumflex humeral a. Circumflex scapular a. Lateral Head Triceps Brachii Long head  Spaces Suprascapular Notch Suprascapular artery and nerve Quadrangular Space “Army over, Navy under” Suprascapular artery goes Axillary nerve over transverse scapular Posterior circumflex lig. humeral artery Suprascapular nerve goes under transverse scapular lig. Triangular Interval Radial Nerve Triangular Space Deep artery of the arm Circumflex scapular a.  Veins mimic the arteries. There are two Veins superficial veins that are important to address Deltopectoral Groove Cephalic Vein Cephalic Vein Deltoid Drains radial side of arm, forearm, and hand Empties into axillary vein Basilic Vein Drains ulnar side of arm, forearm, and hand Drains into axillary v. Median Cubital Vein  Anatomy of the Breast Mammary glands – modified sweat glands that Cooper Ligaments consist of series of ducts and secretory lobules (15-20) Lobules – consists of many alveoli drained by lactiferous ducts Lobules Lactiferous ducts – converge at the nipple like Lactiferous ducts spokes on a wheel Areola – pigmented area of skin that Areola surrounds the nipple Fatty Tissue – creates the shape of the breast Connective tissue stroma - Suspensory ligaments of Cooper, attach & secure breast to dermis Nipple Separate secretory lobules of breast Fatty Tissue **Regardless of sex, the breast anatomy is similar. Males typically have less fatty tissue, undeveloped ducts, and few or absent lobules.**  Blood Vessels of Breast Arterial Supply Venous Drainage Internal thoracic a. Internal thoracic v. Medial mammary branches Medial mammary veins Lateral Thoracic a. Lateral thoracic v. Lateral mammary branches Lateral mammary veins  Breast Quadrants The breast is divided into 4 quadrants - aides in anatomical location and description of tumors and cysts Supero-lateral – 60% of cancer cases occur here Supero-medial – 15% of cancer cases occur here Infero-lateral – 10% of cancer cases occur here Infero-medial – 5% of cancer cases occur here “A hard irregular mass was felt in the superior medial quadrant of the breast at the 2 o’clock position, approximately 2.5cm from the margin of the areola”  Breast Lymphatics Lymph passes from the nipple, areola, and lobules of mammary glands to the subareolar lymphatic plexus Lymph from this plexus then drains as follows: Most lymph, 75%, from lateral breast quadrants, drains into the axillary lymph nodes Parasternal nodes Most of the remaining lymph, from medial breast quadrants drains into the parasternal lymph nodes Lymph from inferior quadrants may drain into abdominal lymph nodes  Breast Cancer Carcinomas of the breast are malignant tumors, usually adenocarcinomas arising from epithelial cells lactiferous ducts The cancer cells can spread through the lymphatics around the breast Can cause lymphedema if cancer blocks drainage of lymph Skin dimpling Edema of skin (orange peel sign) Patient presentation: Changes in the appearance of the nipple as a result of blocked lymphatic drainage Mastectomy, radiation therapy, Nipple Retraction & deviation Abnormal contours chemotherapy Quiz Time!  2 5 1 Teres major 6 m. 4 3  6 7 10 8 11  12 13 15 14 15 16 17 18 19 20 21 24 23 22  Email with any questions. Happy studying! [email protected]