Netter Concise Orthopaedic Anatomy 2nd Edition

3 Shoulder • PHYSICAL EXAM Acromion prominent Both shoulders must be undressed to Shoulder flattened examine the shoulder. Humeral head prominent AC joint Supraspinalus Arm in slight abduction Bicipital groove Elbow flexed Forearm internally Clinical appearance: rotated, supported glenohumeral dislocation by other hand Rupture of tendon of long head of right biceps brachii muscle indicated by active flexion of elbow Rupture of biceps brachii muscle Careful palpation helps isolate the location of the patient’s pain. EXAM/OBSERVATION TECHNIQUE CLINICAL APPLICATION INSPECTION Both shoulders must be undressed for proper inspection and examination of the shoulder. Symmetry Compare both sides Acromioclavicular separation, dislocation, muscle atrophy Wasting Loss of contour/muscle mass RC tear, nerve compression (e.g., suprascapular) Gross deformity Superior displacement Acromioclavicular injury (separation) Gross deformity Anterior displacement Anterior dislocation (glenohumeral joint) Gross deformity “Popeye” arm Biceps tendon rupture (usually proximal end of long head) PALPATION AC joint Feel for end of clavicle Pain indicates acromioclavicular pathology, instability of distal clavicle, AC separation Supraspinatus tendon Feel acromion, down to acromio- Pain indicates bursitis and/or supraspinatus tendon humeral sulcus (rotator cuff) tear Greater tuberosity Prominence on lateral humeral head Pain indicates rotator cuff tendinitis, tear, or fx Biceps tendon/bicipital Feel tendon in groove on humerus Pain indicates biceps tendinitis groove 90 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

PHYSICAL EXAM • Shoulder 3 Flexion and 180˚–160˚ Slight external rotation 180˚ Abduction extension and abduction required to reach maximal elevation 90˚ 60˚ Flexion Extension (elevation) 0˚ Abduction 0˚ EXAM/OBSERVATION TECHNIQUE CLINICAL APPLICATION RANGE OF MOTION Forward flexion Arms from sides forward 0-160°/180° normal Extension Arms from sides backward 0-60° normal Abduction Arms from sides outward 0-160°/180 normal Internal rotation Reach thumb up back, note level Mid thoracic (T7) normal, compare sides External rotation 1. Elbow at side, rotate forearms laterally 30-60° normal 2. Abduct arm to 90°, externally rotate up ER decreased in adhesive capsulitis • Rotator cuff tear: AROM decreased, PROM ok. Adhesive capsulitis: AROM and PROM are both decreased. • Increased ER may indicate a subscapularis tear NETTER’S CONCISE ORTHOPAEDIC ANATOMY 91

3 Shoulder • PHYSICAL EXAM May be tested with 60˚ arm held at side or Internal rotation abducted to 90˚ C7 90˚ T7 Arm held at side External rotation 0˚ Maximal internal S1 Arm abducted 90˚ from side rotation is highest midline spinous process reached by extended thumb (T7 in young adults) EXAM/OBSERVATION TECHNIQUE CLINICAL APPLICATION Supraclavicular nerve (C4) NEUROVASCULAR Axillary nerve (C5) T2 segmental nerve Sensory Spinal accessory (CN11) Superior shoulder/clavicular Deficit indicates corresponding nerve/root lesion Suprascapular (C5-6) area Axillary (C5) Dorsal scapular nerve (C5) Lateral shoulder Deficit indicates corresponding nerve/root lesion Thoracodorsal nerve (C7-8) Lateral pectoral nerve (C5-7) Axilla Deficit indicates corresponding nerve/root lesion U/L subscapular nerve (C5-6) Long thoracic nerve (C5-7) Motor Resisted shoulder shrug Weakness ϭ Trapezius or corresponding nerve lesion Resisted abduction Weakness ϭ Supraspinatus or nerve/root lesion Resisted external rotation Weakness ϭ Infraspinatus or nerve/root lesion Resisted abduction Weakness ϭ Deltoid or corresponding nerve/root lesion Resisted external rotation Weakness ϭ Teres minor or nerve/root lesion Shoulder shrug Weakness ϭ Levator scapulae/rhomboid or corre- sponding nerve/root lesion Resisted adduction Weakness ϭ Latissimus dorsi or nerve/root lesion Resisted adduction Weakness ϭ Pect. major or nerve/root lesion Resisted internal rotation Weakness ϭ Subscapularis or nerve/root lesion Scapular protraction/reach Weakness ϭ Serratus anterior or nerve/root lesion 92 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

PHYSICAL EXAM • Shoulder 3 Winging Normal of scapula Test for rotator cuff tear is resisted flexion in the scapular plane. Adson’s test EXAM TECHNIQUE CLINICAL APPLICATION/DDX SPECIAL TESTS Impingement/Rotator Cuff Impingement sign Forward flexion Ͼ90° Pain indicates impingement syndrome Hawkins test FF 90°, then IR Pain indicates impingement syndrome Supraspinatus/ Pronate arm, resisted FF in Pain or weakness indicates rotator cuff (supraspinatus) tear Jobe empty can scapular plane (partial or full thickness) Drop arm FF Ͼ90°, try to maintain it Inability to hold flexion (arm drops) indicates supraspinatus tear ER lag sign ER shoulder, patient holds it Inability to maintain ER indicates infraspinatus tear Horn blower’s Resisted ER in slight abduction Weakness indicates rotator cuff tear involving infraspinatus Lift off Hand behind back, push backward Weakness indicates subscapularis tear Lift off lag sign Lift hand off back, patient holds it Inability to hold hand off of low back indicates subscapularis tear Belly press Hand on belly, push toward belly Weakness indicates subscapularis tear Biceps/Superior Labrum Active compres- FF 90°, adduct 10°, resisted flex- Pain with resisted flexion, greater in pronation indicates SLAP sion (O’Brien’s) ion; in pronation, then supination tear; may also suggest AC joint pathology Crank Abduct 90°, axial load, rotate Pain indicates a SLAP tear Speed’s test Resisted flexion in scapular plane Pain indicates biceps lesion or tendinitis Yergason’s test Elbow 90°, resisted supination Pain indicates biceps tendinitis Instability Apprehension test Abduct, externally rotate Pain or apprehension of indicates anterior instability Relocation Abduct, ER, posterior force to arm Relief of pain/apprehension indicates anterior instability Load & shift Axial load, ant/post translation Increased translation indicates anterior OR posterior instability Jerk test Supine, adduct, FF 90°, push Pain/apprehension/translation indicates posterior instability posterior Sulcus Pull down on adducted arm Sulcus under lateral acromion indicates inferior instability Other X-body adduction Adduct arm across body Pain at AC joint indicates AC joint pathology (e.g., arthrosis) Scapular winging Push against a wall Winging of scapula indicates nerve palsy or muscle weakness Adson’s test Palpate pulse, rotate neck Numbness or tingling suggestive of thoracic outlet syndrome Wright’s test Extend arm, rotate neck away Numbness or tingling suggestive of thoracic outlet syndrome Spurling’s test Lateral flex/axially compress neck Reproduction of symptoms indicates cervical neck pathology NETTER’S CONCISE ORTHOPAEDIC ANATOMY 93

3 Shoulder • MUSCLES: ORIGINS AND INSERTIONS Deltoid muscle Inferior surface Pectoralis major muscle Costoclavicular ligament Anterior Coracoclavicular Trapezoid Posterior Sternohyoid muscle ligaments ligament Subclavius muscle Conoid ligament Trapezius muscle Superior surface Muscle origins Muscle insertions Posterior Ligament attachments Supraspinatus muscle Deltoid muscle Anterior Sternocleidomastoid Trapezius muscle Levator scapulae muscle Deltoid muscle Pectoralis major muscle muscle Supraspinatus muscle Infraspinatus muscle Rhomboid Teres minor muscle minor muscle Triceps brachii muscle Pectoralis minor (lateral head) Rhomboid major Deltoid muscle Trapezius muscle muscle Omohyoid muscle Triceps Deltoid muscle muscle Infraspinatus brachii muscle muscle Biceps brachii muscle (long head) (long head) Latissimus dorsi muscle (small Teres minor Supraspinatus muscle slip of origin) muscle Subscapularis muscle Teres major muscle Coracobrachialis muscle Triceps and brachii Posterior view Biceps brachii muscle muscle (short head) (long head) Muscle attachments Bicipital groove Subscapularis Origins Pectoralis major muscle muscle Insertions Latissimus dorsi muscle Serratus anterior muscle Teres major muscle Anterior view Deltoid muscle CORACOID GREATER PROXIMAL SCAPULA SCAPULA PROCESS TUBEROSITY HUMERUS (ANTERIOR) (POSTERIOR) ORIGINS Biceps (SH) Subscapularis Supraspinatus Coracobrachialis Triceps brachii Infraspinatus Omohyoid Deltoid (spine/acromion) Teres major & minor Latissimus dorsi INSERTIONS Pectoralis minor Supraspinatus Pectoralis major Serratus anterior Trapezius (spine/acromion) Infraspinatus Latissimus dorsi Levator scapulae Teres minor Teres major Rhomboid major & minor • The scapula has 17 muscles that either originate or insert on it. • Mnemonic for proximal humerus insertions (from lateral to medial): “PLT sandwich” (Pect., Lat., Teres major) 94 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

MUSCLES: PERISCAPULAR • Shoulder 3 Semispinalis capitis muscle Not connected Posterior view Splenius capitis muscle to upper limb Trapezius muscle Spinous process of C7 vertebra Deltoid Levator scapulae muscle muscle Rhomboid minor muscle Infraspinatus fascia Rhomboid major muscle Acromion Supraspinatus muscle Spine of scapula Infraspinatus muscle Teres minor muscle Teres major muscle Latissimus dorsi muscle Long head Triceps Lateral head brachii muscle Spinous process of T12 vertebra Triangle of auscultation Acromion Coracoacromial ligament Supraspinatus tendon Coracoid process Suprascapular artery and nerve Anterior view Greater tubercle of humerus Superior transverse scapular Subscapularis tendon ligament and suprascapular Lesser tubercle of humerus notch Intertubercular tendon sheath Pectoralis minor tendon (cut) Anterior circumflex humeral artery Biceps brachii tendon (short head) (cut) and Biceps brachii tendon coracobrachialis tendon (long head) (cut) (cut) Subscapularis muscle Axillary nerve and Subscapular artery posterior circumflex humeral artery Lower subscapular nerve (to teres major muscle) Quadrangular space Circumflex scapular artery Radial nerve Thoracodorsal artery and Biceps Long head nerve (to latissimus dorsi brachii muscle) muscle Short head Subscapularis muscle Coracobrachialis muscle Teres major muscle Triangular space Latissimus dorsi muscle MUSCLE ORIGIN INSERTION NERVE ACTION COMMENT Cranial nerve XI Elevate & rotate Weakness results in Trapezius C7-T12 spinous Clavicle, acromion process spine of scapula Thoracodorsal scapula lateral winging Latissimus Adduct, extend Used for large free dorsi T7-T12, iliac Humerus (intertu- Dorsal scapular, arm, IR humerus flap crest bercular groove) C3-4 Elevate scapula Connects UE to spine Levator Dorsal scapular scapulae C1-C4 transverse Superior medial Adduct scapula Connects UE to spine process scapula Dorsal scapular Rhomboid Adduct scapula Connects UE to spine minor C7-T1 spinous Medial scapula (at process the spine) Rhomboid major T2-T5 spinous Medial scapula process NETTER’S CONCISE ORTHOPAEDIC ANATOMY 95

3 Shoulder • MUSCLES: ROTATOR CUFF Suprascapular artery and nerve Posterior view Acromion Superior transverse scapular Spinoglenoid notch ligament and suprascapular notch Infraspinatus tendon (reflected) Supraspinatus muscle (cut) Joint capsule of shoulder Spine of scapula Deltoid muscle (reflected) Infraspinatus muscle (cut) Teres minor muscle Triangular space with circumflex scapular artery Quadrangular space deep to space transmitting axillary nerve and posterior Teres major muscle circumflex humeral artery Superior lateral cutaneous nerve of arm Deep artery of arm and Radial nerve shown between Lateral head and Long head of triceps brachii muscle SPACE/INTERVAL BORDERS STRUCTURES Triangular space Circumflex scapular artery Quadrangular space Teres minor Teres major Axillary nerve Triangular interval Triceps (long head) Posterior circumflex artery Humeral artery Teres minor Teres major Radial nerve Triceps (long head) Deep artery of arm Humerus (medial border) Teres major Triceps (long head) Triceps (lateral head) MUSCLE ORIGIN INSERTION NERVE ACTION COMMENT Supraspinatus Infraspinatus Supraspinatus ROTATOR CUFF Abduct FF arm Trapped in impinge- Teres minor fossa (scapula) stability ment, #1 torn ro- Subscapularis Greater tuber- Suprascapular ER arm, stability tator cuff tendon Infraspinatus fossa osity (superior) Weak ER: cuff tear Deltoid (scapula) ER arm, stability or ss nerve lesion Teres major Greater tuber- Suprascapular IR, adduct arm, in notch Lateral scapula osity (middle) stability Rarely torn rotator cuff tendon Subscapular fossa Greater tuber- Axillary Abduct arm At risk from anterior (scapula) osity (inferior) IR, adduct arm approach Clavicle, acromion Lesser Upper and lower Atrophy: axillary spine of scapula tuberosity subscapular nerve damage Inferior angle of Protects radial the scapula OTHER nerve in posterior approach Humerus (del- Axillary toid tuberosity) Humerus (inter- Low subscapular tubercular groove) 96 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

Oblique parasagittal section of axilla MUSCLES: DELTOPECTORAL • Shoulder 3 Trapezius muscle Omohyoid muscle Clavicle Lateral cord Subclavius muscle and fascia Brachial plexus Posterior cord Costocoracoid ligament Thoracoacromial artery and cephalic vein Medial cord Costocoracoid membrane Lateral pectoral nerve Supraspinatus muscle Axillary artery and vein Pectoralis major muscle and fascia Scapula Spine Pectoralis minor muscle and fascia Body Medial pectoral nerve Suspensory ligament of axilla Infraspinatus muscle Axillary fascia (fenestrated) Subscapularis muscle Teres minor muscle Teres major muscle Latissimus dorsi muscle Central Axillary lymph nodes Pectoral (anterior) Anterior view Trapezius muscle Acromion Omohyoid muscle and Deltopectoral triangle investing layer of deep cervical fascia Deltoid muscle Deltoid branch of Sternocleidomastoid thoracoacromial artery muscle Cephalic vein Clavicle Biceps Long head brachii Clavicular Pectoralis muscle Short head head major Triceps brachii muscle Sternocostal muscle (lateral head) head Latissimus dorsi muscle Abdominal part Serratus anterior muscle External oblique muscle Sternum 6th costal cartilage Anterior layer of rectus sheath MUSCLE ORIGIN INSERTION NERVE ACTION COMMENT Deltoid Clavicle, acromion Axillary Pectoralis major Humerus (deltoid Abducts arm Atrophy: axillary Pectoralis minor spine of scapula tuberosity) Lateral pectoral nerve damage Serratus anterior 1. Clavicle Medial pectoral Adducts arm, Subclavius 2. Sternal Humerus (intertu- Medial pectoral IR humerus Can rupture during Ribs 3-5 bercular groove) weight lifting Long thoracic Stabilizes Ribs 1-8 (lateral) Coracoid process scapula Divides axillary ar- (scapula) Nerve to sub- tery into 3 parts Rib 1 (and costal clavius Holds scapula cartilage) Scapula (antero- to chest wall Paralysis results in medial border) medial winging Depresses Clavicle (inferior clavicle Cushions subcla- border/mid 3rd) vian vessels NETTER’S CONCISE ORTHOPAEDIC ANATOMY 97

3 Shoulder • NERVES Note: Usual composition shown. 3 trunks point) (vsepn5itnrraaollonrtaesmrvieos)f Contribution from C4 Prefixed plexus has large C4 (Erb’s Dorsal scapular Dorsal ramus contribution but lacks T1. nerve (C5) Postfixed plexus lacks C5 but 33apnotestreiorirodridviisviiosinosns Suprascapular To phrenic C5 has T2 contribution nerve (C5, 6) nerve C6 To subclavius muscle (C5, 6) 3 cords Superior C7 Tebrmrainncahl es Lateral pectoral Middle C8 nerve (C5, 6, 7) Inferior Musculocutaneous T1 nerve (C5, 6, 7) Lateral 1st rib Posterior Contribution from T2 To longus colli and scalene muscles (C5, Axillary nerve (C5, 6) Medial 6, 7, 8) Radial nerve (C5, 6, 7, 8, T1) 1st intercostal nerve Median nerve (C5, 6, 7, 8, T1) Medial pectoral nerve (C8, T1) Long thoracic nerve Medial cutaneous nerve of arm (T1) (C5, 6, 7) Medial cutaneous nerve of forearm (C8, T1) Ulnar nerve (C7, 8, T1) CRANIAL NERVES Lower subscapular nerve (C5, 6) Spinal Accessory (CN 11): Runs on levator scapulae Thoracodorsal (middle subscapular) nerve (C6, 7, 8) Sensory: None Motor: Trapezius Upper subscapular nerve (C5, 6) Sternocleidomastoid Inconstant contribution CERVICAL PLEXUS Anterior (palmar) view Supraclavicular (C2-3): 3 parts: anterior, middle, posterior Sensory: Over trapezius, clavicle, deltoid (superior shoulder) Motor: None BRACHIAL PLEXUS Supraclavicular nerves Roots (from cervical plexus — C3, 4) Dorsal Scapular (C3-5): Pierces middle scalene, is deep to levator scapulae. Axillary nerve Superior lateral Sensory: None cutaneous nerve Motor: Levator scapulae of arm (C5, 6) Rhomboid major & minor Radial nerve Inferior lateral Long Thoracic (C5-7): Runs on anterior surface of serratus cutaneous nerve anterior with the lateral thoracic artery. of arm (C5, 6) Sensory: None Intercostobrachial Motor: Serratus anterior nerve (T2) and medial cutaneous nerve of Upper Trunk arm (C8, T1, 2) Suprascapular (C5-6): Under the ligament in suprascapular notch, innervates supraspinatus, then through the spinogle- noid notch (where it can be compressed) to infraspinatus fossa (innervates infraspinatus) Sensory: Shoulder joint capsule Motor: Supraspinatus Infraspinatus Nerve to Subclavius (C5-6): Descends posterior to clavicle Sensory: None Motor: Subclavius 98 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

NERVES • Shoulder 3 Dorsal scapular Supraspinatus Suprascapular nerve (C5, 6) nerve (C5) muscle Deltoid muscle Levator scapulae muscle Teres minor muscle Rhomboid Axillary nerve (C5, 6) minor (in quadrangular space) muscle Superior lateral cutaneous nerve of arm Rhomboid Radial nerve major (C5, 6, 7, 8, T1) muscle (in triangular space) Infraspinatus Inconstant contribution muscle Teres major muscle Lower subscapular nerve (C5, 6) BRACHIAL PLEXUS Lateral Cord Lateral Pectoral (C5-7): Named for the cord, runs medial to the medial pectoral nerve with the pectoral artery. Sensory: None Motor: Pectoralis major (clavicular portion) Pectoralis minor (via a branch to the medial pectoral n.) Lateral root to median nerve Medial Cord Posterior (dorsal) view Medial Pectoral (C5-7): Named for cord, is lateral to the lateral Supraclavicular nerves pectoral nerve (from cervical plexus — C3, 4) Sensory: None Motor: Pectoralis minor Pectoralis major (sternal portion) Medial root to median nerve Posterior Cord Axillary nerve Superior lateral Upper Subscapular (C5-6) cutaneous nerve of arm (C5, 6) Sensory: None Motor: Upper subscapularis Intercostobrachial Radial nerve nerve (T2) and medial Thoracodorsal (C7-8): Runs with thoracodorsal artery deep to la- cutaneous nerve of Posterior cutaneous tissimus dorsi muscle arm (C8, T1, 2) nerve of arm (C5, 6, 7, 8) Inferior lateral cutaneous Sensory: None nerve of arm Motor: Latissimus dorsi Posterior cutaneous nerve of forearm Lower Subscapular (C5-6) (C[5], 6, 7, 8) Sensory: None Motor: Lower subscapularis Teres major Axillary (C5-6): Directly inferior to joint capsule, it travels posteri- orly with post. circumflex humeral art. thru quadrangular space, then bends anteriorly approx. 5cm distal to acromion. It can be in- jured in glenohumeral dislocations and lateral approaches. Sensory: Lateral proximal arm: via superior lateral cutaneous n. Motor: Deltoid: via deep branch Teres minor: via superficial branch NETTER’S CONCISE ORTHOPAEDIC ANATOMY 99

3 Shoulder • NEUROVASCULAR STRUCTURES Pectoralis minor tendon (cut) Thoracoacromial artery Trapezius Suprascapular artery and nerve Coracoid process Acromial branch Acromion Deltoid branch muscle Dorsal scapular artery and nerve Cephalic vein Clavicular branch Transverse cervical artery Musculocutaneous nerve Pectoral branch Anterior scalene Anterior circumflex humeral artery muscle Axillary nerve and posterior Axillary artery circumflex humeral artery Sternocleidomastoid Clavicle and muscle Pectoralis major muscle (cut) subclavius muscle Phrenic Coracobrachialis muscle (cut) nerve Deltoid muscle Omohyoid muscle Biceps brachii muscle Musculocuta- neous nerve Brachialis muscle Ulnar nerve Deep Medial cutaneous artery nerve of arm of arm Intercostobrachial Radial nerve nerve Triceps Circumflex brachii scapular artery muscle Lower sub- Brachial veins scapular nerve Ulnar nerve Teres major muscle Median nerve Subscapular artery Subclavian artery and vein Brachial artery Latissimus dorsi muscle 1st rib Medial cutaneous nerve Thoracodorsal artery and nerve Brachial plexus of the forearm Upper subscapular nerve Superior thoracic artery Basilic vein Serratus anterior muscle Lateral pectoral nerve Lateral thoracic artery and long thoracic nerve Medial pectoral nerve Pectoralis minor muscle (cut) BRACHIAL PLEXUS • Brachial (“arm”) plexus (“network”) is a complex of intertwined nerves that innervate the shoulder and upper extremity. • It is derived from the ventral rami from C5-T1 (variations: C4 [prefixed], T2 [post-fixed]). • Subdivisions: rami (roots), trunks, divisions, cords, branches (mnemonic: Rob Taylor Drinks Cold Beer) • Rami exit between the anterior and medial scalene muscles & travel with the subclavian artery in the axillary sheath. • The rami and trunks are supraclavicular. There are 2 nerves from the rami, and 2 nerves from the trunks (upper) • The divisions are under (posterior to) the clavicle. Anterior divisions innervate flexors. Posteriors innervate extensors. • The cords and branches are infraclavicular. The cords are named for their relationship with the axillary artery. • Terminal branches of the cords are peripheral nerves to the shoulder region and upper extremity. • Injury to the plexus can be partial or complete. Injuries affect all nerves distal to the injury (e.g., Erb’s palsy: C5-6). 100 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

Anterior view ARTERIES • Shoulder 3 Transverse cervical artery Suprascapular artery Ascending cervical artery Inferior thyroid artery Dorsal scapular artery Thyrocervical trunk Subclavian artery Anterior circumflex 1 humeral artery 2 Anterior scalene muscle Superior thoracic artery Ascending branch 3 Thoracoacromial artery Posterior circumflex Clavicular branch humeral artery Acromial branch Deltoid branch Subscapular artery Pectoral branch Circumflex scapular artery 1, 2, 3 indicate 1st, 2nd and 3rd parts of axillary artery Brachial artery Thoracodorsal artery Suprascapular artery Lateral thoracic artery Acromial branch of thoracoacromial artery Dorsal scapular artery Infraspinous branch of Supraspinatus muscle (cut) suprascapular artery Superior transverse scapular ligament Posterior circumflex humeral and suprascapular notch artery (in quadrangular space) and ascending and descending Infraspinatus muscle (cut) branches Teres minor muscle (cut) Circumflex scapular artery Posterior view COURSE BRANCHES COMMENT/SUPPLY SUBCLAVIAN ARTERY Branches off aorta (L) Thyrocervical trunk 3 other branches into the neck or brachiocephalic Suprascapular artery Runs over the transverse scapular ligament to rotator trunk (R), b/w anterior cuff muscles & middle scalene Infraspinatus branch Runs around spinoglenoid notch with suprascapular n. muscles with the bra- Dorsal scapular Divides around the levator scapulae muscle chial plexus AXILLARY ARTERY Continuation of subcla- I. Superior thoracic To serratus anterior and pectoralis muscles vian after the 1st rib. II. Thoracoacromial Has 4 branches Runs through the ax- Can be injured in clavicle fractures or surgery illa into the arm, be- Clavicular branch With CA ligament, at risk in subacromial decompression coming the brachial Acromial branch With cephalic vein, at risk in deltopectoral approach artery at the lower Deltoid branch Runs with lateral pectoral nerve border of the teres Pectoral branch Runs with long thoracic nerve to serratus anterior major muscle Lateral thoracic Has 2 main branches III. Subscapular Seen posteriorly in triangular space Circumflex scapular Runs w/thoracodorsal nerve. Used for free flap Thoracodorsal Primary supply of humeral head (via ascending br.) Anterior circumflex humeral Injury (e.g., anatomic neck fx) leads to osteonecrosis Ascending branch Supplies most of humeral head, also tuberosities Seen in quadrangular space with axillary nerve Arcuate artery Posterior circumflex humeral The axillary artery is divided into 3 parts by the borders of the pectoralis minor muscle (1st prox., 2nd behind, 3rd distal). The first part (I) has 1 branch, 2nd part (II) has 2 branches, 3rd part (III) has 3 branches. NETTER’S CONCISE ORTHOPAEDIC ANATOMY 101

3 Shoulder • DISORDERS Adhesions of peripheral Adhesive capsulitis capsule to distal articular cartilage Adhesions obliterating axillary fold of capsule Coronal section of shoulder shows adhesions between Anteroposterior arthrogram of normal shoulder (left). Axillary fold capsule and periphery of humeral head and biceps brachii sheath visualized. Volume of capsule normal. Anteroposterior arthrogram of frozen shoulder (right). Joint capacity reduced. Axillary fold and biceps brachii sheath not evident. AP radiograph of shoulder demonstrates typical changes of osteoarthritis of the shoulder with narrowing of the joints and prominent osteophyte formation at the inferior aspect of the humeral head. Glenohumeral arthritis DESCRIPTION Hx & PE WORKUP TREATMENT ADHESIVE CAPSULITIS (“FROZEN SHOULDER”) • Physical therapy (gentle active and passive ROM) • Synovial inflammation Hx: Pain, stiffness, ϩ/Ϫ XR: Shoulder series: and pain management leads to capsular fibrosis PMHx (DM, thyroid dz), usually normal (6ϩ months) (thickening) & loss of joint trauma, immobilization Arthrogram: shows space (esp. pouch) PE: Decreased active decreased capsular • Arthroscopic lysis of adhe- AND passive ROM volume sions in refractory cases • Three stages: pain, stiff- ness, resolving/”thawing” • Rest, activity modification • Corticosteroid injection ACROMIOCLAVICULAR ARTHROSIS • Open vs arthroscopic • Degeneration of the AC joint Hx: Pain, ϩ/Ϫ grinding XR: AC narrowing/spurs distal clavicle resection • Associated with previous PE: ACJ TTP, crossbody MR: Often not needed; (Mumford) adduction pain, ϩ/Ϫ will show edema & trauma, overuse, rotator subtle instability (on degeneration • NSAIDs, physical therapy cuff disease palpation) • Corticosteroid injections • Osteolysis in weight-lifters • Hemi vs total shoulder ar- ARTHRITIS (GLENOHUMERAL) throplasty • Osteoarthritis #1, also RA Hx: Usually elderly, pain, XR: Joint narrowing, • Physical therapy • Can be posttraumatic stiffness, ϩ/Ϫ old osteophytes • Corticosteroid injection trauma MR: For rotator cuff • Tenodesis vs tenotomy (e.g., fx), 2° to RC tear, or PE: Decreased ROM, evaluation if indicated 2° to surgery (e.g., Puddi- ϩ/Ϫ wasting, crepitus • Physical therapy. Patient Platt) often has residual weak- ness in supination BICEPS TENDINITIS • Consider tenodesis (esp. • Assoc. w/impingement, Hx: Pain, ϩ/Ϫ snapping XR: Often normal in younger/active patients) RC tear (esp. subscapu- PE: Biceps TTP, ϩSpeed MR: Evaluate for tear laris), & tendon sublux- & Yergason tests ation (biceps pulley injury) BICEPS TENDON RUPTURE (PROXIMAL) • Usually in older population Hx: Pain & deformity XR: Usually normal • Often degenerative tear PE: “Popeye” arm defor- MR: Often not needed, • Associated with impinge- mity, weak supination but will show tear ment & RC tears 102 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

DISORDERS • Shoulder 3 Subdeltoid bursa Acromion External impingement Deltoid m. Supraspinatus tendon Capsule Scapula Subscapularis m. Abduction of arm causes repeated impingement of greater tubercle of humerus on acromion, leading to degeneration and inflammation of supraspinatus tendon, secondary inflammation of bursa, and pain on abduction of arm. Calcific deposit in degenerated tendon produces elevation that further aggravates inflammation and pain. Rotator cuff tear Humerus Communication between shoulder Biceps brachii joint and subdeltoid bursa is tendon pathognomonic of cuff tear Infraspinatus m. Supraspinatus m. Acute rupture (superior view). Often associated with splitting tear parallel to tendon fibers. Biceps Torn rotator tendon cuff Humerus Retracted tear, commonly found at surgery DESCRIPTION Hx & PE WORK-UP TREATMENT • Rotator cuff & bursa EXTERNAL (OUTLET) IMPINGEMENT • NSAIDs, activity modification trapped b/w acromion • Physical therapy (rotator cuff & greater tuberosity Hx: Pain w/ overhead ac- XR: Outlet view: look for tivities, lifting, etc. hooked (type 2, 3) strengthening) • Spectrum of disease PE: ϩNeer sign/test, acromion or spur • Subacromial steroid injection from bursitis to tendi- ϩHawkins test. MR: Best study to evalu- • Subacromial decompression nopathy to partial- to RC: strong ϩ/Ϫ painful ate for possible RC tear full-thickness RC tear • Activity modification, NSAIDs ROTATOR CUFF TEAR • PT: ROM, RC strengthening, • Chronic: associated w/impingement (usu. Hx: Pain overhead & at XR: May show Caϩϩ of scapular stabilization on bursal side) tendon, spurs, or hu- • Operative night, ϩ/Ϫ weakness meral head elevation • Acute: in throwers MR: Excellent for cuff tear ‫ ؠ‬Partial tear: SA decompres- (articular side) or after PE: Pain ϩ/Ϫ weakness: imaging; contrast shows sion and cuff debridement dislocation (Ͼ 40y.o.) ‫ ؠ‬SS: FF, ϩ empty can communication b/w joint vs repair ‫ ؠ‬IS: ER, ϩ hornblower’s & subacromial space • Supraspinatus #1 ‫ ؠ‬Subscap: IR, ϩ lift off, ‫ ؠ‬Full tear: RC repair • Graded by size: Ͻ3cm, ϩ belly press, incr. ER 3-5cm, Ͼ5cm or # of tendons involved NETTER’S CONCISE ORTHOPAEDIC ANATOMY 103

3 Shoulder • DISORDERS Detached biceps Labrum Subscapularis tendon and labrum Glenoid tendon Tear Humerus Tear (anterior/ Subscapularis interior labrum) Humerus Glenoid tendon Middle and inferior Type II slap lesion glenohumeral ligament Bankart lesion DESCRIPTION Hx & PE WORK-UP TREATMENT • Result of a dislocation (Trauma) GLENOHUMERAL INSTABILITY • Physical therapy (rotator • Most often Unilateral cuff strengthening) & ROM • Labral tear (Bankart lesion) re- “TUBS” • Bankart (labral) repair with sults from the dislocation Hx: Dislocation, pain, & XR: West point view capsular imbrication (open • Surgery is most often indicated recurrent instability CT: For glenoid lesions or arthroscopically) PE: ϩ apprehension & MR Arthrogram: Sen- (due to 90% recurrence rate) relocation, ϩ load & • Extended physical therapy shift (one direction), ϩ sitive for labral tear; (rotator cuff strengthening) • Atraumatic (no dislocation) jerk (posterior lesion) may show increased • Multidirectional (ant, inf, post) capsular volume • Open inferior capsular shift • Bilateral (1 side often worse) vs arthroscopic capsular • Responds to Rehabilitation “AMBRI” (up to 270°) imbrication • Inferior capsular shift may help Hx: Pain (from in- XR: Often normal • Early repair indicated • Rare injury, usu. young patients creased joint mobility) MR: Often not needed • Late repair controversial • Most common in weight-lifters PE:ϩ load & shift (usu. in absence of • Nonoperative treatment • Maximal eccentric contraction both ant. & post.), ϩ trauma; labrum nor- sulcus sign mal in AMBRI yields adequate results • Medial: serratus anterior weak- ness 2° long thoracic nerve PECTORALIS MAJOR RUPTURE • Observation (1-2 years) palsy • Refractory cases: Hx: Acute pain XR: Look for avulsion • Lateral: trapezius weakness 2° PE: Axilla deformity, MR: Can evaluate for Medial: pect. major transfer spinal accessory (CN11) palsy accentuated with tendon retraction Lateral: levator scapulae adduction transfer • Tear of superior labrum (biceps anchor) from ant. to post. SCAPULAR WINGING • Rest, activity modification, physical therapy • Chronic (with RCT) or acute Hx: Weakness XR: Usually normal (load on outstretched arm) • Superior labral debride- PE: Winging of scapula EMG/NCS: Confirm ment, repair, or biceps te- • 7 types based on extent of tear nodesis based on type of observed from back nerve palsy lesion (I-VII) • Compression of neurovascular structure (artery, vein, brachial SUPERIOR LABRAL TEAR (SLAP LESION) • Activity modification plexus) in the neck by 1st rib & • PT & posture training scalene muscles Hx: Pain ϩ/Ϫ popping, XR: Usually normal • Rib (esp. cervical rib) or weakness, etc MR Arthrogram: Most • Also assoc. w/cervical ribs PE: ϩ O’Brien’s test, ϩ sensitive for labral transverse process resec- crank test, ϩ/Ϫ pain- tears tion rarely indicated ful arc of motion THORACIC OUTLET SYNDROME Hx: Vague sx: pain & XR: Shoulder: normal numbness/coolness C-spine: look for cer- PE: ϩ Adson’s test, ϩ vical rib Wright test, decr. CXR: r/o lung mass pulses EMG: Brachial plexus 104 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

PEDIATRIC DISORDERS • Shoulder 3 Sprengel’s Deformity J Radiograph shows omovertebral bone (arrows) connecting scapula to spinous processes of cervical vertebrae via osteochondral joint (J) Child with congenital elevation of left scapula. Note shortness of neck on that side and tendency to torticollis DESCRIPTION EVALUATION TREATMENT • Small (hypoplastic), undescended SPRENGEL’S DEFORMITY • Mild: observation scapula. Omovertebral bone connects • Symptomatic: omovertebral bone C-spine (spinous process) to scapula Hx: Parents notice abnormal neck/scapula resection, scapula distalization with • Associated with Klippel-Feil syndrome, PE: Neck appears short/full; often muscle transfer, ϩ/Ϫ clavicle scoliosis, kidney disease decreased ROM (esp. abduction) osteotomy to protect brachial plexus XR: Look for omovertebral bone NETTER’S CONCISE ORTHOPAEDIC ANATOMY 105

3 Shoulder • SURGICAL APPROACHES Deltopectoral Approach to Shoulder Joint Coracoid process Conjoined tendon Subscapularis (divided) Joint capsule (opened) Articular surface of humeral head Incision Deltoid site (retracted) Biceps brachii Deltoid (retracted) (longhead) Pectoralis major Biceps brachii (retracted) (shorthead) Humeral Ant. circumflex head humeral artery Biceps tendon Pectoral major (retracted) Cephalic vein Subscapularis tendon Anterior joint capsule Joint space Glenoid USES INTERNERVOUS PLANE DANGERS COMMENT ANTERIOR (DELTOPECTORAL) APPROACH • Open rotator cuff (esp. • Deltoid [axillary] • Musculocutaneous n. • Subscapularis must be subscapularis) or labral • Pectoralis major [lateral & (with vigorous retraction opened and repaired in repairs of conjoined tendon) approach medial pectoral nerves] • Arthroplasty (hemi vs • Cephalic vein • 3 vessels run along inf. total) • Axillary nerve border of subscap.; may need ligation • Proximal humerus fxs • Adduct/ER protects axillary n. COMPLICATIONS: Subscapularis rupture; neurapraxia (musculocutaneous or axillary nerve) 106 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

SURGICAL APPROACHES • Shoulder 3 Anterior superior portal Acromion (posterolateral corner) Anterior inferior portal Port of Wilmington Posterior portal Neviaser portal Port of Wilmington Anterior superior portal Lateral portal Anterior inferior portal PORTAL PLACEMENT DANGERS COMMENT Posterior ARTHROSCOPY PORTALS Primary viewing portal Anterior superior 2cm down, 1cm medial to Posterior capsule/labrum Often used for instruments Anterior inferior posterolateral corner of acro- Lateral mion (in “soft spot”) Enters just above subscap- Wilmington ularis tendon Neviaser (supraspinatus) Both anterior portals are b/w Coracoacromial ligament Visualize RC and acromion the AC joint & lateral coracoid and/or artery Useful in repairs of RC and labrum In the rotator interval Musculocutaneous nerve Anterior glenoid view 2cm distal to acromial edge Axillary nerve (5cm distal) Safe portal 1cm ant, 1cm distal to postero- lateral acromion corner Rotator cuff Posterior to AC joint in sulcus NETTER’S CONCISE ORTHOPAEDIC ANATOMY 107



Topographic Anatomy CHAPTER 4 Osteology Radiology Arm Trauma Joints 110 Other Structures 111 Minor Procedures 113 History 114 Physical Exam 119 Origins and Insertions 121 Muscles 122 Nerves 123 Arteries 124 Disorders 127 Pediatric Disorders 128 Surgical Approaches 131 133 134 136 137

4 Arm • TOPOGRAPHIC ANATOMY Anterior view Deltoid muscle Cephalic vein Biceps brachii muscle Pectoralis major Cubital fossa muscle Cephalic vein Posterior view Median cubital vein Median epicondyle Deltoid muscle Triceps brachii muscle (long head) Basilic vein Triceps brachii muscle Long head Lateral head Tendon Brachioradialis and extensor carpi radialis longus muscles Lateral epicondyle Radial head Olecranon of ulna STRUCTURE CLINICAL APPLICATION Triceps Can be palpated on the posterior aspect of the arm. A tendon avulsion/rupture can be palpated Biceps immediately proximal to the olecranon. Cubital fossa Can be palpated on the anterior aspect of the arm. Lateral epicondyle Biceps tendon can be palpated here. If ruptured, the tendon cannot be palpated. Medial epicondyle Site of common extensor origin. Tender in lateral epicondylitis (“tennis elbow”) Olecranon Site of common flexor origin. Tender in medial epicondylitis (“golfer’s elbow”) Radial head Proximal tip of ulna. Tenderness can indicate fracture. Proximal end of radius. Tenderness can indicate fracture. 110 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

OSTEOLOGY • Arm 4 Acromial angle Acromion Humerus Acromion Supraglenoid Glenoid Medial Greater tubercle tubercle cavity of epicondyle Head of humerus scapula Anatomical neck Anatomical neck Head of Surgical neck humerus Infraglenoid tubercle Greater tubercle Humerus Deltoid tuberosity Lesser tubercle Radial groove Surgical neck Medial Intertubercular supracondylar ridge sulcus Crest of Lateral greater tubercle supracondylar ridge Crest of Olecranon fossa lesser tubercle Lateral epicondyle Trochlea Deltoid tuberosity Groove for ulnar nerve Medial supracondylar ridge Posterior view Lateral Coronoid fossa supracondylar ridge Medial epicondyle Medial Trochlea Condyles Lateral Radial fossa Lateral epicondyle Capitellum Anterior view CHARACTERISTICS OSSIFY FUSE COMMENTS HUMERUS • Cylindrical long bone Primary • Limited remodeling potential in distal fxs • Deltoid is a deforming force in shaft fractures • Deltoid tuberosity Shaft 6-7wk (fetal) Birth • Radial nerve can be entrapped in distal 1⁄3 14-18yr • Spiral groove: radial Secondary humeral shaft fractures (Holstein-Lewis fx) 12-17yr • Fx of lateral condyle common in pediatrics nerve runs in groove Proximal (3): • Capitellum aligns with radial head on x-ray • Lat. epicondyle: origin of extensor mass & LCL • Lateral condyle Head Birth • Supracondylar process present 5%: ligament ‫ ؠ‬Capitellum (articular) ‫ ؠ‬Lateral epicondyle Tuberosities 1-4yr of Struthers may entrap median nerve • Med. epicondyle: origin of flexor mass & MCL • Medial condyle Distal (4): • Ulnar nerve runs post. to medial epicondyle ‫ ؠ‬Trochlea (articular) • Fossae filled with fat; can be displaced in fx, ‫ ؠ‬Medial epicondyle Capitellum 1yr ‫ ؠ‬Cubital tunnel resulting in “fat pad” on x-ray Medial 5yr • Olecranon and coro- epicondyle noid fossae Trochlea 7yr Lateral 11yr epicondyle Elbow ossification order mnemonic: Captain [capitellum] Roy [radial head] Makes [medial epicondyle] Trouble [trochlea] On [olecranon] Leave [lateral epicondyle]; can be used to determine approximate age of patient. NETTER’S CONCISE ORTHOPAEDIC ANATOMY 111

4 Arm • OSTEOLOGY Right elbow Humerus Humerus Medial Condyle Medial Lateral supracondylar ridge Lateral Coronoid Olecranon fossa fossa supracondylar ridge Radial fossa Medial epicondyle Lateral epicondyle Lateral epicondyle Trochlea Olecranon Capitellum Coronoid Head Head process Groove for Neck Neck Tuberosity ulnar nerve Radial notch of ulna Tuberosity Tuberosity Ulna Radius Radius Ulna In extension: anterior view In extension: posterior view Humerus Radius Humerus In extension: lateral view Ulna In extension: medial view Radius Humerus Humerus Lateral epicondyle Capitellum Medial epicondyle Head Capitellum Neck Trochlea Tuberosity Head Neck Tuberosity Radial (lesser Ulna Tuberosity sigmoid) notch Supinator crest Coronoid process Coronoid process Trochlear notch of ulna Trochlear (greater sigmoid) notch Olecranon Olecranon In 90˚ flexion: lateral view In 90˚ flexion: medial view CHARACTERISTICS OSSIFY FUSE COMMENTS • Radial head & physis are PROXIMAL RADIUS intraarticular Secondary • Anterolateral portion of radial head has less sub- • Radial neck: 10-15° angulated Head 2-3yr 16-18yr chondral bone & is most susceptible to fracture • Tuberosity: biceps insertion • Radial head should always align with the capitellum • Olecranon • Tuberosity points ulnarly in supination • Coronoid process • Supinator crest PROXIMAL ULNA • Ulnar tuberosity Secondary 16-20yr • Articulates with trochlea, part of greater notch • Greater sigmoid notch Olecranon 9yr • Coronoid provides anterior stability & MCL insertion • Lesser sigmoid notch • Lateral ulnar collateral ligament (LUCL) inserts on supinator crest • Brachialis inserts on ulnar tuberosity • Greater sigmoid notch: olecranon & coronoid • Lesser sigmoid (radial) notch: articulates with RH 112 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

RADIOLOGY • Arm 4 Olecranon Trochlea Coronoid fossa Olecranon fossa fossa Radial Lateral head epicondyle Medial Capitellum epicondyle Coronoid process Radial Capitellum head Elbow x-ray, lateral Olecranon Radial tuberosity Elbow x-ray, AP Capitellum Medial Olecranon epicondyle fossa Radial Trochlea Trochlea head Coronoid Proximal Radial process ulna tuberosity Radial Elbow CT, coronal head Elbow x-ray, oblique RADIOGRAPH TECHNIQUE FINDINGS CLINICAL APPLICATION Anteroposterior Elbow extended, beam Fractures, dislocations, arthritis/DJD, Lateral Elbow joint, distal humerus, perpendicular to plate proximal radius and ulna supracondylar process Oblique Elbow flexed 90°, beam Fractures (esp. peds: fat pads, anterior Radiocapitellar Elbow joint, fat pads (fat is from lateral to radial displaced by fracture he- humeral line), DJD (osteophytes) CT head matoma) MR Elbow extended, rotated Subtle fx (radial head, occult fx) Bone scan 30º Alignment & position of Lateral, beam 45º to bones Fx: radial head, capitellum, coronoid elbow Isolates capitellum/radial Fractures (esp. coronoid, comminuted Axial, coronal, and sagittal head intraarticular fx) Ligament (e.g., MCL) & tendon Sequence protocols vary OTHER STUDIES (e.g., biceps) rupture, OCD Infection, stress fractures, tumors Articular congruity, bone healing, bone alignment Soft tissues (ligaments, ten- dons, cartilage), bones All bones evaluated NETTER’S CONCISE ORTHOPAEDIC ANATOMY 113

4 Arm • TRAUMA Humeral Shaft Fracture A BC A. Transverse fracture of midshaft After initial swelling subsides, most fractures of B. Oblique (spiral) fracture shaft of humerus can be treated with functional C. Comminuted fracture with marked angulation brace of interlocking anterior and posterior components held together with Velcro straps. Open reduction and fixation Fracture aligned and held Entrapment of radial nerve in with compression plate indi- with external fixator. Most fracture of shaft of distal humerus cated under special conditions. useful for wounds requiring may occur at time of fracture; must frequent changes of dressing. also be avoided during reduction. DESCRIPTION EVALUATION CLASSIFICATION TREATMENT HUMERUS SHAFT FRACTURE • Common long bone fracture Hx: Trauma/fall, pain and Descriptive: • Cast/brace: minimally • Mechanism: fall or direct swelling • Location: site of displaced/acceptable alignment PE: Swelling ϩ/Ϫ defor- blow mity, humerus is TTP fracture • Acceptable: Ͻ3cm shortening • Displacement based on Good neuro. exam (esp. • Displaced, angu- Ͻ20° A/P angulation Ͻ30° radial n.) varus/valgus angulation fracture location and mus- XR: AP & lateral of arm lated, or commi- cle insertion sites. Pectora- (also shoulder & elbow nuted • Surgical treatment: open fx, lis and deltoid are primary series) • Pattern: transverse, floating elbow, segmental fx, deforming forces. CT: Not usually needed spiral, oblique polytrauma, vascular injury • High union rates • Site of pathologic fractures • Options: ORIF, external fixation, IM nail COMPLICATIONS: Radial nerve palsy (esp. distal 1⁄3 fractures [Holstein-Lewis]): most are neurapraxia and resolve spontaneously; nerve exploration is controversial; nonunion/malunion are uncommon. 114 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

TRAUMA • Arm 4 Distal Humerus Fracture Intercondylar (T or Y) Fracture of lateral condyle of Fractured condyle fixed with fracture of distal humerus humerus. Fracture of medial one or two compression screws condyle less common Medial epicondyle of humerus Triceps brachii tendon Extensor carpi radialis longus muscle Anconeus muscle Medial Olecranon epicondyle Ulnar nerve Open (transolecranon) repair. Posterior incision skirts medial margin Olecranon osteotomized and reflected proximally with of olecranon, exposing triceps brachii tendon and olecranon. Ulnar triceps brachii tendon nerve identified on posterior surface of medial epicondyle. Incisions made along each side of olecranon and triceps brachii tendon Articular surface of distal humerus reconstructed and fixed with Olecranon reattached with longitudinal Kirschner wires transverse screw and buttress plates with screws. Ulnar nerve and tension band wire wrapped around them and through may be transposed anteriorly to prevent injury. Lateral column hole drilled in ulna fixed with posterior plate and medial column fixed with plate on the medial ridge. DESCRIPTION EVALUATION CLASSIFICATION TREATMENT DISTAL HUMERUS FRACTURE • Most often intraarticular Hx: Trauma/fall, pain, esp. Descriptive: • Nonoperative: rarely indicated (adults); extraarticular w/ elbow ROM (decreased) • Uni or bicondylar • Surgical: ORIF (plates & (supracondylar) fx un- PE: Swelling & tenderness • T, Y, ␭ type common in adults Good neurovascular exam • Displaced, angu- screws) XR: Elbow series • Ulnar nerve often needs to be • Mechanism: fall CT: Essential for complete lated commi- • Unicondylar or bicondylar evaluation of fracture/joint nuted (esp. coro- transposed anteriorly • Other: epicondyle, capi- nal split) • Early ROM is important • Total elbow arthroplasty: if fx tellum, trochlea fxs all less common is too comminuted for ORIF COMPLICATIONS: Elbow stiffness, heterotopic ossification (prophylaxis is indicated), ulnar nerve palsy, nonunion NETTER’S CONCISE ORTHOPAEDIC ANATOMY 115

4 Arm • TRAUMA Supracondylar Fractures Extension type Lateral radiograph Flexion type Posterior displacement of distal Anterior displacement of fragment (most common) distal fragment (uncommon) Humerus Elevated posterior Posterior fat pad fat pad Anterior fat pad Ulna Normal Lateral radiograph of elbow in a Fracture 5-year-old sustaining injury to left elbow. Radiograph shows elevation of anterior and posterior fat pads. No apparent fracture on this view, but subsequent radiographs con- firmed presence of a nondisplaced supracondylar humerus fracture. DESCRIPTION EVALUATION CLASSIFICATION TREATMENT SUPRACONDYLAR HUMERUS FRACTURE • Common pediatric fracture Hx: Fall, pain, will not move • Extension type • Type I: Long arm cast • Extraphyseal fx at thin arm, ϩ/Ϫ deformity (Gartland) • Types II & III: Closed reduc- PE: Swelling ϩ/Ϫ defor- ‫ ؠ‬I: Nondisplaced portion of bone (1mm) mity. Good neurovascular ‫ ؠ‬II: Partially dis- tion & percutaneous pinning, between distal humeral exam (esp. AIN, radial n., placed (post. 2 or 3 pins (crossed or fossae pulses) cortex intact) divergent) Medial pins can • Extension type most XR: Elbow series. Lateral ‫ ؠ‬III: Displaced (no injure ulnar nerve common view: anterior humeral cortical continuity) • Open reduction for irredu- • Malreduction leads to de- line is anterior to capitel- cible fractures (uncommon) formity: cubitus varus is lum center in displaced • Flexion type • Explore pulseless/ most common fxs. Posterior fat pad in- (uncommon) unperfused extremity for • Relatively high incidence dicates fx. artery entrapment of neurovascular injury COMPLICATIONS: Malunion (cubitus varus #1); neurovascular (median nerve/AIN #1, radial nerve, brachial artery) 116 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

TRAUMA • Arm 4 Olecranon fracture Displaced fracture of Open reduction of olecranon fracture. olecranon requires open Fracture secured with two Kirschner reduction and internal wires plus tension band wire passed fixation around bent ends of Kirschner wires and through drill Fracture of head and neck of radius Type I: nondisplaced Type II: displaced single fragment Type III: severely Comminuted or minimally dis- (usually >2 mm) of the head or comminuted frac- fracture of radial placed. angulated (usually >30°) of the tures of the radial head with dis- neck. head and neck. location of distal radioulnar joint, proximal migration of radius, and tear of interosseous membrane (Essex- Lopresti fracture) DESCRIPTION EVALUATION CLASSIFICATION TREATMENT OLECRANON FRACTURE • Mechanism: fall directly Hx: Trauma (usually fall), Colton: • Nondisplaced: Long arm cast onto elbow or onto hand pain and swelling 3 weeks, then gentle ROM PE: Tenderness, limited • I. Nondisplaced: • Intraarticular fracture: elbow extension. Neuro • Displaced: congruity important for exam, esp. ulnar nerve Ͻ2mm ‫ ؠ‬Transverse: ORIF tension good results XR: Elbow series • II. Displaced band or IM screw. CT: Better defines fracture ‫ ؠ‬Oblique/comminuted: ORIF • Triceps tendon is a de- ‫ ؠ‬Avulsion with contoured plate forming force on proximal ‫ ؠ‬Transverse/oblique fragment ‫ ؠ‬Comminuted • Excise & reattach tendon ‫ ؠ‬Displaced fx-dx COMPLICATIONS: Painful hardware, elbow stiffness, nonunion, arthritis (posttraumatic), ulnar nerve injury RADIAL HEAD FRACTURE • Mechanism: fall onto hand Hx: Trauma/fall, pain Mason: 4 types • Type I: Elbow aspiration, sling • Intraarticular fracture: PE: Decreased motion • I: Nondisplaced for 3 days, early ROM (esp. pronosupination) anterolateral portion is (Ͻ2mm) • Type II: ORIF (esp. for me- weaker and is most Check DRUJ stability • II: Single displaced chanical block to motion) common fracture site XR: Elbow series; radio- • Essex-Lopresti: RH fx capitellar view is help- fragment • Type III: Radial head excision w/ disruption of IM mem- ful,ϩ/Ϫ fat pad sign • III: Comminuted and/or RH arthroplasty brane & DRUJ CT: Useful in types II-IV • IV: Fracture with el- • Associated w/ elbow • Essex-Lopresti: radial head dislocation bow dislocation arthroplasty is required COMPLICATIONS: Elbow stiffness or instability; Wrist instability (Essex-Lopresti) NETTER’S CONCISE ORTHOPAEDIC ANATOMY 117

4 Arm • TRAUMA Elbow dislocation Posterior dislocation. Note Divergent dislocation, anterior- Lateral dislocation prominence of olecranon posterior type (rare). Medial-lateral (uncommon) posteriorly and distal humerus type may also occur (extremely rare). anteriorly. Radial head subluxation Dislocation of radius at elbow Reduction: With thumb in antecubital space as a fulcrum, the forearm is supinated and flexed DESCRIPTION EVALUATION CLASSIFICATION TREATMENT ELBOW DISLOCATION • Mechanism: usually a fall in Hx: Trauma/fall, inability By direction of • Acute: closed reduction young patient to move elbow forearm bones: ‫ ؠ‬Stable: splint for 7-10d PE: Swelling, deformity, • Posterior ‫ ؠ‬Unstable: splint for 2-3wk • #3 most common dislocation limited/no elbow ROM ‫ ؠ‬Posterolateral • Associated with fractures: Good neurovasc. exam • Open reduction for irreducible XR: Elbow series (Ͼ80%) dxs and/or ORIF fxs “Terrible triad”ϭ elbow dx CT: To define associated • Medial with radial head & coronoid fractures • Lateral (rare) • Hinged external fixation for fractures • Anterior (rare) grossly unstable elbows • Collateral ligaments & anterior • Divergent (rare) capsule are typically all torn COMPLICATIONS: Elbow stiffness and instability, neurovascular injury (median and ulnar nerves, brachial artery) RADIAL HEAD SUBLUXATION (NURSEMAID’S ELBOW) • Mechanism: usually a pull on Hx: Child pulled by hand, None • Closed reduction: fully extend the hand by an adult child will not use arm elbow, fully supinate, then flex PE: Elbow flexed, pro- with gentle pressure on radial • Very common in toddlers nated. RH tender head. Usually a click or pop is • Decreased with increasing age XR: Elbow series; normal, felt as it reduces. • Annular ligament stretches & often not needed • Immobilization rarely indicated radial head subluxates COMPLICATIONS: Recurrence 118 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

JOINTS • Arm 4 Right elbow: Humerus MRI coronal, elbow anterior view Medial epicondyle Medial Olecranon Joint capsule epicondyle Lateral epicondyle Medial collateral Capitellum ligament Medial Lateral collateral Insertion of collateral Radial ligament brachialis muscle ligament head Annular ligamen Oblique cord of radius Ulna Biceps brachii tendon Ulna Radius In 90° flexion: lateral view In 90° flexion: medial view Triceps brachii Joint capsule Anterior bundle of MCL Joint capsule tendon Lateral collateral ligament Annular ligament of radius Biceps brachii tendon Posterior bundle Lateral ulnar Annular ligament of radius Oblique cord of MCL collateral Biceps brachii Radius Transverse ligament ligament tendon Radius Ulna Accessory lateral Ulna collateral ligament LIGAMENTS ATTACHMENTS COMMENTS ELBOW • The elbow comprises three articulations: 1. Ulnohumeral (trochlea and greater sigmoid notch): Ginglymus (hinge) joint 2. Radiocapitellar (radial head and capitellum): Trochoid (pivot) joint 3. Proximal radioulnar (radial head and lesser sigmoid notch) • Primary function is as a lever for lifting and placing the hand appropriately in space • Two primary motions: 1. Flexion and extension: 0-150° (functional ROM: 100° [30-130°]); axis is the trochlea 2. Pronosupination: 70° pro. – 80° sup. (functional ROM: 100° [50° pro. – 50° sup.]); axis is RC joint • Stability provided by combination of osseous (articulations) and ligamentous restraints; carrying angle 11-16° valgus Medial (Ulnar) Collateral (MCL) Anterior bundle Inf. medial epicondyle to medial cor- Most important restraint to valgus stress, always onoid process (“sublime tubercle”) taut; usually ruptures off coronoid Posterior bundle Medial epicondyle to sigmoid notch Taut in/resists valgus in flexion (Ͼ90º) Transverse bundle Med. olecranon to inf. medial coronoid Stabilizes the greater sigmoid notch Lateral (Radial) Collateral (LCL) Lateral collateral (LCL) Lat. epicondyle to ant. annular lig. Varus restraint; stabilizes annular ligament Lateral ulnar collateral Lateral epicondyle to supinator crest Buttress to radial head subluxation; injury results (LUCL) of the ulna in posterolateral rotatory instability Accessory lateral collateral Annular ligament to supinator crest Stabilizes annular ligament during varus stress Annular ligament Anterior and posterior portions of sig- Allows radial head rotation; stretched or torn in moid notch radial head subluxation or dislocation Other Capsule Surrounds joint Secondary stabilizer, prone to contracture Quadrate ligament Anterolateral ulna to anterior radial Tight in supination, stabilizes the proximal radio- neck (under the annular ligament) ulnar joint (PRUJ) Oblique cord Proximal lateral ulna to radial neck Stabilizes joint during pronosupination NETTER’S CONCISE ORTHOPAEDIC ANATOMY 119

4 Arm • JOINTS Elbow stability Humerus Humerus Joint capsule (cut edge) Opened joint: Opened joint: Fat pads posterior view anterior view Synovial membrane Articular cartilage Radius Ulna Ulna Radius Olecranon Cubital tunnel Arcuate ligament Medial epicondyle Cubital Ulnar n. Arcuate tunnel ligament wide Compression Cubital Tunnel narrows, stretching nerve Elbow flexion Elbow extension ELBOW STABILITY Primary Stabilizers Ulnohumeral articulation Primary restraint to valgus Ͻ20° or Ͼ120° of flexion Medial collateral ligament (MCL) (esp. anterior bundle) Primary restraint to varus in extension (2° in flexion) Lateral collateral ligament (LCL) (esp. LUCL) Primary restraint to valgus between 20-120° of flexion Anterior bundle is always taut, post. bundle taut Ͼ90° Primary restraint to varus in flexion (2° in extension) LUCL prevents subluxation of radial head (e.g., PLRI) Secondary Stabilizers Radiocapitellar articulation (radial head) Restraint to valgus from 0-30º of flexion Anterior and posterior capsule Restraint to both varus and valgus stress Common flexor and extensor origins Dynamic forces act to restrain both varus and valgus stress STRUCTURE COMPONENTS COMMENTS CUBITAL TUNNEL Borders • Roof: Arcuate (Osborne’s) ligament • Tightens in flexion, compresses ulnar nerve within cubital From med. epicondyle to olecranon tunnel • Floor: Medial collateral ligament (MCL) • Can be injured in decompression surgery • Posterior: Medial head of the triceps • Does not typically compress the nerve • Anterior: Medial epicondyle • Medial epicondylectomy occasionally indicated • Lateral: Olecranon • Does not compress nerve Contents • Nerve: Ulnar nerve • Compressed in cubital tunnel syndrome • Fractures (malunion) of the medial condyle can cause ulnar nerve entrapment in the cubital tunnel. • Arcuate ligament is also known as Osborne’s ligament/fascia and the cubital tunnel retinaculum. • See Forearm chapter for radial tunnel. 120 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

Arcade of Struthers OTHER STRUCTURES • Arm 4 Medial Medial intermuscular head of septum triceps brachii Cubital tunnel m. Arcuate ligament Ulnar n. Medial epicondyle Flexor carpi ulnaris m. Humeral head Ulnar head Supra- Anterior Radial n. condylar interosseous n. Recurrent process radial a. Ligament of Posterior Struthers interosseous n. Medial Supinator m. epicondyle Arcade Lacertus of Frohse fibrosus Pronator teres m. Humeral head Ulnar head Flexor digitorum superficialis m. and arch Superficial radial n. Vascular leash of Henry STRUCTURE DESCRIPTION COMMENTS Fat pads OTHER STRUCTURES Can be displaced by fracture hematoma and seen on x-ray as a lucency (“sail sign”) Olecranon bursa Located in both the coronoid and olecranon Can become inflamed or infected Ligament of Struthers fossae, engaged in full flexion or extension Can compress the median nerve proximally Biceps aponeurosis At the tip of the olecranon process Covers median nerve and brachial artery (lacertus fibrosus) and can compress median nerve Arcade of Struthers A fibrous band running from an anomalous Occurs in 70% of population; can compress supracondylar process to medial epicondyle ulnar nerve proximal to cubital tunnel Leash of Henry Can compress radial nerve/PIN Fascial band from distal biceps and tendon that runs to deep forearm fascia Thickened fascia from IM septum to triceps (medial head), 8cm proximal to epicondyle Branches of recurrent radial artery NETTER’S CONCISE ORTHOPAEDIC ANATOMY 121

4 Arm • MINOR PROCEDURES Sites for tennis elbow injection Olecranon bursa aspiration Elbow joint aspiration STEPS ELBOW ARTHROCENTESIS 1. Flex and extend elbow, palpate lateral condyle, radial head, and olecranon laterally; feel triangular sulcus (“soft spot”) between all three 2. Prep skin over sulcus (iodine/antiseptic soap) 3. Anesthetize skin locally (quarter size spot) 4. May keep arm in extension or flex it. Insert needle in “triangle” between bony landmarks (aim to medial epicondyle) 5. Fluid should aspirate easily 6. Dress injection site OLECRANON BURSA ASPIRATION 1. Prep skin over olecranon (iodine/antiseptic soap) 2. Anesthetize skin locally (quarter size spot) 3. Insert 18-gauge needle into fluctuant portion of the bursa and aspirate fluid 4. If suspicious of infection, send fluid for Gram stain and culture 5. Dress injection site TENNIS ELBOW INJECTION 1. Ask patient about allergies 2. Flex elbow 90º, palpate ECRB insertion (point of maximal tenderness) on the lateral epicondyle 3. Prep skin over lateral elbow (iodine/antiseptic soap) 4. Anesthetize skin locally (quarter size spot) 5. Insert 22-gauge or smaller needle into ERCB tendon at its insertion on the lateral epicondyle. Aspirate to ensure needle is not in a vessel, then inject 2-3ml of 1:1 local/corticosteroid preparation (fan out injection in broad tendon). 6. Dress insertion site 7. Annotate improvement in symptoms 122 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

HISTORY • Arm 4 Elbow fractures and dislo- cations can result from fall on outstretched dorsi- flexed hand Ulnar Nerve Compression Compression of nerve on hard surface (chair arm, desk, operating table, etc.) Numbness and tingling in ulnar nerve distribution in hand. Interosseous wasting between thumb and index finger QUESTION ANSWER CLINICAL APPLICATION 1. Age Young Dislocation, fracture 2. Pain Middle aged, elderly Tennis elbow (epicondylitis), nerve compression, arthritis a. Onset b. Location Acute Dislocation, fracture, tendon avulsion/rupture, ligament injury Chronic Arthritis, cervical spine pathology c. Occurrence Anterior Biceps tendon rupture, arthritis, elbow contracture 3. Stiffness Posterior Olecranon bursitis (inflammatory or septic) Lateral Lateral epicondylitis, fracture (especially radial head) 4. Swelling Medial Medial epicondylitis, nerve entrapment, fracture, MCL strain 5. Trauma Night pain/at rest Infection, tumor 6. Activity With activity Ligamentous and/or tendinous etiology 7. Neurologic Without locking Arthritis, effusions (trauma), contracture symptoms With locking Loose body, lateral collateral ligament injury 8. History of arthritides Over olecranon Olecranon bursitis. Other: dislocation, fracture, gout Fall on elbow, hand Dislocation, fracture Sports, repetitive motion Epicondylitis, ulnar nerve palsy Throwing MCL strain or rupture Pain, numbness, tingling Nerve entrapments (multiple possible sites), cervical spine pathology, thoracic outlet syndrome Multiple joints involved Lupus, rheumatoid arthritis, psoriasis, gout NETTER’S CONCISE ORTHOPAEDIC ANATOMY 123

4 Arm • PHYSICAL EXAM Olecranon bursitis (student’s elbow) Subluxation of Epicondylitis head of radius (tennis elbow) (“pulled elbow”/ Exquisite tenderness “nursemaid’s”) over lateral or medial epicondyle of humerus Cubitus varus deformity Cubital tunnel syndrome Malunion of a Interosseous supracondylar muscle wasting fracture can result in this deformity. EXAM/OBSERVATION TECHNIQUE CLINICAL APPLICATION INSPECTION Unwilling to use arm Fracture, dislocation, radial head subluxation Gross deformity, swelling Observe patient (child) (nursemaid’s elbow) Carrying angle (normal 5-15°) Dislocation, fracture, bursitis Muscle wasting Compare both sides Cubitus varus (e.g., supracondylar fracture) Negative (Ͻ5°) Cubitus valgus (e.g., lateral epicondyle fracture) Medial Positive (Ͼ15°) Nerve entrapment (e.g., cubital tunnel syndrome) Inspect hand muscles Lateral Pain: medial epicondylitis (golfer’s elbow), frac- Anterior PALPATION ture, MCL rupture/strain Posterior Epicondyle and supracondylar line Paresthesias indicate ulnar nerve entrapment Pain: lateral epicondylitis (tennis elbow), fracture Ulnar nerve in ulnar groove Pain: arthritis, fracture, synovitis Epicondyle and supracondylar line Pain: absence of tendon indicates biceps tendon Radial head rupture Biceps tendon in antecubital Olecranon bursitis, triceps tendon rupture fossa Flex elbow: olecranon, olecranon fossa, triceps tendon 124 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

Thumb in line PHYSICAL EXAM • Arm 4 with humerus 0˚ 0˚ Pronation Supination Pronation Supination 0˚ 0˚ 75˚ 85˚ 85˚ Arm stabilized against chest wall with elbow flexed at 90˚ 75˚ 140˚ 90˚ Flexion Adult extension to 0˚ Extension 0˚ 10˚ In children, normal elbow 15˚ extension is 10˚–15˚ EXAM/OBSERVATION TECHNIQUE CLINICAL APPLICATION Flex and extend RANGE OF MOTION Pronate and supinate Elbow at side: flex and extend at elbow Normal: 0° to 140-150°; note if PROM ϾAROM Tuck elbows, thumbs up, rotate forearm Normal: supinate 80-85°, pronate 75-80° NETTER’S CONCISE ORTHOPAEDIC ANATOMY 125

4 Arm • PHYSICAL EXAM Elbow flexion test Paresthesias Posterolateral rotatory in distribution instability test of ulnar nerve Valgus Axial compression Tinel sign Supination EXAM TECHNIQUE CLINICAL APPLICATION NEUROVASCULAR Sensory Axillary n. (C5) Proximal lateral arm Deficit indicates corresponding nerve/root lesion Radial n. (C5) Inferolateral and posterior arm Deficit indicates corresponding nerve/root lesion Medial cutaneous Medial arm Deficit indicates corresponding nerve/root lesion n. of arm (T1) Motor Musculocutaneous Resisted elbow flexion Weakness ϭ Brachialis/biceps or nerve/root lesion n. (C5-6) Musculocutaneous Resisted supination Weakness ϭ Biceps or corresponding nerve/root lesion n. (C6) Median n. (C6) Resisted pronation Weakness ϭ Pronator teres or nerve/root lesion Radial n. (C7) Resisted elbow extension Weakness ϭ Triceps or nerve/root lesion Reflexes C5 Biceps Hypoactive/absence indicates radiculopathy C6 Brachioradialis Hypoactive/absence indicates radiculopathy C7 Triceps Hypoactive/absence indicates radiculopathy Pulses: brachial, radial, ulnar SPECIAL TESTS Tennis elbow Make fist, pronate, extend wrist and Pain at lateral epicondyle suggests lateral epicondylitis fingers against resistance Golfer’s elbow Supinate arm, extend wrist and elbow Pain at medial epicondyle suggests medial epicondylitis Ligament instability 25° flexion, apply varus/valgus stress Pain or laxity indicates LCL/MCL injury Pivot shift (PLRI) Supine, extend elbow, flex shoulder Apprehension, palpable subluxation of radial head, or above head. Supinate, axial load, dimpling of skin over radial head positive test for valgus and flex elbow posterolateral rotatory instability (PLRI) Tinel’s sign Tap on ulnar groove (nerve) Tingling in ulnar distribution indicates entrapment Elbow flexion Maximal elbow flexion for 3 min Tingling in ulnar distribution indicates entrapment Pinch grip Pinch tips of thumb and index finger Inability (or pinching of pads, not tips): AIN pathology 126 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

MUSCLES: ORIGINS AND INSERTIONS • Arm 4 Posterior view Anterior view Triceps Deltoid muscle brachii Supraspinatus Trapezius muscle muscle muscle (long head) Infraspinatus muscle Deltoid muscle Coracobrachialis muscle Teres minor muscle and Triceps brachii Biceps brachii muscle Biceps brachii muscle muscle (long head) (short head) (lateral head) Supraspinatus Triceps brachii Common Deltoid muscle muscle muscle flexor tendon (long head) Brachialis muscle Subscapularis muscle Coracobrachialis Triceps brachii muscle muscle Pectoralis major (medial head) muscle Muscle attachments Origins Common Latissimus dorsi Insertions extensor muscle tendon Teres major Anconeus muscle muscle Deltoid Triceps brachii muscle muscle Brachioradialis Brachialis muscle muscle Extensor carpi Pronator teres muscle radialis longus (humeral head) muscle Common flexor tendon Common extensor (flexor carpi radialis, palmaris tendon (extensor longus, flexor carpi ulnaris and carpi radialis brevis, flexor digitorum superficialis extensor digitorum [humeroulnar head] muscles) with extensor digiti minimi and extensor Flexor digitorum superficialis carpi ulnaris muscles) muscle (humeroulnar head) Brachialis muscle Pronator teres muscle (ulnar head) Supinator muscle Biceps brachii muscle Flexor pollicis longus muscle (ulnar head) CORACOID GREATER ANTERIOR PROXIMAL MEDIAL LATERAL EPICONDYLE PROCESS TUBEROSITY HUMERUS EPICONDYLE Anconeus Biceps (SH) Supraspinatus ORIGINS Common extensor tendon Coracobrachialis Infraspinatus (ECRB, EDC, EDQ, ECU) Teres minor Pronator teres Pectoralis minor Common flex. tendon (FCR, PL, FCU, FDS) INSERTIONS Pectoralis major Latissimus dorsi Teres major NETTER’S CONCISE ORTHOPAEDIC ANATOMY 127

4 Arm • MUSCLES: ANTERIOR Acromion Coracoid process Coracoacromial ligament Pectoralis minor tendon (cut) Subdeltoid bursa Subscapularis muscle Musculocutaneous nerve (cut) Greater tubercle, Coracobrachialis muscle Lesser tubercle Circumflex scapular artery (cut) of humerus Intertubercular Teres major muscle tendon sheath Deltoid muscle Latissimus dorsi muscle (reflected) Pectoralis major Conjoined tendon muscle (reflected) (biceps short head) Anterior circumflex coracobrachialis humeral artery Biceps Long head Biceps brachii brachii tendons (cut) muscle Short head Short head Brachial artery (cut) Long head Median nerve (cut) Coracobrachialis muscle Brachialis muscle Musculocutaneous nerve Deltoid muscle (cut) Lateral cutaneous nerve of forearm Bicipital aponeurosis (lacertus fibrosus) Biceps brachii tendon Brachioradialis muscle Superficial layer Lateral intermuscular septum Brachialis muscle Lateral epicondyle of humerus Lateral cutaneous nerve of forearm Medial intermuscular Head of radius septum Biceps brachii tendon Medial Radial tuberosity epicondyle of humerus Deep layer Tuberosity of ulna MUSCLE ORIGIN INSERTION NERVE ACTION COMMENT Coracobrachialis Middle humerus Musculocutaneous Flex and adduct Coracoid Part of “conjoined” Brachialis process Ulnar tuberosity Medial: MSC n. arm tendon (proximal ulna) Lateral: Radial n. Flex forearm Biceps brachii Distal anterior Split in anterior Long head humerus Radial tuberosity Musculocutaneous Supinate and surgical approach Short head (proximal radius) Musculocutaneous flex forearm Supraglenoid Radial tuberosity Supinate and Rupture, results in tubercle (proximal radius) flex forearm “Popeye arm” Coracoid Part of “conjoined” process tendon 128 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

MUSCLES: POSTERIOR • Arm 4 Acromion Superficial layer Supraspinatus muscle Greater tuberosity of humerus Infraspinatus muscle Teres minor muscle Axillary nerve and posterior circumflex humeral artery Deltoid muscle (cut and reflected) Superior lateral cutaneous nerve of arm Long head Lateral head Triceps brachii muscle Tendon Teres major muscle Brachioradialis muscle Posterior cutaneous Extensor digitorum muscle nerve of arm Extensor carpi radialis brevis muscle (from radial nerve) Teres Capsule of shoulder joint Medial inter- major muscular septum muscle Supraspinatus tendon Ulnar nerve Infraspinatus and Medial epicondyle Teres minor tendons (cut) of humerus Olecranon of ulna Axillary nerve Flexor carpi ulnaris muscle Posterior circumflex humeral artery Anconeus muscle Superior lateral cuta- Extensor carpi neous nerve of arm radialis longus muscle Deep artery of arm Extensor carpi ulnaris muscle Radial nerve Posterior cutaneous nerve of forearm Middle collateral artery (from radial nerve) Radial collateral artery Long head of triceps brachii muscle Inferior lateral cutaneous nerve of arm Lateral head of triceps brachii muscle (cut) Lateral intermuscular septum Medial head of triceps brachii muscle Nerve to anconeus and lateral head of Medial epicondyle triceps brachii muscle of humerus Posterior Ulnar nerve cutaneous nerve Olecranon of ulna of forearm Deep layer Anconeus muscle Lateral epicondyle of humerus MUSCLE ORIGIN INSERTION NERVE ACTION COMMENT Olecranon Radial nerve Extends elbow Triceps brachii Border of quadrangular & Long head Infraglenoid tubercle triangular space & interval Border in lateral approach Lateral head Posterior humerus Olecranon Radial nerve Extends elbow Medial head (proximal) Olecranon Radial nerve Extends elbow One muscular plane in Posterior humerus posterior approach (distal) NETTER’S CONCISE ORTHOPAEDIC ANATOMY 129

4 Arm • MUSCLES: CROSS SECTION Pectoralis major muscle and tendon Musculocutaneous nerve Cephalic vein Median nerve Brachial artery and veins Biceps brachii muscle Short head Deep artery of arm Long head Ulnar nerve Radial nerve Coracobrachialis muscle Deltoid muscle Triceps brachii muscle Lateral head Long head Biceps brachii muscle Latissimus dorsi tendon Musculocutaneous nerve Teres major muscle Brachialis muscle Median nerve Brachial artery and veins Fasciotomy incision site (anterior) Medial cutaneous nerve of forearm Radial nerve Medial cutaneous nerve of arm Posterior cutaneous nerve of forearm (from radial nerve) Radial collateral artery Neurovascular compartment Ulnar nerve Middle collateral artery Superior ulnar collateral artery Medial intermuscular septum Triceps Medial head Fasciotory incision site (posterior) brachii Lateral head muscle Long head Lateral cutaneous nerve of forearm (from musculocutaneous nerve) Cephalic vein Biceps brachii muscle Medial cutaneous nerve of forearm Brachioradialis muscle Basilic vein Brachialis muscle Median nerve Radial nerve Ulnar nerve Extensor carpi radialis Brachial artery and veins longus muscle Posterior cutaneous Triceps brachii muscle and tendon nerve of forearm Lateral intermuscular septum (from radial nerve) STRUCTURE RELATIONSHIP Musculocutaneous n. RELATIONSHIPS Radial n. Ulnar n. Pierces coracobrachialis 8cm distal to coracoid, then lies b/w the biceps and brachialis muscles Median n. where lateral antebrachial cutaneous nerve (terminal branch) emerges Brachial artery Starts medial, then spirals posteriorly and laterally around humerus (in spiral groove) and Anterior emerges b/w brachialis and brachioradialis muscles in distal lateral arm Posterior In medial arm, from anterior to posterior compartment (across IM septum) into cubital tunnel In anteromedial arm, initially lateral to brachial artery, but crosses over it to become medial Runs with median nerve, then crosses under it to become more midline in distal arm/elbow COMPARTMENTS Muscles: brachialis, biceps brachii, coracobrachialis Neurovascular: musculocutaneous nerve, median nerve, brachial artery, radial nerve (distally) Muscles: triceps brachii Neurovascular: radial nerve (mid arm), ulnar nerve (distal arm), radial recurrent arteries 130 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

Cutaneous Innervation NERVES • Arm 4 Anterior (palmar) view Posterior view Axillary nerve (C5, 6) Supraclavicular nerves (from cervical Superior lateral plexus – C3, 4) brachial cutaneous nerve Axillary nerve Superior lateral Radial nerve cutaneous nerve (C5, 6, 7 , 8, T1) of arm (C5, 6) Inconstant contribution Radial nerve Inferior lateral Inferior lateral cutaneous nerve brachial of arm (C5, 6) cutaneous nerve Intercosto-brachial nerve Posterior brachial Posterior (T2) and medial cutaneous cutaneous nerve antebrachial nerve of arm (C8, T1, 2) (branch of radial cutaneous nerve nerve in axilla) Lateral Posterior (dorsal) view intermuscular Triceps Long head septum Supraclavicular brachii Lateral head nerves (from muscle Medial head Brachialis muscle cervical (lateral part; plexus – C3, 4) Triceps brachii tendon remainder of muscle supplied by musculo- Axillary nerve Medial epicondyle cutaneous nerve) Superior lateral Olecranon cutaneous nerve Brachioradialis of arm (C5, 6) muscle Radial nerve Anconeus muscle Posterior cutaneous nerve of arm (C5, 6, 7, 8) Inferior lateral cutaneous nerve of arm Intercosto-brachial nerve (T2) and medial cutaneous nerve of arm (C8, T1, 2) BRACHIAL PLEXUS Lateral and Medial Cord Median (C[5]6-T1): runs in medial arm (anterior compartment), medial to biceps and brachialis (lateral to brachial artery), then crosses over (medial) to artery and enters forearm under biceps aponeurosis (lacertus fibrosus) Sensory: None (in arm, see Hand chapter) Motor: None (in arm, see Forearm & Hand chapters) Posterior Cord Radial (C5-T1): starts medial to humerus, crosses posterior into spiral groove (where it can be entrapped in a humerus fracture, esp. distal 1⁄3 fractures) with deep artery of the arm, then exits between the brachioradialis & brachialis, then divides into deep (motor–PIN) and superficial (sensory) branches Sensory: Posterior arm: via posterior cutaneous n. of arm (posterior brachial cutaneous) Lateral arm: via inferior lateral cutaneous n. of arm Motor: • Posterior compartment ‫ ؠ‬Triceps brachii • Anterior compartment ‫ ؠ‬Brachialis (lateral portion) NETTER’S CONCISE ORTHOPAEDIC ANATOMY 131

4 Arm • NERVES Lateral Cords of Posterior brachial Anterior view Medial plexus Note: Only muscles innervated by musculocutaneous Median nerve nerve shown Musculocutaneous nerve Ulnar nerve (C5, 6, 7) Coracobrachialis muscle Medial cutaneous Biceps brachii muscle nerve of arm (retracted) Medial cutaneous nerve of forearm Brachialis muscle Radial nerve Articular branch Axillary nerve Lateral cutaneous nerve of forearm Anterior branch Posterior branch Nerves of the arm Anterior view BRACHIAL PLEXUS Musculo- Lateral cord, cutaneous Medial cord Lateral Cord nerve of brachial plexus Musculocutaneous (C5-7): pierces coracobrachialis Brachial (6-8cm below coracoid, where it is at risk from retrac- artery Anterior and tion of the conjoined tendon), then runs between the posterior biceps & brachialis, innervating both. Sensory terminal Profunda circumflex branch exits between the biceps & brachialis at elbow. brachii humeral (deep arteries Sensory: None (in arm, see Forearm chapter) brachial) Motor: • Anterior compartment artery Medial cutaneous nerve of arm ‫ ؠ‬Coracobrachialis Median ‫ ؠ‬Biceps brachii nerve Ulnar nerve ‫ ؠ‬Brachialis (medial portion) Radial Medial cutaneous Medial Cord recurrent nerve of forearm artery Medial cutaneous n. of arm (brachial cutaneous [C8- Radial Superior ulnar T1]): branches from the cord, joins intercostobrachial artery collateral artery nerve, and runs subcutaneously in the medial arm. Medial intermuscular Sensory: Medial arm septum Motor: None Inferior ulnar collateral Ulnar (C[7]8-T1): runs from anterior to posterior compart- artery ment in medial arm over the IM septum, then under the Bicipital aponeurosis arcade of Struthers onto the triceps (medial head), then (lacertus fibrosus) into cubital tunnel posterior to the medial epicondyle Ulnar artery Sensory: None (in arm, see Forearm & Hand) Motor: None (in arm, see Forearm & Hand) 132 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

ARTERIES • Arm 4 Acromial branch Clavicular branch Deltoid branch Pectoral branch Axillary artery Superior thoracic artery Anterior circumflex humeral artery Thoracoacromial artery Lateral thoracic artery Posterior circumflex Subscapular artery humeral artery Circumflex scapular artery Thoracodorsal artery Brachial artery Level of lower margin of teres Deep artery of arm major muscle is landmark for (profunda brachii) name change from axillary to brachial artery Anterior radial collateral artery Superior ulnar collateral artery Posterior radial Inferior ulnar collateral artery (middle) collateral artery Anterior ulnar recurrent artery Radial recurrent Posterior ulnar recurrent artery artery Common interosseous artery Recurrent inter- osseous artery Anterior interosseous artery Posterior inter- Ulnar artery osseous artery Radial artery BRANCHES COURSE COMMENT/SUPPLY BRACHIAL ARTERY The continuation of the axillary artery. It runs with the median n., then crosses under the nerve to be midline. Deep artery (profunda brachii) In the spiral groove Runs with the radial nerve, can be injured there Nutrient humeral artery Enters the nutrient canal Supplies the humerus Superior ulnar collateral With ulnar n. in medial arm Anastomosis with posterior ulnar recurrent artery Inferior ulnar collateral Branches in distal arm Anastomosis with anterior ulnar recurrent artery Muscular branches Usually branch laterally Supply musculature of the arm Radial Terminal branch One of 2 terminal branches Ulnar Terminal branch One of 2 terminal branches DEEP ARTERY Anterior radial collateral In anterolateral arm Anastomosis with radial recurrent artery Posterior (middle) radial Posterior to humerus Anastomosis with recurrent interosseous artery collateral Used as pedicle in lateral arm flap RADIAL ARTERY Radial recurrent Runs in anterolateral portion Anastomosis with anterior radial collateral artery of the arm Branches (leash of Henry) can compress radial n. ULNAR ARTERY Anterior ulnar recurrent In anteromedial arm Anastomosis with inferior ulnar collateral artery Posterior ulnar recurrent In posteromedial arm Anastomosis with superior ulnar collateral artery Common interosseous Midline branch Is a trunk with multiple branches Recurrent interosseous Posterior to elbow Anastomosis w/ post. radial (middle) collateral artery Anterior & posterior interosseous Along intermuscular septum Supplies forearm musculature NETTER’S CONCISE ORTHOPAEDIC ANATOMY 133

4 Arm • DISORDERS Inherent stability by mechanical locking of components with hinge arrangement Prosthesis for total elbow arthroplasty Design of prosthesis allows 5˚–7˚ of rotation about flexion-extension, varus-valgus and axial rotation Three types of total elbow arthroplasty have been used. Results were better with an unrestrained prosthesis but with 5%–20% incidence of postoperative instability, most patients are now treated with a semi-constrained prosthesis, which has inherent stability by linking of the component usually with a hinge (shown above) or a snap-fit axis arrangement. Medial Submuscular tranposition of ulnar nerve Repaired flexor-pronator intermuscular over transposed nerve septum Divided tendon of origin Anterior transposition of ulnar nerve Triceps brachii muscle DESCRIPTION Hx & PE WORKUP/FINDINGS TREATMENT • Less common condition ARTHRITIS 1. Conservative (rest, NSAID) • Osteoarthritis seen in 2. Debridement (osteophytes, Hx: Chronic pain, stiffness, • XR: OA vs inflammatory athletes/laborers ϩ/Ϫ previous trauma • Blood: RF, ESR, ANA loose bodies) • Site for arthritides PE: Decreased ROM & • Joint fluid: crystals, 3. Ulnohumeral arthroplasty tenderness (especially 4. Total elbow arthroplasty (RA, gout, etc) in extension) cells, culture 1. Rest, ice, NSAIDs, activity • Entrapment of ulnar CUBITAL TUNNEL SYNDROME modification nerve at elbow Hx: Numbness/tingling in XR: Look for abnormal 2. Splints (day and/or night) • Sites: ulnar distribution, medial epicondyle 3. Ulnar nerve transposition ‫ ؠ‬IM septum ϩ/Ϫ elbow pain EMG: Confirms diagnosis ‫ ؠ‬Arcade of Struthers PE: ϩ/Ϫ decreased grip (submuscular vs subcuta- ‫ ؠ‬Cubital tunnel strength, intrinsic atrophy, neous) ‫ ؠ‬FCU fascia ϩ Tinel’s and/or elbow flexion text 1. Activity modification, NSAIDs • Degenerative of com- 2. Use of brace/strap mon extensor tendons LATERAL EPICONDYLITIS (TENNIS ELBOW) 3. Stretching/strengthening (esp. ECRB) 4. Corticosteroid injection Hx: Age 30-60, chronic XR: Rule out fracture 5. Surgical debridement of • Due to overuse (e.g., pain at lateral elbow, & OA. Calcification of tennis) and/or injury worse w/wrist extension tendons can occur (esp. tendon (ECRB #1) (microtrauma) to tendon PE: Lateral epicondyle ECRB) TTP; pain with resisted 1. Compressive dressing • Inflammation of bursa wrist extension 2. Activity modification (infection/trauma/other) 3. Corticosteroid injection OLECRANON BURSITIS 4. Surgical debridement Hx: Swelling, acute or LAB: Aspirate bursa, send chronic pain fluid for culture, cell PE: Palpable/fluctuant count, Gram stain and mass at olecranon crystals 134 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

DISORDERS • Arm 4 Osteochondral lesion of the capitellum Bone resorption seen as radiolucent areas and Characteristic changes in capitellum of left humerus (arrow) compared irregular surface of capitellum of humerus with normal right elbow DESCRIPTION Hx & PE WORKUP/FINDINGS TREATMENT • Mechanism: eccentric overload DISTAL BICEPS TENDON RUPTURE 1. Early: primary repair (1 of partially flexed elbow or 2 incision techniques) Hx: Acute injury/”pop” XR: Usually normal • Usually male 40-60 y.o. PE: No palpable tendon, MR: Can confirm diag- 2. Late: no surgery; physi- • Early diagnosis important weak and/or painful nosis but usually not cal therapy flexion & supination needed • MCL (anterior bundle) injury 1. Rest, activity modification from repetitive valgus stress MEDIAL ELBOW INSTABILITY 2. Physical therapy (ROM) 3. Ligament reconstruction • Acute or chronic, associated Hx: Pain with throwing XR: Stress view may with throwers (baseball, javelin) or inability to throw show widening (usu. & debridement of osteo- PE: MCL tenderness, dynamic) postmedial phytes/loose bodies • Vascular insufficiency or micro- ϩ/Ϫ valgus laxity osteophytes. trauma to capitellum (at Ͼ30°) MR: Avulsion and tears 1. Rest & physical therapy 2. ORIF of fragments or ar- • Adolescent throwers/gymnasts OSTEOCHONDRITIS DISSECANS OF ELBOW with valgus/compressive loads throscopic debridement Hx: Lateral elbow pain, XR: Lucency, ϩ/Ϫ of loose bodies & • Lateral ulnar collateral liga- ϩ/Ϫ catching, fragmentation of the chondroplasty ment (LUCL) injury stiffness capitellum CT: Helpful to identify 1. Rest, activity modification • Allows radial head to subluxate PE: Capitellum TTP, loose bodies 2. Physical therapy (ROM) • Mech: traumatic (elbow dx) or pain w/ valgus stress 3. LUCL reconstruction iatrogenic (elbow surgery) POSTEROLATERAL ROTATORY INSTABILITY (usually with a palmaris graft) • Ͻ30-120° Hx: Hx of trauma or XR: Often normal • Intrinsic vs extrinsic etiology surgery, pain, ϩ/Ϫ Stress XR: Shows radial 1. Physical therapy: ROM • Intrinsic: articular changes/ ar- clicking head subluxation 2. Operative: Intrinsic: ex- PE: ϩ lateral pivot shift MR: Identifies LUCL tear throsis (posttraumatic, etc) test (often needs EUA) cise osteophytes, LBs • Extrinsic: capsule contracture Extrinsic: capsular STIFF ELBOW release Hx: Trauma, stiffness, XR: AP/lateral/oblique minimal pain Look for osteophytes or PE: Limited ROM other signs of intrinsic (esp. in flexion and joint arthrosis extension) NETTER’S CONCISE ORTHOPAEDIC ANATOMY 135

4 Arm • PEDIATRIC DISORDERS Congenital dislocation of radial head Lateral view of upper extremity reveals posterior bulge of head of radius and inability to fully extend elbow. Anteroposterior and lateral radiographs reveal posterior dis- location of radial head, most evident on elbow flexion. Note also hypoplastic capitulum of humerus. DESCRIPTION EVALUATION TREATMENT CONGENITAL RADIAL HEAD DISLOCATION • Radial head congenitally dislocated Hx: Parents notice decreased ROM, • Asymptomatic: observation • Usually diagnosed from 2-5y.o. ϩ/Ϫ pain or deformity (late) • Symptomatic (pain): excision of • Patients are typically very functional • Unilateral or bilateral PE: Decreased ROM, ϩ/Ϫ visible radial head at skeletal maturity • Associated with other syndromes radial head and/or tenderness (decreases pain, but does not typ- XR: Malformed radial head & ically increase ROM) capitellum RADIOULNAR SYNOSTOSIS • Failure of separation of radius & ulna Hx/PE: Absent pronosupination of the • Synostosis resection unsuccessful • Forearm rotation is absent elbow/forearm. Varying degrees of Mild/unilateral: observation • Can be assoc. with other syndromes fixed deformity (Ͼ60° is severe) • Bilateral in 60% of cases XR: Radius is thickened, ulna is • Osteotomy: dominant hand 20° narrow of pronation, nondominant 30° of supination OSTEOCHONDROSIS OF CAPITELLUM (PANNER’S DISEASE) • Disordered endochondral ossification Hx: Insidious onset lateral elbow pain 1. Rest (no pitching, tumbling, etc) • Mech: valgus (pitcher’s) compression and overuse (baseball, gymnastics) 2. NSAIDs PE: Capitellum TTP, decreased ROM 3. Immobilization (3-4 weeks) or axial overload (gymnasts) XR: Irregular borders, ϩ/Ϫ fissuring, Symptoms may persist for months, • Usually Ͻ10 y.o.; maleϾfemale fragmentation (rarely loose bodies) but most completely resolve • Favorable long-term prognosis 136 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

SURGICAL APPROACHES • Arm 4 Anterolateral Approach to Humerus Head of humerus Deltoid Conjoined tendon (retracted) Biceps brachii Incision site (longhead) Biceps brachii Periosteum (opened) Humerus Brachialis (split) Periosteum (opened) Subscapularis Deltoid Pectoralis (divided) major Pectoralis major Biceps brachii (retracted) Lateral (Kocher) Approach to Elbow Joint Brachialis Biceps (split) brachii Incision Extensor carpi Extensor carpi site ulnaris (retracted) ulnaris (retracted) Extensor Anconeus Joint capsule carpi (retracted) (opened) ulnaris Capitulum Radial head Posterior Anconeus Anterior Olecranon Capitulum Ulnar nerve Radius Olecranon Ulna Supinator Anconeus (retracted) USES INTERNERVOUS PLANES DANGERS COMMENT • ORIF of fractures HUMERUS: ANTERIOR APPROACH • Anterior humeral circumflex • Bone biopsy/tumor artery may need ligation. Proximal Proximal removal • Deltoid (axillary) • Axillary nerve • The brachialis has a split in- • Pectoralis major (pectoral) • Humeral circumflex artery nervation that can be used Most radial head & Distal Distal for an internervous plane. lateral condyle • Brachialis splitting • Radial nerve procedures • Musculocutaneous nerve • Protect PIN: stay above annu- ‫ ؠ‬Lateral (radial) lar ligament; keep forearm ‫ ؠ‬Medial (MSC) pronated ELBOW: LATERAL APPROACH (KOCHER) • Anconeus (radial) • PIN • ECU (PIN) • Radial nerve NETTER’S CONCISE ORTHOPAEDIC ANATOMY 137

4 Arm • SURGICAL APPROACHES Proximal Arthroscopy portals Posterior approach with anterolateral olecranon osteotomy portal Proximal anteromedial Tricep Lateral portal tendon epicondyle Posterolateral portal Posterocentral Triceps portal brachii Lateral tendon epicondyle Olecranon Medial epicondyle Anconeus Medial Direct lateral muscle epicondyle portal Ulnar nerve Radial head Olecranon Posterior Approach to Elbow Joint Triceps (retracted) Posterior Triceps Distal humerus (retracted) Ulnar nerve Ulnar nerve Brachialis ECRL (displaced anteriorly) Anterior Brachioradialis Radial nerve Medial epicondyle Olecranon Anconeus (retracted) USES INTERNERVOUS PLANE DANGERS COMMENT POSTERIOR APPROACH • Distal humerus fractures • No internervous plane • Ulnar nerve • Best exposure of the joint • Loose body removal, • Olecranon is osteotomized • Nonunion of olec- • Olecranon should be drilled chondral procedures and reflected to expose ranon osteotomy and tapped before osteotomy • Ulnohumeral arthroplasty the distal humerus/joint. • Chevron osteotomy is best • Total elbow arthroplasty • Olecranon at risk of nonunion POSTERIOR APPROACH: BRYAN/MORREY • Alternative to posterior • No internervous plane • Ulnar nerve • Joint visualization is not as approach with osteotomy • Triceps is partially de- good as with osteotomy, no concern for nonunion • Same indications as tached and reflected above laterally ARTHROSCOPY PORTALS Uses: Loose body removal/articular injuries, debridements and capsular release, fracture reduction, limited arthroplasty Proximal anteromedial 2cm prox. to med. epicon- Ulnar nerve Anterior compartment, radial dyle anterior to IM septum MAC nerve head & capitellum, capsule Proximal anterolateral 2cm prox. to lat. epicondyle Radial nerve Medial joint, lateral recess, and anterior to humerus radiocapitellar joint Posterocentral 3cm from olecranon tip Safe (thru tendon) Posterior compartment, gutters Posterolateral 3cm from olecranon tip at Med. & post. ante- Olecranon tip & fossa, posterior lat. edge of triceps tendon brachial cutaneous n. trochlea Direct lateral (“soft spot”) Between lat. epicondyle, Posterior antebrachial Inferior capitellum and radiocap- radial head & olecranon cutaneous nerve itellar joint 138 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

Topographic Anatomy CHAPTER 5 Osteology Radiology Forearm Trauma Joints 140 Tunnels 141 Other Structures 143 Minor Procedures 144 History 149 Physical Exam 154 Muscles 155 Nerves 156 Arteries 157 Disorders 158 Pediatric Disorders 161 Surgical Approaches 170 173 174 179 180