Netter's 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