Elbow and Forearm Anatomy

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Elbow and Forearm Anatomy

• Joint is formed by the humerus, radius, and the
  ulna

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• Bony Structures
• Humerus
• Ulna
• Radius

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Humerus

• Medial Epicondyle
• Distal anteriomedial border-trochlea
• Epicondyle serves as axis of rotation of ulna
• Lateral Epicondyle
• Capitulum (radial head)
• Radial Fossa
• Immediately above capitulum to accept radial head
  during elbow flexion

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Ulna

• Forms medial border of forearm
• Semilunar notch
• Lined with articular cartilage and fits snugly
  around trochlea
• Olecranon Process
• Forms proximal border of ulna
• Humeral olecranon fossa
• Coronoid process
• Coronoid fossa during elbow flexion
• Radial notch
• Indentation that accepts radial head to form
  proximal radioulnar joint

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Radius

• Lateral aspect when in anatomical position
• Bicipital tuberosity (radial tuberosity)
• Insertion site for bicep brachii
• Radial Styloid Process
• Projects off lateral border of distal radius

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Articulations

• Humeroulnar
• Humeroradial
• Proximal Radioulnar
• Distal Radioulnar

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Humeroulnar

• Modified Hinge joint
• Allows for 1 degree freedom of motion
• Flexion
• Extension

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Humeroradial

• Modified Hinge joint
• Allows for 2 degrees freedom of motion
• Flexion/extension
• As the radial head glides around the capitulum
• Internal rotation/external rotation
• At capitulum during pronation/supination

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Proximal Radioulnar

• Formed by convex radial head and concave radial
  notch
• Allows for 1 degree freedom of movement
• Pronation
• Supination

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Distal Radioulnar

• Formed by articular disk between radius and ulna
• Interosseous membrane classifies it as syndemosis
  joint
• During pronation the radial head within the notch
  causes the radius to cross over the ulna (reverse
  occurs in supination)

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Ligamentous support

• Ulnar Collateral Ligament
• Lateral Ulnar collateral Ligament
• Radial Collateral Ligament
• Annular Ligament
• Interosseous Membrane

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• Ulnar Collateral Ligament
• Anterior Oblique Band
• Transverse Oblique Band
• Posterior Oblique Band

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Ulnar Collateral Ligament (UCL)

• Medial
• Supports against valgus force
• Anterior Oblique band
• Transverse Oblique band
• Posterior Oblique band

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Lateral Ulnar Collateral Ligament(LUCL)

• Arises from middle lateral epicondyle and inserts
  on the ulnar tubercle
• Disruption results in rotary instability
• Most important lateral stabilizing structure

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Radial Collateral Ligament (RCL)

• Thickened area in lateral joint capsule between
  the lateral epicondyle and annular ligament
• Resists varus stress
• Maintains relationship between humeral and radial
  head

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Annular Ligament

• Permits IR/ER of radius/ulna
• Attach to coronoid process
• Anterior fibers are taut with supination
• Posterior fibers are taut during hyperpronation

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Interosseous Membrane

• Run obliquely from the radius to the ulna between
  the proximal and distal radioulnar joints
• Stabilizer against axial forces applied to the
  wrist
• Origin for many muscles

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Muscular Anatomy

• Elbow Flexor/Supinator Group
• Elbow Extensor/Pronator Group

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Elbow Flexor/Supinator Group

• Prime flexors
• Biceps brachii
• Supinated biceps becomes primary elbow flexor
• Brachialias
• Pronated brachialis becomes primary elbow flexor
• Brachioradialis
• Neutral brachioradialis becomes primary elbow
  flexor
• Supinator(biceps brachii and brachioradialis)
• Brachioradialis pronates from supinated position

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Elbow Extensor/pronator group

• Triceps
• Elbow extension
• Anconeous
• Elbow extension
• Pronator teres(proximally)
• Primary pronator
• Pronator quadratus(distally)
• Primary pronator

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Nerves

• Median
• Ulnar
• Radial

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Median

• Carpal tunnel
• Follows same path as brachial artery and flexor
  digitorum superficialis
• Sensory
• palmar thumb 2,3, portion of 4th
• Dorsal 2 and portion of 4th
• Supplies wrist flexors and pronators
• Except flexor carpi ulnaris and medial portion of
  flexor digtorium profundus

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Ulnar

• Travels between olecranon process and medial
  epicondyle
• Around posterior medial epicondyle
• Innervates flexor carpi ulnaris and medial
  portion of flexor digitorium profundus
• Sensory ½ 4th and 5th palmar and dorsal

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Radial

• Between brachioradialis and brachialis
• Two branches
• Superficial
• Sensation only to dorsum of wrist, hand, and
  thumb
• Deep

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Bursae

• Subcutaneous Olecranon bursa
• Between skin and olecranon
• Subtendinous Olecranon Bursa
• Between tendon triceps and olecranon

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Clinical Evaluation of Elbow and Forearm

• History
• Onset (Acute vs.Chronic)
• Location
• Referred pain to cervical spine, shoulder, hand
• Mechanism of Injury
• Technique
• Associated sounds and sensations
• Previous history
• General Medical Health

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• Inspection
• Contusion, ecchymosis, scars
• Carry Angle (10-15 degrees)
• Cubital Fossa
• Swelling
• Medial Epicondyle
• Flexor/Extensor muscle mass
• Alignment of wrist forearm
• Recurvatum

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• Palpation
• Anterior
• Biceps Brachii
• Cubital Fossa
• Medial
• UCL
• Lateral
• Radial Head
• Capitulum
• RCL
• Annular ligament

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• Functional Testing
• Elbow flexion/extension
• Forearm pronation/supination
• AROM
• PROM
• RROM
• Ligamentous Stress Tests

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Elbow Goniometry

• Flexion/Extension
• Patient
• Supine, shoulder in neutral, forearm supinated
• Fulcrum
• Centered over olecranon
• Stationary Arm
• Aligned with long axis of humerus (use acromian
  as proximal landmark
• Movement
• Aligned with long axis of radius (use styloid as
  distal landmark)

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• Pronation/Supination
• Patient
• Humerus held against torso
• Elbow flexed to 90 degree
• Fulcrum
• Centered to lateral ulnar styloid process
• Stationary Arm
• Aligned parallel to midline of humerus
• Movement

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Special Tests

• Ligamentous Stress Test
• Must perform in flexion in frontal plane
• Olecranon locked within fossa (full extension)

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• Tennis Elbow Test
• Patient
• Test elbow in 90 deg, forearm pronated, fingers
  flexed
• Examiner
• Stand lateral to patient with one hand positioned
  over dorsal aspect of wrist and hand
• Procedure
• Examiner resists wrist extension while palpating
  lateral epicondyle and attachment of wrist
  extensors
• Positive Tests
• Implications

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Golfers Elbow Test

• Examiner
• Palpate patients medial epicondyle while
  patients forearm is passively supinated and
  elbow and wrist are extended by examiner
• Positive Test
• Pain over medial epicondyle of humerus
• Implications
• Medial Epicondylitis

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Tinels Sign

• Area of ulnar n. in groove is tapped
• between olecranon process and medial epicondyle
• Positive sign
• tingling sensation in the ulnar distribution of
  forearm and hand distal to point of compression
  of the nerve
• Implications
• Point of regeneration of sensory nerve fibers

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Special Tests

• Valgus Stress Test
• Patient
• Standing or sitting with elbow flexed to 25
  degrees
• Examiner
• 1 hand supporting lateral elbow (palpated medial
  jt. Line)
• Opposite hand grasping distal forearm
• Procedure
• Apply valgus force in varying degrees of flexion
• Positive Test
• Increased laxity or pain
• Implications

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• Varus Stress Test
• Patient
• Standing or sitting with 25 degree elbow flexion
• Examiner
• 1 hand supporting medial joint line (palpate
  lateral jt. Line)
• Opposite hand grasping distal forearm
• Procedure
• Varus force applied to elbow in varying degrees
  of flexion
• Positive Test
• Increased laxity or pain
• Implications

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• Posterolateral Rotatory Instability Test
• Patient
• Supine, shoulder and elbow flexed to 90 degree,
  forearm supinated
• Examiner
• Standing at head of patient
• One hand grasping proximal forearm with the other
  hand grasping distal forearm at wrist
• Procedure
• Apply valgus stress and axial compression
• Elbow is extended and forearm is maintained in
  full supination
• Elbow is then taken back into flexion

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Neurological Testing

• Dermatomes
• Myotomes
• Reflex
• Bicep (C5-C6)
• Brachioradialis (C5-C6)
• Tricep (C7-C8)

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On field evaluation of elbow/forearm

• History
• Position of arm
• Type of force involved
• Longitudinal
• Lateral
• Medial

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• Inspection
• Alignment of forearm and wrist
• i.e gross deformity
• Posterior triangle of wrist
• Note alignment of medial epicondyle, lateral
  epicondyle and olecranon process

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• Palpation
• Alignment of elbow
• Collateral ligaments
• Radius and ulna

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• Functional Tests
• AROM
• Willingness to move
• PROM
• RROM
• Neurological Screen

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On field management

• Elbow dislocations
• Immobilize in position and monitor distal pulse
• Forearm Fractures
• Distal Pulses

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Elbow Injuries and Conditions
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Olecranon Bursitis

• Mechanism
• Acute/chronic
• Fall on a hard surface
• Signs and Symptoms
• Pain
• Redness/swelling
• Loss of function
• Possible calcium formation in chronic cases

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• Special Tests
• None
• Diagnostic Procedure
• Refer to physician

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Lateral Epicondylitis(Tennis Elbow)

• Mechanism
• Forceful extension of forearm with pronation
  (i.e.golf,tennis)

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• Signs and Symptoms
• Pain on lateral epicondyle with A/R wrist
  extension
• Loss of function
• Tenderness
• Pt tenderness
• Swelling

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• Special Tests
• A/R wrist extension
• Handshaking
• Diagnostic Procedures
• Refer to ortho

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Little League ElbowMedial Epicondylitis

• Mechanism
• Repetitive microtrauma (increased flexion with
  curve/screwball)
• May involve bony structures
• Growth plate
• Traction apophysitis
• Nonunion stress of olecranon epiphysis

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• Signs and Symptoms
• Slow onset
• Flexion contracture
• Tightness anterior capsule
• Weakness in triceps
• Locking/catching
• Decreased pronation/supination
• Inflammation
• Tenderness/ pain over medial epicondylitis

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• Tests
• Varus/valgus
• Medial epicondylitis test
• X-ray/bone scan

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Collateral Ligament Sprain

• Mechanism
• Indirect trauma
• Overuse
• Forced hyperextension
• Valgus/varus force

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• Signs and Symptoms
• Pain on A/P/RROM
• Loss of function
• Tenderness
• Swelling
• Hemorrhage
• Ecchymosis

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• Special tests
• Valgus/varus stress
• A/RROM
• Diagnostic Procedure
• Ortho

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Elbow Sprains

• Mechanism
• Flexed elbow
• Valgus (UCL)
• Varus (RCL)
• Occasionally hyperextension force
• Overhead pitching relies on triceps,
  flexor/pronator group for dynamic stabilization

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• UCL signs and symptoms
• Swelling anterior, medial, posterior
• Anterior oblique band most commonly injured
• Elbow flexed past 60 (posterior oblique band)
• Decreased ROM
• Laxity with valgus stress testing
• UCL tests (valgus _at_ 25 and 60 deg)
• RCL tests (varus)

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Radius Fracture

• Mechanism
• Direct trauma
• Twisting force
• Signs and symptoms
• Sudden pain
• Loss of function
• Tenderness
• Possible deformity/crepitus/bony deviation
• Swelling

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• Special Tests
• Radial pulse
• Diagnostic Procedure
• Refer to ortho
• X-ray

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Radial Head Fracture

• Mechanism
• Fall on outstretched hand
• Signs and symptoms
• Limit in A/P/R extension/supination
• Tenderness over radial head
• Swelling
• Radial nerve irritation possible

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Supracondylar Fracture

• Mechanism
• Fall on outstretched hand/ hyperextended elbow
• Deformity (gunstock deformity)
• Loss of function
• Crepitus
• Nerve or vascular injury

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• Signs and Symptoms
• Sudden pain
• Loss of function
• Tenderness
• Possible deformity/bony deviation/crepitus
• Rapid swelling
• Delayed ecchymosis

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• Special Tests
• Check radial pulse
• Diagnostic Procedure
• Ortho
• X-Ray

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Distal Epiphyseal Plate Injury

• Mechanism
• Direct or indirect trauma
• Fall on outstretched hand or hyperextended wrist
• Repetitious or overuse activities

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• Signs and symptoms
• Sudden pain
• Loss of function
• Direct or indirect tenderness
• Possible deformity
• Rapid swelling
• Possible bony deviations
• Possible crepitus
• Delayed ecchymosis

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• Special Tests
• Check Radial Pulse
• Diagnostic Procedure
• Ortho
• X-ray

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Ulna Fracture

• Mechanism
• Direct trauma
• Indirect or impact force
• Twisting

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• Signs and Symptoms
• Sudden pain
• Loss of function
• Tenderness
• Possible deformity
• Rapid swelling
• Possible bony deviation/crepitus
• Delayed ecchymosis

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• Special tests
• Check radial pulse
• Diagnostic Procedure
• Ortho
• X-Ray

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Elbow dislocation

• Anterior
• Mechanism
• trauma
• Signs and Symptoms
• Deformity(plus swelling, loss of olecranon
  definition)
• Loss of function
• Elbow fixed in extension
• Fullness in cubital fossa from condyles of
  humerus
• Tests
• Radial pulse, motor,sensory function

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• Posterior- most common
• Mechanism
• Fall on hyperextended/ flexed elbow with
  supinated forearm
• Signs and symptoms
• Deformity (swelling plus prominent olecranon
• Loss of function
• Elbow fixed in flexion
• Profuse hemorrhage
• Tests
• Check pulse/motor/sensory

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Median Nerve Injury

• Mechanism
• Direct trauma
• Contusion to nerve
• Repetition
• Compression from fracture/luxation
• Signs and Symptoms
• Weakness in grip
• Muscle atrophy of thenar eminence
• Numbness
• Sensory loss

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• Signs and symptoms
• Weakness in grip/thumb abduction against
  resistance
• Muscle atrophy of thenar eminence
• Numbness
• Sensory loss in n. distribution
• Loss of function

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• Special tests
• Thumb abduction against resistance
• Check sensation on palmer aspect of index finger
• Tinels sign
• Diagnostic Procedure
• Refer to neurologist

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Radial Nerve Injury

• Mechanism
• Direct trauma
• Compression-
• above humerus (triceps contraction)
• Dislocation/ fracture
• Signs and symptoms
• Special Test

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Ulnar Nerve Injury

• Mechanisms
• Direct trauma
• Entrapment in scar tissue
• Repetitive valgus stress (subluxation of ulnar
  n.)

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• Signs and Symptoms
• Pain
• Loss of function(forearm 4th/5th finger)
• Numbness
• Tingling and/or burning sensation in forearm and
  hand over ulnar n. distribution

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• Special tests
• Sensation and motor test over lunar n.
  distribution
• Tinels sign
• Diagnostic Procedures
• Refer to neurologist

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Volkmanns contracture

• Mechanism
• Supracondylar fracture of humerus
• Median n. brachial a.
• Signs and symptoms
• Medical Emergency

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• Signs and symptoms
• Pain in forearm that increases when fingers
  extended
• Paralysis
• Ischemia
• Neurological changes (coldness/stiffness/numbness)
  
• Swelling
• Eccchymosis
• Deformity

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• Special Tests
• Compartment pressure
• Allens Test
• Referral
• Ortho
• Neurologists
• X-Ray

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Osteochondritis Dissecans

• Mechanism
• Unknown
• Impaired blood supply to area
• Articular or hyaline cartilage degeneration

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• Signs and symptoms
• Pain after exercise
• Loss of function
• Chronic nonspecific swelling
• Muscle atrophy
• Crepitus
• Transient locking

85

• Special Tests
• A/P/RROM
• Diagnostic Procedures
• Refer to ortho
• X-Ray