Dr. Kevin Yip

Dr Kevin Yip
Orthopaedic Surgeon
MBBS(UK), FRCS(EDIN), FAM(SING), FHKCOS(ORTHO)

Featured on Channel NewsAsia

Elbow Anatomy and Examination

Basics
Description
  • Bones
    • Ulnohumeral joint:
      • The trochlea of the humerus articulates with the trochlear notch of the proximal ulna.
      • The olecranon process of the ulna lies posterior to the joint.
      • Allows for elbow flexion and extension
    • Radiohumeral joint:
      • The capitulum of the humerus articulates with the radial head.
      • Allows for forearm supination and pronation
  • Ligaments:
    • UCL: Stabilizes the elbow medially
    • RCL: Stabilizes the elbow laterally
  • Muscles:
    • Biceps: Flexor and supinator
    • Brachialis: Flexor
    • Triceps brachii: Extensor
    • Pronator teres: Flexor and pronator
  • Nerves:
    • Median nerve:
      • Crosses the elbow anteriorly, superficial to the brachialis muscle, and medial to the brachial artery
      • Innervates the flexors of the forearm
    • Ulnar nerve:
      • Crosses the elbow superficially and posterior to the medial epicondyle in cubital tunnel
      • Innervates the intrinsic muscles of the hand
    • Radial nerve:
      • Crosses the elbow anteriorly to the lateral epicondyle
      • Innervates wrist, hand, and elbow extensors
Signs and Symptoms
Physical Exam
  • Initial assessment:
    • Assess completely the contralateral elbow for comparison.
    • Assess the neck, shoulder, and wrist.
    • Perform a complete neurovascular examination of the extremities.
  • Inspection:
    • Expose both upper extremities from the shoulder girdle to the hand, inspecting for asymmetry anteriorly and posteriorly.
    • The elbow-carrying angle should be 5-10° of valgus for males and 10-15° of valgus for females.
  • Palpation:
    • Localize pain to an anatomic structure with digital palpation.
  • ROM and strength testing:
    • Compare active and passive ROM.
      • Flexion: 140-150°
      • Extension: 0-10° of hyperextension
      • Supination: 90°
      • Pronation: 80-90°
    • Activities of daily living require 30-130° of flexion, 50° of supination, 50° of pronation.
    • Test isometric strength, testing bilaterally
  • Elbow effusion:
    • Palpate elbow laterally in the center of the anatomic triangle formed by the lateral epicondyle, radial head, and tip of the olecranon.
    • Effusion may indicate intra-articular abnormality and can be accompanied by loss of elbow extension.
Diagnosis
  • Lateral epicondylitis (tennis elbow):
    • Repetitive overuse of the wrist and finger extensors
    • Tenderness to palpation of lateral epicondyle
    • Resisted wrist extension test:
      • Test resisted dorsiflexion of the wrist with forearm in pronation.
      • Test is positive if it reproduces pain near the lateral epicondyle.
  • Medial epicondylitis (golfer’s elbow):
    • Resisted flexion/supination test:
      • Place the patient’s elbow in slight flexion and the forearm in full supination.
      • Test resisted wrist flexion and/or pronation against resistance.
      • The test is positive if pain is reproduced at the medial epicondyle.
  • Olecranon bursitis:
    • Bursa lies subcutaneous and posterior to the olecranon process.
    • Bursitis may be secondary to trauma, hemorrhage, sepsis, or a rheumatologic condition.
    • Effusion can present with or without erythema and may be tender to palpation over the tip of the olecranon.
  • Instability:
    • UCL insufficiency (valgus stress test):
      • Secure the wrist between the examiner’s forearm and trunk.
      • Flex the elbow to 30° and apply a valgus stress.
      • Palpate the UCL along its course from the medial epicondyle toward the proximal ulna during this maneuver.
      • Increased medial joint-space opening with loss of a firm endpoint suggests UCL insufficiency.
    • RCL insufficiency (posterolateral rotatory instability test):
      • With the patient supine and the shoulder flexed overhead, externally rotate the humerus to stabilize it.
      • Grasp the forearm in full supination.
      • Starting with forearm supination and elbow extension, slowly flex the elbow while applying a slight valgus.
      • A positive test results in a palpable clunk, a posterior prominence of the radial head, and an obvious dimple in the skin proximal to the radial head as the elbow subluxates.
  • Valgus extension overload:
    • Overuse injury associated with a throwing athlete
    • Often associated with UCL insufficiency, intra-articular loose bodies, and radiocapitellar articular cartilage injury
    • Caused by posterior medial impingement of ulnohumeral articulation and compression of radiocapitellar joint during throwing motion
    • Passive hyperextension of the elbow reproduces pain posteromedially.
  • Elbow arthritis:
    • Commonly presents with flexion contracture (incomplete passive and active extension) and pain at terminal extension
    • Can present with limitation in elbow flexion
    • Elbow effusion can be variable.
  • Cubital tunnel syndrome:
    • Created by compression of ulnar nerve at the elbow
    • Usually presents with pain
    • May be associated with numbness and paresthesias in distribution of the ulnar nerve
    • Symptoms worsen with prolonged elbow flexion
    • Positive Tinel sign: Tapping of the ulnar nerve at the posterior aspect of lateral epicondyle reproduces radicular pain and or paresthesia down the ulnar aspect of forearm/hand.
  • Distal biceps rupture:
    • Nonpalpable biceps tendon
    • Pain to palpation in the antecubital space
    • Popeye sign:
      • The biceps resembles a Popeye muscle when resisted elbow flexion is tested.
      • Note: The Popeye sign also occurs with proximal biceps tendon rupture.
Miscellaneous
FAQ
Q: What are 3 common causes of atraumatic elbow pain?
A: Lateral epicondylitis, olecranon bursitis, and ulnar neuritis.

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