Denise A. Vanacore-Chase The elbow is a hinged joint that is a three-joint complex formed by the humerus, radius, and ulna.1 It allows flexion and extension of the elbow. Microtears of the muscles, ligaments, and tendons from inflammation and trauma are common causes of acute and chronic elbow pain. Most elbow injuries result from overuse during high-force or repetitive motion activities. Two groups of people seem to be at increased risk for elbow disorders. The first is high-performance athletes, especially in racket and throwing sports such as baseball, tennis, racquetball, golf, and basketball. The second group includes those with jobs that require forceful or repetitive wrist and elbow rotation, lifting, gripping, or torqueing motions. High-risk occupations include factory workers, laborers, carpenters, and grocery checkers. The prevalence of occupational lateral epicondylitis is as high as 5.2% and the prevalence of medial epicondylitis is 1.5%.1 In the general population, injuries may occur from pursuing recreational hobbies. Improper preparation, lack of strength or conditioning, and overzealousness can all contribute to elbow pain. The lateral side is affected 7 to 10 times more often than the medial.1 The elbow is also vulnerable to inflammatory arthritides, including rheumatoid arthritis and the spondyloarthropathies. It is critical that the elbow joint be fully functional for an individual to have full hand and wrist movement. The elbow is formed by the articulations of the humerus, radius, and ulna. The humeroulnar articulation is a hinge joint and allows flexion and extension of the elbow and flexion, extension, pronation, and supination of the wrist.1 The humeroradial and radioulnar articulations are partially ligamental; their flexibility allows rotation of the radius and pronation-supination of the forearm. This inhibits the amount of excessive motion in the joint and limits the joint to operating as a hinge. Stability of the elbow is accomplished through bones, ligaments, and muscles. The humeroulnar joint is the main stabilizer for flexion and extension of the elbow. Rotational stability is divided into valgus and varus stabilizers. A valgus stress is a force on the medial elbow from throwing or axial compression. Primary valgus stabilizers are the medial (ulnar) collateral ligaments and their supporting muscles. A varus stress is a force on the lateral elbow. The lateral (radial) collateral ligaments stabilize for varus stress. Elbow injuries may be classified as acute or chronic. Acute injuries result from a single high force, such as a fall or direct blow, that is greater in strength than the tendon, ligament, or bone affected. However, most injuries are chronic. Chronic injuries occur from repetitive, submaximal forces that overload the elbow’s ability to adequately heal, causing recurrent pain.2 Elbow pain may be traced to a specific activity or chain of events or may appear insidiously, with no identifiable trigger. The pain may or may not radiate into the shoulder or into the wrist. The patient may experience weakness in the hand, wrist, or elbow.1 Once an injury has occurred, everyday activities such as picking up groceries, reaching, or pulling can cause pain. A thorough history, including occupational and recreational activities and any prior elbow injury, is essential. An assessment of the onset and type of pain is also important.3 Pain can be described as sharp, intermittent, and usually in the vicinity of the lateral or medial epicondyle. A history of falls, a direct impact to the elbow, or a history of other joint pain or swelling is also needed to exclude fracture, rheumatoid arthritis, seronegative spondyloarthropathy, crystal arthropathies, or other systemic diseases. Physical examination of both elbows is performed to assess for alteration in carrying angle, posture, strength, and range of motion. Bone and soft tissue landmarks should be assessed for asymmetry, malalignment, erythema, swelling, and tenderness. Bone landmarks to be examined are the medial and lateral epicondyles of the humerus and the olecranon process of the ulna. Range-of-motion testing includes flexion and extension and pronation and supination. Normal flexion and extension are 0 to 135 degrees. The elbow can rotate from 0 to 180 degrees. Normal range of motion effectively rules out involvement of the elbow joint itself. Functional range of motion for normal activities of daily living is 30 to 130 degrees of flexion, with the greatest strength and greatest stress on the elbow at 70 degrees.1 Extra-articular pathologic conditions, including epicondylitis and olecranon bursitis, rarely affect elbow range of motion.4 The extensor tendons at the lateral epicondyle and the flexor tendons at the medial epicondyle are palpated for tenderness. Several confirmatory tests or maneuvers may be helpful. Resisted wrist extension or flexion may help diagnose lateral or medial epicondylitis, respectively. A local anesthetic block can be placed near the suspected involved tendon. Relief of pain with this injection is confirmatory.1 Posteriorly, the olecranon bursa overlies the olecranon process. The olecranon bursa is inspected and palpated for redness, swelling, tenderness, or chronic thickening. The ulnar nerve sits in a groove between the medial epicondyle and the olecranon process.4 The Tinel sign is present when tapping over the ulnar groove reproduces pain or numbness felt in the fourth and fifth fingers. Muscles for wrist flexion and pronation originate through tendons from the medial epicondyle and then spread out along the palmar surface of the forearm. Physical examination should include the wrist, shoulder, and neck because pathologic conditions at these sites may cause referred pain to the elbow. Location and radiation of the pain are critical for accurate assessment. Lateral elbow pain with passive wrist flexion and active wrist extension usually indicates lateral epicondylitis, and medial epicondylitis is indicated by pain with resisted wrist flexion and forearm pronation and passive wrist extension.5 Testing is based on the mechanism of injury or duration of symptoms. X-ray studies of the elbow are the most commonly ordered tests. Standard x-ray studies include an anteroposterior film with the elbow fully extended and supinated and a lateral view with the elbow flexed at 90 degrees and the forearm supinated. Oblique views may be needed to better study the radial head and shaft, the humeral condyles, and the coronoid process of the ulna.6 Laboratory testing is based on the clinical history. A complete blood count (CBC), erythrocyte sedimentation rate (ESR), rheumatoid factor, antinuclear antibody test, Lyme titer, or elbow joint or bursal aspiration may be indicated to exclude infection or systemic disease. Joint aspirate should be evaluated with a culture and Gram stain and examined for crystals.7 Magnetic resonance imaging (MRI) is the diagnostic tool of choice to examine the joint for loose bodies, ligament injury, stress fractures, or osteochondral lesions. Ultrasound is being used more frequently to determine the loss of the tendon’s normal fibrillar pattern and neovascularization.1 Ultrasound is best reserved for patients with atypical presentations or poor response to treatment.
Elbow Pain
Definition and Epidemiology
Pathophysiology
Clinical Presentation
Physical Examination
Diagnostics
Elbow Pain
Chapter 174
