Lateral epicondylitis (LE), or tennis elbow, is an overuse syndrome that primary care providers commonly see. For affected patients, LE can represent an extensive problem, as noncompliance with simple conservative therapies commonly prolongs this condition. For most patients, surgical intervention is considered a last resort.
In patients who develop LE, repetitive wrist dorsiflexion with supination and pronation causes overuse of the extensor tendons of the forearm, resulting in subsequent microtears, collagen degeneration, and angiofibroblastic proliferation.1
LE affects men and women equally. It occurs in 1% to 3% of the population but primarily in those ages 40 and older who perform relevant repetitive motion. Considerable improvement or complete resolution of LE symptoms can be achieved with conservative treatment, although six to 24 months’ continuation of such a regimen may be required. Apparent remission of symptoms can be interrupted by recurrences.1
Once a diagnosis of tennis elbow is made, the patient’s response may be, “But I don’t play tennis.”
Patient Presentation and History
Patients with LE usually present with a history of several weeks’ elbow pain of an insidious onset, followed by worsening rather than improvement. Most patients deny any history of direct elbow trauma, although pain can be secondary to an acute event.2
The most commonly reported symptom is increased pain with overhand lifting and point tenderness over the lateral epicondyle or just distal to this area. Frequently patients report weakness or decreased grip strength.
The diagnosis of LE is based on the history and physical exam and may be supported by x-ray findings. Diagnosis may be prefaced by a routine patient history regarding onset of symptoms, aggravating or alleviating factors, hand dominance, occupation, and recreational activities. A more pressing history of recent repetitive motion activities, such as raking leaves, painting, or keyboard use, may illuminate the cause of symptoms.
The clinician should inquire about the effectiveness of any home self-treatments, such as NSAIDs or other pain medication, orthotics (ie, a brace or strap), or other supportive measures. An atypical presentation (eg, elbow pain just distal to or below the lateral epicondyle) might suggest a more complex diagnosis, such as radial tunnel syndrome. Such a case may warrant a more comprehensive exam; referral to an orthopedic specialist would be suggested. A differential diagnosis for LE is shown in the table2,3 below.
Physical Examination
A detailed history will usually direct the physical exam, enhancing its basic principles, and provide a preliminary diagnosis. The examining clinician should begin by observing for any noticeable deformity. Subtle or obvious swelling can be present over the lateral epicondyle, with localized erythema. Elbow joint effusion may indicate intra-articular disease.4
In the assessment for elbow range of motion, 0° (full extension) to 140° of flexion, and 50° of pronation (palm down) and supination (palm up) is required. Instability is checked with the patient’s arm fully extended. The examiner grasps the elbow with both hands and gently applies medial, then lateral pressure, observing for any ligament laxity.
Palpation of the bones should begin over the medial epicondyle and progress to the olecranon, then to the lateral epicondyle. Direct palpation over the lateral epicondyle increases the pressure over the origin of the extensor musculotendinous structures—specifically, the extensor carpi radialis brevis and extensor digitorum tendons. This pressure generally reproduces the pain associated with LE.
The most revealing diagnostic test in the physical exam is resisted extension of a dorsiflexed clenched fist on the affected side (see the figure, below). Other physical tests for assessing this pain are with resisted extension of the long finger and resisted supination of the affected extremity. These maneuvers will elicit distinct pain at the lateral epicondyle and guarding. Neurovascular status should be assessed distally.
A brief exam of the shoulder and wrist on the affected side is suggested for completeness and to rule out other etiologies, particularly in the event of a fall or other traumatic injury.
Radiographic Imaging
Plain film x-rays are obtained to rule out fracture, tumor, or degenerative changes. There is no clear evidence in the literature that plain film x-rays are helpful with the initial diagnosis, and repeat x-rays at subsequent visits are not required when no further trauma has occurred. In cases of extreme LE refractory to conservative treatment, further evaluation with MRI is required.5
Treatment
Treatment for LE is generally conservative. The use of NSAIDs, rest, ice, and a tennis elbow strap (ie, a nonarticular proximal forearm strap or brace) are considered first-line treatment options.1 The purpose of a tennis elbow strap is to relieve pressure over the lateral epicondyle by increasing pressure over the forearm muscles. Correct application of the strap is essential to alleviate pain.