LATERAL EPICONDYLITIS

LATERAL EPICONDYLITIS

Lateral epicondylitis, or tennis elbow, is the most common overuse injury of the elbow and is observed up to 10 times more frequently than medial epicondylitis.

Lateral epicondylitis is usually precipitated by repetitive contraction of the wrist extensors and is characterized by aching pain that is worsened with activity.

Early conservative management is the key to symptom resolution, which eventually allows return to vocational and avocational activities without restriction.

PATHOPHYSIOLOGY

Lateral epicondylitis is a result of inflammation, or enthesitis, at the muscular origin of the extensor carpi radialis brevis (ECRB). This inflammation leads to microtears of the tendon, with subsequent fibrosis and, ultimately, tissue failure.

Less commonly, the attachments of the extensor carpi radialis longus (ECRL), extensor digitorum communis (EDC), or extensor carpi ulnaris (ECU) are involved.

SEX

The condition affects men and women with equal frequency.

AGE

Lateral epicondylitis most often occurs between the third and fifth decades of life.

CLINICAL

HISTORY

The patient usually describes a gradual onset of lateral elbow pain, which is characterized as follows:

• The aching pain generally increases with activity. The patient may describe symptoms occurring during simple activities of daily living (ADL), such as picking up a cup of coffee or a gallon of milk.

• Pain may be present at night.

• Symptoms are typically unilateral.

PHYSICAL

Most commonly, the examination reveals localized tenderness to palpation just distal and anterior to the lateral epicondyle. Other symptoms include the following:

• Pain increases with resisted wrist extension, especially with the elbow in extension.

• The patient may have a weakened grip on the affected side.

• Elbow range of motion (ROM) is typically normal.

• In chronic, refractory cases, be sure to fully assess shoulder integrity and scapular stability. Weakness or instability of the scapular stabilizers may perpetuate lateral epicondylitis by leading to overuse of the wrist extensors.

CAUSES

• Lateral epicondylitis is an overuse syndrome generally caused by repetitive use of the wrist extensors or sustained power gripping.

• Lateral epicondylitis can be associated with an imbalance secondary to muscle weakness and soft-tissue inflexibility.

DIAGNOSIS

LABORATORY STUDIES

• Laboratory studies generally are not indicated for the diagnosis of lateral epicondylitis.

IMAGING STUDIES

• Imaging studies usually are not necessary, but tendinopathies can be visualized with magnetic resonance imaging (MRI) and with ultrasonography.

OTHER TESTS

• Electrodiagnostic studies may help to determine whether other causes of lateral elbow pain, such as cervical radiculopathy or posterior interosseous nerve palsy, are present.

HISTOLOGIC FINDINGS

Findings can include collagen disorientation, collagen disorganization, fiber separation by increased mucinoid substance, an increased prominence of cells and vascular spaces (with or without neovascularization), and focal necrosis or calcification.

Superimposed evidence of a tear, including fibroblastic proliferation, hemorrhage, and organizing granulation tissue, may be revealed. 

TREATMENT

PHYSICAL THERAPY

Acutely, the goals of treatment are to reduce pain and inflammation.

Anti-inflammatory modalities include ice, ultrasonography, and iontophoresis. Iontophoresis with topical nonsteroidal anti-inflammatory drugs (NSAIDs) has been shown to help reduce pain. 

The use of iontophoresis with corticosteroids is not supported. A wrist splint used during activities can be helpful, because it places the extensor muscles in a position of rest and prevents maximal muscle contraction.

Counterforce bracing (tennis elbow strap) is another orthotic alternative that can be used to unload the area of muscle origin at the elbow. 

A splint or brace should not be used in isolation but should be employed only as an adjunct to modalities and exercise/stretching.  

Deep-tissue and friction massage help to release underlying adhesions and promote improved circulation to the area.

In the subacute stage, emphasis is placed on the restoration of function of the involved muscle group.

Flexibility, strength, and endurance of the wrist extensor muscle group can be achieved through a graded program.

ROM for wrist flexion/extension and pronation/supination should be achieved prior to proceeding with a strengthening program.

Strength and grip training should progress from isometric to concentric to eccentric contractions of the forearm muscles, especially the wrist extensors.

Jafarian et al compared 3 common types of orthoses for their effect on grip strength in patients with lateral epicondylitis.

In a randomized, controlled laboratory study in 52 patients, maximum and pain-free grip strength were assessed, with patients wearing an elbow strap orthosis, an elbow sleeve orthosis, a wrist splint, or a placebo orthosis.

Use of either the elbow strap or sleeve orthosis resulted in an immediate and equivalent increase in pain-free grip strength (p <0.02); consequently, the researchers suggested that either of these types of orthosis may be used.

The wrist splint provided no immediate improvement in either pain-free or maximum grip strength.

In chronic refractory cases of lateral epicondylitis, scapular stabilization should be addressed to prevent overuse of the wrist extensors during activities.

Sports-specific training should also be included in the rehabilitation program, if appropriate.

OCCUPATIONAL THERAPY

As activities are resumed, the patient's vocational and avocational pursuits must be considered. Job and recreational tools and/or equipment may need to be modified, especially if repetitive gripping is required.

Gradual resumption of activities is recommended to improve tolerance and prevent recurrence.

COMPLICATIONS

The so-called radial tunnel syndrome should be considered for refractory cases of lateral epicondylitis.

Criteria for diagnosis of radial tunnel syndrome are controversial in the literature. There exist cases of posterior interosseous nerve palsy

associated with weakness in muscles that are innervated by that nerve.

However, syndromes of forearm pain without associated weakness in muscles that are innervated by the posterior interosseous nerve are also seemingly labeled as radial tunnel syndrome.

Electrodiagnostic studies should be helpful in demonstrating nerve injury in cases of radial tunnel syndrome, thereby differentiating this entity from a forearm pain syndrome.

In compression of the posterior interosseous nerve, patients report pain at the lateral aspect of the elbow and weakness in the wrist and hand, but no sensory symptoms.

Electrodiagnostic findings in posterior interosseous nerve compression may include denervation in radial-supplied muscles distal to the supinator, and possibly slowing across the area of entrapment.

Surgical intervention for radial tunnel syndrome or persistent tennis elbow should be approached with caution and only after a thorough workup and extensive conservative management.

SURGICAL INTERVENTION

For cases of refractory lateral epicondylitis, surgical resection of the lateral extensor aponeurosis might be considered.

OTHER TREATMENT

Topical NSAIDs may provide short-term pain relief, but evidence is conflicting on the use of oral NSAIDs.

If a patient does not seem to be responding to conservative care, a steroid injection about the lateral epicondyle using local anesthetic can be performed.

However, the role of corticosteroid injection in tendinopathy remains controversial. Most lateral epicondylitis is degenerative rather than inflammatory, and injecting steroid around a tendon can inhibit collagen repair; therefore, steroid injections should be used on a limited basis.

Additionally, injecting a corticosteroid directly into a tendon can be deleterious. Nonetheless, steroid injections in some cases can bring about dramatic, albeit short-term, relief.

When employing steroid injections, the following steps should be taken:

• Palpate the lateral epicondyle to locate the painful area (usually inferior and radial to the lateral epicondyle).

• Using a 25- or 30-gauge needle, inject 0.5-1 mL of triamcinolone (20 mg/mL) and 1-2 mL of 1% lidocaine. Infiltrate the area, distributing small aliquots of medication in a fanlike fashion. To avoid tissue rupture, take care not to inject directly into the origin of the extensor muscle group.

• Heavy lifting or repetitive activity by the patient should be minimized for 48-72 hours after the injection.

Other substances used for injection include local anesthetics and botulinum toxin. However, studies have provided conflicting evidence as to whether botulinum toxin injection has positive long-term benefits for lateral epicondylitis.

Other types of treatment have included acupuncture and extracorporeal shockwave therapy.  However, there is insufficient evidence to support acupuncture as a treatment for epicondylitis. Likewise, reviews of trials using shockwave therapy have found reasons not to support this as a treatment option.

MEDICATION

The goal of drug treatment in cases of lateral epicondylitis is pain control, in order to facilitate the performance of ADL.

NONSTEROIDAL ANTI-INFLAMMATORY DRUGS (NSAIDS)

These agents have analgesic, anti-inflammatory, and antipyretic activities. Their mechanism of action is not known, but they may inhibit cyclooxygenase (COX) activity and prostaglandin synthesis. Other mechanisms may exist as well, such as inhibition of leukotriene synthesis, lysosomal enzyme release, lipoxygenase activity, neutrophil aggregation, and various cell membrane functions. 

DICLOFENAC (Solaraze)

Designated chemically as 2-[(2,6-dichlorophenyl) amino] benzeneacetic acid, monosodium salt, with an empirical formula of C 14 H 10 Cl 2 NO 2 NA. Diclofenac is one of a series of phenylacetic acids that has demonstrated anti-inflammatory and analgesic properties in pharmacologic studies. It is believed to inhibit the activity of COX, which is essential in the biosynthesis of prostaglandins.

Adult: Apply topically to affected area(s) bid

Pregnancy

B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals

D - Fetal risk shown in humans; use only if benefits outweigh risk to fetus

Precautions

Pregnancy category D in third trimester of pregnancy; may cause hypersensitivity, caution in those predisposed (eg, aspirin allergy); may cause contact dermatitis, rash, pruritus, or exfoliation at application sites 

IBUPROFEN (Motrin, Ibuprin, Advil, Excedrin IB)

DOC for patients with mild to moderate pain. Ibuprofen inhibits inflammatory reactions and pain by decreasing prostaglandin synthesis.

Adult: 400-800 mg PO qid

Pregnancy

B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals

D - Fetal risk shown in humans; use only if benefits outweigh risk to fetus

Precautions

Pregnancy category D in third trimester of pregnancy; caution in congestive heart failure, hypertension, and decreased renal and hepatic function; caution in coagulation abnormalities or during anticoagulant therapy 

NAPROXEN (Naprosyn, Naprelan, Anaprox, Aleve)

For relief of mild to moderate pain. Naproxen inhibits inflammatory reactions and pain by decreasing the activity of COX, which is responsible for prostaglandin synthesis.

Adult: 250-500 mg PO bid; may increase to 1.5 g/d for limited periods

Pediatric:

<2 years: Not established

>2 years: 2.5 mg/kg/dose PO; not to exceed 10 mg/kg/d

Pregnancy

B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals

D - Fetal risk shown in humans; use only if benefits outweigh risk to fetus

Precautions

Pregnancy category D in third trimester of pregnancy; acute renal insufficiency, interstitial nephritis, hyperkalemia, hyponatremia, and renal papillary necrosis may occur; patients with preexisting renal disease or compromised renal perfusion risk acute renal failure; leukopenia occurs rarely, is transient, and usually returns to normal during therapy; persistent leukopenia, granulocytopenia, or thrombocytopenia warrants further evaluation and may require discontinuation of drug 

CELECOXIB (Celebrex)

Inhibits primarily COX-2. COX-2 is considered an inducible isoenzyme, being induced by pain and inflammatory stimuli. Inhibition of COX-1 may contribute to NSAID GI toxicity.

At therapeutic concentrations, COX-1 isoenzyme is not inhibited; thus, GI toxicity may be decreased. Seek the lowest dose of celecoxib for each patient.

Adult: 200 mg/d PO qd; alternatively, 100 mg PO bid

Pregnancy

B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals

D - Fetal risk shown in humans; use only if benefits outweigh risk to fetus

Precautions

Pregnancy category D in third trimester of pregnancy; may cause fluid retention and peripheral edema; caution in compromised cardiac function, hypertension, and conditions predisposing to fluid retention; caution in severe heart failure and hyponatremia because celecoxib may deteriorate circulatory hemodynamics; NSAIDs may mask usual signs of infection; caution in the presence of existing controlled infections; evaluate therapy when symptoms or laboratory results suggest liver dysfunction

CORTICOSTEROIDS

The medications have anti-inflammatory properties and cause profound and varied metabolic effects. Corticosteroids modify the body's immune response to diverse stimuli. 

TRIAMCINOLONE (Amcort, Aristospan Intra-articular)

For inflammatory dermatosis responsive to steroids. This agent decreases inflammation by suppressing the migration of polymorphonuclear leukocytes and by reversing capillary permeability.

Adult: 0.5-1 mL (20 mg/mL formulation) IM

Pregnancy

C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus

Precautions

Multiple complications (eg, severe infections, hyperglycemia, edema, osteonecrosis, myopathy, peptic ulcer disease, hypokalemia, osteoporosis, euphoria, psychosis, myasthenia gravis, growth suppression) may occur; abrupt discontinuation of glucocorticoids may cause adrenal crisis

ANALGESICS

Pain control is essential to quality patient care. Analgesics ensure patient comfort and have sedating properties, which are beneficial for patients who experience pain. 

ACETAMINOPHEN (Aspirin-Free Anacin, Tempra, Feverall)

DOC for pain in patients who have documented hypersensitivity to aspirin or NSAIDs, who have upper GI disease, or who are taking PO anticoagulants.

Adult: 1000 mg PO tid/qid.