Abstract
Lateral elbow pain is a common issue amongst adult populations today, and the most common factors that causes the pain is lateral epicondylitis. The pathogenesis of the disease originates from the extensor carpi radialis brevis tendon (ERCB), but their are other concomitant structures that can cause the lateral pain. Injury to the ERCB is diagnosed using a history, physical examination, and imaging consisting of MRI, radiographs, and ultrasonography. Most patients diagnosed with lateral epicondylitis are able to be healed through conservative treatment including braces, antiinflammatories, and injections. When non-surgical treatment fails, surgical intervention is required, and the novel technique of ultrasonography ablation is proving to be highly successful. The disease causes pain in the ECRB region, but the positive outlook for patients is that either non-surgical or surgical management is likely going to create a satisfactory result.
Keywords
extensor carpi radialis brevis tendon, lateral epicondylitis, ultrasonography, percutaneous
Introduction
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Lateral epicondylitis is the most common overuse disorder affecting the lateral side of the elbow.
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This syndrome typically presents with intense pain about the extensor origin (lateral aspect) of the elbow. The pathogenesis of this disease originates from the extensor carpi radialis brevis (ECRB) tendon, but other closely associated structures can cause similar pain.
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Lateral epicondylitis historically was associated with the sport of lawn tennis, but this tendon injury can occur from various activities involving repetitive wrist extension.
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Typical patients are in their 40s or 50s. Surprisingly, there is no difference in occurrence between men and women.
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Angiofibrotic dysplasia is the term coined for the microscopic appearance of the diseased ECRB tendon. Lateral epicondylitis is now thought to be a dysvascular degenerative-type process termed tendinosis rather than tendonitis.
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Eighty-five percent of patients with tennis elbow will have a resolution in symptoms after conservative treatments. These treatments include resting, antiinflammatories, bracing, and injections.
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Only 10% of patients will go on to have surgical intervention for symptom relief, and 85% to 95% will be satisfied after these interventions.
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Ultrasound ablation can be considered the currently most effective treatment of lateral epicondylitis. Most patients—as high as 95%—will be pain free after this procedure.
Lateral elbow pain is a common presentation into most sports medicine clinics. It is seen in 1% to 3% of adult patients who are aged between 35 and 50 years old ( ). There are multiple causes of lateral elbow pain, including lateral epicondylitis, radial tunnel, instability, plica syndrome, annular ligament hypertrophy, radiocapitellar chondromalacia, and arthritis. Originally, lateral elbow pain was described in association with playing lawn tennis; today this complaint is less often associated with this sport. Extensive research has shown that the pathogenesis contributing to lateral epicondylitis originates from the ECRB tendon ( ). The primary objective for this chapter is to describe the relationships between lateral elbow pain and the ECRB tendon. By doing so, we will summarize the most acceptable definition for the disease, lateral epicondylitis. Next, we will discuss some of the current nonsurgical options for managing patients with lateral epicondylitis as well as the surgical options when non- to minimally invasive options fail to alleviate symptoms.
Anatomy of the Extensor Carpi Radialis Brevis and Lateral Epicondyle
When trying to understand the pathogenesis of lateral epicondylitis, one must appreciate the anatomy of the lateral elbow, particularly the lateral epicondyle and its neighboring structures. The morphology of the lateral epicondyle has been described as a pyramidal bony prominence ( ). characterized the ECRB origin as diamond shaped, beginning just anterior to the most distal aspect of the lateral supracondylar ridge. The ECRB tendon originates adjacent to the extensor digitorum communis (EDC). The ECRB footprint is located between the most proximal aspect of the capitellum and the midline of the radiocapitellar joint. Research has determined that lateral epicondylitis pathology occurs in the more superficial and the marginally deeper fibers of the ECRB tendon. The lateral collateral ligamentous complex (the radial collateral ligament, annular ligament, accessory collateral ligament, and lateral ulnar collateral ligament) lies immediately posterior to the ECRB origin, and the anconeus originates from the posterior face of the lateral epicondyle. The brachioradialis and extensor carpi radialis longus (ECRL) have their origin proximal to the ECRB along the anterior aspect of the supracondylar ridge.
Proximal to the elbow joint, the radial nerve is located between the brachialis and brachioradialis, which further divides into the two terminal branches, the superficial radial nerve and the posterior interosseous nerve (PIN). This division occurs at the level of the radial head. The PIN courses distally entering the supinator muscle. This location is sometimes termed the radial tunnel, and compression here has been implicated in cases of refractory lateral epicondylitis ( ).
Lateral Epicondylitis
History
Lateral epicondylitis was first described in 1873 in German literature by . In 1883, Morris ( ) suggested an association of symptoms with the game of lawn tennis, which led to the common term tennis elbow . Historically, it was believed that an inflammatory process was the cause of lateral epicondylitis, proposing a partial tearing of the ECRB tendon alone, with separation of the periosteum from the lateral epicondyle to elicit this inflammatory response, resulting in symptoms. Currently, several neighboring structures to the ECRB tendon have been identified as contributing to lateral elbow pain, including the annular ligament, radial nerve, lateral capsule, and several different bands of the extensor digitorum communis. In addition, microscopic studies of excised tissue demonstrate a failure of reparative response in the ECRB tendon rather than an inflammatory response within the tissue. Nirschl is credited with redefining the pathology of damage to the ECRB as angiofibrotic dysplasia, or tendinosis, rather than tendonitis.
The clinical presentation of a patient with lateral epicondylitis is an adult individual in their fourth or fifth decade of life. There are no differences in diagnosis between men and women. It is more common in the dominant arm. Recent studies have identified several risk factors for lateral epicondylitis, including a history of manual labor with heavy tools and significant strain while performing repetitive tasks ( ). Roughly 80% of patients with newly diagnosed lateral epicondylitis improve over time, and most report symptomatic relief at one year. Most experience some residual symptoms, and only 4% to 11% of those seeking medical attention require surgical intervention ( ). Poor prognostic factors for successful nonsurgical treatment include participation in manual labor, dominant arm involvement, long duration of symptoms with high baseline pain levels, and poor coping mechanism ( ).
Pathoanatomy and Histology
and outlined the most commonly accepted theory of the pathogenesis of this disease. Nirschl built on the previous findings of , and , highlighting the fundamental underlying lesion was within the origin of the ECRB tendon. Overuse and repetitive motions lead to microtears in the ECRB origin. As described earlier, most microscopic studies of excised tissue demonstrate a failure of reparative response in the ECRB tendon. The normal ECRB tendon tissue is invaded by immature fibroblasts and nonfunctional vascular buds, and adjacent tissue is often disorganized and hypercellular ( ). coined the term angiofibroblastic tendinosis because of this microscopic appearance; here there is no evidence of acute inflammation. As a result of their research, tennis elbow is now thought to be a dysvascular degenerative-type process termed tendinosis rather than tendonitis . Nirschl and colleagues have noted that 35% to 50% of patients also have degenerative changes in the EDC. These changes, as seen within the ECRB tendon, are responsible for the pain that is associated with this condition.
Physical Examination and Workup
The typical presentation of a patient with lateral epicondylitis consists of pain at the lateral elbow worsened by active wrist extension or passive wrist flexion with the elbow extended. Patients may describe an inability to hold objects in their hand because of lateral elbow pain. Physical examination typically reveals a point of maximal tenderness 1 to 3 mm anterior and distal to the tip of the lateral epicondyle, which is reproducible by resisted wrist and finger extension. This location corresponds to the origin of the EDC and ECRB tendon. Infrequently, this pain is accompanied by warmth, swelling, or erythema. The tennis elbow stress test is performed when the examiner asks the patient to resist wrist extension from neutral while the elbow is flexed and extended, with pain isolated to the ECRB origin indicating a positive test. ( Box 29.1 and Table 29.1 ).
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Poor technique
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Weak shoulder and wrist muscles
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Increased string tension
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Improperly sized grip
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Hitting heavy, wet, or dead balls
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Hitting “off center” on the racket
| Condition | Description |
|---|---|
| Radial tunnel syndrome | Maximal tenderness is usually more distal (3–4 cm) and anterior to the lateral epicondyle, primarily deep to the brachioradialis. Resisted wrist extension may not be painful, but resisted extension of the third and fourth fingers with the wrist supported may reproduce the pain. |
| Cervical radiculopathy | Usually more diffuse weakness and associated numbness without point tenderness over the lateral epicondyle |
| Posterolateral elbow plica | Palpable band of synovium posterior to the epicondyle near the posterior radiocapitellar joint. May click and pop with extension and supination. Often associated with other elbow pathology such as lateral epicondylitis and arthritis. |
| Posterolateral elbow instability | May be associated with lateral epicondylitis but has more pain with supination than resisted wrist extension. Often hypersupination in 90 degrees of flexion reproduces the symptoms and increases the index of suspicion. |
| OCD lesion of the radiocapitellar joint | Deep posterior and lateral pain that does not diminish with cessation of activity; loss of motion. Positive findings on radiographs and usually affects a completely different age population. |
Imaging
Lateral epicondylitis is predominantly a clinical diagnosis, but several imaging modalities have been used to provide supplementary information. Plain films can occasionally show calcinosis within the mobile wad origin or intraarticular pathology ( ). Nirschl noted the findings of calcifications forecast persistent and refractory disease and were present in up to 20% of patients who required surgery ( ).
Magnetic resonance imaging (MRI) can be useful during the workup of lateral elbow pain. It is an excellent tool that can evaluate for intraarticular involvement, radial collateral ligament competency, and definition of the degree of tearing of the extensor origin. In 90% of symptomatic patients, MRI scans may show thickening and edema of the extensor tendon origin ( ). High-resolution and fine-cut scanning shows that the ECRB origin can be classified as the following: full tear of the tendon, partial tear of the tendon, thinning of the ligament, or separation away from the ulnar collateral ligament complex. However, there are some limitations when using MRI while assessing response to treatment for lateral epicondylitis. T2 signaling may persist for weeks after symptoms resolve following treatment ( ). One must correlate the findings of MRI with a clinical examination because 14% to 51% of asymptomatic elbows have edema in the common extensor origin ( ) ( Fig. 29.1 ).
Ultrasonography has a sensitivity of 64% to 88% when used to examine for pathology in the ECRB tendon, but specificity is variable, ranging from 36% to 100% ( ). It can identify peritendinous fluid, thickening of the common extensor origin, intrasubstance tears, and focal hypoechoic areas. This image modality is user dependent.
Nonsurgical Treatment
Several treatment modalities have been proposed for lateral epicondylitis, and all steer to aid or enhance normal healing. proposed a methodical treatment program that parallels the natural healing response: (1) controlling exudation and hemorrhage; (2) promoting tissue healing; (3) encouraging general fitness; (4) control of force loading; and in a minority of patients, (5) removal of diseased tissue.
Nonsteroidal Antiinflammatory Drugs and Rest
Rest and nonsteroidal antiinflammatory drugs (NSAIDs) are the two most commonly used treatment modalities for acute lateral epicondylitis; the combination of both reduces tendon inflammation, relieves tendon strain, and provides time for tendon healing. As previously mentioned, lateral epicondylitis is described as a noninflammatory condition; NSAIDs are thought to reduce pain by reducing inflammation in the surrounding soft tissue such as the synovium, connective tissue, muscle tissue, and supportive tissue. Research has shown limited benefit in using NSAIDs for the treatment of lateral epicondylitis. performed a multicenter, double-blinded, randomized controlled trial comparing the use of an oral NSAID (diclofenac) with placebo, and they concluded that the treatment group reported less pain. However, they did not endorse the use of NSAIDs—they found no significant benefit to overall functional ability and grip strength along with undesirable gastrointestinal side effects. To date, there is only one study comparing the use of multiple NSAIDs, and it did not find any differences between the treatment groups versus placebo ( ). There have been mixed reviews evaluating the effects of topical NSAIDs as well.
Physical Therapy
Physical therapy is often prescribed to patients with lateral epicondylitis. There are no definite modes and duration of therapy plans, but the most acceptable protocol has been outlined by , and . This particular protocol consists of increasing strength, flexibility, and endurance of the forearm. It integrates stretching of the extensor origin by bringing the wrist into flexion with the elbow extended and the forearm pronated. In modern protocols, eccentric muscle training has been popular. This mode of therapy induces hypertrophy of the musculotendinous unit and increases the tensile strength of the unit, which in theory will reduce strain on the unit ( ). Additionally, eccentric contractions could provide the ideal stimulus for collagen production from tendon cells and reduce the neovascularization that may contribute to the pain of lateral epicondylitis ( ). also found the use of iontophoresis to be helpful in the management of lateral epicondylitis.
Injections
Steroid injections have been shown to positively correlate with improvement of lateral elbow pain. They are used for acute pain control, allowing patients to begin rehabilitation. Multiple studies have evaluated the efficacy of steroid injections versus NSAIDs and placebo. Pain relief during the first 5 days to 6 weeks are favorable for injections ( ). However, at longer follow-up for 12 weeks to 12 months, the results of injections were the same as those in other treatment groups. There have been only a few case reports discussing common extensor tendon rupture after local steroid injection. When comparing steroid injections with platelet-rich-plasma (PRP), PRP has been shown to produce better pain relief and functionality ( ). In 2014, published a prospective randomized double-blinded control study evaluating the clinical usefulness of needling with PRP in patients with chronic lateral epicondylitis. This study consisted of 230 patients who had at least 3 months of symptoms and had failed conventional therapy. The study population was equally divided into a treatment group and an active control group, both of which showed no significant difference in pain at 12 weeks. However, at 24 weeks, the PRP-treated patients reported a statistically significant improvement of pain compared to the control group ( ).
Orthoses
The two orthotic devices usually prescribed to patients with chronic lateral epicondylitis are the proximal forearm counterforce brace and the cock-up wrist splint. Both devices are designed to reduce tension and load at the extensor origin, thus allowing time for tendon healing. Proximal forearm banding is thought to prevent extensor muscle expansion, creating a new extensor origin ( ). Cock-up wrist splints are used to prevent extensor muscle contraction and, by decreasing muscle contraction, provide mechanical rest to the extensor origin ( ). Currently, there are no comparative studies between forearm bands and wrist splints that demonstrate any superiority of one device over the other ( ). Most physicians usually prescribe a proximal forearm brace for chronic lateral epicondylitis because it allows patients the most functional use of their upper extremity ( Fig. 29.2 ).
