Tennis elbow

Tennis elbow, also known as lateral epicondylitis, is an enthesopathy (attachment point disease) of the origin of the extensor carpi radialis brevis on the lateral epicondyle. It causes pain and tenderness over the lateral epicondyle. It usually has a gradual onset, but it can seem sudden and be misinterpreted as an injury.

Tennis elbow is idiopathic, meaning its cause is unknown. It may be associated with work or sports, classically racquet sports (including paddle sports), but most people with the condition are not exposed to these activities. The diagnosis is based on the symptoms and examination. Medical imaging is not very useful.

Untreated enthesopathy usually resolves in 1–2 years. Treating the symptoms and pain involves medications such as NSAIDs or acetaminophen, a wrist brace, or a strap over the upper forearm. Pain intensity varies from mild to severe and can be intermittent or constant, significantly impacting daily life. Patients also commonly report grip weakness and difficulty lifting.

Terminology

The term "tennis elbow" is widely used (although informal), but the condition affects non-tennis players. More recently, with the explosive growth of pickleball, the term "pickleball elbow" is frequently used. Historically, the medical term "lateral epicondylitis" was most commonly used for the condition, but "itis" implies inflammation and the condition is not inflammatory. It is also referred to as enthesopathy of the extensor carpi radialis origin. In 2019, a group of international experts suggested that "lateral elbow tendinopathy" was the most appropriate terminology. But a disease of an attachment point (or enthesia) is most accurately referred to as an "enthesopathy."

Causes

thumb|Location of tennis elbow

The exact cause of lateral epicondylitis remains unclear. However, it is often linked to repetitive microtrauma resulting from excessive gripping, wrist extension, radial deviation, and/or forearm supination.

Traditionally, people have speculated that tennis elbow is a type of repetitive strain injury resulting from tendon overuse and failed healing of the tendon, but there is no evidence of injury or repair, and misinterpretation of painful activities as a source of damage is common.

thumb|Example of repetitive movement that may cause tennis elbow

Pathophysiology

The extensor carpi radialis brevis is the most commonly affected muscle in lateral epicondylitis (LE), along with other extensor carpal muscles. Therefore, the disorder is more appropriately referred to as tendinosis or tendinopopathy. It was observed that tennis elbow symptoms were most painful after awakening. It was hypothesized that a very common sleep position was interfering with healing and causing pain. The study evaluated if changing this position would avoid pressure on the lateral elbow while asleep. Patients who changed this sleep position reported successful resolution of symptoms, whereas those who were unable to change continued to have pain. The conclusion reached is that the pathophysiology of tennis elbow is due to an initial microscopic tear from a sprain/strain. This initial injury is aggravated at night by pressure on the sprain which delays healing. In other words, tennis elbow is neither a tendonitis nor a tendinosis, but more like a pressure sore. If the pressure is removed the initial injury goes on to heal. The importance of this finding is that other conditions characterized by nocturnal or early morning symptoms may also be worsened by a "pathological sleep position." We know this applies to carpal and cubital tunnel syndrome, plantar fasciitis, shoulder/neck pain and Gerd.

Clinical evaluation

Physical examination

Diagnosis is based on symptoms and clinical signs that are discrete and characteristic. For example, the extension of the elbow and flexion of the wrist causes outer elbow pain. The physical examination usually reveals marked tenderness at the origin of the extensor carpi radialis brevis muscle from the lateral epicondyle (extensor carpi radialis brevis origin). Pain may worsen with resisted wrist extension, middle finger extension, and forearm supination with an extended elbow, although normal elbow movement is often maintained, even in severe cases. The test is said to be positive if a resisted wrist extension triggers pain to the lateral aspect of the elbow owing to stress placed upon the tendon of the extensor carpi radialis brevis muscle. The test is performed with extended elbow. NOTE: With elbow flexed the extensor carpi radialis longus is in a shortened position as its origin is the lateral supracondylar ridge of the humerus. To rule out the ECRB (extensor carpi radialis brevis), repeat the test with the elbow in full extension.

Medical imaging

Medical imaging is not necessary or helpful.

Radiographs (X-rays) may demonstrate calcification where the extensor muscles attach to the lateral epicondyle.

Longitudinal sonogram of the lateral elbow displays thickening and heterogeneity of the common extensor tendon that is consistent with tendinosis, as the ultrasound reveals calcifications, intrasubstance tears, and marked irregularity of the lateral epicondyle. Although the term "epicondylitis" is frequently used to describe this disorder, most histopathologic findings of studies have displayed no evidence of an acute, or a chronic inflammatory process. Histologic studies have demonstrated that this condition is the result of tendon degeneration, which replaces normal tissue with a disorganized arrangement of collagen. Colour Doppler ultrasound reveals structural tendon changes, with vascularity and hypo-echoic areas that correspond to the areas of pain in the extensor origin.

Table of Clinical classification of lateral epicondylitis phases.

{| class="wikitable"

!Phase

!Description of pain changes at different phases

|Mild pain after activity, usually recovers within 24 hours

|II

|Mild pain more than 48 hours after activity, no pain during activity, can be relieved with warm-up exercises, and recovers within 72 hours

|III

|Mild pain before and during activity, no significant negative impact on the activities, and can be partially relieved with warm-up exercises

|IV

|Mild pain accompanies the activities of daily living and has negative impact on the performance of activities

|Harmful pain unrelated to activities, great negative impact on the performance of activities but does not prevent the activities of daily life. Need complete rest to control the pain

|VI

|Persistent pain despite complete rest and can prevent the activities of daily life

|VII

|Consistent pain at rest, aggravated after activities, and disturbed sleep

Prevention

Activity modification is the best way to prevent the occurrence of lateral epicondylitis. Prevention can include avoiding extreme end range motions in extension and flexion, limit repetitive hand and wrist motions, and modification of heavy lifting with extended arms. Lifestyle factors such as smoking, alcohol drinking, and dietary habits are known to influence the prognosis of various medical conditions. Smokers showed a higher chance of developing lateral epicondylitis compared to non-smokers. Current research indicates that alcohol intake is not significantly associated with lateral epicondylitis.

Treatment

Non-operative treatment

Non operative treatment resolves 90% of symptomatic lateral epicondylitis. Nonoperative care usually includes activity modification, physical therapy, non-steroidal anti-inflammatory medications, bracing, extracorporeal shock-wave therapy, and acupuncture. Modifying activity and avoiding overuse are key to treatment. Lifting with the palm up and avoiding palm-down movements can shift strain from the lateral to the medial epicondyle, easing pain.

Orthotic devices

thumb|Counterforce orthosis reduces the elongation within the musculotendinous fibers

thumb|Wrist extensor orthosis reduces the overloading strain at the lesion area

Orthosis is a device externally used on the limb to improve the function or reduce the pain. Orthotics may be useful in tennis elbow; however, long-term effects are unknown. There are two main types of orthoses prescribed for this problem: counterforce elbow orthoses and wrist extension orthoses. Counterforce orthosis has a circumferential structure surrounding the arm. This orthosis usually has a strap which applies a binding force over the origin of the wrist extensors. The applied force by orthosis reduces the elongation within the musculotendinous fibers. Wrist extensor orthosis maintains the wrist in the slight extension.

Speculative treatments

Other approaches that are not experimentally tested include eccentric exercise using a rubber bar, joint manipulation directed at the elbow and wrist, spinal manipulation directed at the cervical and thoracic spinal regions, low level laser therapy, and extracorporeal shockwave therapy.

Medication

Recent studies demonstrate that topical nonsteroidal anti-inflammatory medications are effective within four weeks for lateral epicondylitis.

Alternative treatments

While many alternative treatments, such as shockwave, laser, low-frequency electrical nerve stimulation, ultrasound, and pulsed magnetic wave therapies, have been used, none have been proven effective. Current evidence is inconclusive on the effectiveness of acupuncture for lateral epicondylitits.

Platelet-rich plasma (PRP) injections

Platelet-rich plasma (PRP) has emerged as a potential treatment for lateral epicondylitis. PRP is derived from the patient's own blood and contains concentrated platelets, which are rich in growth factors. These growth factors are believed to initiate and accelerate tissue repair and regeneration support healing of the tendons and connective tissue and promote the growth of new blood vessels, aiding the recovery process. the overall literature is still unclear on its effectiveness. Additionally, variations in PRP preparation methods and injection techniques across different commercial systems add further complexity to assessing its effectiveness.

Overall, current research on PRP as a treatment for lateral epicondylitis is promising. However, more studies are needed to provide clear evidence of its effectiveness.

Percutaneous surgery

Percutaneous surgical approach is mainly used for releasing the common extensor tendon origin at the lateral epicondyle. This technique has been demonstrated to be safe, reliable, and cost-effective Good midterm outcomes in pain relief have been widely reported with a percutaneous surgical approach. In recent years, a new technique termed as ultrasound-guided percutaneous tenotomy has been reported as a safe and effective for the treatment of lateral epicondylitis, with improvements in symptoms, function, and ultrasound imaging at 1-year follow-up.

Arthroscopic surgery

Arthroscopic surgery is a minimally invasive option for treating lateral epicondylitis. This technique fully visualizes the elbow joint, and leads to a quicker return to work. While results are generally positive, arthroscopic surgery carries risks of injury to the radial nerve and lateral ulnar collateral ligament.

Epidemiology

Tennis elbow is a commonly seen condition and has been reported to affect 1% to 3% of adults each year. The incidence of lateral elbow tendinosis has declined, which could be due to shifts in diagnostic practices or an actual drop in cases. Understanding the typical disease progression can help patients and providers choose the best treatment approach.

Symptoms of lateral epicondylitis

Symptoms suggestive of lateral epicondylitis are present in about 1% of the adult population and are most common between ages 40 and 60. The prevalence varies somewhat between studies, likely as a result of varied diagnostic criteria and limited reliability between different observers. is usually credited for the first description of the condition, calling it "writer's cramp" (Schreibekrampf) in 1873. Later, it was called as "washer women's elbow". British surgeon Henry Morris published an article in The Lancet describing "lawn tennis arm" in 1883.