Extensor Pollicis Longus Tendinitis – 5 Risk factors, Important Causes, Symptoms, Diagnosis

Reviewed by Dr ShivaShakthi

What is Extensor Pollicis Longus Tendinitis

• Extensor Pollicis Longus Tendinitis is a condition in which the EPL tendon lining (sheath) becomes irritated and swollen. This causes pain on the thumb side of the back of the wrist.
• Extensor Pollicis Longus (EPL) tendinitis is a condition characterized by inflammation or irritation of the EPL tendon, which is responsible for extending the thumb.
• Tendons attach muscles to bones. They also help with joint movements. When tendons become irritated or swollen, it is called tendinitis.
• The extensor pollicis longus (EPL) tendon connects the EPL muscle to a bone that is near the end of the thumb. The EPL muscle helps to straighten and extend the thumb.

Anatomy of the extensor pollicis longus (EPL) tendon

• The extensor pollicis longus (EPL) tendon resides within the 3^rd dorsal extensor compartment of the wrist, inserts upon the distal phalanx of the thumb, and is the primary extensor of the thumb. 
• The tendon most commonly ruptures near Lister’s tubercle in association with distal radial fractures, but can also rupture spontaneously.  
• Extensor pollicis longus (EPL) is a long muscle located at the deep layer with extensor pollicis brevis, abductor pollicis longus, extensor indicis, and supinator muscle in the posterior compartment of the forearm.
• It originates from the mid-third of the ulna, and interosseous membrane then courses down to the distal phalanx of the thumb.
• Though it is situated at the forearm, it is classified as part of the extrinsic muscles of the hand as it’s function is seen in thumb movement.

What are the causes?

Several factors can contribute to the development of EPL tendinitis. Causes of Extensor Pollicis Longus Tendinitis include:

1. Overuse or Repetitive Movements: Engaging in activities that involve repetitive and forceful use of the thumb and wrist can lead to EPL tendinitis. This is common in individuals who perform activities such as playing certain sports (e.g., racquet sports), using tools that require a gripping motion, or repetitive typing on a computer keyboard.
2. Trauma or Injury: A direct injury or trauma to the thumb or wrist, such as a fall onto an outstretched hand or a forceful impact to the thumb, can cause inflammation and irritation of the EPL tendon.
3. Tendon Degeneration: Over time, the EPL tendon may degenerate due to wear and tear, especially in older individuals or those with chronic repetitive use of the thumb and wrist.
4. Inflammatory Conditions: Conditions like rheumatoid arthritis or psoriatic arthritis can cause inflammation of the tendons, including the EPL tendon.
5. Anatomical Abnormalities: Certain anatomical variations or abnormalities in the thumb and wrist joint may predispose individuals to EPL tendinitis.
6. Systemic Diseases: Conditions such as diabetes or thyroid disorders may affect the tendons and contribute to the development of tendinitis.
7. Poor Ergonomics: Poor posture or improper ergonomics in daily activities or work can put extra stress on the thumb and wrist, leading to tendinitis.
8. Activities that repeatedly cause your thumb and wrist to extend.
9. Sudden increase in activity or change in activity.

What are the symptoms of Extensor Pollicis Longus Tendinitis?

Here are the Symptoms of Extensor Pollicis Longus Tendinitis:

• Pain or tenderness over the thumb side of the back of the wrist when your thumb and wrist are not moving.
• Pain that gets worse when you straighten your thumb or extend your wrist.
• Pain when the injured area is touched.
• Locking or catching of the thumb joint while you bend and straighten your thumb.
• Decreased thumb motion due to pain.
• Swelling over the affected area.

What increases the risk of Extensor Pollicis Longus Tendinitis?

Extensor Pollicis Longus Tendinitis is more likely to develop in:

1. People who play sports and activities that involve repeated hand and wrist motions, such as tennis, golf, bowling, and gardening.
2. People who do heavy labor.
3. People who have had a previous wrist injury.
4. People who have poor wrist strength and flexibility.
5. People who do not warm up properly before activities.

What research says about the Extensor Pollicis Longus Tendinitis?

Current literature suggests that tendonitis of the extensor pollicis longus (EPL) is a rare condition that has a high rate of progression to rupture.

Two cases were reported in the English literature by Mogensen and Mattsson, who referenced several additional case reports in the Scandinavian and German literature.

Both of their patients had diffuse wrist pain for several months before the pain and tenderness became localized to the third compartment.

A Study present 2 cases of extensor pollicis longus tenosynovitis caused by the unusual course of the extensor pollicis longus tendon.

The extensor pollicis longus tendon passed through the first extensor compartment and was constricted severely.

The symptoms were similar to those of de Quervain’s disease.

The clinical presentation, diagnosis, and surgical technique of this very rare anatomic condition are discussed.

A study documents the prodrome of impending EPL rupture in patients with prior nondisplaced distal radial fracture.

A retrospective study identified patients with EPL tendonitis or tendon rupture. Seven patients (6 females and 1 male) had sustained a nondisplaced distal radius fracture within the past year.

Among these 7 patients, 4 eventually developed EPL tendon rupture and 3 had tendonitis without rupture. Of the 4 patients with EPL rupture, 2 presented to another provider before rupture with prodromal symptoms documented in the medical record, with pain and difficulty extending the affected thumb at the interphalangeal (IP) joint.

The 3 patients with EPL tendonitis but no EPL tendon rupture all presented following a nondisplaced distal radius fracture with tenderness over the EPL tendon and pain with thumb motion.

These 3 patients underwent EPL tendon decompression and subsequently did not go on to experience EPL rupture.

Extensor pollicis longus tendonitis is a condition that is classically seen in the setting of nondisplaced distal radius fractures and often progresses to tendon rupture.

In this study, the following prodrome of impending EPL rupture was identified: tenderness over the EPL tendon and Lister’s tubercle and pain with thumb motion.

This study suggests that patients with EPL tendonitis and possible impending rupture present with a prodrome of symptoms.

If these patients can be identified, they may undergo EPL tendon decompression, which may prevent EPL tendon rupture. 

Does Radial Fracture cause Extensor Pollicis Longus Tendinitis?

A study conducted on seven patients (out of 7, 6 were women and 1 man) who has sustained a nondisplaced distal radius fracture an year back.

Among these 7 patients, 3 had developed Extensor Pollicis Longus Tendinitis without rupture, 4 had eventually developed EPL tendon rupture.

Significance of increased renal echogenicity on Ultrasound

Increased cortical echogenicity is commonly attributed to chronic kidney disease (CKD) and has been correlated with interstitial fibrosis, tubular atrophy, and glomerulosclerosis in histologic studies.

However, increased echogenicity can also be seen in acute kidney injury (AKI) where inflammatory infiltrates and proteinaceous casts reflect sound waves (e.g. acute glomerulonephritis, acute tubular necrosis). 

How is Extensor Pollicis Longus Tendinitis diagnosed?

• This condition is diagnosed with a medical history and physical exam.
• Your health care provider will ask for details about your injury and ask about your symptoms.

How is this condition treated?

• Treatment may include the use of icing and medicines to reduce pain and swelling. You may also be advised to wear a splint or brace to limit your thumb and wrist motion.
• In less severe cases, treatment may also include working with a physical therapist to strengthen your wrist and calm the irritation around your EPL tendon sheath. In severe cases, surgery may be needed.

What is the prognosis of Extensor Pollicis Longus Tendinitis?

Extensor Pollicis Longus Tendinitis and possible impending rupture present with a prodrome of symptoms. If these patients can be identified, they may undergo EPL tendon decompression, which may prevent EPL tendon rupture

General instructions

• Return to your normal activities as told by your health care provider. Ask your health care provider what activities are safe for you.
• Take over-the-counter and prescription medicines only as told by your health care provider.
• Keep all follow-up visits as told by your health care provider. This is important.
• Do not drive or operate heavy machinery while taking prescription pain medicine.

Follow these instructions at home:

If you have a splint or brace:

• Wear it as told by your health care provider. Remove it only as told by your health care provider.
• Loosen the splint or brace if your fingers become numb and tingle, or if they turn cold and blue.
• Keep the splint or brace clean and dry.

Managing pain, stiffness, and swelling

• If directed, apply ice to the injured area.
  • Put ice in a plastic bag.
  • Place a towel between your skin and the bag.
  • Leave the ice on for 20 minutes, 2–3 times per day.
• Move your fingers often to avoid stiffness and to lessen swelling.
• Raise (elevate) the injured area above the level of your heart while you are sitting or lying down.

Contact a health care provider if:

• Your pain, tenderness, or swelling gets worse, even if you have had treatment.
• You have numbness or tingling in your wrist, hand, or fingers on the injured side.