What is Extensor Carpi Ulnaris Tendonitis? - Symptoms, Causes, Treatment

The extensor carpi ulnaris muscle originates from the common extensor origin linked to the lateral epicondyle and the middle third to half of the ulnar posterior surface. Usually, the muscle fibers that give rise to the extensor carpi ulnaris tendon can be observed between 2 to 6 centimeters adjacent to the proximal border of the extensor retinaculum. The insertion of the tendon is at the base of the 5th metacarpal.

The 6th dorsal compartment of the wrist serves as the extensor carpi ulnaris tendon's passageway between its origin and insertion. This passageway is a clearly defined fibro-osseous tunnel. It is important to understand the connection between the extensor carpi ulnaris tendon and the fibro-osseous tunnel of the 6th dorsal compartment in cases of tendonitis and tendonitis-like disease.

It's likely unclear and underreported how frequently extensor carpi ulnaris tendonitis occurs. The majority of cases are centered on a single or a few individuals with partial or full tendon ruptures that were accompanied by manifestations of suspected tendonitis in the sixth dorsal compartment.

Extensor Carpi Ulnaris Tendonitis Symptoms

To properly identify ECU tendon diseases, a thorough clinical history and evaluation are essential. The emergence of symptoms is a useful criterion for distinguishing between acute and chronic conditions. This illness is frequently characterized by the presence of mechanical symptoms at the time it first manifests itself. In the case of an acute sheath rupture, patients will utilize terms such as "snap," "pop," and "tear." Tendon subluxation can cause agonizing discomfort in certain people. In other cases, the subluxation may not cause any symptoms at all and may be easy for the patient to repeat. A tenderness that is specifically localized to that structure can be found by palpating the ECU tendon over its entire length, beginning distally at the point where it enters the base of the 5th metacarpal. Pain with active extension against resistance and ulnar deviation is a sign of an ECU problem. Pain is commonly linked with weakness. 

Extensor Carpi Ulnaris Tendonitis Causes

Tendonitis of the extensor carpi ulnaris refers to swelling or inflammation of this tendon. This tendon can be found in the wrist, and its job is to extend (or straighten) the wrist as well as the fingers. Tendonitis can result from acute accidents or trauma to the wrist as well as from repetitive motions such as texting or playing an instrument that put too much strain on the tendon. Arthritis and gout are two underlying illnesses that might trigger these symptoms. There are some cases in which the cause of tendonitis in the extensor carpi ulnaris muscle is unknown.

Extensor Carpi Ulnaris Tendonitis Treatment

Non-operative treatments for severe tendonitis of the extensor carpi ulnaris include rest, activity moderation, splintage, and, rarely, immobilization for 3 weeks. The degree of tendinopathy determines the approach taken during rehabilitation.

As the pain subsides (usually for 5–10 days), load reduction and isometric exercises are used to treat the early reactive phase. After then, the load can be gradually increased during the process. In this stage, ibuprofen is recommended as a supportive measure to reduce pain sensations.

In cases of persistent tendinopathy without a sharp rise in discomfort, a combination of load control, eccentric work, isometric exercise, and resistance training is likely to be helpful. If conservative treatment fails to alleviate symptoms, a steroid injection into the fibro-osseous sheath may be tried.