Ulnar-Sided Wrist Pain (Including ECU Tendonitis)

What it is

Pain on the small-finger (ulnar) side of the wrist is very common. Because many bones, cartilage surfaces, ligaments, and tendons sit close together here, finding the exact cause takes a careful examination, X-rays, and sometimes a CT scan or MRI.

Common causes

• Fractures of the ulna or the small wrist bones on this side (pisiform, triquetrum, hamate), usually from a fall or twist
• Cartilage wear or arthritis, including ulnocarpal impaction, where a long ulna presses into the wrist bones
• ECU tendonitis: inflammation of the extensor carpi ulnaris tendon, which runs in a groove at the end of the ulna
• Snapping ECU: the ECU tendon slips out of its groove, causing painful clicking
• Ligament injuries, most often a TFCC tear, which can cause clicking, weakness, and instability
• Ulnar nerve compression or injury, causing pain and numbness in the ring and small fingers
• Masses such as ganglion cysts and lipomas, which are usually benign

Symptoms

• Pain at rest or with movement
• Clicking or popping, especially when turning the forearm
• Weaker grip and less motion

Treatment

Treatment depends on the cause and can combine activity changes, a splint or cast, hand therapy, anti-inflammatory medication, and steroid injections. Simple, well-aligned fractures heal with immobilization.

If symptoms continue, surgery may be considered: arthroscopic cleanup or ulnar shortening for impaction, stabilizing a dislocating ECU tendon in its groove, arthroscopic cleanup or repair of a TFCC tear, releasing a compressed nerve, or removing a mass.