An Overview of Ulnar Styloid Fractures

Wrist fractures often involve the ends of two bones in your forearm—the radius and the ulna. The bony part of your wrist next to your pinky finger is the end of the ulna, also known as the ulnar styloid process. When you break that part of the wrist, it's called an ulnar styloid fracture.

If you have an ulnar styloid fracture in your wrist, it usually happens along with another break called a distal radius fracture, which is at the end of the radius. Distal radius fractures are the most common type of wrist fracture and account for up to 20% of all fractures treated in emergency departments.  At least half of these distal radius fractures also have ulnar styloid fractures. While distal radius fractures usually require a cast or surgery, ulnar styloid fractures may or may not require treatment.

Symptoms

The symptoms of a broken wrist, including an ulnar styloid fracture, include:

• Pain
• Swelling
• Tenderness
• Bruising
• Wrist hanging or bent in an odd angle 

Causes

The most common cause of ulnar styloid fracture, or any other wrist fracture, is falling onto an outstretched arm. This could happen when playing sports, falling off a bike, having a car accident, or just falling hard as you trip over something.

Osteoporosis can increase your risk of an ulnar styloid fracture. This is because your bones are more likely to break, even with minor falls.

Diagnosis

Your physician will examine your wrist and order an X-ray to show how the bone is broken and whether any of the bones are displaced.  Imaging from a computed tomography (CT) scan can also help identify the cause of any pain in the wrist.

Treatment

While distal radius fractures usually require realignment, a cast, or surgery, ulnar styloid fractures themselves usually don’t require treatment.

To help with any pain, your physician may recommend that you use Advil (ibuprofen) or Tylenol (acetaminophen). If pain is severe, your doctor may suggest a prescription-strength pain medication.

A study of patients with distal radius fractures found that their outcome was not affected by the presence or absence of an ulnar styloid fracture. The study also concluded that when the ulnar styloid fracture was out of position or didn’t heal, it didn’t affect the patients’ prognosis.

One exception is when the distal radioulnar joint (DRUJ), which is between the ulna and radius, is unstable. In those cases, treating the unlar styloid fracture can improve outcomes. The ulnar styloid fracture may be treated with open reduction and internal fixation, which is surgery to realign and immobilize the broken bones. Those cases are rare, though, and in most wrist fractures, the DRUJ is stable. 

A Word From Verywell

While an ulnar styloid fracture itself doesn’t usually require treatment, you should always check with your physician to get a correct diagnosis. If you have a wrist fracture, your doctor will likely decide your treatment based on the injury to the radius bone, if applicable, rather than the ulnar styloid fracture.