What is the treatment for a closed styloid fracture of the ulna?

Treatment of Closed Styloid Fracture of the Ulna

Conservative management with immobilization is the primary treatment for most closed ulnar styloid fractures, with surgical fixation reserved only for cases with persistent distal radioulnar joint instability after treatment of associated distal radius fractures. 1

Initial Management

• Immobilization: Cast immobilization is the first-line treatment for isolated ulnar styloid fractures

  • Typical casting period: 6-8 weeks (average 7.67 weeks) 2
  • Rigid immobilization is preferred over removable splints 1

• Pain management:

  • Ice application in the first 3-5 days post-injury 1
  • Appropriate analgesics as needed

Indications for Surgical Management

Surgical intervention is generally not required for most ulnar styloid fractures. The American Academy of Orthopaedic Surgeons (AAOS) guideline states they are "unable to recommend for or against fixation of ulnar styloid fractures associated with distal radius fractures" due to insufficient evidence 1.

Surgery should be considered only in specific circumstances:

1. Persistent distal radioulnar joint (DRUJ) instability after fixation of associated distal radius fracture 3
2. Large, significantly displaced base fractures with DRUJ instability (Type 2 nonunions) 4
3. Symptomatic nonunions causing persistent pain and dysfunction 5

Surgical Options (When Indicated)

For the rare cases requiring surgery:

• Open reduction and internal fixation using:

  • Tension band wiring 3
  • Angle-stable hook plate for displaced fractures or symptomatic nonunions 5

• Fragment excision: For symptomatic nonunions with stable DRUJ (Type 1) 4

• Fragment excision with TFCC repair: For nonunions with DRUJ instability (Type 2) 4

Outcomes and Prognosis

• Nonunion rates: Approximately 64% of ulnar styloid fractures may result in nonunion 2

  • However, nonunion itself does not typically affect functional outcomes
  • No significant difference in range of motion, grip strength, or DASH scores between united and non-united ulnar styloid fractures 2

• DRUJ stability: The status of ulnar styloid union (united vs. non-united) and fracture location (tip vs. base) do not significantly impact DRUJ stability in most cases 2

• Surgical vs. Conservative treatment:

  • Non-surgically treated patients show better wrist function at 6 months 3
  • By 12 months, functional outcomes equalize between surgical and non-surgical groups 3
  • Higher complication rates with surgical treatment 3

Important Caveats

• Temporary DRUJ immobilization may allow for triangular fibrocartilage complex (TFCC) recovery in cases with mild instability 2

• Base fractures are more likely to be associated with DRUJ instability than tip fractures, but this alone is not an indication for surgery unless instability persists 2, 3

• Routine surgical fixation of ulnar styloid fractures is not indicated as standard of care 3

• When ulnar styloid fractures occur with distal radius fractures, the priority should be proper treatment of the radius fracture, with the ulnar styloid managed based on subsequent DRUJ stability 1, 3