Management of Avulsion Fractures of the Wrist
For avulsion fractures of the wrist, obtain standard 3-view radiographs initially, then determine management based on fracture location and size: most require only immobilization for 3 weeks, but operative fixation is indicated when the fragment involves >1/3 of the articular surface, shows >3mm displacement, or causes joint instability.
Initial Diagnostic Approach
Start with 3-view radiography (PA, lateral, and 45° semipronated oblique) as this is always the first-line imaging for suspected wrist trauma 1. Two views alone are inadequate for detecting wrist fractures.
Key Imaging Considerations by Location:
- Triquetral avulsions: Best seen on lateral radiographs; these are the second most common carpal fractures and frequently missed on initial emergency department evaluation 2, 3
- Volar triquetral avulsions: Particularly subtle and easily overlooked on standard views—consider instability series if clinical suspicion remains high 3
- Extensor mechanism avulsions (mallet injuries): Standard radiographs are usually sufficient 1
If Initial Radiographs Are Negative But Clinical Suspicion Persists:
- CT without contrast to confirm or exclude occult fractures 1
- MRI without contrast if ligamentous injury is suspected—this can detect associated ligament tears that affect treatment decisions 1
Treatment Algorithm
Conservative Management (Most Common):
Immobilize in short-arm cast for 3 weeks for:
- Dorsal triquetral shear/avulsion fractures (93% of triquetral fractures) 2
- Small avulsion fragments without significant displacement
- Purely osseous lesions without ligamentous disruption 2
Important caveat: Residual symptoms may persist for several months even with appropriate treatment—this is not uncommon and patients should be counseled accordingly 2.
Operative Fixation Required When:
Articular involvement >1/3 of joint surface 1
- This threshold applies to mallet injuries at the DIP joint and other articular avulsions
Displacement criteria met:
Associated instability present:
- Volar triquetral avulsions with confirmed lunotriquetral ligament tears require arthroscopic evaluation and possible LT joint transfixation 2
- Large fragments that may impair wrist range of motion or cause persistent pain 4
Surgical Technique Selection:
- Open reduction and internal fixation (ORIF) for large fragments, particularly ECU avulsions at the fifth metacarpal base 4
- Suture anchor fixation for tendon avulsions with adequate bone quality 5
- Arthroscopic debridement may be considered for small fragments with ligamentous injury, though outcomes show variable success with persistent pain and instability in many cases 3
Critical Pitfalls to Avoid
Missing volar triquetral avulsions: These are associated with significant perilunate ligament injuries and carpal instability in nearly all cases. When identified, obtain instability series, stress videofluoroscopy, and consider MRI 3.
Underestimating associated ligamentous injury: Four of five volar triquetral avulsions showed lunotriquetral ligament tears, and three had associated scapholunate ligament tears 3. Don't treat the bone fragment in isolation.
Delayed diagnosis: Initial misdiagnosis as "wrist contusion" can lead to poor outcomes. Maintain high clinical suspicion with localized tenderness over specific anatomic sites 2, 6.
Inadequate immobilization duration: The standard 3-week immobilization period is evidence-based for triquetral avulsions 2. Shorter periods risk nonunion or persistent instability.
Rehabilitation Considerations
Initiate active finger motion exercises immediately following diagnosis, even during immobilization 7. Finger stiffness is one of the most functionally disabling complications and can require extensive therapy or additional surgery if not prevented early.
Wrist motion: Early wrist mobilization after stable fixation does not improve outcomes and is not routinely necessary 7.