What is the recommended initial management for an acute triquetral avulsion fracture?

Treatment of Triquetral Avulsion Fracture

Most triquetral avulsion fractures (dorsal chip fractures) should be treated conservatively with immobilization for 3 weeks, as this approach has proven successful with good functional outcomes and no indication for surgical intervention. 1

Initial Diagnostic Approach

• Obtain standard 3-view wrist radiographs (posteroanterior, lateral, and 45-degree semipronated oblique) as the initial imaging study for suspected triquetral fractures 2
• If initial radiographs are negative but clinical suspicion remains high for triquetral fracture, consider CT or MRI to evaluate for occult fractures, as triquetral body fractures can be missed on plain radiographs 3, 4
• Triquetral fractures account for 15-18% of all carpal bone fractures, making them the second most commonly fractured carpal bone 3

Classification and Treatment Algorithm

Dorsal Cortical (Avulsion) Fractures - Most Common Type

Conservative management is the standard of care:

• Immobilize the wrist for 3 weeks using a short arm cast or volar splint 1, 5
• These fractures typically heal within 6-8 weeks if bone union occurs 1
• No surgical intervention is indicated for non-displaced dorsal chip fractures 1
• Prognosis is excellent with complete functional recovery expected 1, 5

The mechanism involves the chisel action of the dorso-proximal edge of the hamate striking against the fully extended and ulnar-deviated wrist 1

Triquetral Body Fractures - Less Common

Treatment depends on displacement:

• Non-displaced or minimally displaced body fractures: Conservative treatment with immobilization for 3-6 weeks 3, 5
• Significantly displaced body fractures or evidence of instability: Surgical treatment is indicated 3, 4
• Body fractures have good vascularization, excluding the possibility of avascular necrosis 1

Volar Cortical Fractures - Least Common

• These are the most problematic type and may require closer monitoring 3
• Treatment approach follows similar principles, with surgery reserved for displaced or unstable fractures 3

Post-Immobilization Management

• Begin early active finger motion exercises of the proximal interphalangeal (PIP) and metacarpophalangeal (MCP) joints immediately after immobilization is discontinued to prevent stiffness 2
• Aggressive finger and hand motion is necessary to facilitate optimal outcomes once the immobilization period ends 2

Important Clinical Pitfalls

• Do not overlook triquetral body fractures in patients with ulnar-sided wrist pain after falling on an outstretched hand, as these can be missed on plain radiographs 3, 4
• Maintain clinical suspicion and obtain advanced imaging (CT or MRI) if plain films are negative but clinical findings suggest fracture 4
• Avoid premature discontinuation of immobilization, as inadequate treatment can lead to non-union, though this complication is very rare 4, 6
• Post-traumatic instability is not typically seen with these fractures when properly treated 1

Potential Complications

• Non-union (very rare, particularly with dorsal chip fractures) 4, 6
• Triangular fibrocartilage complex injury 3
• Pisotriquetral arthritis 3
• Loss of motion and potential arthrosis if inadequately treated 3

When to Consider Surgical Referral

Immediate orthopedic referral is warranted for:

• Significantly displaced triquetral body fractures 3
• Evidence of carpal instability 3
• Symptomatic non-union (rare) that may require open reduction internal fixation or fragment excision 4, 6