How should I evaluate and manage a triquetral fracture presenting with ulnar‑side wrist pain after a fall onto an outstretched hand?

Triquetral Fracture: Evaluation and Management

Initial Evaluation

Begin with standard three-view wrist radiographs (PA, lateral, and oblique) to identify the fracture pattern, as triquetral fractures can be missed on inadequate imaging. 1, 2

Clinical Assessment

• Mechanism of injury: Fall on outstretched hand (FOOSH) with wrist in dorsiflexion and ulnar deviation is the classic mechanism 1, 2
• Pain location: Ulnar-sided wrist pain is the hallmark presentation 1, 3, 4
• Physical examination: Tenderness over the dorsal-ulnar aspect of the wrist, pain with wrist extension and ulnar deviation 1

Radiographic Evaluation

• Standard views: PA, lateral, and oblique projections are essential, as two-view examination is inadequate 5, 4
• Oblique views: Specifically request oblique wrist radiographs, as these improve detection of triquetral fractures 4
• If radiographs are negative but clinical suspicion remains high: Proceed to CT or MRI within 10-14 days 5, 3

Fracture Classification and Implications

Three Main Types 1, 2:

1. Dorsal cortical (chip) fractures (most common, 15-18% of all carpal fractures):

   • Caused by chisel action of the hamate striking the triquetrum in full extension and ulnar deviation 2
   • Generally benign with excellent prognosis 1, 2

2. Triquetral body fractures (second most common):

   • Higher risk of complications including non-union, instability, and arthrosis 1, 3
   • May be associated with TFCC injury and carpal ligament tears 1, 4

3. Volar cortical fractures (least common):

   • Most problematic subtype 1
   • Can involve the pisotriquetral joint 4

Advanced Imaging Indications

Obtain CT or MRI when radiographs are negative but clinical suspicion persists, or when evaluating body fractures for displacement and associated injuries. 3, 4

• CT scanning: Superior for assessing fracture displacement, fragment size, and involvement of the pisotriquetral joint 3, 4
• MRI: Useful for detecting occult fractures, evaluating TFCC tears, and assessing dorsal carpal ligament injuries 6, 4

Management Algorithm

Non-Surgical Management (Most Cases) 1, 2, 7:

Immobilize non-displaced or minimally displaced fractures in a short-arm cast or volar splint for 3-6 weeks, followed by progressive range of motion exercises. 2, 4, 7

• Dorsal chip fractures: 3 weeks of immobilization typically sufficient 2
• Body fractures without displacement: 6 weeks of immobilization 4, 7
• Expected healing time: 6-8 weeks for complete union 2
• Outcomes: Conservative treatment results in good functional outcomes with complete pain resolution 2, 4, 7

Surgical Management Indications 1, 3:

Operate on fractures with significant displacement (>2mm articular step-off) or evidence of carpal instability. 1, 3

• Technique: Open reduction and internal fixation with compression screws 3
• Bone grafting: May not be necessary in all cases 3
• Post-operative protocol: Early wrist immobilization followed by progressive mobilization 3

Associated Injuries to Evaluate 1, 4:

• TFCC tears: Common with triquetral body fractures 1
• Dorsal carpal ligament injuries: Particularly with intra-articular fractures 4
• Pisiform subluxation: With pisotriquetral joint involvement 4
• Carpal instability: Assess for scapholunate diastasis >4mm on PA radiographs 8

Complications and Long-Term Monitoring 1, 3, 7:

• Non-union: Rare but associated with considerable morbidity and functional impairment 1, 3
• Pisotriquetral arthritis: Can develop with delayed diagnosis or inadequate treatment 1, 4
• Loss of motion and instability: More common with body fractures 1
• Avascular necrosis: Not reported in the literature, as the triquetrum has good vascularization 2

Critical Pitfalls to Avoid:

• Inadequate initial imaging: Failure to obtain oblique views leads to missed diagnoses 4
• Delayed diagnosis: Can result in non-union, persistent instability, and chronic pain 3, 4
• Underestimating body fractures: These require more careful evaluation than simple chip fractures due to higher complication rates 1, 3
• Missing associated injuries: Always evaluate for TFCC tears and carpal ligament injuries with body fractures 1, 4