summary Triquetrum fractures are common carpal fractures that are often associated with other injuries to the wrist. Diagnosis is confirmed with orthogonal views of the wrist. Treatment is generally nonoperative but injuries associated with wrist instability require surgical fixation. Epidemiology Incidence second most common carpal bone fracture accounts for up to 15% of all carpal fractures Associated conditions perilunate dislocations (seen in 12-25% of triquetral fractures) radius or ulna fractures Etiology Pathophysiology mechanism of injury dorsal cortical fractures login to view 9 more bullets body fractures login to view 10 more bullets palmar cortical fractures login to view 2 more bullets Anatomy Osteology triquetrum is a wedge-shaped carpal bone located in the proximal row articulates with hamate pisiform lunate Ligaments extrinsic ulnotriquetral ligament login to view 2 more bullets dorsal radiotriquetral (radiocarpal) ligament login to view 2 more bullets intrinsic palmar and dorsal lunotriquetral ligaments login to view 2 more bullets triquetrocapitate and triquetrohamate ligaments login to view 1 more bullet dorsal intercarpal ligament login to view 2 more bullets Blood Supply receives blood supply from nutrient arteries to non-articular surfaces Classification Triquetrum Fractures Classification Dorsal cortical fractures Most common (accounts for up to 93%) Mechanism includes avulsion, shearing force, or impaction Body fractures Second most common Subtypes: sagittal, medial tuberosity, transverse proximal pole, transverse body, comminuted Palmar cortical fractures Mechanism includes avulsion or shearing force Risk of instability Presentation Physical exam swelling/deformity of ulnar wrist pain with palpation directly over triquetrum pain with wrist flexion and extension if dorsal cortical fracture Imaging Radiographs recommended views PA lateral login to view 1 more bullet IR oblique login to view 1 more bullet optional views radial deviation login to view 1 more bullet findings "pooping duck" sign login to view 1 more bullet CT indications obtain if high suspicion of triquetral fracture MRI indications recommended for palmar cortical fractures due to concern for carpal instability obtain if concern for extrinsic intercarpal ligament injuries or occult fracture Differential Trapezial fracture Hook of Hamate fracture Pisiform fracture Lunate dislocation Diagnosis Radiographic diagnosis confirmed by history, physical exam, and radiographs Treatment Nonoperative immobilization for 4-6 weeks indications login to view 3 more bullets Operative ORIF indications login to view 3 more bullets Techniques Immobilization for 4-6 weeks short arm cast with thumb free Open reduction internal fixation approach dorso-ulnar approach login to view 1 more bullet soft tissue longitudinal capsulotomy instrumentation interfragmentary screws suture anchors login to view 1 more bullet K wires login to view 1 more bullet Complications Non-union rare in triquetral body fractures can perform excision if symptomatic Persistent carpal instability Pisotriquetral arthritis