Triquetrum |
Dorsal cortical fracture (most common) |
Mechanism: Avulsion of the dorsal radiotriquetral and triquetroscaphoid ligaments during hyperflexion and radial deviation; impaction by the ulnar styloid and hamate during hyperextension and ulnar deviation |
Treatment: short arm cast/splint for 3–4 weeks followed by wrist brace for comfort with progressive ROM |
Ulnar tuberosity fracture |
Mechanism: direct blow to ulnar wrist |
Treatment: nondisplaced—short arm cast for 4–6 weeks; displaced—CRIF versus ORIF |
Sagittal body fracture |
Mechanism: AP directed force; crush injury |
Treatment: no instability and nondisplaced—short arm cast for 4–6 weeks; displaced or unstable—CRIF versus ORIF |
Transverse body fracture |
Mechanism: greater arc perilunate fracture-dislocation injury |
Treatment: nondisplaced—short arm cast for 4–6 weeks; displaced—ORIF (most common) versus CRIF |
Palmar cortical fracture |
Mechanism: avulsion of the volar lunotriquetral ligament; shear impaction from the pisiform |
Treatment: short arm cast/splint for 2–3 weeks followed by wrist brace for comfort with progressive ROM |
Trapezium |
Sagittal body fracture |
Mechanism: axial load through the thumb (associated with thumb metacarpal base fracture-dislocation) |
Treatment: nondisplaced—short arm-thumb spica cast for 4–6 weeks; displaced or CMC joint subluxation—CRPP versus ORIF versus external fixator |
Transverse body fracture |
Mechanism: shear force |
Treatment: nondisplaced—short arm-thumb spica cast for 4–6 weeks; displaced—CRPP versus ORIF versus external fixator |
Dorsal-radial ridge fracture |
Mechanism: shearing by the radial styloid during hyperextension |
Treatment: nondisplaced—short arm-thumb spica cast for 4–6 weeks; displaced—CRPP versus ORIF |
Volar ridge fracture |
Mechanism: direct blow to palm or avulsion of the transverse carpal ligament |
Treatment: short arm-thumb spica casting for 4–6 weeks; painful fracture nonunions can undergo excision |
Lunate |
Volar lip fracture |
Mechanism: wrist hyperextension with tension and subsequent avulsion by the radiolunate ligaments |
Treatment: small fragment with no carpal instability—short arm cast immobilization for 4–6 weeks with close follow-up; large fragment (with or without displacement) or carpal instability—ORIF |
Dorsal lip fracture |
Mechanism: wrist hyperextension with impaction on the dorsal distal radius ridge |
Treatment: nondisplaced or small fragment and stable—short arm cast for 4–6 weeks; large fragment with displacement or unstable—ORIF |
Coronal body fracture |
Mechanism: axial load or dorsal extension force with palmar flexion force distraction injury |
Treatment: nondisplaced—short arm cast for 4–6 weeks; displaced—ORIF |
Transverse body fracture |
Mechanism: shear force during a radiocarpal fracture-dislocation |
Treatment: nondisplaced—short arm cast for 4–6 weeks; displaced—ORIF |
Capitate |
Transverse/oblique waist/neck fracture |
Mechanism: hyperextension of the wrist with abutment on the dorsal ridge of the distal radius, leading to distractive forces on the volar capitate |
Treatment: nondisplaced—short arm cast for 6–8 weeks; displaced—ORIF with headless compression screws through the third and fourth extensor compartments |
Volar/dorsal avulsion fracture |
Mechanism: axial load through the third metacarpal |
Treatment: nondisplaced or fleck avulsion—short arm cast for 4–6 weeks; displaced fragment large enough to fix—ORIF between the third and fourth extensor compartments |
Hamate |
Hook of hamate fracture (type 1): |
Mechanism: direct external blow or ligamentous avulsion |
Treatment: nondisplaced and minimally displaced—ulnar gutter cast for 3 weeks followed by short arm cast for 3 weeks; evidence of carpal tunnel syndrome, ulnar neuropathy, chronic symptomatic nonunions, or acute displaced fractures—fragment excision |
Transverse fracture (type 2b) |
Mechanism: shear force during greater arc perilunate fracture-dislocation |
Treatment: nondisplaced with no evidence of CMC instability—ulnar gutter cast for 3 weeks followed by short arm cast for 3 weeks; displacement or CMC instability—ORIF with injury-specific treatment of perilunate dislocation |
Coronal body fractures (type 2a) |
Mechanism: axial load through the fourth and fifth metacarpals |
Treatment: nondisplaced and extra-articular—ulnar gutter cast for 3 weeks followed by short arm cast for 3 weeks; displaced or intra-articular extension into the CMC joint—ORIF |
Pisiform |
Transverse and sagittal/comminuted body fractures |
Mechanism: crush injury of the pisiform between a hard surface and the triquetrum (sagittal/comminuted) or a similar position with the additional strong pull of the FCU tendon insertion (transverse) |
Treatment: nondisplaced and minimally displaced—short arm cast in slight ulnar deviation and 30_ of flexion for 4–6 weeks; displaced—pisiformectomy |
Trapezoid |
Volar rim or coronal fracture |
Mechanism: axial load through second metacarpal base |
Treatment: nondisplaced—short arm-thumb spica cast immobilization for 4–6 weeks; displaced or CMC subluxation—ORIF (fragment excision is contraindicated) |