Evaluation and Management of Carpal Fractures Other Than the Scaphoid

Louis W. Catalano III, MD; Shobhit V. Minhas, MD; David J. Kirby, MD

J Am Acad Orthop Surg. 2020;28(15):e651-e661.

Abstract and Introduction

Abstract

Fractures of the carpus can be debilitating injuries and often lead to chronic pain and dysfunction when not properly treated. Although scaphoid fractures are more common, fractures of the other carpal bones account for nearly half of all injuries of the carpus. Often missed on initial presentation, a focused physical examination with imaging tailored to the suspected injury is needed to identify these fractures. In addition to plain radiographs, advanced imaging such as CT and MRI are helpful in diagnosis and management. Treatment of carpal fractures is based on the degree of displacement, stability of the fracture, and associated injuries. Those that require surgical fixation often affect the congruency of the articular surfaces, are unstable, are at risk for symptomatic nonunion, are associated with notable ligamentous injury, or are causing nerve or tendon entrapment. Surgical strategies involve percutaneous Kirschner wires, external fixation, screws and/or plates, excision, or fusion for salvage. Owing to the intimate articulations in the hand, small size of the carpal bones, and complex vascular supply, carpal fracture complications include symptomatic nonunion, osteonecrosis, and posttraumatic arthritis.

Introduction

The carpus is a complicated mosaic of polyarticular bones that allows for the impressive range of motion of the human wrist. Scaphoid fractures are the most common, representing 60% of carpal fractures, and deservedly receive the most attention. However, the neglected neighbors of the scaphoid still represent 40% of carpal fractures, which accounts for 1.1% of all fractures. Carpal fractures from most to least common are scaphoid (68%), triquetrum (18%), trapezium (4%), lunate (4%), capitate (2%), hamate (2%), pisiform (1%), and trapezoid (0.5%)^[1–3] (Figure 1). These injuries most often occur in young adults after a fall on to an outstretched hand and are frequently missed on initial presentation.^[4,5] This is partly because of their small and densely packed arrangement that makes imaging difficult and limits physical examination specificity. Trained orthopaedic surgeons have a 30% to 88% precision in palpating the various bony landmarks of the carpal bones, with emergency medicine-trained physicians having a third to a fifth of this precision.^[6] This underscores the difficulty of diagnosing carpal fractures on initial presentation and the high index of suspicion that must be maintained during this evaluation. All suspected fractures should be evaluated with a general hand and wrist examination as well as basic PA and lateral hand and wrist radiographs. Additional examination maneuvers and imaging can then be tailored to the suspected injury.

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Figure 1.

Illustration showing carpal bone fracture prevalence.

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Table 1. Carpal Fractures Mechanism and Treatment
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)

CRIF = Closed reduction and internal fixation, CRPP = Closed reduction and percutaneous pinning, FCU = Flexor carpi ulnaris, ORIF = Open reduction and internal fixation, ROM = Range of motion