Page 110 - ASOP Orthopedic Casting Manual

2.5.1 Fracture Type(s) for Thumb

Spica Cast

First Metacarpal Fractures LBennett ʼs and Rolandoʼs Fractures)
✓ Clinical Relevant Anatomy: the first metacar pal for ms the thumb's base and

ar ticulates with the trapezium, allowing for a wide range of thumb
movements. Stabilit y is provided by the ulnar collateral ligament, volar plate,
and dorsal capsule.
✓ Epidemiology / Etiology / Mechanism of Injur y:

✓ Bennettʼs fracture (a single intra-ar ticular fracture-dislocation) and

Rolandoʼs fracture (a comminuted intra-ar ticular fracture) are common in
younger, active populations. These injuries t ypically resul t from axial
loading or direct trauma during spor ts or falls.
✓ Clinical Characteristics / Presentation: Patients repor t pain, swelling, and

defor mit y at the thumb base. Movement, par ticular ly pinching and grasping,
is mar kedly painful. Visible shor tening or angulation may be present.
✓ Fracture Diagnosis Process: Radiographs confir m the fracture patter n, with

Bennettʼs fractures showing a triangular fragment attached to the trapezium
and Rolandoʼs fractures displaying a Y- or T-shaped comminuted patter n.
✓ Differential Diagnosis / Associated Injuries: Gamekeeper ʼs or skier ʼs thumb

(ulnar collateral ligament tear); Car pometacar pal joint dislocations
✓ Treatment / Management Considerations: Non-displaced fractures may be

immobilized in a thumb spica cast for 4]6 weeks. Displaced or unstable
fractures usually require open reduction and inter nal fixation.