Authors of section

Authors

Renato Fricker, Matej Kastelec, Fiesky Nuñez, Terry Axelrod

Executive Editor

Chris Colton

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Base, intraarticular

Principles

A common site for metacarpal base fractures is the fifth metacarpal. Most of these fractures are comminuted and impacted, and are often associated with carpo-metacarpal fracture dislocations. Additional dorsal shearing fractures of the hamate may be present. These fractures are usually fixed with plates, or K-wires in the case of small fragments, and may need bone grafting.

CT scans are very helpful to determine the number, size and position of the fragments.

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Simple fractures

Depending on the fracture geometry, simpler fractures can be treated with lag screws (e.g. extensor carpi ulnaris tendon avulsion fractures), or with T-, Y- or L-shaped plates.

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Dislocation of the 4th metacarpal

Fractures of the fifth metacarpal base may be associated with a carpo-metacarpal dislocation of the fourth ray. In that case, the fourth metacarpal displacement is reduced first and usually stabilized with transfixion K-wires. Occasionally, there is a subluxation of the 3rd metacarpal, or even the 2nd metacarpal, and any combination of additional fractures can be seen.

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