Bennett and Rolando Fractures

Prepared and reviewed by the PrepElephant Academic Review Team

First published 14 Oct 2026 · Spot an error?

Reference basis: Campbell's Operative Orthopaedics; Green's Operative Hand Surgery

On this page

Direct answer
What you must remember
Reading the base of the thumb metacarpal
Where the exam tries to catch you
Frequently asked questions
Related topics

Direct answer

A Bennett fracture is an intra-articular fracture-dislocation at the base of the first metacarpal, in which a small volar-ulnar fragment stays attached to the thumb carpometacarpal joint while the shaft is pulled away. Rolando fracture is a comminuted, T- or Y-shaped variant of the same base fracture. Both are intra-articular, so anatomical reduction and stable fixation are needed to prevent post-traumatic arthritis.

What you must remember

Bennett fracture: a two-part oblique fracture of the first metacarpal base, with the volar-ulnar fragment held by the anterior oblique ligament, which is the volar beak.
Displacing force: the abductor pollicis longus pulls the shaft proximally and radially, so the fracture displaces even when the volar fragment is in place.
Rolando fracture: a comminuted, T- or Y-shaped intra-articular fracture of the base, often with more than two fragments.
Key feature: both lie in the first carpometacarpal joint, so articular step-off is the main determinant of outcome.
Treatment of Bennett: closed reduction with abduction and traction, then percutaneous K-wire fixation, or open reduction with a lag screw when reduction fails.
Treatment of Rolando: open reduction and internal fixation with a plate or screws, sometimes supplemented by external fixation.
Complications: post-traumatic thumb carpometacarpal arthritis, loss of thumb length and a painful, weak pinch.

Reading the base of the thumb metacarpal

The base of the first metacarpal is the key to separating the two fractures, because the volar beak determines whether the shaft is held in place. The sequence below follows the usual way a surgeon works through the injury.

Identify the articular fracture: a fracture line through the carpometacarpal joint means the injury is not a simple extra-articular fracture.
Look for the volar fragment: a single volar-ulnar fragment with the shaft displaced radially and proximally suggests a Bennett fracture.
Look for comminution: multiple fragments with a T or Y pattern across the joint suggest a Rolando fracture.
Assess reduction: check for articular step-off and restore length, which is a major factor in joint stability.
Choose fixation: percutaneous K-wires serve a stable Bennett pattern, while a plate or screws serve an unstable or comminuted Rolando fracture.
Protect and rehabilitate: immobilise for the period needed for union, then start early active movement once fixation is secure.

Where the exam tries to catch you

Most lost marks come from calling every thumb base fracture a Bennett or from treating a comminuted fracture with a simple pin.

Trap: the shaft of a Bennett fracture stays in place because the volar fragment is intact. Correct: the abductor pollicis longus pulls the shaft away, so reduction and fixation are needed.
Trap: a Rolando fracture can be fixed with a simple percutaneous K-wire. Correct: comminution across the joint needs open reduction and internal fixation, since a pin alone cannot hold the fragments.
Trap: a thumb base fracture with good alignment on X-ray needs no further check. Correct: articular step-off or residual subluxation must be excluded, because it predicts later arthritis.

Frequently asked questions

What is a Bennett fracture?

A Bennett fracture is an intra-articular fracture at the base of the first metacarpal, with a volar-ulnar fragment that stays attached by the anterior oblique ligament. The shaft is pulled radially and proximally by the abductor pollicis longus, so the fracture is unstable.

How does a Rolando fracture differ from a Bennett fracture?

A Rolando fracture is a comminuted, T- or Y-shaped intra-articular fracture at the base of the first metacarpal. It has more than two fragments, so it is usually treated with open reduction and plate or screw fixation rather than a simple pin.

What is the usual treatment of a Bennett fracture?

A Bennett fracture is usually treated with closed reduction and percutaneous K-wire fixation when the reduction is stable. Open reduction with a lag screw is used when closed reduction fails or the articular surface is not restored.

Why is articular step-off important in thumb base fractures?

Articular step-off is important in Bennett and Rolando fractures because a residual incongruity of the carpometacarpal joint leads to post-traumatic arthritis. Restoring a smooth joint surface is the main determinant of long-term thumb function.