Metacarpal fracture

Mittelhandbruch: Description

In a metacarpal fracture (metacarpal fracture or metacarpal fracture), one or more of the five metacarpal bones are broken. The technical term is metacarpal fracture. The fracture line can be on the head, just below the head, on the shaft and at the base of a metacarpal bone. Physicians speak of head fractures, subcapital fractures, shaft fractures and basal fractures. Depending on the course of the fracture and the number of bone fragments, a middle hand fracture can be characterized, for example, as fragment breakage, transverse fracture or multi-fragment fracture.

The five metacarpal bones connect the carpal bones with the finger bones and form the palm of your hand. The most common form of metacarpal is a fracture of the 5th metacarpal bone, in the distal area, ie near the base of the little finger.

Due to its special function, the thumb occupies a special position under the fingers. The metacarpal bone leading to it (Os metacarpale I) is connected via a saddle joint with the large polygon bone (Os trapezium), a carpal bones. He is quite often affected by a Mittelhandbruch. A distinction is made between different types of fractures:

• Bennett fracture
• Rolando fracture
• Winterstein fracture

Mittelhandbruch: Bennett fracture

The Bennett fracture is a dislocation fracture (dislocation fracture) of the 1st metacarpal bone. The break line runs at its base and extends into the saddle joint. There are two bone fragments: The larger bone fragment, the stem fragment, is displaced because it pulls up the tendon of the long thumb spreader (abductor pollicis longus muscle). By contrast, the smaller bone fragment remains in its original position in the saddle joint through the surrounding ligaments. The Bennett fracture is the second most common form of metacarpal after the distal fracture of the 5th metacarpal bone.

Middle hand fracture: Rolando fracture

In the case of the Rolando fracture, a fracture gap is formed at the base of the 1st metacarpal bone, shaped like a Y. As with the Bennett fracture, the thumb saddle joint is also involved here. The Rolando fracture is also called metacarpal fracture.

Mittelhandbruch: Winterstein fracture

A Winterstein fracture is a transverse fracture at the base of the 1st metacarpal bone, where the fracture gap does not extend into the joint space of the saddle joint.

Mittelhandbruch: Symptoms

A middle hand fracture is painful, the mobility of the hand restricted. It forms a swelling and a bruise (hematoma) on the hand. If there is an open fracture, the bone fragments protrude through the skin. Sometimes with a metacartral fracture also a clear misalignment of the affected finger is recognizable.

Mittelhandbruch: causes and risk factors

The most common cause of a middle hand break is a punching of a solid object, such as a wall, a door, or the skull bones of an opponent. This so-called “boxer fracture” usually affects the fourth or fifth metacarpal bone (Os metacarpale IV or V).

Even direct impact trauma (such as in a traffic or work accident) can lead to a Mittelhandbruch. Sometimes a fall on the bent-back hand is the reason for the fracture.

The bone fragments may be displaced or unshifted, which has an impact on the therapy.

Mittelhandbruch: examinations and diagnosis

The responsible specialist in suspected middle hand fracture is a doctor for orthopedics and trauma surgery. He will first talk to you carefully about your complaints and medical history (anamnesis). Possible questions of the doctor are:

• Have you injured your hand in an accident?
• How did the accident happen?
• Do you have pain?
• Is the mobility of the hand and fingers limited?

After that, the doctor will examine your hand for broken bones, swelling, bruising, soft tissue injuries and sensory disturbances. When the fist is closed, a rotational malalignment of the affected finger can be detected.

Mittelhandbruch: Imaging technique

For further diagnostics, the doctor will arrange an X-ray examination. In a fracture of the 1st metacarpus, X-rays are usually sufficient in two planes. In order to diagnose a metacarpal fracture of the metacarpals II to IV, however, recordings in three levels are necessary.

In some cases a mid-hand fracture requires high-resolution computed tomography (CT). Thus, possible bony accompanying injuries (such as finger fracture) can be assessed and the extent of a joint involvement can be better assessed.

Especially with open fractures, the doctor will look for concomitant injuries, such as the tendons, nerves and vessels.

Mittelhandbruch: Treatment

If the hand is broken, the hand should be spared, stabilized and cooled as an immediate measure. Thereafter, depending on the type of fracture, a conservative or surgical treatment follows.

Mittelhandbruch: Conservative treatment

Conservative treatment is considered for unshaken, stable fractures. In this case, a rail made of plaster or plastic is applied for four to six weeks. If the 2nd to 5th metacarpal fractures, the thumb can remain free. When creating the splint, care is taken to ensure that the non-injured areas of the hand are included as little as possible. For the immobilization of the long fingers in the rail, the so-called intrinsic plus position is preferred: The fingers are bent in the base joint, on the other two joints – finger joint and finger joint – but stretched The sidebands (collateral ligaments) are taut and can in the Do not shorten episode so easily.

Mittelhandbruch: Operative treatment

If a step has formed or bone fragments have shifted, surgery must be performed to re-set the articular surfaces correctly. This concerns in particular the Bennett fracture. If such a metacarpal fracture is not operated on, it heals with faulty fractures. This can lead to certain movements such as gripping being no longer possible. Even open fractures must be surgically treated.

During surgery, the fracture is fixed by means of miniplates, screws or Kirschner wires.

Mittelhandbruch: Disease course and prognosis

The prognosis for a middle hand break is usually good. In the radiograph, the fracture is still visible for a long time, even if a callus (new bone tissue) forms after only three weeks and the bone thus regains sufficient stability. As soon as the patient no longer feels any pressure pain in the area of ​​the fracture, he can and should move the hand intensively without stress. After the fifth week, it is possible to start slowly with pain-adjusted movements (under consideration of the pain thresholds) with movements under stress.

In some cases it heals Metacarpal fracture not out: The broken bones do not grow together again, but it forms a “false joint” (pseudarthrosis).