Executive Editor: Chris Colton

Authors: Renato Fricker, Matej Kastelec, Fiesky Nuñez, Terry Axelrod

Metacarpals - Multifragmentary

back to Hand overview

Glossary

1 Principles top

These fractures tend to be unstable, and bone healing is often prolonged. Internal fixation allows for anatomical reduction, ... enlarge

Comminuted fractures often result from crushing or high-energy injuries and may include several metacarpals. Compartment syndrome may occur with these types of injuries, and fasciotomy may therefore be necessary. These fractures are very unstable.


Bridge plating uses the plate as an extramedullary splint fixed to the two main fragments, while the complex fracture zone ... enlarge

Bridge plating

Bridge plating uses the plate as an extramedullary splint fixed to the two main fragments, while the complex fracture zone is bridged. The dissection required for anatomical reduction of all fragments would risk disturbing their blood supply and is not necessary. If the soft-tissue attachments of these fragments are preserved, and they are relatively well aligned, healing is predictable. Occasionally, a larger wedge fragment can be fixed to one of the main fragments using a lag screw. However, it is important to restore axial alignment, length and correct rotational alignment of the main shaft fragments.
Relative mechanical stability, provided by the bridging plate, leads to healing by callus formation.


When multiple metacarpals are injured, restoration of length and rotation is difficult. If one of the finger metacarpals is ... enlarge

Multiple metacarpal fractures

When multiple metacarpals are injured, restoration of length and rotation is difficult. If one of the finger metacarpals is intact, the fixation is started on the adjacent metacarpal, and then continued sequentially.


If all four metacarpals are fractured, fixation is started with the least comminuted, and then the adjacent metacarpals are ... enlarge

If all four metacarpals are fractured, fixation is started with the least comminuted, and then the adjacent metacarpals are fixed. With one incision it is possible to fix two metacarpals.

2 Reduction top

The fracture is reduced by using longitudinal traction on the finger, manually, using a finger trap, or with pointed reduction f enlarge

The fracture is reduced by using longitudinal traction on the finger, manually, using a finger trap, or with pointed reduction forceps. Additional pressure can be exerted on the metacarpal head from the palmar aspect.


Length should be restored in relation to the neighboring intact metacarpals so that their heads form a gentle arc with its ... enlarge

Restoration of length

Length should be restored in relation to the neighboring intact metacarpals so that their heads form a gentle arc with its apex over the third metacarpal.


Correct rotation has to be checked with the metacarpophalangeal (MCP) joints flexed to detect any overlapping of the fingers. enlarge

Check for correct rotation

Correct rotation has to be checked with the metacarpophalangeal (MCP) joints flexed to detect any overlapping of the fingers.
Flexing the MCP joints whilst preventing overlap of the fingers will reduce a rotational displacement.


Under general anesthesia, the tenodesis effect can be used, the surgeon fully flexing the wrist to produce extension ... enlarge

Rotation check

Under general anesthesia, the tenodesis effect can be used, the surgeon fully flexing the wrist to produce extension of the fingers, and fully extending the wrist to cause flexion of the fingers.


Alternatively, the surgeon can exert pressure against the muscle bellies of the proximal forearm to cause passive flexion ... enlarge

Alternatively, the surgeon can exert pressure against the muscle bellies of the proximal forearm to cause passive flexion of the fingers.

3 Plate selection & preparation top

The plate should be long enough to allow for 2 screws in each main fragment. Usually, 2 mm plates are used for the fixation ... enlarge

Plate selection

The plate should be long enough to allow for 2 screws in each main fragment.
Usually, 2 mm plates are used for the fixation of the metacarpals. For comminuted fractures, 2.4 mm plates may be indicated.
As these fractures are very unstable, more stable fixation devices may be preferable, such as the Locking Compression Plate (LCP).
If the fracture zone extends far distally or proximally, a T-plate, or minicondylar plate, may be indicated.


The plate is placed dorsally onto the metacarpal. The plate is contoured to conform with the normal shape of the metacarpal. enlarge

Bending and contouring the plate

The plate is placed dorsally onto the metacarpal.
The plate is contoured to conform with the normal shape of the metacarpal.


As there is to be no axial compression, overbending is not necessary and would result in a flexion deformity. enlarge

Pitfall

As there is to be no axial compression, overbending is not necessary and would result in a flexion deformity.

4 Fixation top

The plate is applied dorsally onto the metacarpal in its long axis. Correct rotational alignment of the distal main fragment ... enlarge

Plate application

The plate is applied dorsally onto the metacarpal in its long axis. Correct rotational alignment of the distal main fragment may be difficult to achieve but is essential.
Ensure that at least 2 screw holes come to lie over each of the main fragments.


Using a drill guide, the first hole is drilled in the proximal fragment close to the fracture zone. Make sure that the screw ... enlarge

Drilling

Using a drill guide, the first hole is drilled in the proximal fragment close to the fracture zone.
Make sure that the screw does not enter the fracture zone.


If an LCP is used with locking screws, a drill sleeve with centering thread must be used for drilling. The screw direction ... enlarge

Option: Using an LCP

If an LCP is used with locking screws, a drill sleeve with centering thread must be used for drilling. The screw direction is strictly perpendicular to the plate.


Use a depth gauge to determine screw length. enlarge

Measuring

Use a depth gauge to determine screw length.


Insert the first screw. Ensure that it engages the far cortex. Failure to take accurate measurement of the required screw ... enlarge

Screw insertion

Insert the first screw. Ensure that it engages the far cortex. Failure to take accurate measurement of the required screw length risks not engaging the far cortex, thereby weakening the fixation and creating the risk of implant failure.


Make sure that the plate is correctly aligned in the longitudinal axis of the metacarpal. Insert a second neutral screw into ... enlarge

Insert second screw

Make sure that the plate is correctly aligned in the longitudinal axis of the metacarpal. Insert a second neutral screw into the distal main fragment after the same fashion as above.
Confirm correct axial alignment and length using image intensification. Check correct rotation by flexing all fingers at the MCP joints.


Drill for the third and fourth screws. Measure for screw length, and insert the screws in neutral position. If an LCP is ... enlarge

Complete fixation

Drill for the third and fourth screws. Measure for screw length, and insert the screws in neutral position.
If an LCP is used with locking head screws, the centering thread drill guide must be used.


If a large intermediate fragment is present, it can be approximated to the plate with a single screw. enlarge

Option: Approximate large fragments with a screw

If a large intermediate fragment is present, it can be approximated to the plate with a single screw.

v1.0 2008-11-08