Minicondylar plate fixation

Fractures of the metaphysis can be transverse, oblique, or comminuted. Reduction is achieved by traction and digital manipulation. When the fracture is stable, it can be treated nonoperatively.
If the fracture is irreducible, ORIF is indicated.
Other indications for ORIF are open fractures or soft-tissue lacerations.

For this procedure the following approaches may be used:

• Dorsal approach to the phalangeal metaphysis (after Pratt)
• Dorsal approach to the MCP joint

Reduction can be obtained by traction and flexion exerted by the surgeon.
Confirm reduction using image intensification.
Often, these fractures are stable after reduction, in which case nonoperative treatment is indicated.

Direct reduction is necessary when the fracture can not be reduced by traction and flexion, or is unstable because of surrounding soft-tissue lesions.
When indirect reduction is not possible, this is usually due to interposition of parts of the extensor apparatus.
Use two pointed reduction forceps for direct reduction.

Insert a K-wire for provisional fixation.

At this stage, after provisional fixation, it is advisable to check the alignment and rotational correction by moving the finger through a range of motion.
Rotational alignment can only be judged with the fingers in a degree of flexion, and never in full extension. Malrotation may manifest itself by overlap of the flexed finger over its neighbor. Subtle rotational malalignments can often be judged by tilting of the leading edge of the fingernail, when the fingers are viewed end-on.
If the patient is conscious and the regional anesthesia still allows active movement, the patient can be asked to extend and flex the finger.
Any malrotation is corrected by direct manipulation and later fixed.

Under general anesthesia, the tenodesis effect is 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 of the fingers.

Two types of plate are available for treatment of this fracture:

• 1.5 Minicondylar plate
• 1.3 or 1.5 T-plate (adaption plate)

Select a plate according to fragment size, fracture geometry, and surgeon‘s preference.

Measure the length of the drill hole using a measuring device.
Cut the blade to the determined length, so that it just fills the drill hole.

Pitfall
Avoid protrusion from the opposite cortex, as friction during movement and eventual ligament injury may result.

Adapt the plate length to fit the length of the proximal phalanx. Avoid sharp edges which may be injurious to the tendons. There should be at least 3 plate holes distal to the fracture available for fixation in the diaphysis. At least two screws need to be inserted into the diaphysis.

Pearl: Cut the blade transversely
If you cut the blade on the flat, it will compress and widen very slightly as it is cut. This makes its maximal width very slightly larger than 1.5 mm. It may not fit in the 1.5 mm hole that you have drilled.
Therefore, cut the blade on edge (to deform it through its narrower dimension) to the correct length. The resultant tip is somewhat arrow-shaped.

Use pliers to contour the plate so that it fits exactly the anatomy of the base of the proximal phalanx.
The plate was designed for condylar fractures and is precontoured to fit around a condyle. It has to be adapted for the less curved shape of the base of the proximal phalanx.

In order to determine the position of the first drill hole, it can be very helpful to turn the plate over and use it as a template ...

... as shown in this photo.

Drill a 1.5 mm transverse hole through the base of the proximal phalanx adjacent to the subchondral bone.

The drill hole needs to be dorsal enough as to leave enough space for the plate’s most proximal screw hole.

Introduce the blade into the drill hole. Gently push with the thumb until the plate is fully seated.

Before inserting the first (distal) screw, ensure that the plate is in line with the phalangeal diaphysis in the sagittal plane by rotating it around the long axis of the blade.

Use a 1.1 mm drill bit to prepare the first screw hole at the distal end of the plate.
This hole must be drilled eccentrically in order to produce axial compression.

Measure the screw length and insert a self-tapping 1.5 mm screw as a load screw.
Tightening this screw will compress the fracture axially.

The proximal screw is inserted next in a neutral position.
The screw should engage the far cortex.
Note
Be careful to avoid screw protrusion through the far cortex, as ligament injury may result from friction during movement.

Insert a third screw into one of the diaphyseal holes in a neutral position in order to complete the fixation.

Protect the digit with buddy strapping to the adjacent finger, to neutralize lateral forces on the finger.

The patient can begin active motion (flexion and extension) immediately after surgery.

See patient after 5 days and 10 days of surgery.

The implants may need to be removed in cases of soft-tissue irritation.

In case of joint stiffness, or tendon adhesion’s restricting finger movement, tenolysis, or arthrolysis become necessary. In these circumstances, take the opportunity to remove the implants.