Bridge plating

Multifragmentary diaphyseal fractures are usually best treated with relative stability techniques, such as IM nailing, bridge plating, or, occasionally, external fixation.

Bridge plating uses the plate as an internal, extramedullary splint, fixed to proximal and distal intact fragments. The intermediate fracture zone is left untouched, bypassed by the plate. Anatomical reduction of comminuted wedge fragments is not necessary. Direct exposure injures the soft-tissue attachments, which provide blood supply and aid realignment when length is restored.

When soft-tissue attachments are preserved, fracture healing is predictable.

Correction of length, rotation and axial alignment of the main shaft fragments can usually be achieved indirectly, using traction and soft-tissue tension.

Relative fracture-site stability, provided by the bridge plate, supports indirect healing (callus formation).

Bridge plates can be inserted, as illustrated, either with an open exposure that carefully preserves soft-tissue attachments to the fracture fragments, or with a minimally invasive approach that leaves skin and soft tissue intact over the fracture site.

With the minimally invasive osteosynthesis (MIO) approach, incisions are made proximally and distally, and the plate is inserted through an extraperiosteal tunnel. Such minimally invasive plating should be done using image intensification (if available).

This procedure is normally performed with the patient in a supine position.

Fixation of tibial fractures is preferably done through the medial approach, especially for distal fractures.

For the MIO technique, the use of an image intensifier can allow the surgeon to use smaller incisions to insert the plate and screws.

The lateral approach is used if the medial soft tissues are injured.

This approach is also used when a precontoured plate is placed laterally for fixation of proximal and mid-tibial fractures.

For the MIO technique, the use of an image intensifier can allow the surgeon to use smaller incisions to insert the plate and screws.

It is important to restore length, axial alignment, and rotation.

Apply longitudinal traction to the foot until the cortices of the two main fragments are in contact, thus restoring length.

When length is restored, correct the axial and rotational alignment.

Compare length, alignment, and rotation with the uninjured side.

If reduction cannot be achieved by manual traction, use a large distractor for closed reduction. Place one Schanz pin in both the proximal and distal main fragments. Distraction is applied across these pins by turning the thumb screw.

If a distractor is not available, an external fixator can be used instead.

Rotational alignment is aided by inserting the Schanz pins in the same plane. Check reduction, and if necessary, correct rotational deformity before proceeding.

As bridge plating should span a long section of the bone, the length of the implant has to be chosen accordingly. A good rule of thumb is to calculate that one third of the plate should cover the fracture zone, with one third of the length on either side of the fracture. Usually, a narrow large fragment plate is chosen.

An angular stable (locking) plate is a good option in osteoporotic bone, and for fractures with a short end segment. Although it can be helpful, such a plate needs not to be contoured precisely to fit the bone, since it functions as an internal fixator. Attaching it to the bone does not alter fracture alignment, since the screws do not pull the main bone fragments to the plate.

Minimal contouring will be necessary over the fracture site; however, it may be helpful to contour the ends to fit the bone where the plate will be affixed.

To match the orientation of the anteromedial surface of the distal tibia, the distal end of the plate will need to be twisted.

The plate can be inserted either through the proximal or distal incision.

The tunnel for the plate should be prepared first, either with a specialized tunneling tool, with blunt instruments (eg, Cobb elevator), or provisionally with the plate, using a handle.

Fixation begins with one end of the plate and then progresses to the other end.

Each end of the plate must be placed in the center of the bone.

If a 4.5 mm cortical screw is used, drill with a 3.2 mm drill bit and neutral drill guide through the plate hole. Measure for screw length and insert the first screw, but do not completely tighten it.

At this point, length, rotation, and coronal alignment should be checked and, if necessary, corrected.

Again, position the plate centrally on the exposed bone surface. Then insert the distal screw similarly to the first.

Some sagittal displacement (anterior or posterior angulation) can be corrected after the second screw has been inserted by placing a rolled towel as a fulcrum under the fracture site.

If image intensification is available, check the completed reduction before inserting further screws.

Alternating from one main fragment to the other, insert the remaining screws.

For these screws, additional small incisions over the plate are necessary.

Place two screws as close to the fracture zone as practicable in each main fragment. A minimum of three screws on each side should be used.

Perioperative antibiotics may be discontinued before 24 hours.

Attention is given to:

• Pain control
• Mobilization without early weight bearing
• Leg elevation in the presence of swelling
• Thromboembolic prophylaxis
• Early recognition of complications

A brief period of splintage may be beneficial for protection of the soft tissues but should last no longer than 1–2 weeks. Thereafter, mobilization of the ankle and subtalar joints should be encouraged.

Active, active assisted, and passive motion of all joints (hip, knee, ankle, toes) may begin as soon as the patient is comfortable. Attempt to preserve passive dorsiflexion range of motion.

For fractures treated with plating techniques, limited weight bearing (15 kg maximum), with crutches, may begin as tolerated, but full weight bearing should be avoided until fracture healing is more advanced (8–12 weeks).

For fractures treated with intramedullary nailing, weight bearing as tolerated, with crutches, may begin immediately.

Follow-up is recommended after 2, 6, and 12 weeks and every 6–12 weeks thereafter until radiographic healing and function are established. Weight bearing can be progressed after 6–8 weeks when x-rays have indicated that the fracture has shown signs of progressive healing.

Implant removal may be necessary in cases of soft-tissue irritation caused by the implants. The best time for implant removal is after complete bone remodeling, usually at least 12 months after surgery. This is to reduce the risk of refracture.