ORIF - Lag screws through protection plate

For the treatment of simple oblique fractures in the diaphyseal area, absolute stability can be considered.

For this, direct anatomical reduction and interfragmentary compression are necessary.

The method of interfragmentary compression is determined by the fracture geometry and the plane of the obliquity.

In example one, shown here, the apex of the fracture is in the center of the anteromedial or anterolateral surface of the tibia.

In this case, the fracture can be compressed with a compression plate with a supplementary lag screw through the plate.

The apex of the fracture should be underneath the plate.

In example two, shown here, the apex of the fracture is not in the center of the anteromedial or anterolateral surface, but is either posterior or anterior.

In this case, compression must be done with a lag screw, inserted either inside or outside the plate. In this case, the plate is used in protection rather than compression mode. The apex of the fracture is not underneath the plate but is either anterior or posterior to it.

In example three, shown here, the apex of the fracture lies on the tibial crest.

In this case, a lag screw outside of the plate (applied in protection mode) is usually required.

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

An anteromedial approach can be used if the soft-tissue envelope allows. The advantage of this approach is that it removes no muscle from the fracture fragments. Also, the medial surface of the tibia is normally flat, and conventional plates can be contoured to fit it or precontoured plates used with minimal or no modification.

The anterolateral approach can also be used if the plate is best placed on the lateral surface of the tibia. It can also be used when the medial soft tissues are compromised.

Open, or direct, reduction is necessary to achieve the required anatomical reduction.

Mobilize just enough of the periosteum around the fracture edges to assess the quality of the reduction. Take care to protect the periosteum wherever possible.

Pointed reduction forceps are preferred because they do less damage to the soft tissues.

As a first step, length and rotation must be restored. This may be possible with manual traction. Otherwise, mechanical aids such as a large distractor, or bone spreader, should be considered.

As a second step, once length and rotation are restored, pointed reduction forceps are used to compress and anatomically reduce the fracture. The tips of the forceps should be applied perpendicular to the plane of the fracture, just like a lag screw. Place the forceps outside the intended path of the lag screw.

Confirm the fracture plane and ensure that the plate can be applied over the apex of the fracture. If this is possible, a compression plate construct with a lag screw through the plate will be used. If the apex of the fracture lies on the tibial crest, the lag screw must be inserted outside of the protection plate as a plate placed in this area will cause significant soft-tissue irritation.

Before starting the procedure, the exact position of the plate should be determined according to the position of the lag screw. The screw should be inserted perpendicular to the fracture plane.

The chosen plate, usually a narrow, 4.5 mm dynamic compression plate (DCP), should provide the following:

• A hole near the middle of the fracture, for the first lag screw to be inserted as perpendicularly as possible to the fracture plane
• Sufficient length for at least 4 screws proximal and distal to the fracture zone

Usually a 9–10 hole straight 4.5 mm DCP is used. Remember that whenever the plate is placed distally, it must be twisted and bent to match the shape of the tibia in that region.

Place the contoured plate onto the bone.

Using a 4.5 mm drill guide and a 4.5 mm drill bit, drill a gliding hole in the near cortex.

Ensure that the direction of the drill is as perpendicular to the fracture plane as possible, and the plate is properly positioned on the bone.

More information about lag screw insertion is provided here:

• Cortical lag screw insertion

Insert the 4.5 mm/3.2 mm drill guide through the plate and into the gliding hole. Use a 3.2 mm drill bit to drill a thread hole just through the far cortex.

Use a depth gauge through the plate to measure for screw length.

Measure the longer side of an oblique drill hole, as shown, to ensure sufficient screw length.

A screw should protrude 1–2 mm through the opposite cortex to ensure thread purchase. If a screw is too long, it may irritate the surrounding soft-tissue envelope in which the tip protrudes.

Use a 4.5 mm tap and the corresponding drill sleeve to tap the thread hole (if self-tapping screws are not used).

Insert the lag screw and carefully tighten it. Confirm that the fracture is reduced anatomically and compressed.

Insert the screws alternating between the proximal and distal fragments. Start with the screws closest to the fracture plane and work outwards.

At least three screws should be used on the proximal fragment, and at least three screws on the distal fragment.

For diaphyseal fixation, use cortical screws.

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.