Executive Editor: Peter Trafton

Authors: Theerachai Apivatthakakul, Surapong Anuraklekha, George Babikian, Fabio Castelli, Antonio Pace, Vajara Phiphobmongkol, Raymond White, Kodi Kojima, Matthew Camuso

Tibial shaft 42-B1 ORIF

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Glossary

1 Principles top

In some cases, when the fracture geometry requires, the lag screws must be inserted through the plate. enlarge

Indication

If nailing and MIPO are contraindicated, ORIF should be performed. If the fracture configuration does not allow axial compression, a lag screw should be used to achieve interfragmentary compression.

Depending on plate position and fracture configuration, the lag screw will be introduced either through a plate hole or outside the plate. If possible, insert the lag screw outside the planned plate. If not, the lag screw is introduced through one of the plate holes after application of the plate with one screw in each main fragment. This technique requires a fracture configuration and plate placement that permit insertion of screws perpendicular to the fracture plane.

The remaining shearing and rotational forces have to be eliminated by a so called protection plate.


Plate selection and preparation enlarge

Plate selection and preparation

The chosen plate (usually a narrow, 4.5 mm DCP) should allow

1. A hole near the middle of the fracture, for the first lag screw to be inserted as perpendicularly as possible to the fracture plane.

2. Sufficient length for at least 3 screws proximal and distal to the fracture zone.

Usually a 10-12 hole straight 4.5 mm DCP is used. The plate has to be twisted and bent to fit perfectly on the surface of the tibia where it will lie.


The bend of the plate is usually a 20 cm radius, and the twist is approximately 35 degrees. enlarge

The bend of the plate is usually a 20 cm radius, and the twist is approximately 20 degrees.

2 Direct reduction top

Direct reduction enlarge

Reduce and preliminarily hold the fracture and the plate with two reduction clamps. This can be difficult, because of the need to maintain both fracture reduction and plate position. Be careful to protect soft-tissue attachments which provide bone vascularity.

Pearls
1. Reduce fracture and fix temporarily with small screws, or predrilled K-wires - to be removed before lag screws are tightened.
2. Plan plate position carefully. Fix one side of fracture definitively, then reduce the opposite side before its definitive fixation.

3 Drilling and tapping top

Drilling the gliding hole for the first lag screw enlarge

Drilling the gliding hole for the first lag screw

Using a 4.5 mm drill guide and a 4.5 mm drill bit, drill a gliding hole in the near cortex, with the plate properly positioned.
Ensure that the direction of the drill is as perpendicular to the fracture plane as possible.


Drilling the thread hole for the first screw enlarge

Drilling the thread hole for the first screw

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


Measuring for screw length enlarge

Measure for screw length

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. However, too long a screw may be tender, or injure soft tissues.


Tapping the thread hole enlarge

Tap the thread hole

Use a 4.5 mm cortical tap with the corresponding drill sleeve to tap the thread hole.

4 Lag screw insertion top

Insertion of first lag screw enlarge

Insertion of first lag screw

Carefully insert the first lag screw and tighten it.


Insertion of the second lag screw enlarge

Insertion of the second lag screw

Repeat the process described above for the second lag screw. Drill the gliding and thread holes, measure and tap the thread hole.
Insert the second lag screw and tighten it.

After each screw is inserted and tightened, confirm satisfactory reduction and compression.

5 Plate fixation top

Insertion of diaphyseal fixation screws enlarge

Insertion of diaphyseal fixation screws

The screws closest to the fracture zone are inserted first. Alternately insert the following screws, working your way outwards.

In the diaphysis, use cortical screws, observing the following steps:

  1. Drill both cortices using the appropriate drill guide to ensure a central drill hole with the 3.2 mm drill bit.
  2. Measure for screw length.
  3. Tap both cortices using the 4.5 mm tap and appropriate drill sleeve.
  4. Insert the screw.

Insertion of metaphyseal plate screws enlarge

Insertion of metaphyseal plate screws

If the plate extends over the metaphysis, use 6.5 mm cancellous screws, observing the following steps:

  1. Drill using the appropriate drill guide to ensure a central drill hole with the 3.2 mm drill bit. Do not penetrate the joint.
  2. Measure for screw length.
  3. Tap just the near cortex using the 6.5 mm tap and appropriate sleeve.
  4. Insert cancellous screws and carefully tighten them, checking fracture and plate.

Metaphyseal screws should be as long as possible. They must avoid the ankle joint. Slight penetration of the thin metaphyseal cortex is permissible, with pre-drilling.

v2.0 2012-05-13