1 Principles top
Oblique fractures of the tibial diaphysis can be treated nonoperatively if the initial displacement is small and there is <1 cm shortening.
Operative treatment with a nail
Nailing is usually a good option for tibial fractures, but is technically more difficult for proximal and distal locations.
Operative treatment with plate and screws
For the treatment of simple oblique fractures in the diaphyseal area, absolute stability is recommended.
For this, anatomical reduction and interfragmentary compression are necessary.
Choosing the method of interfragmentary compression
The method of interfragmentary compression is determined by the fracture geometry and the plane of the obliquity.
1. The tip 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 an axial compression plate, with a supplementary lag screw through the plate.
The apex of the fracture should be underneath the plate.
2. The tip of the fracture is not in the center of the anteromedial or anterolateral surface, but either posterior or anterior
In this case, compression must be done with a lag screw, usually inserted through 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 either anterior or posterior of it.
3. The tip of the fracture lies on the tibial crest
In this case, a lag screw outside of the plate (protection mode) is usually required.
2 Open reduction topenlarge
As anatomical reduction is necessary, open, or direct, reduction is needed.
Mobilize just enough of the periosteum around the fracture edges to control the reduction. Take care to protect the periosteum wherever possible.
Because they do less damage to the soft tissues, pointed reduction forceps are best used.
In 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.
Reduction of the fracture
In a second step, once length and rotation are restored, pointed reduction forceps are used to compress and anatomically reduce the fracture. The forceps tips 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.
Provisional fixation with the pointed reduction forceps
Use the pointed reduction forceps to provisionally stabilize the fracture. Select a position for the forceps so that it will not interfere with the planned position of the screw and the plate.
Also, consider that the forceps can be positioned either medially or laterally. Choose the position that allows the most stability with the least soft-tissue damage.
3 Confirm fracture plane topenlarge
Confirm that the fracture apex lies on the tibial crest. This indicates that the lag screw must lie outside the plate.
If the fracture apex is on the anteromedial or anterolateral surface and the plate can be applied over it, an axial compression plate with a lag screw should be applied instead.
On the other hand, if the plate can not be applied over the fracture apex, a lag screw through a protection plate should be employed.
4 Lag screw insertion topenlarge
Drilling the gliding hole for the lag screw
Using a 4.5 mm drill guide and a 4.5 mm drill bit, drill a gliding hole in
the near cortex. This screw must not interfere with planned plate
Ensure that the direction of the drill is as perpendicular to the fracture plane as possible.
Drilling the thread hole
Insert the 4.5 mm / 3.2 mm drill guide through the plate and the gliding hole. Use a 3.2 mm drill bit to drill a thread hole just through the far cortex.
Countersinking in diaphyseal bone
There are two important reasons for countersinking:
1. Countersinking ensures that the screw head has a maximal contact area with the bone, so that its compressive forces are widely distributed.
2. A countersunk screw head is less prominent and tender.
Measure for screw length
Use a depth gauge 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.
Tap the thread hole
Use a 4.5 mm tap and the corresponding drill sleeve to tap the thread hole.
Insertion of the lag screw
Insert the lag screw and carefully tighten it. Confirm that the fracture is reduced anatomically and compressed.
5 Plate fixation top
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 4 screws proximal and distal to the fracture zone.
Usually a 8-9 hole straight 4.5 mm DCP is used.
Remember that whenever the plate is placed distally, the plate must be twisted and bent to match the shape of the tibia in that region.
Insertion of screws
Insert the screws alternating between the proximal and distal fragments. Start with the screws closest to the fracture plane and work your way outwards.
Drill for the fixation screws. At least 4 screws should be used on the proximal fragment, and at least 4 screws on the distal fragment.
Use cortical screws for the diaphysis, observing the following steps:
- Drill both cortices using the appropriate drill guide to ensure a central drill hole with the 3.2 mm drill bit.
- Measure for screw length.
- Tap both cortices using the 4.5 mm tap and appropriate drill sleeve.
- Insert the screw.