External Fixator Application Types

Stability Directions:

The basic principle in fracture healing is to keep the broken pieces, that is, the fragments, motionless until tissue union develops. In order for external fixation to be successful, the movement of the fragments must be adequately restricted by the technique used. Fragments have movement in 3 basic directions. These; They are Axial, Rotational and Bending directions.

Axial Stability: It means the restriction of the up and down movements of the fragments.

Rotational Stability: It shows the degree of restriction of the rotational movements of the fragments on each other.

Bending Stability: It refers to the restriction of the movement of the fragments in the front-back direction.

Stability levels differ according to frame types.

Frame Types:

Basically, 5 types of frames are defined in the application of the External Fixator.

Adequate 3-ways stability is required for each type.

1. Type IA:

It is applied with clamps arranged on a single-sided frame. It is a simple system.

Axial stability is sufficient. Its rotational stability is poor but adequate. Bending stability is poor but adequate.

It is sufficient in cases where the fracture line is single and transverse.

2. Type IB:

It is the application of 2 single-sided frames. These are usually placed at an angle of 90-120 degrees to each other.

Axial stability is good. Its rotational stability is sufficient. Bending stability is good.

Sometimes rods can be linked together to increase rotational stability.

It is preferred in cases where the fracture line is oblique or in communited fractures.

3. Type II MIN:

They are frames established by connecting wires or pins to 2 opposite rods on the same plane by passing them to the opposite side. The angle between rods is 180 degrees. In this frame type, only one pin from each fragment is passed to the opposite side. Other pins are placed on one side.

Its axial stability is high. Its rotational stability is good. Bending stability is sufficient.

It is preferred in cases where the fracture line is oblique or in communited fractures.

4. Type II MAX:

They are frames established by connecting wires or pins to 2 opposite rods on the same plane by passing them to the opposite side. The angle between rods is 180 degrees. At least 2 pins from each fragment must be passed to the opposite side.

Its axial stability is very high. Its rotational stability is very good. Bending stability is good.

It is preferred in comminuted or defective fractures.

5. Tie In:

It is an external fixator system established with a unilateral frame after primary fixation with an intramedullary pin. If the intramedullary pin is not too thick, it is bent and fixed on the rod. In cases where the intramedullary pin is thick, an additional clamp and rod can be used to fix the main rod.

Axial stability is good. Its rotational stability is sufficient. Bending stability is very good.

It is a preferred system mostly in femur and humerus fractures.