The following components are needed to construct a large external fixator (the principles for smaller sets are the same):
- Threaded pins (Schanz type pins, standard or self-drilling/self-tapping with radial preload
- Carbon fiber rods or metal tubes
- Rod-to-pin clamps (titanium, MRI safe)
- Combination clamps (rod-to-rod or rod-to-pin, self-holding, titanium, MRI safe)
- Rod-to-pin clamps (old type, still in use)
- Rod-to-rod clamps (old type, still in use)
Selection of a large, medium, small, or mini external fixator depends on the age, anatomic region, and bone size.
The pins, rods and clamps are similar in all systems, but vary in dimensions.
Recommended pin diameters:
- 2.5–4.0 mm for upper extremity
- 3.0–6.0 mm for lower extremity
Recommended rod/tube diameters:
- 4 mm for small external fixator
- 8 mm for medium external fixator
- 11 mm for large external fixator
Additional components may be needed for the application of more sophisticated frames.