1 Note on illustrations topenlarge
Throughout this treatment option illustrations of generic fracture patterns are shown, as four different types:
A) Unreduced fracture
B) Reduced fracture
C) Fracture reduced and fixed provisionally
D) Fracture fixed definitively
2 Principles of modular external fixation topenlarge
The modular external fixator is optimal for temporary use. It is rapidly applied without need for intraoperative x-rays and can be adjusted later.
Details of external fixation are described in the basic technique for application of modular external fixator.
Specific considerations for the humerus shaft are given below.
Typical scenarios for the use of external fixation
There are two typical scenarios for using an external fixator for humeral shaft fractures:
- Polytraumatized patients with multiple injuries of the extremities
- Severe injuries of the humerus including extensive soft-tissue damage with or without neurovascular injuries
In both situations, the patient is typically placed in supine position.
3 Pin insertion (humeral shaft) topenlarge
As in all locations of long bones safe zones for pin placement can be defined. In the typical emergency situation, the patient is supine. Therefore, the safe zone of the distal third of the humerus is not practical.
For bridging the humerus two pins are placed proximal and distal to the fracture. Proximally, the pins are placed anterolaterally. Take care not to injure the axillary nerve or the long head of the biceps.
Distally the pins can be placed laterally. Doing so, the radial nerve is at high risk. To reduce radial nerve injuries, it is recommended to use incisions large enough to ensure palpation and/or direct visualization of the radial nerve (no stab incisions). It may be better to use a single incision for the insertion of both pins.
Pearl: To minimize the size of the incision, yet still obtain adequate hold in the distal fragment it is useful to insert pins in divergent directions.
After stab incision of the skin perform a blunt dissection of the soft tissues with scissors down to the bone. Use of drill sleeves with trocar prevents damage to muscular, vascular and neurological structures.