Authors of section

Author

Anton Fürst

Executive Editor

Jörg Auer

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Wire fixation

1. Principles

Anatomical reduction of the outer part of the orbit is crucial for correct function of the eye.

wire fixation

It is important to palpate the inner surface of the orbit to identify and remove any bone fragments that can damage the eye.

wire fixation

2. Preparation and approach

This procedure is performed with the patient placed in lateral recumbency through the approach to the orbit.

approach to the orbit

3. Reduction

After wound déebridement has been achieved and the trauma assessed, the fracture is reduced.
The outer parts of the orbit (frontal, temporal and zygomatic bones) are typically displaced inwardly. They must be reduced to their normal position cautiously using one of several methods.
Periosteal elevators or Langenbeck retractors are often necessary for complete fracture reduction.

wire fixation

In addition, a specially designed reduction instrument, manufactured in two sizes (2.4 mm and 3.5 mm), has recently become available. It consists of a horizontal cross handle, connected to a tap-like rod that is twisted into the bone fragment.

Of all the various instruments that are available, these are best suited for the use in horses. Depending on the size of the fragment a 1.8 or 2.4 mm drill hole is prepared and the instrument inserted into the bone fragment.

wire fixation

Occasionally it is necessary to trim the bone fragments to facilitate correct anatomic repositioning and fracture reduction.

wire fixation

4. Fixation

Holes are drilled into the fragment and the intact parent bone close to the fragment with a 2 mm drill bit.

wire fixation

A cerclage wire of 0.8-1 mm diameter is pre-placed and twisted to tighten.

Note: Remember to protect the globe with a periosteal elevator while drilling the holes and placing the wires.

facial skull orbital region

5. Closure

The skin incision is closed routinely.

plate fixation

6. Aftercare

A head bandage and padded head protection are applied to the patient during recovery from anesthesia.

The horse is maintained in stall rest for about two weeks followed by small paddock exercises for another two weeks.

Depending on the healing progress, nonsteroidal anti-inflammatory drugs and antibiotics are given for 3 to 5 days, or longer if required.

In most cases implants do not need to be removed provided that wound healing is normal and no persistent draining tracts develop.