Authors of section

Author

Anton Fürst

Executive Editor

Jörg Auer

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Flap fix

1. Principles

The treatment principles for the frontal, nasal and maxillary bone are the same, so that those three bones are described together.
The illustrations show an example of a frontal bone fracture.

2. Preparation and approach

This procedure is performed with the patient standing or placed in lateral recumbency through the approach to the frontal/nasal bone.

approach to frontalnasal bone

3. Reduction

After wound debridement has been achieved and the trauma assessed, the fragments are reduced using one of several methods.

Repositioning hooks can be made easily from 2.0 mm or 2.6 mm Kirschner wire by creating a 90° angle. These hooks are introduced into bone fragments or intact bone through predrilled 3 mm holes or through small gaps between the fragments.
Careful and controlled traction to the hook is applied and thereby the fragments are reduced into their normal anatomical position.
Usually several holes are drilled so that the traction force is evenly distributed.

flap fix

Alternatively, periosteal elevators or Langenbeck retractors can be effectively applied through small gaps between the fragments for fracture reduction.

flap fix
flap fix

4. 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 through a previously prepared hole.

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.

flap fix

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

flap fix

Implant selection

The titanium implants are available textured or smooth in four different sizes: 11, 13, 18 and 22 mm. The clover-leaf design allows the implant to adapt to the shape of the bone.

flap fix

Application of the flapfix

The top disk is slid towards the upper end of the tube until it locks in place.

flap fix

The bottom disk is placed through the fracture gab and placed under the intact and fractured bone. Following anatomic reduction of the fragment the top disc is slid distally until it it comes to lie on top of the fragment and adjacent intact bone.

flap fix

The application forceps is subsequently slid over the vertical bar. Tightening of the main handle applies tension to the vertical bar and in doing so squeezes the fragment and adjacent intact bone between the two rosettes. By tightening the most distal handle, the vertical bar is cut on top of the proximal clover-leaf rosette.

flap fix

Several flapfixes are used for multifragment fractures.

facial skull frontal nasal and maxillary bone

Fixation with flapfixes in a fracture of the frontal and nasal bones and maxilla in a horse that was kicked by another horse.

flap fix

5. Closure

The skin overlying the fracture should be sutured whenever possible and the use of distant relief incisions usually facilitates primary skin closure.
However, primary wound closure is not always possible, particularly in fractures associated with extensive loss of bone, soft tissue- and skin damage. Many of these fractures and wounds heal surprisingly well via second intention and have a satisfactory functional and cosmetic outcome. Depending on the degree of contamination, a flush tube may be inserted into an injured sinus to facilitate flushing during follow-up treatment. Drains may also be required if dead space occurs between bone and skin.

flap fix

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.