CHAPTER 6 Acquired Posttraumatic Defects
In this chapter we will consider acquired total and subtotal defects of the ear. These cases differ significantly from congenital cases of microtia, because elements of the previously normal ear may still exist, and because the scars must be considered when planning the skin approach.
Although the principles of the two-stage autologous technique were developed for microtia, we have also found them to be very useful in the management of acquired defects of the ear. Through our experience, we have developed a separate set of principles specific to acquired defects of the ear.
Acquired ear deformities have many causes, including motor vehicle accidents, burns, surgical excision, and animal and human bites. Regardless of the cause, a precise analysis of the local condition of the ear and surrounding skin is necessary. There are three categories of indications for reconstruction:
The defect is limited to the ear, with good retroauricular skin.
The defect is limited to the ear, with poor retroauricular skin.
The defect extends beyond the auricular region.
DEFECT LIMITED TO THE EAR, WITH GOOD RETROAURICULAR SKIN
Regardless of the cause of an ear amputation (for example, human bite, chondritis after piercing, surgical excision for carcinoma, and motor vehicle accident, as seen below), the retroauricular skin is often unharmed. This skin is a good texture and color match to the auricular skin and can be used to cover a costal cartilage framework, providing a very good aesthetic result after the first stage. A second stage is required to elevate the reconstructed ear after at least 4 months.
In such cases, determining exactly which components of the ear to reconstruct and which skin approach to use is essential.
Analysis of the Missing Contours
In cases of traumatic amputation, the tragus is usually retained in its normal position. Therefore the choice of framework is between TYPE II and TYPE III.
The different types of framework are classified as TYPE I (complete framework, including the tragus and antitragus), TYPE II (without a tragus), and TYPE III (without a tragus and antitragus).
If the antitragus is damaged, a TYPE II framework should be used. If it is intact, a TYPE III framework is indicated.
In the following cases, the first patient has a total amputation of the ear with only the tragus undamaged. A TYPE II framework should be used.
In the second case the amputation is subtotal, because the tragus, root of the helix, and anterior part of the helix are undamaged. A TYPE II framework should still be used preserving only the tragus.
The third case is a subtotal amputation of the upper and middle thirds. The tragus and antitragus are unharmed and should be retained. The rest of the cartilage should be excised and a TYPE III framework used.
The anatomic subunits of the ear need to be respected. The major subunits of the ear are the helix and the antihelix. If the anatomic subunits are not respected, then the junction between the native and reconstructed contours will be visible.
Deformed Contours
When analyzing the defect, deformed contours need to be considered as defects to be removed and reconstructed.
Posterior Wall of the Concha
Acquired auricular defects almost always retain the tragus, which is the landmark around which the ear can be reconstructed. The depth of the concha determines the normal, three-dimensional contour of the ear; therefore the posterior wall of the concha should always be analyzed for damage.
When operating on adults (as in this case), sufficiently thick cartilage may be present; thus reconstruction of the antihelix and posterior wall of the concha in a single carved piece may be possible. It is only necessary to add the helical portion and secure it with wire.
Choosing the Best Skin Approach
Two types of skin approach are used in acquired ear amputations when good retroauricular skin is available: a type 2 transfixion incision or a type 3b skin incision (see Chapter 1, Principles of the Two-Stage Autologous Ear Reconstruction).
Type 2 Skin Approach in Trauma
Type 2 is a transfixion incision allowing adherence of the portion of the ear comprising anterior and posterior skin surfaces. Part of the framework will be inserted between these two skin layers, and the rest of the framework will be covered by only a single layer and will need secondary elevation.
Low Type 2
When only the upper portion of the ear has been amputated, a low type 2 skin approach is used, consisting of adhesion of the lobule.
The deformed fibrocartilage was removed and reconstructed with a TYPE III framework, leaving only the tragus and antitragus, which were unharmed. Several months later the upper part of the ear was elevated to re-create the sulcus (type B).
High Type 2
When the lower portion of the ear has been amputated, then a type 2 incision can be used in the reverse fashion, which means that the upper part of the framework will be inserted between the two skin layers of the upper part of the ear. (We call this a high-adhesion high type 2.)
The upper fibrocartilage is discarded, and the upper ear skin transfixed. The lower part of the ear is covered by the retroauricular skin and elevated in the second-stage procedure. A TYPE I framework was used to reconstruct the defect, because the antitragus had been preserved.
NOTE: We do not recommend preserving the upper curvature of the helix unless the whole curvature is undamaged. Attempts to attach normal fibrocartilage to costal cartilage along the curvature frequently lead to a notch in the normal curve of the helix. It is better to join fibrocartilage to costal cartilage in the straight portion of the helix.
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