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12

POSTEROLATERAL/ANCONEUS APPROACH

USES

This approach to the radial head is easy and safe. It is generally used for radial head resections or open reduction internal fixation of radial head fractures.

ADVANTAGES

This approach is easy.

DISADVANTAGES

This approach is limited to the radial head or capitellum. It is not suitable for proximal or distal extension.

STRUCTURES AT RISK

It is difficult to get lost with this exposure. The radial nerve is at risk anteriorly, but you would need to be far anterior to reach it. The posterior interosseous branch in the supinator muscle is at risk if the dissection is carried distal to the annular ligament. Pronation of the forearm moves this nerve farther away from the approach.

TECHNIQUE

The incision starts at the lateral epicondyle and then proceeds at a 45-degree angle in relation to the axis of the humerus toward the ulna. After splitting the subcutaneous tissue, the oblique fibers of the anconeus are identified. The capsule is opened along the anterior aspect of those fibers, exposing the radial head and the capitellum.

TRICKS

The only significant trick to this approach is finding the interval between the anconeus and the extensor musculature by looking at the fiber orientation. As you come to the superficial fascia, the anconeus fibers run obliquely toward the ulna, whereas the extensor muscles run parallel to the ulna down the forearm.

HOW TO TELL IF YOU ARE LOST

If you are too far posterior, you will split the fibers of the anconeus. If you run into the longitudinal fibers of the triceps, you are far posterior. Anteriorly, you will see longitudinal fibers of the extensor origin running parallel to the ulna. As long as you see the anterior edge of the oblique fibers and stay out of the longitudinal fibers, this is an easy approach.

FIGURE 12–1 Skin incision and lateral epicondyle is at the top.

FIGURE 12–2 The subcutaneous tissue retracted out of the way and the fibers of the anconeus running from the area of the lateral epicondyle down toward the ulna. The fiber orientation is critical for identifying the muscle versus the extensors.

FIGURE 12–3 The anconeus retracted in a posterior direction, exposing the soft tissue overlying the elbow.

FIGURE 12–4 The elbow open. The capitellum and radial head are clearly visible.

Lateral Epicondyle

Anconeus

Elbow Capsule

Radial Head

Capitellum