Lateral Approach to the Distal Humerus
Lateral Approach to the Distal Humerus
The lateral approach exposes the lateral epicondyle and the origin of the
wrist extensors. Its uses include the following:
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Open reduction and internal fixation of fractures of the lateral condyle
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Surgical treatment of tennis elbow (lateral epicondylitis)11,12
The lateral approach does not afford access to the lateral portion of the elbow joint except by extension. The joint itself should be accessed by the posterior, posterolateral, or anterolateral approach.
Position of the Patient
Landmarks and Incision
Landmarks
Palpate the lateral epicondyle on the lateral aspect of the distal arm. It is the smaller of the two epicondyles.
The lateral supracondylar ridge of the humerus is defined better and longer than is the medial supracondylar ridge. It extends almost to the deltoid tuberosity (Fig. 2-30).
Incision
Internervous Plane
There is no true internervous plane, because both the triceps and the brachioradialis muscles are supplied by the radial nerve. Because the nerve supplies these muscles well proximal to the area of the surgical approach, the plane between them can be exploited distally without fear of damaging the nerve supply to either muscle (Fig. 2-31A).
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Figure 2-29 Position of the patient on the operating table. Place the patient supine on the operating table with the arm lying across the chest.
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Figure 2-30 Make a straight or curved incision over the lateral supracondylar ridge of the elbow.
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Figure 2-31 A, B: Intermuscular plane between the triceps and brachioradialis
muscles. Both are supplied by the radial nerve proximal to the incision.
Superficial Surgical Dissection
Incise the deep fascia in line with the skin incision (Fig. 2-31B). Define the plane between the brachioradialis, which originates from the lateral supracondylar ridge, and the triceps, and cut between these muscles down to bone, reflecting the brachioradialis anteriorly and the triceps posteriorly (Fig. 2-32; see Fig. 2-50).
Deep Surgical Dissection
Identify the common extensor origin as it arises from the lateral epicondyle of the humerus (see Fig. 2-32). If further exposure of the bone is required, reflect the triceps off the back of the humerus. Release the extensor origin if a better view of the lateral epicondyle is needed (Fig. 2-32).
Dang
Nerves
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Figure 2-32 Incise the deep fascia in line with the skin incision. Define the plane between the brachioradialis and the triceps muscle and make an incision between them down onto the lateral supracondylar ridge. Reflect the brachioradialis anteriorly and the triceps posteriorly.
How to Enlarge the Approach
Extensile Measures
Proximal Extension. Proximal extension is not possible, because the radial nerve crosses the proposed line of dissection.
Distal Extension. The lateral approach can be extended to the radial head only by using the intermuscular plane between the anconeus muscle (which is supplied by the radial nerve) and the extensor carpi ulnaris muscle (which is supplied by the posterior interosseous nerve; see Posterolateral Approach to the Radial Head in Chapter 4; and see Fig. 2-
33). This approach cannot be extended further distally due to the presence of the posterior interosseous nerve winding round the neck of the proximal radius.
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Figure 2-33 The incision may be extended to expose the radial head by using the internervous plane between the anconeus (radial nerve) and the extensor carpi ulnaris (posterior interosseous nerve). The common extensor origin is detached and reflected anteriorly. The triceps also may be reflected more posteriorly. Proximal extension is not possible because of the course of the radial nerve.