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ANTEROLATERAL APPROACH

USES

This approach is useful for biceps tendon repairs. (Sometimes just the middle part of the approach is needed for biceps repair.) It can also be used for coranoid process open-reduction internal fixation. Additionally, it may be used for exploration of radial tunnel.

ADVANTAGES

This approach can be extended proximally and distally as necessary. By staying lateral to the biceps tendon, it stays in the internervous plane between the median and radial nerves.

DISADVANTAGES

There are important structures at risk with this approach and great care must be taken to identify and protect them.

STRUCTURES AT RISK

Laterally, the structure at risk is the radial nerve. This nerve enters the forearm underneath the brachioradialis muscle, which is the first muscle identified with this approach. The anterior edge of that muscle should be dissected and the nerve will be found on the inner border of the muscle. It should be retracted out of the way and protected.

The brachial artery and the median nerve are at risk if you are dissecting medial to the biceps tendon. As long as you stay lateral to those tendons, there is no significant risk.

The recurrent branch of the radial artery is at risk with this approach if you are dissecting distally. It will need to be clamped and sacrificed, which can be done without any major problem for the patient.

TECHNIQUE

A curved incision is made starting 5 or 6 cm proximal to the elbow flexor crease along the lateral side down to the lateral elbow joint, crossing the flexor crease at an angle almost parallel to the crease, going over to the medial side, and then going distally. This incision is carried through the subcutaneous tissue. The brachioradialis is identified and its anterior border developed so that the radial nerve can be identified and protected.

The muscle just medial to the brachioradialis is the brachialis muscle, and it is traced distally. The biceps tendon sheath is anterior to the brachialis and, once opened, the tendon of the biceps is identified and traced distally. If the surgery is being done for a biceps tendon rupture, then it is frequently necessary to work proximally along the brachialis until you encounter the retracted end of the biceps. This may require a fairly long proximal extension of the incision. If the surgery is to free up the radial nerve, dissection along the brachialis and biceps is not necessary.

If the purpose of the surgery is to reattach an avulsed biceps tendon, then follow the brachialis down to the ulna and go just lateral to that. Obviously, if the biceps is avulsed, you cannot trace it down to its insertion. By tracing the brachialis, you will stay lateral to the median nerve and brachial artery and you can then feel the bicipital tuberosity.

TRICKS

The key to this approach is finding the fat between the brachialis and brachioradialis. Once you are deep to the subcutaneous tissue, any fat between muscles is a warning sign that there are nerves or arteries close by. Therefore, if you find the fat between the brachialis and brachioradialis, it will lead you to the radial nerve. Similarly, medial to the biceps tendon, the fat will guide you to the neurovascular structures. Except for radial nerve release, generally speaking, the fat is used as a warning sign of where not to go. The key to protecting the median neurovascular structures is staying lateral to the biceps tendon.

HOW TO TELL IF YOU ARE LOST

The fiber orientation of the muscles will guide you to them. The brachioradialis runs from proximal to the elbow in a straight line toward the radial styloid, whether the elbow is flexed or extended. With the elbow flexed, the tendons of the brachialis and biceps will be at a 60- or 70-degree angle, or perhaps greater, to the fiber direction of the brachioradialis. If you dissect too far proximally along the brachioradialis, you will not see the brachialis muscle well. You should, however, see the fat in the gap between those two muscles and you will come in through the fat.

If you are lost medially, the artery will be closest to the biceps tendon. The median nerve will be medial to that. If you do not see the biceps tendon, then go back proximally until you find muscle and work your way along the muscle distally.

When coming in from the lateral side, if you retract the brachioradialis and radial nerve laterally, the first muscle you see will be the brachialis. It starts slightly more laterally and crosses to insert more medially, and the biceps goes the other direction.

FIGURE 10–1 The skin incision.

FIGURE 10–2 The brachioradialis muscle and the brachialis muscle. Seen between the two is some fat, which is always the warning sign that there may be a nerve or artery close by. Note that the gap between the biceps and brachioradialis is covered by overlying fascia and is not apparent immediately.

FIGURE 10–3 The fascia overlying the brachialis muscle has been split. You can see clearly the fat around the radial nerve and you can see anteriorly the biceps tendon.

FIGURE 10–4 The radial nerve, which has now been identified underneath the brachioradialis muscle and just lateral to the brachialis muscle. The fat that is overlying it has been removed, making the nerve's location more obvious.

FIGURE 10–5 The lacertus fibrosis of the biceps anteriorly. All of the mediail neurovascular structures will be medial to this area.

FIGURE 10–6 The bicipital tuberosity, tracing the tendon down to its insertion on the radius. This is facilitated by rotation of the forearm.

FIGURE 10–7 The medial neurovascular structures encased in their fat just medial to the biceps tendon.

Brachioradialis

Brachialis

Fat Around Radial Nerve

Biceps

Radial Nerve

Lacertus Fibrosis

Bicipital Tuberosity

Median Nerve and Brachial Artery