Atlas of Orthopaedic Surgical Exposures. Christopher Jordan. Читать онлайн. Newlib. NEWLIB.NET

Автор: Christopher Jordan
Издательство: Ingram
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Жанр произведения: Медицина
Год издания: 0
isbn: 9781588905888
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olecranon osteotomy is done. This then allows the triceps to be retracted in its entirety exposing the back of the distal humerus. The radial nerve is usually not encountered in the approaches to the distal humerus. It will be seen underneath, that is, deep to the triceps, as you go more proximally. For the distal medial dissection, the ulnar nerve needs to be identified and separated from its underlying tissues and allowed to fall in an anterior direction.

      TRICKS

      There are no special tricks with this approach except to protect the nerves.

      HOW TO TELL IF YOU ARE LOST

      It is difficult to get lost in this approach because it is a midline approach. The major way you can get lost is by being too far proximal or distal for the pathology, and then you simply need to extend your incision.

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      FIGURE 9–1 The skin incision starting 10 cm from the olecranon and going distally.

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      FIGURE 9–2 The subcutaneous tissue spread with the fibers of the triceps running toward the olecranon.

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      FIGURE 9–3 The triceps split with the humerus seen in the depth of the incision.

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      FIGURE 9–4 The tissue retracted such that the olecranon and posterior elbow joint are visible. The olecranon fossa has also been cleaned out and is visible.

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      FIGURE 9–5 The ulnar nerve on the ulnar side. This is at risk if the triceps is going to be retracted completely off the distal humerus.

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      FIGURE 9–6 The proximal extension of the dissection with the radial nerve just barely visible.

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      FIGURE 9–7 The radial nerve now more thoroughly exposed as the overlying triceps is split.

      

Triceps

      

Humerus

      

Triceps Split

      

Olecranon Fossa

      

Olecranon

      

Ulnar Nerve

      

Radial Nerve

      SECTION

      III

      ELBOW

      10

      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