major trick with this approach is feeling the acromioclavicular joint and paralleling the incision over the top of it. It is important to remember that the acromioclavicular joint is not always exactly vertical. It will sometimes angle in a medial or lateral direction, as it goes superiorly. If you do not find the joint with an initial attempted opening of the capsule, you can identify it with a needle. That will tell you where it is located. You would then reflect your capsule in that direction until you can see the joint. If you are approaching the coracoacromial ligament or the coracoclavicular ligament, it is important to reflect the deltoid subperiosteally so that its reattachment is more effective. Once that is reflected, you lift it anteriorly, which will show the underlying ligaments.
HOW TO TELL IF YOU ARE LOST
It is practically impossible to get lost with this approach. If you are too far anterior, you will see the fibers of the deltoid. If you are too far posterior, you will see the fibers of the trapezius coming in from the back. If you are too far lateral, again you will run into the fibers of the deltoid as they approach the lateral acromion. If you are too far medial, you will see the shaft of the clavicle.
Once you are deep to the deltoid muscle, again it is difficult to get lost posteriorly because you will simply run into the clavicle. It is possible to be too far medial or lateral. It is very dangerous to be too far medial because the vascular structures are quite close to the clavicle medial to the coracoid. If you see anything that looks like a blood vessel, you are lost medially. If you are more than 2 cm lateral to the acromioclavicular joint while underneath the deltoid, you are lost laterally. The coracoid is actually medial to the acromioclavicular joint.
FIGURE 6–1 The skin incision, which is an incision paralleling the acromioclavicular joint over the top of the joint. It is typically centered over the joint and is usually 4 or 5 cm in length.
FIGURE 6–2 The subcutaneous fat.
FIGURE 6–3 The transverse fibers of the dorsal capsule of the acromioclavicular joint.
FIGURE 6–4 The capsule open, exposing the acromioclavicular joint.
FIGURE 6–5 The anterior extension of this approach, if you were going to go down to the coracoid for a reconstruction of the coracoclavicular ligament. The deltoid is seen attaching to the clavicle.
FIGURE 6–6 The coracoacromial ligament running transversely across the approach. The deltoid muscle has been dissected off of the clavicle and is retracted anteriorly.
FIGURE 6–7 The coracoid just at the end of the retractor. The acromioclavicular joint is at the top.
FIGURE 6–8 The coracoacromial ligament running transversely, and the coracoclavicular ligament on the edge of the picture, running up toward the clavicle. The prominence in the picture is the tip of the coracoid process itself.
SECTION
II
UPPER ARM
7
ANTEROMEDIAL APPROACH
USES
This approach is useful exposure of the musculocutaneous nerve, or access to the anterior or medial humerus. It is a distal extension of the deltopectoral groove approach.
ADVANTAGES
This approach allows access to the medial side of the humerus without coming directly over the neurovascular bundle.
DISADVANTAGES
Because the anterior humerus is overlaid by the biceps and brachioradialis, this approach requires either splitting or retracting large muscles.
STRUCTURES
