FIGURE 2–1 The skin incision.
FIGURE 2–2 The deltoid muscle and the fascia underlying the subcutaneous fat.
FIGURE 2–3 The deltoid muscle split.
FIGURE 2–4 A close-up of the infraspinatus fibers.
FIGURE 2–5 The capsule opened and the humeral head in the depth of the incision.
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DELTOID SPLITTING APPROACH
USES
This approach is used for anterior acromioplasties if they are done open. It is usually used for rotator cuff repairs and for fractures of the humerus where a rod(s) will be started proximally in the region of the greater tuberosity. Hoppenfeld calls this the lateral approach.
ADVANTAGES
This approach is easy, as it comes directly down on the pathology and can also be extended anteriorly and posteriorly by taking the deltoid off of the acromion subperiosteally.
DISADVANTAGES
This approach is limited inferiorly by the axillary nerve, which usually crosses below, 5 cm distal to the acromion. If the axillary nerve is cut, the entire anterior deltoid will be denervated and shoulder flexion will be markedly impaired. The nerve has been seen as high as within 4 cm of the acromion.
STRUCTURES AT RISK
The only significant structure at risk is the axillary nerve, but it is not a problem as long as distal splitting of the deltoid is limited to the safe zone.
TECHNIQUE
The incision usually starts 1 cm proximal, that is, superior, to the lateral edge of the acromion, crosses the edge of the acromion, and proceeds distally. A so-called saber incision can be made from anterior to posterior, 1 cm distal to the edge of the acromion. Once deep to the skin, the approach is the same. The incision should not go beyond 5 cm distal to the lateral edge of the acromion. Splitting the deltoid more distally than that puts the axillary nerve at risk. The subcutaneous tissue is split. The fascia overlying the deltoid is split and its fibers are separated. The bursa is then encountered, which can be split or resected. This brings you down on the rotator cuff tendons. For greater exposure, you can subperiosteally take the deltoid off anteriorly or posteriorly.
TRICKS
Subperiosteal stripping of the deltoid allows this approach to be extended anteriorly or posteriorly and provides greater exposure. Distal splitting of the deltoid down to the axillary nerve also provides greater exposure. Any distal splitting beyond 4 cm should be done with the use of a nerve stimulator guiding the dissection, so that the axillary nerve going to the anterior deltoid is not inadvertently transected.
Repair of the deltoid is critical. It should be done through drill holes in the acromion if it has been stripped off. If it was simply split, it can be closed loosely with absorbable sutures. If an acromioplasty is done, it is important to avoid over thinning the acromion so that it fractures.
HOW TO TELL IF YOU ARE LOST
The main way of getting lost with this approach is being too far anterior or posterior for the pathology you are trying to fix. If the shoulder was arthroscoped prior to the open procedure, a suture can be placed percutaneously into the rotator cuff tear, so you come directly down on the tear. If you are too far superior, you will hit the acromion and that will be obvious.
FIGURE 3–1 The skin incision, which starts 1 cm medial to the edge of the acromion and proceeds distally for approximately 4 cm.
FIGURE 3–2 The subcutaneous tissue split with the deltoid underneath it.
FIGURE 3–3 The deltoid split with the underlying bursa now apparent.
FIGURE 3–4 The bursa split with the rotator cuff visible underneath it.
FIGURE 3–5 The view of the subacromial space when the bursa is resected. The rotator cuff is seen in the bottom of the figure.
