Fig. 5.1
Deltopectoral approach. (a) The deltopectoral sulcus is identified together with the cephalic vein. (b) The anterior circumflex artery crosses the humeral metaphysis and is accompanied by two veins. This vascular complex is referred to as “three sisters” (arrow). (c) Deltopectoral approach. The subscapularis muscle (SbS) is incised 2 cm medially with respect to its insertion, and the tendon is cleaved from the anterior capsule (C) only in its proximal three quarters in order to protect the axillary nerve
5.2.1.3 Limitations
In case of an intra-articular inspection, this approach requires the detachment of the subscapularis tendon. There are different detachment techniques (transosseous-lesser tuberosity, complete, L-shaped), but all of them carry the risk of inducing iatrogenic complications to the subscapularis muscle, such as re-rupture and fat degeneration, with the loss of strength in internal rotation and possible anterior instability [10].
5.2.1.4 Risks
Several neurovascular structures must be isolated and protected with this approach: the brachial plexus; the axillary artery, vein, and nerve; and the musculocutaneous nerve, as well as the anterior circumflex artery (in case of reduction and fixation of fractures).
Numerous anatomic studies on cadavers have tried to correctly define the safety margins of the deltopectoral structures [11]. Loomer and Graham [12] described the path of the axillary nerve, at about 3.5 mm inferiorly and laterally with respect to the myotendinous margin of the subscapular muscle and in contact with the inferior margin of the glenoid. Other studies have described the path of the axillary nerve , 3–8 mm from the inferior margin of the joint capsule [11, 13]. In a cadaver study, McFarland et al. [14] examined the relationships between the retractors positioned during an anterior capsuloplasty and the adjacent nerve structures. In particular, this study showed that the brachial plexus is at about 2 cm distance from the glenohumeral joint and, in some cases, the variability amounted to 0.5 cm. The musculocutaneous nerve was found at about 1.5 cm from the articular rim. The posterior and medial cords were at about 1–2 cm from the articular rim. The minimum distance measured was about 5 mm for the axillary nerve, 7 mm for the posterior cord, and 9 mm from the medial one.
The deltopectoral approach requires the displacement or the ligation of the cephalic vein . Even though the ligation does not entail any major complications, it is better to preserve it. Generally, for practical purposes, it is better to retract it laterally together with the deltoid muscle since there are a higher number of collaterals laterally rather than medially [15]. However, the author’s personal experience shows that medial retraction requires a longer preparation, but it does not overstretch the vein and so it is less traumatic.
Very often, this approach leaves an ugly scar because it does not follow the skin cleavage.
5.2.2 Anterior Extended Deltopectoral Approach
The deltopectoral approach can be extended distally along the arm down to the elbow. On the contrary, the proximal extension is infrequently used because it does not allow for an easy access to the subacromial space and to the rotator cuff that are more easily reached with a transdeltoid or posterior approach.
The distal extension of the deltopectoral approach is performed through an anterolateral access to the humerus. The route goes through the space between the deltoid and the biceps muscles proximally and through a split in the brachialis muscle distally [16] (Fig. 5.2).
Fig. 5.2
The distal extension of the deltopectoral approach is used to treat complex fractures of the proximal humerus extending to the diaphysis. The route goes through the space between the deltoid and the biceps muscles proximally and through a split in the brachialis muscle distally
5.3 Variations to the Anterior Approach
5.3.1 Combined Anterior Approach
Several variations of the anterior approach have been described. Each of them provides a limited exposure of the shoulder joint. A combined anterior and posterior or anterior and lateral approach is required to treat complex injuries.
Sometimes, the deltopectoral approach does not allow for a complete exposure of the lateral and posterior parts of the proximal humerus and requires a partial detachment of the deltoid [17, 18]. This procedure can lead to a significant deterioration of the deltoid function, with a long and difficult postoperative rehabilitation.
The combined approach to the shoulder makes it possible to easily reach the anterior, lateral, and posterior regions of the shoulder, thus avoiding detachment of the deltoid muscle. This route results from the combination of an anterior deltopectoral approach and of a subcutaneous transdeltoid access . It uses a single skin incision thus sparing the deltoid [3].
The patient is placed in a beach-chair position, and a traditional deltopectoral approach is performed. If a lateral or posterior approach is necessary, the subcutaneous tissue is dissected laterally. Once the deltoid is exposed, it is incised along the acromion up to a maximum of 5 cm distally. If required, the deltoid can be dissected more anteriorly or posteriorly. Thanks to the rich vascularization of the skin on the shoulder and to its elasticity, both the intermuscular and the intramuscular approaches can be performed with a single skin incision.
During the procedure, it is possible to move from one approach to the other according to the need, without damaging the muscle insertions or neurovascular structures. This approach allows for the open reduction and the internal fixation of comminuted fractures of the humeral head with a good exposure of its lateral and posterior portion.
5.3.2 Anteromedial Approach
A skin incision is performed 1 cm laterally to the coracoid, and then it is extended to the clavicle and laterally along the anterior fibers of the deltoid [19] (Fig. 5.3). By carefully separating the subcutaneous layer, it is possible to identify the anterior acromion, the insertion of the deltoid on the lateral aspect of the clavicle, the anterior deltoid, and the deltopectoral interval. Gradually the deltoid is detached first from the lateral aspect of the clavicle, from the acromioclavicular (AC) joint, trying to preserve the joint capsule and finally, from the anterior acromion, by incising the fascia and by lifting the muscle from the bone, thus preserving the coracoacromial ligament. The deltoid muscle is retracted laterally to expose the subacromial region. Once the procedure is over, the deltoid is reinserted with transosseous sutures to the acromion and to the clavicle and with simple sutures to the AC joint and to the fascia of the trapezius muscle.
Fig. 5.3
Anteromedial approach. A skin incision (red line) is performed 1 cm laterally to the coracoid (black circle), and then it is extended to the clavicle and laterally along the anterior fibers of the deltoid
This technique is safe and without complications [20] and is particularly indicated in the three following situations:
1.
To implant a shoulder prosthesis and to repair a posterior rotator cuff tear with a single procedure
2.
To protect the very fragile anterior deltoid that is not able to tolerate tractions or in a patient with severe osteopenia (e.g., in rheumatoid arthritis ) so as to avoid iatrogenic fractures
3.
In case of a shoulder arthroplasty revision surgery when the soft tissues are stiff and fragile
5.4 Lateral Approaches
5.4.1 Transdeltoid or Lateral Approach
5.4.1.1 Indications
This approach is indicated to treat the fractures of the greater tuberosity and of the proximal humerus in general (Fig. 5.4). Moreover, it allows for the repair of the rotator cuff.
Fig. 5.4
The transdeltoid approach is used to treat the fractures of the greater tuberosity. A 5 cm longitudinal incision is made, starting 1 cm proximally to the lateral edge of the acromion. The subcutaneous tissue is incised together with the fascia above the deltoid, and its muscle fibers are split
5.4.1.2 Technique
The patient is placed in a beach-chair position, with the arm on the edge of the Table. A 5 cm longitudinal incision is made, starting 1 cm proximally to the lateral edge of the acromion and with a distal extension.
The subcutaneous tissue is incised together with the fascia above the deltoid, and its muscle fibers are split. In order to protect the axillary nerve , an anchoring suture is applied on the inferior apex of the splitting so as to prevent the approach from extending distally. Once the subacromial bursa is removed, the rotator cuff is identified. By means of the subperiosteal detachment of the deltoid, both anteriorly and posteriorly, it is possible to obtain a large exposure. The repair of the deltoid is crucial for a good functional recovery. If necessary, it is possible to enlarge this approach with a proximal extension. The incision is prolonged superiorly and medially by passing over the acromion, then it is extended along the anterosuperior margin of the spine of the scapula for its two thirds laterally. The trapezius muscle along the spine of the scapula is detached and lifted. The supraspinatus muscle is exposed. The osteotomy of the acromion is performed in line with the skin incision. By retracting the stumps obtained, the supraspinatus muscle is completely exposed from its origin in the supraspinatus fossa up to its insertion on the greater tuberosity of the humerus [21]. If, on the one hand, this extended approach allows for a greater exposure with respect to the traditional transdeltoid route, on the other, it is more invasive, with a poor cosmetic result and an impact on the functional recovery and the risk of residual pain or poor strength.
5.4.1.3 Limitations
This approach allows for a good access to the greater tuberosity and to the supraspinatus tendon, while the exposure of the proximal humerus is limited.
5.4.1.4 Risks
The greatest risk of this approach is the excessive distal extension that can damage the axillary nerve if the incision is extended beyond 5 cm distally with respect to the acromion [22].
5.5 Variations to the Lateral Approach
5.5.1 Anterosuperior Approach
In1993, MacKenzie [23] described an anterosuperior approach that provides for a large and easy exposure of the glenoid and of the proximal humerus.
This approach is used to implant primary or inverse prostheses [24] and to address humeral head fractures.
The patient is placed in the same position as for the deltopectoral approach, but the elbow must be left without any support so as to allow the assistant to apply the force in the proximal direction. This is required to subluxate the humeral head. The surgeon moves laterally with respect to the shoulder, helped by two assistants on the two sides of the patient. The incision starts 1 cm medially to the anterior margin of the AC joint and continues along the anterior edge of the clavicle. The surgeon proceeds with the incision 5 mm. posteriorly to the anterior margin of the acromion and finally 4–5 cm distally with respect to the lateral margin of the acromion. The deltoid muscle is detached from the anterior margin of the acromion, and the splitting is prolonged distally for 5 cm. Then, the coracoacromial ligament is dissected.
Many authors use the anterosuperior approach to treat complex fractures of the proximal humerus in elderly patients [25–27]. In addition to the better exposure of the proximal humerus and of the glenoid, this approach makes it possible to detach and fix the greater tuberosity more easily with respect to the deltopectoral approach. Moreover, it is simple and preserves the subscapularis tendon with a low risk of postoperative anterior instability. However, the anterior deltoid may be weakened because of a mechanical injury or a lesion of the distal branches of the axillary nerve; moreover, the glenoid component of a prosthesis may be positioned incorrectly (too high or too low or too tilted superiorly).
5.5.2 Extended Anterolateral Approach
In 2004, Gardner et al. [28] described a lateral approach designed to treat complex fractures of the proximal humerus extending to the diaphysis. As shown by cadaver studies, the axillary nerve does not have any branches in the anterior portion of the deltoid muscle, before going through the fibrous raphe that separates the anterior head from the middle head of the muscle.
The technique envisages a conservative skin incision at the level of the anterolateral angle of the acromion, which is extended distally for about 5 cm. The fibrous raphe separating the anterior deltoid head from the medial one is identified and then incised for about 2 cm distally starting from the acromion. By palpating the deep surface of the deltoid, it is possible to identify the axillary nerve that feels like a “chord-like” structure. Then, the raphe is further dissected for about 6.5 cm from the acromion or for 3.5 cm from the greater tuberosity. The axillary nerve and the posterior circumflex vessels are isolated and protected. From here, the dissection can be extended distally up to the deltoid tuberosity without any risk in order to reduce and fix metaphyseal fractures of the humerus [28–30] (Fig. 5.5).
Fig. 5.5
Extended anterolateral approach. (a) Skin incision is performed at the level of the anterolateral angle of the acromion and is extended distally for about 5 cm. (b) The dissection can be extended distally up to the deltoid tuberosity in order to reduce and fix metaphyseal fractures of the humerus
A very similar approach, with a different skin incision called “extended deltoid-splitting approach ,” has been recently proposed by Robinson [31, 32]. A suspender-like incision is performed, its apex centered over the tip of the acromion. This incision follows the tension lines of the relaxed skin around the shoulder [33] so as to obtain a good cosmetic result, as in the case of the traditional direct lateral approach; moreover, the surgical scar resulting from this route in women is easily hidden by the bra strap. The skin is incised and is detached en bloc with the subcutaneous tissue, and an elliptical flap is created and lifted in order to expose the superior part of the deltoid. A longitudinal split of this muscle is performed for about 3 cm at the origin of the anterior raphe. With the extension of the incision, the superior split of the deltoid muscle allows for a superior approach and so for the visualization of the whole anterolateral and posterolateral portion of the proximal humerus. By palpating the axillary nerve, it is possible to isolate and protect it with a portion of the deltoid muscle and to enlarge the split distally so as to expose the distal humerus.
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