For proximal humeral fractures, most upper extremity surgeons recommend the delto-pectoral approach, especially in cases of comminuted or dislocated fracture types.

A 10–12 cm skin incision is made starting from the coracoid process to the distal insertion of the deltoid muscle (Fig. 15.3). The deltopectoral interval is blunt dissected from medially to the cephalic vein, followed by a blunt dissection of the subdeltoid and subpectoral spaces. Superiorly, the incision reaches the clavicle and a Hohmann-retractor can be placed above the acromiohumeral ligament for a wider exposition, if necessary. The deltopectoral groove is opened distally until the insertion of the pectoralis muscle. The clavipectoral fascia is split vertically just lateral to the conjoined tendons and up to the coracoacromial ligament to expose the fracture by internal and external rotation. One must consider that the coracoacromial ligament remains intact to avoid cranial glenohumeral instability. The upper insertion of the pectoralis major muscle can be cut for about 1–2 cm to allow better exposure of the metaphyseal region of the humerus or the inferior aspect of the glenohumeral joint. While putting the arm in abduction and internal rotation, a partial release of the deep surface of the deltoid can be performed to facilitate drilling and plate positioning [10]. Medially, the conjoint tendon is freed and retracted using a self-retaining, symmetric retractor that simultaneously retracts the deltoid muscle at the lateral side (Fig. 15.4). If the arm is anteverted with the elbow flexed during this procedure the conjoint tendon is relaxed, and thereby, the placement of the retractor is facilitated. Alternatively, a Hohmann-retractor can be placed around the humeral shaft to retract the deltoid muscle. After resection of the subdeltoid bursa, the subscapularis muscle is exposed, and following the anterior humeral circumflex vessels (at the inferior border of the subscapularis muscle) as well as the axillary nerve, both should be palpated in an effort to prevent iatrogenic injury during further preparation.

Several surgeons, however, note that this approach may not be the appropriate method for angular stable plate fixaton of proximal humeral fractures [4, 6, 28]. They note that it is difficult to gain the correct drill angle, possibly leading to slight anterior plate placement, and subsequently criticize the substantial soft tissue dissection, the retraction of the deltoid muscle as well as the humeral manipulation to access the lateral aspect of the humerus. To obtain the correct drill angle using a standard deltopectoral appraoch, the partial release of the humeral insertion of the deltoid muscle is described [10]. Certainly, this procedure has to be carefully considered because a release of more than one fifth of the deltoid insertion is reported to probably deteriorate anterior deltoid function [3, 15]. Furthermore, this approach may negatively influence postoperative outcomes due to devascularization of fracture fragments during dissection and plating or disruption of the critical blood supply to the humeral head [5, 7, 18]. According to Hertel et al. [12], the most relevant predictors of humeral head ischemia are the length of the dorsomedial metaphyseal extension, the integrity of the medial hinge, and the basic fracture type itself. Therefore, care must be taken with the deltopectorial approach to not deteriorate the initial situation of blood supply preventing an avascular necrosis of the humeral head.

In recent years the originally developed for rotator cuff surgery and intramedullary nailing of humeral shaft fractures deltoid-splitting (antero-lateral) approach has become more and more popular for plate osteosynthesis of the proximal humerus [5, 9, 24, 25, 29].

The first skin incision of this less-invasive approach starts from the antero-lateral tip of the acromion extending 5 cm distally in line with the arm. For superficial dissection, the deltoid muscle is split in line with its fibers (in the avascular raphe between the anterior and middle head) no more than 5 cm distal to the acromion to protect the axillary nerve. The subacromial bursa should be resected to reveal the underlying rotator cuff and the proximal humerus. Then, the axillary nerve is identified by palpation and consequently protected during the further procedure. After fracture reduction, the plating implant is inserted along the humeral shaft and positioned at the upper end of the greater tuberosity and approximately 2 mm posterior to the bicipital groove. Using the antero-lateral approach the lateral plating zone can be directly accessed with minimized muscle retraction. Then, the second skin incision is performed over the distal 3 holes of the plate following fluoroscopic control. After blunt dissection, the distal ending of the plate is displayed for fixation to the humeral shaft.