39 Deltopectoral Approach for Shoulder Arthroplasty

10.1055/b-0039-167688

39 Deltopectoral Approach for Shoulder Arthroplasty

Wame N. Waggenspack, Jr. and T. Bradley Edwards

Abstract

The deltopectoral approach, utilizing the internervous plane between the deltoid (axillary nerve) and the pectoralis major (medial and lateral pectoral nerves), is the standard for shoulder arthroplasty, allows unhindered access to the anterior glenohumeral joint, and is fully extensile to the anterolateral approach to the humerus. Following a stepwise surgical technique allows reliable and reproducible humeral and glenoid exposure for optimal preparation and implantation of components. We present our preferred technique in this chapter.

39.1 Introduction

The deltopectoral approach is the workhorse approach in open shoulder surgery and is the standard approach for anatomic shoulder arthroplasty. Reverse shoulder arthroplasty may be performed through either the deltopectoral approach or the anterosuperior approach, each with advantages and disadvantages. The anterosuperior approach uses a deltoid split, which violates the primary arm elevator, and is not extensile.

We prefer to use the deltopectoral approach for all shoulder arthroplasty for several reasons. It provides reliable and uncompromised access to the anterior shoulder and excellent glenoid exposure with proper capsular release and humeral head retraction without potential compromise of deltoid function. In addition, this approach is fully extensile into the anterolateral humerus approach. We describe our preferred stepwise surgical technique to reliably achieve adequate exposure for humeral and glenoid preparation and component implantation.

39.2 Operating Room Setup and Patient Positioning

Shoulder arthroplasty is performed under general anesthesia. It is important for the patient to be kept fully relaxed by anesthesia until implantation of components is complete to allow uniform assessment of soft-tissue tension during trialing. We prefer to have the operating room setup so that the operative extremity is opposite the sterile field. This allows the surgical technician to act as a second assistant. The patient is positioned in the modified beach-chair position. A small folded sheet should be placed under the patient at the medial scapular border to stabilize the scapula for the glenoid portion of the procedure. The patient must be positioned sufficiently near the edge of the table to allow for full extension and adduction of the surgical arm, which is essential for humeral preparation. The arm is then prepped and draped, and the axilla sealed off from the surgical field with a barrier drape ( Fig. 39.1 ).

**Fig. 39.1** Patient is positioned in the modified beach-chair position with the operative side opposite the sterile field. A barrier drape should be used to seal the axilla.

39.3 Operative Technique

39.3.1 Anatomy

The deltopectoral approach uses the internervous plane between the deltoid muscle, innervated by the axillary nerve, and the pectoralis major muscle, innervated by the medial and lateral pectoral nerves. The surgical approach begins with identification of the topographic anatomy of the shoulder. The coracoid process is typically readily palpable except in very obese patients or patients who have previously undergone a procedure involving the coracoid process. In thinner and muscular patients, the deltopectoral interval may be directly palpated to help guide the orientation of the skin incision, which extends approximately 10 to 15 cm distal and lateral from the coracoid ( Fig. 39.2 ). The approach is also fully extensile to the anterolateral approach to the humerus if needed.

**Fig. 39.2** The deltopectoral interval is marked beginning at the coracoid and extending 10 to 15 cm distal and lateral using the anterior border of the deltoid muscle as a guide if palpable.

39.3.2 Superficial Dissection

With the arm in neutral rotation and adducted position, a no. 10 scalpel is used to sharply incise only the skin. Needle electrocautery is then used for subcutaneous dissection and most of the deep dissection throughout the procedure. Maintaining meticulous hemostasis with the initial dissection is important to prevent bleeding from the superficial vessels. Medium skin rakes are used to retract and tension the subcutaneous tissue. The dissection continues through the deltopectoral fascia to expose the cephalic vein, which identifies the interval between the deltoid and the pectoralis major muscles. The vein is surrounded by a layer of fat and typically easily identified. If difficulty is encountered due to a congenitally small or absent vein, a small triangular area devoid of muscle proximally at the coracoid allows identification of the interval ( Fig. 39.3 ).

**Fig. 39.3** The cephalic vein marks the deltopectoral interval and typically is located in a layer of fat between the deltoid and pectoralis major muscles.

The cephalic vein is then dissected free of the pectoralis major muscle with Metzenbaum scissors, and may be taken either medially or laterally depending on surgeon preference. We prefer to retract the vein laterally, as most branches from the cephalic vein are deltoid based and retracting the vein medially may disrupt these branches and introduce unwanted hemorrhage. The deltoid and pectoralis major muscles are then retracted with the Army Navy retractors and a self-retaining retractor placed to develop the interval. The superior centimeter of the pectoralis major may be released sharply to enhance exposure of the inferior subscapularis, anterior circumflex vessels, and axillary nerve. Curved Mayo scissors are used to bluntly dissect superior to the coracoid and a Hohmann-type retractor is placed in the space to complete the initial exposure ( Fig. 39.4 ).