Locate the following structures on the skeleton:

• Clavicle
• Sternum
• Humeral head
• Sternoclavicular joint
• Acromioclavicular joint
• Coracoid process
• Glenoid fossa
• Superior, medial and lateral borders of scapula
• Scapular spine
• Acromion
• Suprascapular notch
• Spinoglenoid notch
• Greater and lesser tubercle of humerus

If your donor has previously undergone a dissection of the chest wall, proceed to Section 3 – Superficial Muscles.

Make the following incisions:

• Midline mandible to inferior to the nipple (T6)
• Lateral below the nipple to posterior axillary line
• Jugular notch to acromion
• Jaw line to mastoid

Reflect the skin flaps laterally.

With the flaps reflected identify the:

• Pectoralis major
• Deltoid
• Serratus anterior
•  Latissimus dorsi
•  Biceps

In the axilla identify the long thoracic nerve to the serratus anterior and the thoracodorsal nerve to the latissimus dorsi.

Question 1: What is the surgical significance of the long thoracic and thoracodorsal nerves?

Identify the pectoralis major and deltoid. Note the cephalic vein between them.

Reflect the pectoralis major laterally to the humerus by incising along its lateral border and separating this muscle along its clavicular, sternal and costal attachments. This will expose the pectoralis minor and the medial and lateral pectoral nerves.

Breast implants are frequently placed in the plane beneath the pectoralis major.

Incise the deltoid along the clavicular origin and reflect it laterally to reveal the humeral head.

Identify the coracoid process, the greater and lesser tubercles of the humerus and the biceps tendon.

Dissect medial to the pectoralis minor to identify the cephalic vein entering the axillary vein.  Adjacent to the axillary vein locate the axillary sheath, which contains the axillary artery and brachial plexus.

Expose the tendon of the long head of the biceps. Locate nearby bony landmarks:

• Acromion
• AC joint
• Coracoid process

Divide the tendon of the short head of biceps and coracobrachialis (conjoined tendon) at the coracoid process. Reflect the tendon laterally.

Divide the pectoralis minor at the level of the coracoid process and reflect medially to reveal the axillary sheath.

Laterally rotate the shoulder to bring the tendon of the subscapularis into view. Incise the tendon of the subscapularis to expose the shoulder joint.

With the subscapularis tendon divided further rotate the arm laterally to expose the articular surface of the humeral head.

Elevate the skin and superficial fascia from arm, neck and back to expose the underlying deep fascia and musculature.  Counter incisions across the neck, superior shoulder and back may be needed.

Look at a skeleton and compare with the donor.  Note the following on the scapula:

• Spine
• Acromion
• Lateral and medial borders
• Superior and inferior angles

Define the margins of the following superficial muscles:

• Deltoid
• Trapezius
• Latissimus dorsi
• Rhomboids
• Infraspinatus
• Teres minor
• Teres Major
• Triceps

At the superior aspect of the shoulder reidentify the spine of scapula, acromion, clavicle and attachment of the trapezius.

Detach the trapezius from the spine of scapula. Reflect it superiorly in order to identify the supraspinatus muscle. Continue this dissection anteriorly along the clavicle.

Reflect the trapezius medially and identify the spinal accessory nerve (XI) along its deep surface. This nerve may be difficult to locate.

The rhomboids and levator scapulae will now be in view along the medial border and superior angle of the scapula, respectively.

Detach the deltoid from the spine of scapula and acromion in order to expose more of the rotator cuff muscles.  Reflect the deltoid laterally.

Identify the infraspinatus, teres minor and teres major.  On the deep surface of the deltoid identify the axillary nerve and the posterior humeral circumflex vessels which supply the deltoid and teres minor.

Detach the rhomboids from the medial border of the scapula and reflect medially in order to reveal the erector spinae and serratus anterior.  The medial border of the scapula needs to be elevated in order to appreciate the serratus anterior.

Detach the serratus anterior from the medial border of the scapula in order to identify the subscapularis muscle which is one of the four rotator cuff muscles of the shoulder joint.

Examine the shoulder from a superior perspective.  Note the spine of the scapula, acromion, AC joint and clavicle from this angle of view.  

Incise the supraspinatus muscle and remove it to expose the supraspinatus fossa. Find the suprascapular notch. Reexamine this notch on a skeleton to assist in its location. The suprascapular nerve passes through the notch and the vessels pass over it.

With the deltoid reflected laterally, note the acromion, head of humerus, greater tubercle and proximal shaft of humerus (surgical neck).

Locate the rotator cuff muscles and their attachments to the humerus.  The supraspinatus, infraspinatus and teres minor all attach to the greater tubercle.  The subscapularis attaches to lesser tubercle.

Re-identify the axillary nerve and posterior humeral circumflex vessels as they pass around the humerus to supply the deltoid and teres minor.

Divide the tendon of the long head of the biceps. This will provide for further mobilization of the shoulder joint to view the glenoid fossa and labrum.

Externally rotate the arm to provide this view. Identify the articular surface of humerus, glenoid fossa and glenoid labrum. Exercise care since this maneuver will stretch the brachial plexus and axillary artery.