An anterior approach to the shoulder and humerus is used. Landmarks (coracoid process, acromion, clavicle) should be outlined prior to the incision. The incision is lateral to the true deltopectoral interval as it extends proximally to the superior aspect of the shoulder midway between the coracoid and the lateral aspect of the acromion process. Distally follow the lateral aspect of the biceps as far as necessary toward the elbow, depending on the length of planned humeral resection. The fact that the resection is being performed for metastatic disease means that a wide margin is usually not necessary (radiation is added postoperatively if an intralesional resection is performed). Often the surgeon will want to preserve tissue to improve function, which may lead to positive margins. If a truly wide resection is performed, however, it precludes the need for postoperative radiation and minimizes the chance of local recurrence. The following description presumes that there is a purely intraosseous destructive lesion in the proximal humerus and can be modified depending on the anatomic location and extent of any associated soft tissue mass. In general, involvement of the glenoid with metastatic disease is rare, and this section focuses on resection and reconstruction of only the proximal humerus with placement of a humeral head only without a glenoid component.

Develop wide medial and lateral subcutaneous flaps. Expose the deltopectoral interval. If the cephalic vein is maintained, it can be retracted medially or laterally with the deltoid (author prefers laterally). The pectoralis insertion is identified on the humerus, released, and tagged with a cuff of tendon maintained. The deltoid is retracted laterally, and its insertion on the humerus is detached and tagged. Sometimes a portion
of this attachment can be maintained for shorter humeral resections. For patients with an extensive proximal soft tissue mass, the deltoid can be released from the clavicle and acromion as far as the lateral acromion to increase exposure. The anterior humeral circumflex vessels are ligated and tied. This may cause some devascularization of the anterior deltoid, but it usually maintains viability with collateral flow. The conjoined tendon (short head of the biceps and coracobrachialis) originates at the coracoid process and is gently retracted medially. Do not abduct the arm or this will pull the axillary sheath toward the coracoid process. The musculocutaneous nerve is most likely to be injured if dissection occurs in this position. If additional exposure is necessary, the short head of the biceps and coracobrachialis are detached with a cuff of tendon and tagged. If the coracoacromial ligament can be maintained, it will help prevent superior subluxation of the humeral prosthesis. The teres major and latissimus dorsi are released from the humerus and tagged. The subscapularis is released from the humerus and tagged. Beware the axillary nerve as it exits through the quadrangular space inferior to the subscapularis. The long head of the biceps is identified and released distal to its origin on the glenoid and tagged.

The planned transaction of the humerus is marked and circumferential subperiosteal dissection is performed at this level. Maintain as much biceps and brachialis as possible in the setting of metastatic disease. Identify and protect the radial nerve within the spiral groove. At this point, the remaining proximal dissection can be completed (shoulder capsule, rotator cuff) or the humerus can be cut and elevated from the wound (author prefers the latter). Prior to humeral transection, the anterior cortex should be marked with an osteotome and marking pen to allow appropriate rotational placement of the prosthesis. Next, the triceps are released posteriorly. Proximally, the supraspinatus, infraspinatus, and teres minor are released as close as possible to the greater tuberosity and tagged with long sutures as they will retract. The shoulder joint capsule is incised as close as possible to the humeral head and neck to facilitate a stable soft tissue reconstruction. The proximal humerus is then delivered from the wound with careful dissection of the axillary nerve and posterior humeral circumflex vessels posteriorly. A distal marrow margin can be checked by frozen section if a wide resection is planned.