**2.2 Operative technique**

Key goals in prosthetic replacement for proximal humerus fractures include atraumatic exposure of the fracture site with protection of the deltoid origin and insertion while avoiding further devascularization of the fracture fragments, proper positioning of the prosthesis both in terms of height and version, and secure anatomic fixation of the tuberosities. The exact indications for the use of reverse prosthesis in the management of proximal humerus fractures is not well understood currently and is undergoing a period of development and research. Surgery is recommended within 7-10 days after the patient is cleared medically. Delay beyond this time makes dissection more challenging due to early fibrosis. Surgery must be followed by a safe physical therapy program which allows adequate healing of the tuberosities while avoiding excessive stiffness.

This surgery is typically performed under interscalene block anesthesia and general anesthesia. Relaxation during surgery decreases the pull of the pectoralis major and improves exposure. Interscalene block is contraindicated in the face of documented neurologic injury. This block results in excellent postoperative pain relief when indicated. The patient is placed in the beach chair position with the back of the table elevated approximately 30°. The patient is placed at the edge of the operating table with a bolster along the medial border of the scapula to stabilize this structure during surgery. Lateral placement of the arm allows extension off of the table for exposure and access to the humeral shaft. A well-padded neurosurgical head rest allows increased exposure and access to the superior shoulder and a short arm board supports the elbow without blocking access to the arm. All bony prominences are well-padded. A fluoroscan is utilized from above to allow evaluation of the fracture itself and tuberosity positioning. (Figure 6) Broad-spectrum antibiotics are routinely used. Surgical approach is planned to contribute minimal additional trauma to the soft tissues and vascular structures in the area of the proximal humerus. In situations in which the humeral head is displaced into the axilla in the area of the brachial plexus, caution must be exercised in its removal as this can result in hemorrhage. Assistance from a vascular surgeon may be required in such cases.

Shoulder Hemiarthroplasty in Proximal Humerus Fractures 541

The first step in controlling the 4-part proximal humerus fracture is to control the tuberosities. The lesser tuberosity is displaced medially by the pull of the subscapularis

Fig. 7.

**2.4 Control of fracture** 

Fig. 6.
