We prefer to perform all glenoid arthroplasty prior to performing humeral arthroplasty. We place the arm in a posterior and inferior position, thereby moving the humerus out of the surgical window in order to adequately access the glenoid. Placement of the patient in the semisupine position with the head of bed elevated 20–30° as previously described allows for gravity to assist the exposure by aiding to place the arm in a posterior position. The center of the glenoid articular surface is first marked with a Bovie. Our preferred starting point for placement of the baseplate peg is just posterior and inferior to the native center of the glenoid (Fig. 10.2). After the center hole is drilled, a curette is used to confirm that the drill has not perforated the glenoid vault either anteriorly or posteriorly. The glenoid is sequentially reamed up to the size of the glenosphere. After each reamer is engaged within the center hold of the glenoid, we drop our hand approximately 10–15° to allow for inferior tilt of the baseplate/glenosphere. We prefer to ream the glenoid minimally so as to create a smooth, flat surface on which the baseplate will sit while preserving the structural stability of the subchondral bone. An enlarging drill is then used to finish the preparation for the central post and the baseplate is impacted into place. Our preference is to “match” the size of the baseplate and glenosphere to each individual patient based on height and weight. With the particular implant system, we prefer for reverse arthroplasty, there are two different-sized baseplates available. As a general rule, we implant the smaller baseplate in women and the larger baseplate in men. Similarly, each baseplate is also available with either a “short” or “long” central post. We prefer to use a long central post in all fracture patients in an effort to maximize the stability between the glenoid and baseplate. We place two compression screws (anterior and posterior) followed by two locking screws (superior and inferior) through the baseplate. The posterior screw captures the lateral pillar of the scapula, the anterior screw the scapular spine, the superior screw the coracoid base, and the inferior screw parallels the central post of the baseplate along the glenoid neck. We feel this represents the four most important points of fixation for the baseplate screws within the native scapula. The baseplate is then exposed circumferentially in order to allow for appropriate engagement of the morse taper and countersunk screw of the particular medial center of rotation glenosphere we utilize for reverse TSA. The glenosphere is then impacted onto the baseplate and locked into place.

The humeral shaft is exposed with an osteotome anteriorly and posteriorly. Since the metaphysis is typically “absent” due to the fracture, the humeral shaft is prepared with hand reamers until there is gentle cortical resistance. A humeral trial is then placed. Appropriate height of the humeral implant and length of the greater tuberosity fracture fragment is calculated preoperatively as noted above (see Sect. 10.2) based on comparison to the contralateral limb. This measurement is confirmed intraoperatively (Fig. 10.3). It should be noted that if the radiographic measurement of length of the greater tuberosity fragment performed preoperatively is not equal to that measured intraoperatively, the latter number should supersede the former. Humeral version is then set by placing the arm in a neutral position at the side and pointing the humeral component/tray toward the glenoid (Fig. 10.4). Two drill holes are then placed on either side of the bicipital groove and a single heavy nonabsorbable suture is placed through each for final vertical, tension-band fixation of the tuberosities. A cement restrictor is then placed at a distance equal to two canal diameters distal to the tip of the prosthesis and the humeral canal cleaned and dried with pulsatile lavage and an epinephrine soaked sponge. We then cement the humeral canal using a third-generation technique utilizing a ventilation tube to remove all blood and minimize embolic phenomenon within the endosteal vessels of the humeral shaft. The proximal 1–2 cm of cement is removed and the final humeral implant is manually placed down the shaft of the humerus. The height and version of the prosthesis are set as noted previously. Once the cement is cured, we place a constrained polyethylene trial onto the humeral component and the prosthesis is gently reduced to confirm adequate positioning and stability. The humeral component is then dislocated, and the final constrained polyethylene liner is impacted in place. The four nonabsorbable sutures previously placed at the greater tuberosity at the bone-tendon junction are then cerclaged around the humeral stem prior to gentle reduction of the final humeral component (Fig. 10.5).

The greater tuberosity is then reduced and held in its anatomic position with a pointed awl. Two of the four nonabsorbable sutures previously placed around the greater tuberosity at the bone-tendon junction and cerclaged around the prosthesis are tied. The two remaining sutures are then placed through the lesser tuberosity bone-tendon junction and tied with the lesser tuberosity held in an anatomic position with the pointed awl (Fig. 10.6). This affixes the tuberosities to one another around the prosthesis in the horizontal plane. The two nonabsorbable sutures previously placed through bone tunnels on either side of the intertubercular groove are not passed through the rotator cuff (one anterior to posterior and the other from posterior to anterior), thereby creating a figure-of-eight vertical tension-band fixation of the tuberosities to the shaft (Fig. 10.7). After all sutures are tied, trial motion is demonstrated to ensure stable fixation of the tuberosities to the shaft and to rule out any abnormal impingement of the implant prior to closure. The deltopectoral interval is then closed with no. 2 absorbable braided suture, followed by closure of the subcutaneous tissue with interrupted 0 absorbable sutures and a running 2/0 absorbable suture. The skin edges are re-approximated with staples and a sterile dressing applied. The ipsilateral extremity is then placed into a simple Velpeau arm sling with the arm resting at the side prior to extubation.