Total Shoulder Arthroplasty Using Intraoperative 3D Navigation

Glenohumeral arthritis has become increasingly prevalent. For patients with glenohumeral arthritis and an intact rotator cuff, an anatomic total shoulder arthroplasty (TSA) has been shown to provide substantial pain relief with consistent, reproducible results. The primary indication is intractable pain that has not responded to nonoperative treatment, resulting in a substantial negative impact on the quality of life of the patient. Other indications for anatomic TSA include posttraumatic glenohumeral arthritis, inflammatory arthritis, and humeral head osteonecrosis. Contraindications include active infection, deltoid insufficiency, severe glenoid bone deficiency, and excessive glenohumeral posterior subluxation or laxity that cannot be surgically corrected. In order to provide the stability necessary to withstand the forces that impact the glenoid, the implant used in TSA should replicate the native anatomy of the individual patient by using a combination of implant modularity with different humeral neck angles and glenoid version augments, as well as dual eccentricity of the neck and head implant. The major steps in TSA include (1) preoperative planning, (2) patient positioning and setup, (3) surgical exposure, (4) accessing the glenohumeral joint, (5) preparation of the humerus, (6) exposure and preparation of the glenoid with component insertion, (7) humeral component insertion and trial reduction, (8) subscapularis reattachment and closure, and (9) postoperative immobilization and rehabilitation. The expected outcomes of TSA include improved quality of life (as indicated by improved outcome and patient satisfaction scores), shoulder active range of motion, and strength. In a large study examining outcomes of TSA in patients >55 years old, Patel et al. 1 reported improved American Shoulder and Elbow Surgeons (48.3 ± 23.0), Constant (33.1 ± 16.7), and University of California Los Angeles (16.7 ± 6.3) shoulder scores, as well as improved active range of motion in active abduction (42° ± 41°), forward flexion (46° ± 40°), external rotation (33° ± 23°), and internal rotation (2.2° ± 1.8°) and decreased visual analog scale scores (-5.1 ± 2.9). Another study 2 showed increased maximal weight improvement of 7.7 ± 4.0 lbs (3.5 ± 1.8 kg).