Fracture vs. standard stem for proximal humerus fractures using reverse total shoulder arthroplasty

Abstract

Background

Reverse total shoulder arthroplasty (rTSA) and hemiarthroplasty are recognized treatment options for significantly displaced proximal humerus fractures. Repair of the tuberosities and preservation of rotator cuff function is a principle of treatment to enhance function and prevent instability. Humeral fracture stems were developed to improve tuberosity union with hemiarthroplasty, and similarly fracture stems are used with rTSA with promising results. However, there are conflicting studies on the use of fracture stems in improving outcomes in rTSA for proximal humerus fracture. The purpose of this study is to determine the clinical and radiographic outcomes, complication and revision rates, and patient satisfaction for fracture vs. standard stems for acute proximal humerus fracture treated with rTSA.

Methods

A prospective multi-institutional institutional review board approved registry with a minimum two-year follow-up was queried and identified 231 patients that underwent rTSA for acute proximal humerus fracture, 187 of which received a fracture stem and 44 that received a standard stem. Patients were excluded if there was a previous fracture repair, malunion, or nonunion. Patient demographics, clinical and radiographic outcomes, complications, revision surgery, and patient reported outcome measures were collected preoperatively and at latest follow-up postoperatively.

Results

The mean follow-up was 48 $\pm$ 24 and 54 $\pm$ 34 months, mean age was 74 $\pm$ 7.9 and 72 $\pm$ 8.6 years, and mean body mass index was 28 $\pm$ 6.1 and 30 $\pm$ 5.3 kg/m² for fracture and standard stems, respectively. Both fracture and standard stem groups showed significant improvements in patient reported clinical outcomes preoperative to postoperatively. Postoperatively, patients with fracture and standard stems had comparable abduction, forward elevation, internal rotation, external rotation, Visual Analog Scale pain, Global Shoulder Function scale, Simple Shoulder Test scale, American Shoulder and Elbow Surgeons scale, University of California Los Angeles Shoulder score, and Shoulder Arthroplasty Smart score. Patient satisfaction was high and did not differ between the two groups. Similar rates of humeral radiolucent lines, scapular notching, complications, and revision rates occurred between the fracture vs. standard stem groups.

Conclusion

There were no significant differences in postoperative clinical outcomes, radiographic outcomes, complication rate, revision rate, and patient satisfaction between the fracture and standard stem groups for the treatment of acute proximal humerus fracture using rTSA. Both stems significantly improved clinical outcomes postoperatively. Either a fracture or standard stem may be used to achieve improved clinical outcomes for acute proximal humerus fracture using rTSA.