Hemiarthroplasty with a fracture stem is non-inferior to reverse shoulder arthroplasty for proximal humeral fractures in Japanese patients: a retrospective study

Abstract

Abstract Background Hemiarthroplasty (HA) is performed for treating proximal humeral fractures (PHFs) in which avascular necrosis of the humeral head is a concern. However, as the outcomes of HA depend on tuberosity healing, most studies did not report excellent results, and reverse shoulder arthroplasty (RSA) showed better and more predictable functional outcomes than HA. Since the Aequalis fracture stem yields better tuberosity healing and postoperative outcomes than conventional stems, we aimed to examine the postoperative outcomes of HA with Aequalis fracture stems in comparison with those of RSA. Methods Between 2017 and 2022, 26 patients with PHFs were treated with HA or RSA. Among these 26 patients, 15 (5 men, 10 women; mean age, 78 ± 6 years) who were followed up for at least 1 year were included in the study. Two patients were excluded because they were aged < 65 years. Results Active elevation, external rotation, and internal rotation in the RSA and HA groups were, respectively, 103°±15°, 14°±18°, and 3 ± 1 and 104°±37°, 30°±14°, and 5 ± 1. The pain scores in the RSA and HA groups were 26 ± 4 and 29 ± 4, respectively, while the final Japanese Orthopedic Association scores were 77 ± 8 and 84 ± 11, respectively. The clinical outcomes, except for internal rotation, did not differ significantly between the two groups. Two patients in the HA group showed intraoperative local complications (axillary nerve palsy and axillary artery injury), while one patient in the RSA group showed a local postoperative complication (late infection). The complications observed on radiographs differed between the two groups: the RSA group showed an acromial fracture, a periprosthetic fracture, and two cases of aseptic stem loosening in the nonunion of tuberosities, while the HA group showed two cases of bone resorption of the tuberosities. Conclusion Postoperative outcomes of HA with Aequalis fracture stems were comparable to those of RSA, and postoperative complications with HA were fewer than those with RSA. HA using this stem was relatively safe and can be expected to have good postoperative results. Therefore, it may be a treatment option for PHFs in the elderly.