Hemiarthroplasty in Proximal Humerus Fractures: Does Modular Metaphyseal Stem Design Lead to Better Results? An Analysis of 24 Cases.

Introduction: Anatomic hemiarthroplasty (aHA) is a treatment option for non-reconstructable constructable multifragment proximal humeral fractures that preserves range of motion. Our study aims to evaluate the radiographic and clinical outcomes of patients who received a modular aHA with anatomical sizing of the tubercle-bearing metaphyseal components.

Materials and methods: The medical records of thirty-nine consecutive patients were reviewed. Patients were treated at a single institution with aHA as first-line treatment following a non-reconstructable constructable proximal humeral fracture. Tubercle resorption and cranialization of the aHA were analyzed using radiographic controls. Patient clinical function was assessed using the Constant Murley Score (CS).

Results: Twenty-four patients (62%) were available for clinical follow-up, with a mean CS of 54 points after a mean 56-month follow-up period. There was no significant difference in functional outcome on average between patients with healed tubercles (CS = 57) and resorbed tubercles (CS = 51). Radiographic follow-up was available in 33 patients (85%), demonstrating healed tubercles in 33% of the patients. Patients with resorbed tubercles had significant smaller acromio-humeral distances (AHD) than patients with healed tubercles (p = 0.043). A positive correlation was observed between greater AHD and increased constant scores (p = 0.022).

Conclusions: The final patient outcome measures demonstrated a positive correlation with a greater acromio-humeral distance and tubercle healing rates. However, the modular stem design with sizing of the metaphyseal components did not result in superior outcomes when compared with the literature.