粉砕性（3部および4部）近位上腕骨骨折における再建術対ヘミアートロプラステイ：6ヶ月時点での遡及的機能転帰分析

Background: The optimal management of comminuted proximal humerus fractures in the elderly remains controversial. Although hemiarthroplasty is widely used for complex fracture patterns, its functional superiority over reconstruction is not consistently demonstrated. The aim of this study was to compare early functional outcomes following open reduction and internal fixation (ORIF) versus hemiarthroplasty in elderly patients with three- and four-part proximal humerus fractures. Methods: This retrospective single-center study included elderly patients with comminuted proximal humerus fractures treated between 2020 and 2024 by either ORIF or hemiarthroplasty. Functional outcomes were assessed at 6 months using the Constant-Murley and DASH scores. Secondary outcomes included complication rates, range of motion, and early reintervention. Results: At 6 months, the ORIF group showed a mean Constant-Murley score of 62.1 ± 9.4 compared with 58.0 ± 10.2 in the hemiarthroplasty group. DASH scores were 34.2 ± 10.8 for ORIF and 38.5 ± 11.3 for hemiarthroplasty. Pain levels were similarly low in both groups (VAS 2.6 ± 1.1 vs. 2.9 ± 1.2). Complication rates were comparable, with fixation-related issues occurring in 17% of ORIF cases and tuberosity-related complications in 11% of hemiarthroplasty cases. Conclusions: Hemiarthroplasty should not be regarded as the default treatment strategy for comminuted proximal humerus fractures in elderly patients. When stable anatomic reduction is achievable, ORIF can yield comparable early functional results, emphasizing that patient selection and tuberosity management remain more important than the choice of implant.