CT-Based Morphometric Analysis of Proximal Humerus Fractures: A Quantitative Framework

Introduction:Proximal humeral fractures (PHFs) represent approximately 4–5% of all fractures, with increasing incidence among elderly women due to osteoporosis. Conventional radiography often underestimates displacement and fails to characterize complex patterns. Computed tomography (CT) with multiplanar reconstruction (MPR) offers superior visualization and measurement accuracy. This study aimed to establish a quantitative CT-based morphometric framework for assessing fracture configuration, bone quality, and ischemic risk predictors in Vietnamese patients with PHFs.Methods:A retrospective analysis was performed on 80 non-contrast CT scans of PHFs obtained between January 2024 and April 2025. Multiplanar reconstruction was aligned to the humeral shaft axis. Quantitative parameters included greater and lesser tuberosity displacement (d_GT, d_LT), neck–shaft angle (NSA), calcar length (L_calcar), medial hinge gap (d_hinge), and head-split gap (d_split). Bone quality was evaluated using the Deltoid Tuberosity Index (DTI) and mean Hounsfield Unit (HŪ). Hertel risk criteria were applied to identify predictors of humeral head ischemia. Statistical analyses used t-test, chi-square, and logistic regression, with p < 0.05 considered significant.Results:The mean patient age was 53.7 ± 16.2 years (range 18–84), with a female predominance of 67.5% and left-sided involvement in 52.5%. Neer Type II and two-part fractures were most frequent (62.5% and 61.3%, respectively). Surgical-neck fractures (61.3%) had a mean NSA of 122° ± 21.8°, calcar length 6.58 ± 2.47 mm, and medial hinge gap 1.66 ± 2.17 mm; 81.6% fulfilled ≥2 Hertel ischemic criteria. Mean DTI was 1.75 ± 0.32, with 20% osteoporotic (DTI <1.44), and mean HŪ was 125.1 ± 6.3, significantly higher in males (p = 0.028). Fracture complexity correlated with direct trauma (p < 0.01) but not with age, sex, or bone quality.Discussion and Conclusion:CT-based morphometry provides reproducible and objective assessment of PHFs, surpassing plain radiographs in evaluating displacement, calcar integrity, and ischemic predictors. Quantitative thresholds—L_calcar < 8 mm, d_hinge > 2 mm, DTI < 1.44, and HU < 120—effectively identify risk factors for head ischemia and osteoporosis. Integration of algorithmic logic into computer-aided diagnosis may enhance decision-making for fixation or arthroplasty. This study establishes a data-driven framework linking quantitative CT imaging to orthopedic treatment planning.