Objective: Classification systems play a crucial role not only in determining diagnostic and therapeutic strategies but also in predicting patient prognosis. As the severity of trauma increases, the complexity of fractures and the classification level also tend to rise accordingly. In this study, we aimed to investigate how inflammatory markers that reflect trauma severity – such as the neutrophil-to-lymphocyte ratio (NLR) and the C-reactive protein-to-albumin ratio (CAR) – vary according to the NEER classification of proximal humerus fractures, and whether these markers can predict complications related to fracture healing.
Materials and
Methods: This retrospective study reviewed patients with proximal humerus fractures treated with plate-screw osteosynthesis between January 2016 and January 2022 at a single medical center. 171 patients were grouped by bone union status and NEER classification. Non-union (5.4%) was defined as the absence of radiographic healing signs up to 6 months post-operatively. Blood samples for routine full blood count and biochemical analysis were collected within the first 24 h of emergency department admission for surgical evaluation. The correlation between the number of Neer fragments and inflammatory biomarkers was assessed. In addition, the association between inflammatory biomarkers and fracture healing was analyzed.

Results: The non-union rates of 3-part and 4-part fractures were higher than those of 2-part fractures. (p=0.047, p=0.048). However, there was no significant difference in blood parameters between the two groups. No statistically significant differences in C-reactive protein, Albumin, CAR, or NLR levels were found among Neer fracture types.

Conclusion: Inflammatory status may not have been affected by union or Neer classification, but integrating these classifications into multivariate union models for proximal humerus fractures might yield more scientifically rigorous and precise outcomes.