Temporal Changes in Key Hematological and Inflammatory-Immune Markers Among Elderly Patients Following Hip Fracture: A Five-Day Serial Assessment.

OBJECTIVE

Hip fracture is a severe injury in the elderly population and can trigger a strong physiologic stress reaction with potential impact on clinical outcomes. However, few data are available on the temporal evolution of hematologic parameters after this injury. This study aimed to evaluate the temporal trends of key hematological and inflammatory-immune markers in elderly patients with hip fractures.

METHODS

A retrospective cohort study was conducted among elderly patients with hip fractures managed at a tertiary referral center from January 2022 to October 2024. Included patients were required to have both complete serial hematological measurements obtained during the first 5 days post-fracture and relevant clinical data. We used generalized estimating equation models for repeated measurements to describe the temporal trends of key hematological markers, with analyses stratified by fracture type and age group.

RESULTS

A total of sixty patients were included, with a mean age of 80 ± 7.4 years (range: 65-96 years) and 68.3% females (n = 41). Within the first 1-5 days post-fracture, hemoglobin decreased by a mean of 9.66 g/L, hematocrit by 3.10 percentage points, neutrophil percentage by 8.12 percentage points, neutrophil count by a mean of 2.41 × 109/L, and neutrophil-to-lymphocyte ratio (NLR) by 3.07 (all p-values < 0.001). Conversely, lymphocyte and monocyte counts exhibited a biphasic change, peaking on day 4 prior to subsequent decline. Subgroup analyses revealed that monocyte levels demonstrated significant interactions between time and fracture type (p = 0.036), whereas both lymphocytes (p = 0.034) and monocytes (p = 0.012) exhibited significant interactions between age and time.

CONCLUSIONS

Hemoglobin, hematocrit, neutrophil percentage, neutrophil count, and NLR progressively decrease during days 1-5 after hip fracture in older patients, whereas lymphocyte and monocyte counts exhibit biphasic patterns and vary significantly according to fracture type and age. These findings may help clinicians in interpreting early post-fracture laboratory dynamics and provide a basis for future outcome-oriented validation.