Exploratory Analysis of Bone Marrow IL-10 and Plasma IL-1RA in Acute Traumatic Versus Chronic Non-Traumatic Orthopedic Patients: A Prospective Observational Study

Introduction: Inflammation is a central component of the biological processes involved in orthopedic interventions, whether performed for acute traumatic injuries or chronic non-traumatic conditions. Cytokines play major roles in modulating these responses; however, data describing cytokine activity in bone marrow, particularly during orthopedic procedures, remain limited. This study aimed to examine variations in cytokine levels in traumatic and non-traumatic orthopedic surgeries by analyzing simultaneous bone marrow and plasma samples. Methods: This single-center prospective observational study with exploratory objectives included skeletally mature patients undergoing urgent surgery for acute traumatic fractures or planned surgery for chronic non-traumatic degenerative orthopedic conditions. Bone-marrow and peripheral plasma samples were collected simultaneously intraoperatively. All samples were tested in duplicate for interleukin-8 (IL-8), interleukin-6 (IL-6), interleukin-10 (IL-10), interleukin-4 (IL-4), interleukin-1 receptor antagonist (IL-1RA), and tumor necrosis factor-α (TNF-α) using developmental ELISA kits. Cytokine levels were compared between traumatic and non-traumatic groups and between bone-marrow and plasma samples. Results: Nineteen participants were included, providing 19 bone-marrow samples and 15 plasma samples, with the number of available measurements varying among cytokines. Bone-marrow IL-10 was detected in three of five available traumatic samples and in none of the eight available non-traumatic samples (unadjusted p = 0.035; false-discovery-rate-adjusted q = 0.178). Plasma IL-1RA concentrations were higher in traumatic than in non-traumatic patients (median 2828.00 versus 1269.00 pg/mL; unadjusted p = 0.038; q = 0.178). Bone-marrow IL-8 also showed higher concentrations in traumatic patients and approached the unadjusted significance threshold (p = 0.053; q = 0.178). No comparison remained statistically significant after FDR correction. Discussion: Bone-marrow IL-10 detection and plasma IL-1RA concentrations showed nominal between-group differences that did not remain statistically significant after multiple-comparison adjustment. Although preliminary and hypothesis-generating, these observations identify potentially informative local and systemic cytokine patterns and highlight the value of further investigating bone-marrow cytokine responses in orthopedic trauma.