Abstract
BACKGROUND: The objective of this study was to investigate the impact of preoperative antibiotic administration timing on pus culture results in children with acute osteomyelitis. METHODS: Clinical data of 87 children with acute osteomyelitis diagnosed and treated from January 2020 to July 2024 were retrospectively analyzed. All the children received antibiotic therapy prior to surgical debridement and drainage. During the surgical procedure, pus samples were collected for both standard bacterial culture and enrichment medium culture, and the enrichment medium culture yielded positive results in all cases. Based on the outcomes of the standard bacterial culture, 17 children with negative culture were classified into the negative group. 70 children with positive culture were assigned to the positive group. RESULTS: There was no significant difference in gender between the two groups (P = 0.644). The age of the negative and positive group was 72.00 (39.50,90.00) months and 69.50 (25.50,108.00) months (P = 0.785), the duration of onset was 6.00 (4.00,9.50) days and 7.00 (4.00,7.00) days(P = 0.770), white blood cell counts were 14.23 (11.39,15.95)×10(9)/L and 13.31 (9.42,16.55)×10(9)/L (P = 0.979), neutrophil counts were 10.59 (6.92,12.61)×10(9)/L and 9.17 (5.65,13.41)×10(9)/L (P = 0.483), C-reactive protein was 69.80 (42.87,148.83) mg/L and 77.98 (41.11,127.17) mg/L (P = 0.856), erythrocyte sedimentation rate was (58.94 ± 29.31) mm/h and (55.34 ± 26.29) mm/h (P = 0.622), the differences were not statistically significant. The preoperative antibiotic administration timing of the negative group and positive group was 5.00 (3.00,9.00) days and 3.00 (2.00,5.00) days, the difference was statistically significant (P = 0.008). The optimal cutoff of the preoperative antibiotic administration timing was 3.5 days, and the sensitivity, specificity and area under the curve were 70.6%, 61.4% and 0.704 (0.569-0.839), respectively. Logistic regression analysis indicated that preoperative antibiotic administration timing > 3.5 days (OR = 3.822, 95%CI: 1.212-12.058) was an independent risk factor for predicting negative culture of standard bacteria (P = 0.022). CONCLUSIONS: When antibiotics were administered for more than 3.5 days, the bacterial culture yield of pus decreased, and the standard bacterial culture was more likely to be negative.