Factors predicting the need for surgery in infectious spondylodiscitis: a retrospective single-center study.

This study aimed to identify parameters that could predict the need for surgical intervention by comparing the clinical, radiological, and laboratory data of patients with infectious spondylodiscitis who underwent either medical or surgical treatment. In this retrospective cross-sectional study, 80 patients diagnosed with infectious spondylodiscitis and followed up between January 2020 and December 2023 were analyzed. Patients were categorized into two groups: those who underwent surgical treatment and those who did not. Demographic characteristics, laboratory results, and radiological findings were compared between the two groups. The mean age was 55.8 ± 14.4 years, and 55% were male. The most common symptoms were back pain (97.5%), fever (45%), and night sweats (35%). The infection was most frequently localized in the lumbar vertebrae (55%). The most isolated etiological agents were Brucella (38.8%) and Staphylococcus aureus (18.8%). Pyogenic spondylodiscitis was detected in 58.8% (n = 47) of cases. Surgical treatment was performed in 47% (n = 38) of the patients. Pyogenic spondylodiscitis (81.6% vs. 38.1%, p < 0.001), thoracic localization (36.8% vs. 16.7%, p = 0.04), presence of epidural abscess (52.6% vs.,11.9%, p < 0.001), presence of psoas abscess (21.1% vs.,4.8%, p < 0.001) and Gram-positive coccal infections (50% vs. 7.1%, p < 0.001) were higher in the surgical treatment group compared to the medical treatment group. Leucocytes count (11.5 vs. 8.7, p = 0.003) and neutrophil counts (8 vs. 5.5, p = 0.003) were significantly higher in patients who underwent surgical treatments (p = 0.03). In the multivariate logistic regression analysis, thoracic involvement (p = 0.009, OR = 7.37, 95% CI = 1.65–32.8) and gram-positive coccal infections (p < 0.001, OR = 11.92, 95% CI = 2.18–65.2) were found to be significant risk factors for the necessity of surgical treatment. Leukocyte and neutrophil counts demonstrated moderate discriminatory power in predicting the need for surgical intervention, with area under the curve (AUC) values of 0.696 and 0.691, respectively. A leukocyte count > 10.7 showed a sensitivity of 60.5%, specificity of 71.4%, positive predictive value (PPV) of 66%, and negative predictive value (NPV) of 67%. Similarly, a neutrophil count > 6.9 yielded a sensitivity of 60.5%, a specificity of 69%, PPV of 64%, and NPV of 66%.The results of this study have shown that factors such as thoracic involvement and gram-positive infections were found to be independent risk factors for surgical intervention. Laboratory findings, such as leukocyte and neutrophil counts, may serve as supportive, though not definitive, markers in predicting the need for surgical treatment. Assessing these parameters in patients diagnosed with spondylodiscitis will be beneficial for early prediction of surgical necessity.