Predictive value of the C-reactive protein to albumin ratio in the treatment of septic arthritis in young children: A retrospective study.

Introduction: Septic arthritis (SA) can cause lifelong disability in children due to joint dysfunction but there is controversy regarding the timing of surgery in SA. The C-reactive protein to albumin ratio (CAR) has emerged as a novel marker of inflammation and has been extensively used in predicting inflammatory bowel disease, arthritis, and systemic inflammation. Despite advancements, few studies have evaluated the role of CAR in SA. Therefore, the present study was aimed to investigate whether CAR could serve as predictive indicators for determining whether patients under four years old with SA should be managed conservatively or require surgical intervention, and to analyze its predictive accuracy.

Hypothesis: An increase in CAR values among patients under four years old with SA indicates the requirement of surgical intervention.

Materials and methods: This retrospective study enrolled SA children under four years old and divided them into two groups, the surgery and conservative groups. The clinical data between the two groups were compared and multivariate logistic regression was performed to assess the independent predictors of SA requiring surgery. The receiver operating characteristic (ROC) curve and the area under the curve (AUC) were used to determine the predictive ability of CAR in SA requiring surgery.

Results: A total of 82 SA children were included, with 42 children (51.3%) in the surgery group and 40 children (48.7%) in the conservative group. CAR ≥ 1.165 [OR = 12.641, 95% CI (4.264 - 37.479),p < 0.001] was an independent predictive indicator for surgery in SA children under four years old, with a predicted sensitivity of 0.714, specificity of 0.850, and AUC of 0.793 [95% (0.694-0.893)] indicating good predictive accuracy.

Discussion: CAR to be an independent predictive indicator patients under four years old with SA. And a CAR value ≥ 1.165 upon admission in these patients suggests the necessity for surgical intervention.

Level of evidence: IV, Retrospective study.