A preoperative inflammation-oxidative stress imbalance strongly predicts post-traumatic arthritis after acetabular...

This study aimed to evaluate the correlation between the development of post-traumatic arthritis (PTA) and a preoperative inflammation and oxidative stress imbalance. Further, the study aimed to evaluate the predictive power of a model based on inflammation and oxidative stress imbalance Index (IOSI).

This retrospective cohort study was conducted from January 2020 to December 2023 and included 258 patients who underwent open reduction and internal fixation of acetabular fractures (training cohort) and 127 patients from another center (external validation cohort). Blood specimens were collected and analyzed for preoperative and discharge levels of IL-6, TNF-α, MDA, SOD, and IOSI. Multivariate logistic regression was applied to identify independent predictors of PTA. Two predictive models were constructed that were a conventional preoperative indicator prediction model (Risk1) and an IOSI-based model (Risk2). Receiver operating characteristic curves, area under the curve AUC, and net reclassification improvement NRI were used to assess model performance.

Post-traumatic arthritis (PTA) occurred in 66/258 patients (25.6%) in the training cohort. Compared with the non-PTA group, patients who developed PTA had significantly higher preoperative IL-6, TNF-α, and malondialdehyde (MDA) levels and lower superoxide dismutase (SOD) levels (all P<0.001), resulting in a markedly increased preoperative inflammation-oxidative stress imbalance index (IOSI) (P<0.001). Multivariate logistic regression identified delayed time from injury to surgery (OR=8.463, 95% CI 4.107-18.436; P<0.001), concomitant femoral head fracture (OR=2.832, 95% CI 1.226-6.672; P=0.015), and preoperative IOSI (OR=23.388, 95% CI 10.107-60.825; P<0.001) as independent predictors of PTA. Preoperative IOSI showed the best discriminative performance among individual indicators (AUC 0.813-0.919; cut-off 1.302; sensitivity 84.85%; specificity 78.12%). The IOSI-based model (Risk2) achieved an AUC of 0.911 in the training cohort and 0.821 in the external validation cohort, outperforming the conventional model (Risk1; AUC 0.879 and 0.700, respectively). In the training cohort, the AUC difference between Risk2 and Risk1 was not significant (DeLong P=0.232), whereas Risk2 showed significantly improved discrimination in external validation (P<0.05) and better reclassification (NRI=0.3565).

A preoperative inflammation-oxidative stress imbalance could predict PTA after acetabular fracture fixation.