The PEARL Score for Predicting Postoperative Complication Risk in Patients with Pelvic and Acetabular Fractures: Development of a Novel Comprehensive Risk Scoring System

<i>Background and Objectives:</i> The objective of this study was to construct and validate a novel, clinically practical risk-stratification score, PEARL (Pelvic and Acetabular Adverse-event Risk Level), integrating established preoperative and intraoperative predictors, to accurately estimate the likelihood of major postoperative complications in patients undergoing open reduction and internal fixation for pelvic and/or acetabular fractures. <i>Materials and Methods</i><b><i>:</i></b> We retrospectively analyzed 200 adult patients treated surgically between January 2019 and January 2024 at two tertiary trauma centers. Demographic, injury-related, and perioperative data were collected. Major complications were defined as postoperative adverse events occurring within 30 days after surgery or during hospitalization, whereas delayed union and nonunion were evaluated as secondary long-term outcomes. Multivariable logistic regression identified independent risk factors, which were weighted to create the PEARL score (range: 0-6). Predictive performance was assessed using ROC (Receiver Operating Characteristic) analysis. We randomly split the sample into a 70% derivation and a 30% validation cohort. A multivariable LASSO-penalized logistic model identified independent predictors, which were weighted to construct the PEARL score. Discrimination (AUC) and calibration (Brier score, calibration curve) were assessed. <i>Results:</i> Major complications occurred in 29% of patients. Four independent predictors were identified: age ≥ 60 years, BMI ≥ 30 kg/m², severe associated injury, and operative time ≥ 180 min. The score showed good discrimination (derivation AUC = 0.82) and acceptable external validation (validation AUC = 0.78), with Brier scores of 0.19 and 0.21, respectively. PEARL demonstrated good discriminative ability, AUC (Area Under the Curve) = 0.82. Complication rates increased across risk strata: low (7.5%), moderate (30%), and high risk (62%). <i>Conclusions:</i> The PEARL score is a simple, reliable tool to stratify the risk of major postoperative complications after pelvic and acetabular fracture surgery. Early identification of high-risk patients may facilitate targeted preventive strategies and improve outcomes. Further multicenter prospective validation is warranted.