Introduction: Femoral implant surgery is frequently complicated by early inflammatory reactions that may be difficult to distinguish from normal postoperative responses. Because C-reactive protein reflects systemic inflammatory activity, preoperative measurement may help identify patients at greater risk of acute pathologic inflammation after surgery. The aim of this study was to evaluate the diagnostic value of preoperative CRP in predicting acute inflammation following femoral implant placement.

Material and methods: This descriptive cross-sectional study was conducted at Shahid Madani Hospital in Tabriz, Iran. Using Cochran’s formula, the sample size was estimated at 73 patients, who were enrolled through convenience sampling. Data were extracted from medical records on demographic characteristics, comorbidities, preoperative CRP and other laboratory findings, operative details, and early postoperative inflammatory outcomes to assess the diagnostic value of preoperative CRP.

Results: Among 73 patients, acute postoperative inflammation occurred in 21.9%. Affected patients had higher preoperative CRP (24.18 vs 12.32 mg/L, P < 0.001), ESR (34.50 vs 25.98 mm/h, P = 0.009), and WBC (9.96 vs 8.40 x10³/muL, P = 0.015), but lower hemoglobin (11.28 vs 12.34 g/dL, P = 0.021) and albumin (3.29 vs 3.70 g/dL, P = 0.003). CRP showed good diagnostic performance (AUC = 0.812, sensitivity 78.9%, specificity 73.6%, NPV 95.1%).

Conclusion: Preoperative CRP appears to be a clinically useful marker for identifying patients at risk of acute inflammation after femoral implant placement. Its strong discriminatory capacity and high negative predictive value suggest particular value in perioperative risk stratification, especially when interpreted alongside comorbidity burden, nutritional status, and operative complexity.