Impact of Preoperative Alkaline Phosphatase Following Ankle Fracture Open Reduction and Internal Fixation

Research Type: Level 3 - Retrospective cohort study, Case-control study, Meta-analysis of Level 3 studies Introduction/Purpose: Ankle fractures are commonly treated with open reduction and internal fixation (ORIF) to restore function and stability. While alkaline phosphatase (ALP) is recognized as a marker for bone metabolism and inflammation, its role in predicting postoperative complications remains underexplored. Previous studies in joint arthroplasty have demonstrated that elevated ALP levels are associated with increased risks of periprosthetic fractures, infections, and longer hospital stays. This study aims to investigate the impact of preoperative ALP levels on outcomes following ORIF of ankle fractures. Methods: The American College of Surgeons National Surgical Quality Improvement Program database was queried between 2005 and 2020 to include all ankle fractures treated with open reduction and internal fixation (ORIF). Cases with identifiable preoperative ALP levels were included. A total of 32,889 patients were identified, with the majority female (61.4%). Patients were stratified by ALP level (low = < 44 IU/L, normal = 44-147 IU/L, high = >147 IU/L) Multivariate linear and logistic regression analyses were used to determine the impact of preoperative ALP as a predictor of postoperative outcomes after controlling for age, sex, race and comorbidities. Results: Preoperative ALP levels were significantly associated with increased risks of postoperative complications and longer hospital stays. Low ALP was a significant predictor of cardiac arrest requiring CPR and unplanned reoperation. High ALP was associated with septic shock, unplanned intubation, organ space surgical site infection, Clostridium difficile infection, prolonged hospitalization, return to the operating room, and discharge to a non-home setting. Both high and low ALP levels correlated with increased risks of unplanned reoperations and other adverse outcomes. Conclusion: High and low serum ALP levels are significant predictors of postoperative complications following ankle fracture ORIF. Orthopedic foot and ankle surgeons should take into account preoperative serum ALP when counseling patients undergoing ankle fracture ORIF.