• Decreased serum bone turnover markers (BSAP, NMID, P1NP) are independently associated with poor healing after Ilizarov bone transfer for large-segment infectious tibial defects.
• Soft tissue injury, wound infection, fibula fracture, and early weight-bearing (within 6 weeks) are significant risk factors for delayed or nonunion.
• A combined model incorporating these markers and clinical factors can predict healing outcomes with good discrimination and accuracy.
• Long-term smoking and diabetes also contribute to poor healing, emphasizing the need for comprehensive preoperative optimization.