Femoral Malunion and Its Correction: A Review

Background and Objectives: Femoral malunion, defined as healing of a femoral fracture in an anatomically incorrect position, can lead to significant biomechanical and functional impairment despite modern fixation techniques achieving union rates near 99%. The lack of a universal definition and standardized management approach continues to hinder optimal outcomes. This review aims to synthesize the literature on the causes, clinical presentation, radiologic assessment, surgical indications, corrective procedures, and outcomes of femoral malunion to guide clinical decision-making and future research. Materials and Methods: A narrative review of peer-reviewed orthopedic literature was conducted, focusing on adult femoral malunions across anatomical regions. Articles detailing deformity thresholds, imaging modalities, corrective osteotomies, and fixation strategies were included. Particular emphasis was placed on region-specific deformities-femoral head, neck, intertrochanteric, diaphyseal, and distal femur-and their corresponding surgical correction methods, including valgus intertrochanteric osteotomy, clamshell osteotomy, and lengthening with external or magnetic intramedullary devices. Results: Malunion most commonly presents as angular, rotational, or length deformity, with thresholds of >5-10° angulation, >10° rotation, or >1-2 cm shortening being clinically significant. Patients may experience pain, limp, gait asymmetry, and early-onset arthritis. Corrective techniques tailored to the anatomical site yield favorable results: valgus intertrochanteric osteotomy restores leg length and alignment; diaphyseal malunions respond well to single- or multi-plane osteotomies with internal fixation or gradual correction; distal femoral malunions often require multiplanar osteotomy to reestablish the joint line. Most series report high union rates and functional improvement, though complications such as infection and hardware failure may occur. Conclusions: Femoral malunion remains a complex but treatable condition. Successful outcomes rely on accurate deformity characterization, patient-specific surgical planning, and restoration of mechanical alignment. Standardized deformity criteria and long-term functional outcome studies are needed to refine management algorithms and improve patient care.