Surgically Treated Non-Unions and Fractures of the Femur and Tibia in Adults: A Nationwide Analysis of 888,442 Cases from the German InEK Database

Abstract Background Non-unions (NU) after fractures, especially in cases with the need of surgical intervention, represent one of the most severe complications in traumatology. As previous studies estimate post-fracture NU risk between 2% and 10% data inconsistencies persist. In particular, the data on the influence of different anatomical regions, age and sex on fracture associated NU is scarce. Therefore, this study aims to provide a comprehensive descriptively assessment of the ratio of surgically treated tibia and femur NU to tibia and femur fractures based on a nationwide dataset, with a specific focus on differences across anatomical regions. Methods This retrospective, population-based, cross-sectional analysis of the German InEK database (2019–2023) was conducted, including 888,442 fractures and 3,017 NU cases. The study focused on ICD- (International Statistical Classification of Diseases and Related Health Problems-) coded diagnoses of femur and tibia NU and their associated fractures. To enhance precision, fracture and NU sites were grouped according to different anatomical regions assessed by documented OPS- (Operation and Procedure Classification System) codes. Subgroup analyses were performed for age and sex. Results Surgically treated femoral shaft NU had the highest incidence (0.18 cases per 100,000 residents and year), followed closely by tibial shaft NU (0.16). The highest NU/100-fractures ratio was observed in tibial shaft (1.277), followed by distal tibia (1.095) and distal femur (0.996). Across all localisations, men had clearly higher NU/100-fractures ratios than women. NU/100-fractures ratios also varied with age, with highest ratio in the economically active population, followed by a generally decline in older patients. Conclusion This nationwide database study indicates that surgically treated NU/fracture ratios of femur and tibia are generally low. The proportion of NU to fracture differ between different anatomical regions. In general, proximal localisations showed lower NU/100-fractures ratios than distal localisations within the femur and in comparison of femur and tibia. Independently of the anatomical localisation men had a higher NU/100-fractures ratio than women. As highest NU/100-fractures ratios were detected in the economically active population, this highlights the substantial socioeconomic burden associated with this condition.