Supplemental cerclage wiring in angle stable plate fixation of distal tibial spiral fractures enables immediate post-operative full weight-bearing: a biomechanical analysis

Purpose Distal tibial fractures generally require post-operative weight-bearing restrictions. Especially geriatric patients are unable to follow these recommendations. To increase post-operative implant stability and enable early weight-bearing, augmentation of the primary osteosynthesis by cerclage is desirable. The purpose of this study was to identify the stabilizing effects of a supplemental cable cerclage following plate fixation of distal tibial spiral fractures compared to solitary plate osteosynthesis. Methods In eight synthetic tibiae, a reproducible spiral fracture (AO/OTA 42-A1.1c) was stabilized by angle stable plate fixation. Each specimen was statically loaded under combined axial and torsional loads to simulate partial (200 N, 2 Nm) and full (750 N, 7 Nm) weight-bearing. Tests were repeated with supplemental cable cerclage looped around the fracture zone. In a subsequent stepwise increased dynamic load scenario, construct stiffness and interfragmentary movements were analyzed. Results With supplemental cable cerclage, construct stiffness almost tripled compared to solitary plate osteosynthesis (2882 +/- 739 N/mm vs. 983 +/- 355 N/mm;p < 0.001). Under full weight-bearing static loads, a supplemental cerclage revealed reduced axial (- 55%;p = 0.001) and shear movement (- 83%;p < 0.001), and also lowered shear movement (- 42%;p = 0.001) compared to a solitary plate under partial weight-bearing. Under dynamic loads supplemental cerclage significantly reduced axial (p = 0.005) as well as shear movements (p < 0.001). Conclusion Supplemental cable cerclage significantly increases fixation stiffness and reduces shear movement in distal tibial spiral fractures. This stabilizing effect enables from a biomechanical point of view immediate mobilization without any weight-bearing restrictions, which may improve the quality of care of orthopedic patients and may trigger a change towards early weight-bearing regimes, especially geriatric patients would benefit from.

Automated summary

This study compared the stabilizing effects of supplemental cable cerclage and solitary plate fixation in distal tibial spiral fractures. The results showed that supplemental cable cerclage significantly increased fixation stiffness and reduced interfragmentary movements, allowing immediate mobilization without weight-bearing restrictions from a biomechanical perspective.