Wire cerclages as part of osteosynthesis- examination for optimal placement

Wire cerclages are commonly used during osteosynthesis of bone shaft fractures. To date, there is no study that examines the intraoperative utilization by different experienced surgeons in terms of reproducibility. This study aimed to test the hypothesis that a double-looped-cerclage is superior to a single-looped-cerclage in terms of reproducibility and uniform contact pressure. 27 medical doctors working in orthopedics/trauma surgery took part in this study. A wire cerclage was applied to a bovine bone half-shell model mounted on a dynamometer. A single-looped-cerclage and a double-looped-cerclage were applied alternately 5 times each. The applied force before modelling the cerclage knot on the bone (fbM) and the applied force after modelling on the bone (faM) were recorded in a blinded manner. The median faM in a double-looped-cerclage was 375 N (IQR 230-531 N) and therefore significantly higher (p < 0.05) than in a single-looped-cerclage (150 N (IQR 83-232 N)). As a result of applying the cerclage knot to the bone, the force decreased by an average of 80 N, with no differences in single-looped-cerclage or double-looped-cerclage. (Force-loss single-looped-cerclage 84 N (IQR 35.75-132 N); Force-loss double-looped-cerclage 82 N (IQR 46-116 N). The quartile dispersion coefficient as an expression of dispersion for the 5 applications each was 0.7121 (IQR 0.6544-0.8979) for single-looped-cerclage and was significantly higher than for double-looped-cerclage 0.3876 (IQR 0.2376-0.5184). In summary, this study showed that a double-looped-cerclage was superior to a single-looped-cerclage when used intraoperatively in terms of contact pressure and reproducibility.