Risk factors associated with breakage of tibio-fibular syndesmotic screws.

PURPOSE: This retrospective study aimed to investigate the factors associated with the breakage of tibio-fibular syndesmotic screws (SS).

METHODS

69 patients with unstable AO-Weber Type 44-B ankle fractures who underwent three cortex SS (3.5 mm ø) fixation were included. Patients were followed for at least one year (mean, 18.3 ± 7.6 months). At the final follow-up, patients with broken (Group I) and intact (Group II) SS were compared regarding age, gender, height, weight, body mass index, fracture type, SS length, location, and orientation. Multivariate logistic regression was used to identify the independent risk factors associated with SS breakage. The sensitivity, specificity, cut-off value, and area under the ROC curve were analyzed.

RESULTS

A stepwise backward logistic regression analysis revealed that age was the only independent predictor for SS breakage (OR = 0.938, 95% CI = 0.904-0.973, R2 = 0.270). ROC curve analysis demonstrated that patients younger than 36 years were associated with seven times increased risk of SS breakage [Odds ratio (95% CI), 7.042 (2.251-22.031)].

CONCLUSION

Age under 36 years was the only significant risk factor for SS breakage. The higher incidence of breakage of the syndesmotic screw can be informed to patients younger than 36.