Biomechanical Comparison of Single- and Double-Twist Tension Band, Cancellous Screw, and Single-Screw Tension Band Models in Medial Malleolus Fractures.

Background: Models using a double-twist tension band, two partially threaded cancellous screws, a single-twist tension band, and a single-screw tension band were biomechanically compared for fixation of medial malleolus fractures.

Methods: All 72 composite cortical tibial bones used in the study were osteotomy suitable for medial malleolus fracture. They were divided into four groups: double-twist tension band (group 1), two partially threaded cancellous screws (group 2), single-twist tension band (group 3), and single-screw tension band (group 4), with 18 composite tibial bones in each group. Bones in each group were divided into three subgroups and subjected to biomechanical tests by applying force as tension, transverse, and axial loading.

Results: In the tension and transverse loading tests, the highest mean stiffness was in groups 1 and 4. Group 4 had statistically significantly higher stiffness values than groups 2 and 3. All of the other groups had statistically significantly higher stiffness values than group 2. A statistically significant difference was found comparing group 4 (with the highest value in the axial loading test) with the other groups. No significant difference was found between groups 1 and 3 in any of the biomechanical tests.

Conclusions: Tension band method did not make a difference biomechanically when applied as a double or single twist. Single-screw tension band was found to be the most stable fixation method in tension, transverse, and axial loading tests. We think that the single-screw tension band method is a stable and suitable fixation method and should find more place in current surgical practices.