A biomechanical comparison of the double-row suture fixation and compression screw techniques in the treatment of lateral malleolar avulsion fracture

Background: Avulsion fractures of fibula occur with ankle sprains. The purpose of this study was to compare the biomechanical characteristics of double-row suture versus compression screw techniques in treatment of lateral malleolar avulsion fracturelarger than 10 mm in size, which is typically not associated with an anterior talo-fibular ligament injury.Methods: We simulated lateral malleolus avulsion fractures in six matched pairs of 12 human cadaveric ankles. These were then randomly divided into two groups: a double-row fixation group and a compression screw group. Biomechanical testing was performed after surgical fixation. The foot was rotated from the neutral position toward inversion at a rate of 1 degrees /s until 12.5 N-m or structural failure was reached. The final rotation torque, rotation angle, stiffness, and displacement of the ossicles were recorded.Results: No significant difference was found in the final rotation torque (7.60 +/- 3.70 vs 7.23 +/- 2.06 N-m, p = 0.87), rotation angle (43.61 +/- 14.77 degrees vs 40.93 +/- 10.94 degrees, p = 0.56), stiffness (0.19 +/- 0.08 vs 0.13 +/- 0.07, p = 0.33), or displacement (6.11 +/- 5.23 vs 7.09 +/- 5.93 mm, p = 0.77) between the two groups.Conclusions: The stability of the double-row suture fixation was equivalent to compression screw fixation in treating a lateral malleolar avulsion fracture larger than 10 mm in size with ligament injury, as determined by our biomechanical testing.