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 talofibular 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°/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° vs 40.93 ± 10.94°, 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.