[BIOMECHANICAL STUDY ON SUTURE WITH NECKWEAR-KNOT-LOOP-LIGATURE FOR TIBIAL EMINENCE AVULSION FRACTURES].

OBJECTIVE

To study the biomechanical stability of neckwear-knot-loop-ligature fixation for tibial eminence avulsion fractures by comparing with cannulated screw fixation and suture anchor fixation.

METHODS

Twenty-four fresh porcine knee joints were selected. After the model of tibial eminence avulsion fracture (type III) was made, 24 samples were randomly divided into 3 groups: neckwear-knot-loop-ligature group (group A), cannulated screw group (group B), and suture anchor group (group C), 8 samples in each group. The Universal electromagnetic and mechanical testing machines were used for the biomechanical tests. After 200 cyclic tests, pull-out test was done until fixation failure. The maximum failure load, yield load, stiffness, and displacement were measured.

RESULTS

Failure mode: the displacement was beyond limit in 8 samples of group A; screws extraction (5 samples) and bone fragment re-fracture (3 samples) were observed in group B; and suture anchor extraction (4 samples), suture rupture (3 samples), and suture thread cutting (1 sample) were found in group C. Biomechanical test: From groups A to C, the maximum failure load and yield load showed significant decreasing tendency (P<0.05), but the displacements showed significant increasing tendency (P<0.05). The stiffness also gradually decreased, but differences was not significant (P>0.05).

CONCLUSION

Compared with cannulated screw and suture anchor, neckwear-knot-loop-ligature fixation for tibial eminence avulsion fracture has good biomechanical performance and the advantages of firm fixation and simple operation.