Biomechanical evaluation of different fixation methods for tibial eminence fractures.

BACKGROUND: Tibial eminence fractures have become more common, but the best method of fixing these fractures arthroscopically has not been elucidated.
OBJECTIVE: The objective of this study is to assess the stability of different fixation methods for tibial eminence fractures. STUDY
DESIGN: Controlled laboratory study.
METHODS: The authors evaluated the initial fixation strength of 4 different fixation techniques for tibial eminence fractures (2 screws, 1 screw, suture fixation with 1 mm Ethibond, and suture fixation with No. 5 FiberWire) using single cycle and cyclic loading tests. The tests were performed by loading the knee with an anterior tibial shear force.
RESULTS: Suture cerclage with the FiberWire showed significantly higher maximum load (599.6 N) and stiffness (36.99 N/mm) than all other fixation methods tested. The lowest maximum load in the single cycle loading test was observed in the group with 2 screws (1 screw, 371.2 N; 2 screws, 249.8 N). The lowest stiffness was found in the Ethibond group (14.5 N/mm). After 1000 cycles of loading, the maximum load of the FiberWire fixation was significantly higher than the maximum load of the Ethibond fixation (399.4 N), the fixation with 1 screw (354.2 N), and the fixation with 2 screws (301.5 N).
CONCLUSION: These biomechanical data suggest that under cyclic loading conditions, suture fixation of tibial eminence fractures provides more fixation strength than screw fixation. CLINICAL RELEVANCE: A second screw has no positive effect on the biomechanical characteristics of screw fixation.