Biomechanical analysis of bicondylar tibial plateau fixation: how does lateral locking plate fixation compare to dual plate fixation?

OBJECTIVES: This study is designed to test the comparative strength of lateral-only locked plating to medial and lateral nonlocked plating in a cadaveric model of a bicondylar proximal tibial plateau fracture.

METHODS: Ten matched pairs of human cadaveric proximal tibia specimens were used for biomechanical testing. Cyclic loading using a materials testing device simulated initial range of motion and load bearing following surgical repair. Subsidence of the medial and the lateral condyles was measured following 10,000 cycles from 100N to 1,000N; the maximum load to failure on the medial condyle for both plate constructs was also measured.

RESULTS: On the lateral side, dual plating (DP) allowed an average of 0.68 +/- 0.14 mm of subsidence, compared with 1.03 +/- 0.27 mm for the fixed-angle plate (FAP) (P = 0.077). On the medial side, DP allowed an average of 0.78 +/- 0.15 mm of subsidence, compared with 1.51 +/- 0.32 mm for the FAP (P = 0.045). No significant difference was found in the maximal load to medial condyle fixation failure between either plating construct (P = 0.204).

CONCLUSIONS: The results of this study demonstrate that dual-plate fixation allows less subsidence in this bicondylar tibial plateau cadaveric model when compared to isolated locked lateral plates. This may raise concerns about the widespread use of isolated lateral locked plate constructs in bicondylar tibial plateau fractures.