Objective: To compare the mechanical stability of þxation of bicondylar tibial fractures using available internal and external þxation techniques. Method: A bicondylar tibial fracture was simulated on a uniform synthetic bone and tested with loading to failure. Following power calculations, seven tibias were used for each þxation method;þve types of þxation were tested: 1)Dual plating. 2)Ring Fixator with interfragmentary screws. 3)Hybrid þxator (Ring-Bar) with interfragmentary screws. 4)Lat-eral plate and medial monolateral external þxator. 5)Lateral plate and medial interfragmentary screws. The specimens were tested in compression to failure. The vertical subsidence in either medial or lateral plateau was measured using an electrical transducer. Results: In all cases the mode of failure was consistent with collapse occurring in the medial plateau. There was no signiþcant difference in the ultimate strength between dual plating and the ring þxator [4218N, 4184N respectively; P=0.28, t test]. Failure was seen at lower loads with the other þxation systems

Conclusion: The Ring Fixator and dual plating demonstrated a greater strength and the most stable þxation, choice may depend on tissue viability and surgeon preference. Furthermore mobilisation of the patient may be undertaken earlier with more conþdence using these two methods rather than less stable techniques.