Abstract
Objective: To compare the mechanical stability of fixation of bicondylar tibial plateau fractures using available internal and external fixation techniques.
Method: A bicondylar tibial plateau fracture was simulated on a uniform synthetic bone and tested with loading to failure. Following power calculations, seven tibias were used for each fixation method; five types of fixation were tested: 1) Dual plating. 2) Ring Fixator with inter-fragmentary screws. 3) Hybrid fixator (Ring-Bar) with interfragmentary screws. 4) Lateral plate and medial monolateral external fixator. 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 significant difference in the ultimate strength between dual plating and the ring fixator [4218N, 4184N respectively; P=0.28, t test]. Failure was seen at lower loads with the other fixation systems (Table).
Conclusion: The Ring Fixator and dual plating demonstrated a greater strength and the most stable fixation, choice may depend on tissue viability and surgeon preference. Furthermore mobilisation of the patient may be undertaken earlier with more confidence using these two methods rather than less stable techniques.
Correspondence should be addressed to Carlos Widgerowitz, Honorary Secretary BORS, Division of Surgery and Oncology, Section of Orthopaedic and Trauma Surgery, Ninewells Hospital and Medical School, Tort Centre, Dundee DD1 9SY, Scotland.
