BIOMECHANICAL COMPARISON OF DOUBLE AND TRIPLE TITANIUM ELASTIC NAIL FIXATION IN FEMUR FRACTURE MODELS

OBJECTIVE: The aim of this study is to investigate biomechanical stability of vertical and rotational forces on two retrograde titanium elastic nail (TEN) and three (two retrograde and one anterograde) TEN applications in pediatric femur diaphysis transverse and communited fracture models. MATERIAL AND METHODS: The transverse and fragmented fracture patterns formed in 24 synthetic femur models were fixed with double and triple TEN. The fixation models were subjected to rotational and vertical forces and their stability was examined biomechanically. RESULTS: While the mean rotational forces that leads to 10 degree angulation of the transverse fracture pattern fixed with triple TEN models was 4.92N, it was 1.86N in the double TEN models (p=0.002). The rotational forces required for the 10-degree angulation in the communited fracture models fixed with triple and double TEN were found to be 3.43N and 1.77N, respectively (p = 0.002). The mean rotational forces that leads 5-mm displacement at the fracture site in transverse fracture patterns fixed with double TEN was 103.6N, on the other hand these mean forces was 135.7N in the triple TEN models. In communited fracture models, the vertical forces results in 10 degree angulation were found to be 83.8N and 86.1N, respectively, in the double and triple TEN models (p=0.87). CONCLUSIONS: Although it was found that triple TEN models provided more stable fixation in transvers and communited fracture in terms of rotational forces, there was no significant difference between them in terms of the amount of displacement and angulation occurred against vertical forces. It was concluded that a more stable fixation could be achieved in pediatric femur fractures by applying smaller in size but multiple TEN combined anterograde and retrograde technique