NEW REDUCTION CLASSIFICATION WHICH IS BASED ON POST-OPERATIVE DISPLACEMENT IN FEMORAL INTERTROCHANTERIC FRACTURES

Materials and method This study included 309 patients, over the age of 60 (44 men, 256 women, mean age 85.6 years) who underwent osteosynthesis using a short femoral nail(Gamma)for femoral intertrochanteric fractures. The new reduction classification was defined, in AP view by the degree of contact between the medial cortex of the proximal fragment and that of the medial cortex of the distal fragment. The classification in AP view is divided into three Types: Anatomical Type, Medial Type, and Lateral Type. As for the ML view was defined based on the degree of anterior cortex contact between proximal and distal fragment, was divided also into Anatomical Type, Intramedullary Type, and Extramedullary Type. We assessed lag screw sliding amount at 2 weeks period after surgery as the post-operative displacement. Results The sliding at 2 weeks was in AP Anatomical Type 3.7mm, in Medial Type 3.2mm and in Lateral Type 9.4mm. The sliding in the Lateral Type was much greater than those of Anatomical Type and Medial Type (Significant p-value, p=0.01, 0.01). Likewise, in the ML view, Anatomical Type 3.0mm, Intramedullary Type 6.2mm and Extramedullary Type 4.7mm respectively. There was a significant difference between ML Anatomical Type and Intramedullary Type(p=0.01). Conclusion The AP Lateral Type and the ML intramedullary Type were the most post-operative displacement. A new reduction classification could be useful to assist in the prediction of post-operation displacement.