[Inter-trochleo-bicondylar fracture of the femur. An unusually traumatic lesion. Mechanism. Therapeutic implications].

UNLABELLED: The authors present a curious type of fracture of the distal end of the femur. They discuss the mechanism and the factors responsible for that lesion. The treatment and results are finally presented.

MATERIAL: A 65 years old female, submitted to a crash accident while driving a car, with a seat in maximaly low position. She presented a bilateral open transverse fracture of the patella associated in the right limb to a fracture line between condyles and the patellar surface of the femur.

METHOD: Bilateral osteosynthesis of both patella had been realised in emergency through a transverse approach. Through the fractured right patella two anteroposterior screws had been used to fix the fractured femur.

RESULT: A plaster cst had been used for three weeks. Full weight bearing was permitted after three months. Full range of motion of both knees was noticed after six months follow-up.

DISCUSSION: The femoral fracture could have been fixed by another device like D.C.S. platescreen but it would be weaker. That type of fracture was produced because of flexed low position of the knee at the moment of the accident. Usually, supra-condylar femoral fractures are due to a force vector applied on the upper extremity of the tibia without any patellar fracture. In our case, the patella involved associated to a fracture line between the condyles and the patellar surface. The structural anatomy (noeud sutural de Chevrier) explains the solidarity of the two femoral condyles.