Dynamic hip screws that fail

A series of 87 trochanteric fractures of the femur treated by dynamic hip screw, was reviewed. The relationship between the position of the fracture fragments and the position of the hip screw in the femoral head was investigated. Hip screws inserted into some parts of the femoral head were more likely to cut out than others. Some fractures were undisplaced or had been perfectly reduced. A lateral radiograph of some of the others showed that the femoral head and neck were aligned with the shaft. Only among these fractures was the number of good screw placements as great as among those that were undisplaced or perfectly reduced.