In the younger patients the cause of this fracture is high energy impact injuries such as vehicle accidents.
Spontaneous fracture without a fall may occur if the area of bone is involved with cancer or infection
and this type of fracture is called a pathologic fracture.
Hip joint fractures comprises of four subtypes
. The differences between these subtypes are significant as each is treated differently.
But to understand these subtypes it is important to know the anatomy of the femur. The upper end of the femur (thigh bone) is made up of the head, the neck and two trochanters – the greater and lesser tronchanter located like a ridge on the upper end of the long bone. 1. Femoral head fracture
involving the femoral head is usually the result of high impact trauma, such as motor accidents, and often results in the dislocation of the hip joint. 2. Femoral neck fracture
(also called Neck of Femur (intracapsular or subcapital fracture) denotes a fracture in the neck region between the femoral head and the greater (or) upper trochanter. The neck is narrow between the head and the shaft of the bone and at an angle making it the weaker part of the bone that is prone to fracture. Fracture of the neck disrupts the blood supply to the head of the femur. It is also referred to as trans-cervical (cervical for neck) fracture. The fracture may or may not displace the bone involved. Hip fracture or Broken hip or Fracture Neck of Femur
all mean the same type of fracture.
The more vertical the fractured bone appears on the X- ray films the poorer is the prognosis. This disrupts the blood supply to the head of the bone which comes in a retrograde fashion (i.e) from the region of the neck upwards. This leads to loss of blood supply which in turn results in necrosis or cell death – this is referred as avascular necrosis
of the head of the femur.
Garden has classified this fracture into four sub-types:-
• Type 1 is a stable fracture. Here there is a minor crack in the neck of the bone
• Type 2 is complete crack in the neck of the femur but without bone displacement
• Type 3 is displaced fracture but with the fragments retaining contact between them, there may also be rotation and/ or angulation of the fragments.
• Type 4 is completely displacement with no contact between the fracture fragments. In this type the chances of blood supply disruption is more likely. 3. Intertrochanteric fracture
is the most common type of hip fracture and refers to a fracture line between the greater and lesser trochanter. The prognosis for this type of fracture is fairly good, especially in a healthy patient. 4. Subtrochanteric
fracture occurs in the shaft (body) of the femur, below the lesser trochanter.