Until the middle of this century a fractured neck of femur would inevitably lead to the death of the sufferer. With the discovery of penicillin, surgery on the hip became possible and hip replacements began. Today approximately 50,000 people in the UK have hip replacement every year.
Femoral neck fracture is most common in people in their 80's where it is usually associated with osteoporosis. The fracture often results from a low impact accident such as a minor fall. In younger people femoral neck fracture is usually due to a major trauma, such as a car crash.
The arterial supply of the hip joint, especially that of the head and neck of femur is of particular clinical importance. The degree of damage to the blood supply, and thus fracture treatment, is greatly affected by the exact site and the severity of the fracture.
Fracture healing is dependant on blood supply. In parts of the femur outside the hip capsule (extracapsular), blood is normally conveyed through both the endosteum and the periosteum. In the event of an extracapsular fracture the bone depends on the periosteum for the maintenance of blood supply and the formation of a callus.
Intracapsular blood supply is normally conveyed entirely through the endosteum, because there is essentially no periosteum. This lack of periosteum means that intracapsular fracture healing can be slow and difficult because it depends on the union of the endosteum (endosteal union) which is by definition disrupted by a fracture. A severe fracture will leave little endosteal union and this reduces the likely success of healing.
The major supply of blood to a long bone is by it's nutrient artery, in the case of the femur this is a perforating branch of the profunda femoris. In the case of the upper end of the femur there is an intracapsular supply:
A major disruption to either of the main sources of intracapsular blood can lead to avascular necrosis.
The fracture site is important to the treatment of hip fracture and the success of fracture healing. Shown here are the common fracture sites.
|A sub-capital fracture severely compromises the blood supply to the head of the femur resulting in a high risk of avascular necrosis. The fracture would usually result in a replacement of the femoral head (hemiarthroplasty), leaving the natural acetabulum.||A petrochanteric fracture only partially compromises the blood supply and has a good chance of healing. The fracture would usually be treated by internal fixation with screws.|
Traditionally hip fractures were treated using traction, but this was associated with a very high mortality. Now hip fracture is commonly treated operatively, either by open reduction and internal fixation (dynamic hip screw), or by hip replacement (hemiarthroplasty). In some cases hip fracture is still treated by traction.
|Fractures of type I & II are usually treated by internal fixation using a Dynamic hip screw.|
|In type III & IV fractures the degree of disruption results in an unacceptably high level of avascular necrosis and the femoral head should be replaced (hemiarthroplasty).|
|If there is damage to the acetabulum the patient may require a Complete hip replacement.|