Introduction
Neck of femur fractures (#NOF) are a common presentation to the emergency department. They typically occur in elderly female patients with osteoporosis – although often the osteoporosis is often undiagnosed.
- Also occur in high impact trauma – e.g. car accident
- Female:Male ratio is 4:1
- Mean age is 75
- Dementia or cognitive impairment present in 30% of cases
The majority will require corrective surgery
Mortality – 20-35% in the first year
- 80% of mortality is in women
Types
Extracapsular – fractures that occur outside the joint capsule
- Do not affect the blood supply to the femoral head
- Typically occur in well vascularised bone, and thus complications of bone union are rare
- Often described as stable, ort unstable. Unstable fractures are generally those where there is detatched fragment of lesser trochanter.
Intracapsular – fractures that occur inside the joint capsule
- Can affect the blood supply to the femoral head, especially if the fracture is displaced.
- Complications of fracture union are common
Presentation
- History of fall / trauma
- Leg may be shortened and externally rotated in displaced fractures.
- 10% will have a fracture at another site, usually proximal humerus, or distal radius.
- Neurovascular injury is rare…
- But avascular necrosis is more common here than at other sites. Often treated with total hip replacement.
- The sciatic nerve is at risk in dislocation fractures, and dislocations (15% of patients).
Treatment
Nearly all will be given surgery, unless there are significant CIs.
Intracapsular fractures:
- Undisplaced – up to 15% will displace without treatment, and thus the usual treatment is internal fixation using a dynamic hip screw.
- 5% will have avascular necrosis – these cases will need arthroplasty (hip replacement)
- Displaced – can be treated by reduction and fixation, but there is a high risk of non-union, and fixation failure. 15% will have avascular necrosis .40% of patients treated in this way will require arthroplasty at some point in the future. Thus, many surgeons opt for hemiarthroplasty as the first line. In hemiarthroplast, the femoral head but not the actebular cup is replaced. (In a total hip replacmenet both the head and the cup are replaced, but this is typically reserved for osteoarthritis).
- Reduction and fixation more likely to be carried out in younger patients – as long as there is no underlying pathology (e.g. steroids causing osteoporosis) that caused the initial fracture.
Extracapsular fractures
- Internal fixation is the treatment of choice for inter-trachanteric fractures. as the blood supply
