Hip fracture

Hip fractures are those which involve the proximal femur, including femoral head fractures, femoral neck fractures, trochanteric fractures, and subtrochanteric fractures. Hip fractures are one of the most common fractures of the elderly, and a common cause of admission to the hospital. They’re also severe and can cause severe morbidity and mortality.

Hip fractures affect 169 / 100 000 each year, and females more often than males. It almost exclusively affects elderly. 30-day mortality is 9% and increases with time since the injury. Many of the patients require long-term nursery care or at least help with everyday activities after a hip fracture.

Femoral head and neck fractures are intracapsular, while trochanteric and subtrochanteric fractures are extracapsular. Femoral neck fractures are sometimes abbreviated as FCF (fractura colli femoris). Fracture of the femoral neck is the most common hip fracture. Femoral head fractures are uncommon.

See also trochanteric fracture.

Etiology

Hip fractures occur in elderly who fall from standing height, especially onto the lateral hip (low energy trauma), and so the risk factors for hip fractures are those which predispose to falls (+ osteoporosis):

• Heart disease
• Lung disease
• Cognitive impairment
• Polypharmacy (especially with benzodiazepines, opioids, antihypertensives)
• Muscle weakness
• Dehydration

It may also occur in young due to high energy trauma, although this is much less common.

Classification

Femoral neck fractures are classified according to the Garden classification:

Garden stage	Description
Garden I	Incomplete fracture, impacted, valgus
Garden II	Complete fracture without displacement
Garden III	Displacement with contact, varus
Garden IV	Displacement without contact, varus

Femoral head fractures are classified according to the Pipkin classification. Not covered in lecture, so not included.

Clinical features

Patient presents with pain in the groin or hip and immobilisation of the affected leg. There’s often an associated hip dislocation, causing shortening, external rotation, and abduction of the hip. As the fracture is intracapsular, there is usually no haematoma.

Diagnosis and evaluation

X-ray of the hip and pelvis is usually sufficient for femoral neck fractures. Femoral head fractures usually require CT for surgical planning.

Treatment

Femoral neck fractures always require surgery, at the latest 48 hours later. Choice of procedure depends on the Garden stage:

Garden stage	Choice of treatment
Garden I	ORIF with screw fixation
Garden II	ORIF with screw fixation
Garden III	ORIF with screw (in younger) or hip replacement (in older)
Garden IV	Hip replacement (total or hemi)

Femoral head fractures usually require surgery, but not always. Stable, nondisplaced Pipkin I and II fractures may be treated conservatively. Other cases require ORIF or hip replacement.

Complications

• Avascular necrosis of the femoral head
• Non-union
• Arthritis
• Deformity (shortening, varus)
• Re-dislocation

The majority of the blood supply of the femoral head arises from the medial circumflex femoral artery, and injury to this artery is relatively common in case of femoral neck fractures. Osteonecrosis may develop months or years after the injury.