Abstract

Hip fractures are classified according to their anatomical location as intracapsular, which involves the femoral head and neck, and extracapsular, which includes intertrochanteric, trochanteric, and subtrochanteric fractures. A low impact fall is the typical mechanism of injury in the eldery and is often associated with underlying osteoporosis. Motor vehicle accidents are typical in younger individuals. Clinical features include groin pain and deformity of the hip. An x-ray is usually diagnostic, while an MRI may be required to confirm a pathological fracture. Surgical therapy is usually considered definitive treatment, especially for unstable or displaced hip fractures. Thromboembolism and avascular necrosis are common but serious complications.

Hip fractures, especially fractures of the femoral head, are often associated with a hip dislocation. Posterior hip dislocations account for 90% of hip dislocations and typically follow a dashboard injury. Early reduction is vital to avoid vascular compromise and sciatic nerve injury.

Epidemiology

Peak incidence:> 70 years
Sex: ♀ > ♂ ^[1]
More common in whites^[1]

Epidemiological data refers to the US, unless otherwise specified.

Etiology

Mechanism of injury
- Elderly
  - Fall onto greater trochanter/lateral hip
  - Forced lateral rotation (e.g., from tripping)
  - Chronic overburdening can lead to insufficiency fractures which can then completely fracture spontaneously
  - Pathological fracture due to metastases
- Youth; : High-speed trauma (e.g., motor vehicle accidents or falls from great heights) or underlying disease (e.g., fibrous dysplasia) ^[1]
Risk factors^[2]
- Osteoporosis (especially post-menopausal women and elderly)
- Muscle weakness
- Difficulty walking and impaired coordination
- Estrogen deficiency
- Low body weight
- Poor nutrition (vitamin D or calcium deficiency)
- Smoking, alcohol use

Pathophysiology

Abduction fracture → femoral neck fracture
Adduction → fracture dislocation

Types of hip fractures

Hip fractures are generally divided into intracapsular or extracapsular

Femoral head fracture

Uncommon but often associated with a posterior hip dislocation following a dashboard injury
Clinical features
- Groin pain
- Local swelling and ecchymosis
Diagnostics
- Hip x-ray; (AP with internal rotation and lateral view; should include the proximal thigh) : abnormal trabecular pattern, cortical defects, shortening and angulation of the femoral neck
- MRI if findings are unclear or if an occult fracture is suspected

Pipkin Classification
	Description	Treatment after rapid repositioning
Pipkin I	Luxational fracture of the femoral head: The fracture line lies below the fovea capitis, ie. not in the weight-bearing portion (horizontal fracture).	Surgical: open reduction internal fixation, e.g., with a traction bolt Conservative: immobilization
Pipkin II	Luxational fracture of the femoral head: The fracture line lies above the fovea capitis. The fragment is attached to the femoral head ligament. and thus in the weight-bearing portion (vertical fracture).	Surgical: open reduction internal fixation, e.g., with a traction bolt
Pipkin III	Pipkin I or II fracture in combination with a medial fracture of the femoral neck	Surgical Young patients: open reduction internal fixation with maintenance of the femoral head Elderly patients or those with predispositions: total hip replacement
Pipkin IV	Pipkin I or II fracture in combination with an acetabular fracture	Surgical Young patients: open reduction internal fixation with maintenance of the femoral head Elderly patients or those with predispositions or instabilities: total hip replacement

A patient with an MVA dashboard injury may present with a femoral head fracture and hip dislocation!

Watch out for sciatic nerve injury in patients with femoral head fractures!

References:^[1]

Femoral neck fracture

Clinical features
- Groin pain
- Shortened and externally rotated leg^[1]
- Minimal bruising
Diagnostics
- X-ray (AP and lateral view of the pelvis with internal rotation of the affected limb)
- MRI or bone scan if clinical suspicion is high despite absent findings on x-ray

Garden Classification
Garden I	Impaction fracture, nondisplaced and incomplete
Garden II	Nondisplaced but complete fracture
Garden III	Varus displacement of the femoral head, partially displaced complete fracture
Garden IV	Entirely displaced, complete fracture

Treatment
- Conservative management
  - Indication: stable, nondisplaced fractures, especially abduction fractures (Garden I), mostly in debilitated patients
  - Methods
    - Temporary bed rest; or use of crutches followed by mobilization with physical therapy
    - Thrombolytic therapy
- Surgical therapy (usually within within 72 hours^[1] is indicated for unstable fractures (; Garden II–IV), typically adduction fractures, and fragment dislocation
  - For young patients^[1]
    - Attempt preservation of the femoral head
    - Early open reduction internal fixation (ORIF) (within 6 hours)
  - For elderly patients: total hip replacement (THR) or hemiarthroplasty

A femoral neck fracture may be associated with femoral shaft fractures in ∼8% of cases

Trochanteric fracture

Clinical features
- A greater trochanter fracture is suggested by local pain exacerbated by abduction
- A lesser trochanter fracture presents with groin pain, which radiates to the knee or posterior thigh, and worsens with hip flexion and rotation
Diagnostics
- X-ray showing avulsion of the greater or lesser trochanter
- MRI if a pathological fracture is suspected )
Treatment
- Most heal with conservative treatment (e.g., nonweightbearing)
- Surgical repair for displaced fractures (> 1 cm)

Subtrochanteric fracture

Clinical features
- Hip pain with swelling
- Shortened and externally rotated leg
- Significant ecchymosis
Diagnostics
- X-ray : fracture between the lesser trochanter up to 5cm below that (distally)
- MRI if a pathological fracture is suspected
Treatment
- Consider conservative approach (i.e., traction) in surgically unstable patients
- Surgery is indicated in displaced/nondisplaced fractures in adults, especially if associated with multiple trauma, an open fracture, or pathological fractures
  - Long intramedullary nail with a lag screw
  - Locking plate may be considered for complicated fractures (e.g., pre-existing femoral deformity, associated femoral neck fracture)

Intertrochanteric fracture

Clinical features
- Hip pain and swelling
- Shortened and externally rotated leg
- Significant ecchymosis
- Often associated with other injuries (e.g. other extremity fractures)
Diagnostics
- X-ray (AP view with maximal internal rotation and lateral view): proximal femur fracture between the greater and lesser trochanters
- MRI if a pathological fracture is suspected
Treatment
- Nonsurgical approach for high risk patients
- Surgery
  - Dynamic hip screw (DHS) for stable fractures
  - Intramedullary nail (Gamma locking nail) for stable or unstable fractures, fractures extending into the subtrochanteric region, or reverse oblique fractures
  - Arthroplasty may be considered for comminuted fractures, pathological fractures, or if other surgical modalities fail

Fracture-dislocation

Hip fractures, especially fractures of the femoral head, are often associated with a hip dislocation

Type of hip dislocation	Etiology	Clinical features	Diagnostics	Treatment	Complications
Posterior hip dislocation (90% of cases)	Dashboard injury in which a posteriorly directed force (e.g., dashboard during a motor vehicle accident) is directed towards an internally rotated, flexed, and adducted hip	Hip pain which radiates to the knee Shortened, internally rotated (adducted) hip	X-ray CT/MRI to exclude associated (especially pathological) fractures	Closed reduction within 6 hours Open reduction if closed reduction is unsuccessful, the joint is unstable, or if bony fragments/tissue sit within the joint space	Sciatic nerve injury or peroneal nerve injury (branch of the sciatic nerve)
Anterior hip dislocation (10% of cases)	Direct blow to the posterior hip or to an abducted leg	Hip pain which radiates to the knee Lengthened, externally rotated leg			Femoral nerve injury

Fracture dislocations are at greatest risk of avascular necrosis of the femoral head!

Complications

Avascular necrosis (AVN) of the femoral head^[1]
Thromboembolism
Infection
Chronic pain and posttraumatic arthritis
Nonunion^[1]
Dislocation^[1]

Thrombolytic therapy reduces the risk of deep vein thrombosis in patients with hip fractures!

We list the most important complications. The selection is not exhaustive.

Prognosis

Intracapsular fractures (i.e., femoral head and neck fractures) have an increased rate of nonunion which leads to AVN ^[1]
Intertrochanteric fractures have a good prognosis following surgery
Subtrochanteric fractures have a high rate of implant failure

Hip fractures have a high rate of associated morbidity and mortality in elderly patients!

Prevention

Fall risk assessment, for example with the Tinetti-Test, which is used to evaluate a patient's gait and balance.
Early preventative efforts such as fall training, physical therapy, removal of tripping hazards, appropriate shoes, etc.
Osteoporosis prophylaxis