Hip fractures

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 and 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.

• Peak incidence: > 70 years
• Sex: ♀ > ♂
• Incidence: highest in the whites of Northern Europe (Scandinavia) and North America.

References:^[1]

Epidemiological data refers to the US, unless otherwise specified.

• Mechanism of injury
  • Older adults
    • 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
  • Children and young adults: high-speed trauma (e.g., motor vehicle accidents or falls from great heights) or underlying disease (e.g., fibrous dysplasia)
• Risk factors
  • Osteoporosis (especially postmenopausal women and older individuals)
  • Muscle weakness
  • Difficulty walking and impaired coordination
  • Estrogen deficiency
  • Low body weight
  • Poor nutrition (vitamin D deficiency or calcium deficiency)
  • Smoking, alcohol use

References:^[2]

Hip fractures are divided into:

• Intracapsular
  • Femoral head
  • Femoral neck
• Extracapsular
  • Trochanteric
  • Intertrochanteric
  • Subtrochanteric

• Occurrence: 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 ^[3]
  • MRI if findings are unclear or if an occult fracture is suspected

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.

• Clinical features
  • Groin pain
  • Shortened and externally rotated leg
  • 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

• Treatment
  • Conservative management
    • Indication: stable, nondisplaced fractures, especially abduction fractures , mostly in debilitated patients
    • Methods
      • Temporary bed rest; or use of crutches followed by mobilization with physical therapy
      • Venous thromboembolism prophylaxis ^[4]
  • Surgical therapy (usually within 72 hours ; is indicated for unstable fractures , typically adduction fractures, and fragment dislocation
    • For children and young adults
      • Attempt preservation of the femoral head
      • Early open reduction internal fixation (ORIF)(within 6 hours)
    • For older adults: total hip replacement (THR) or hip hemiarthroplasty

• 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)

• 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 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.

• 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 (e.g., 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)

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

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

• Avascular necrosis (AVN) of the femoral head
• Thromboembolism
• Infection
• Chronic pain and posttraumatic arthritis
• Nonunion
• Dislocation

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.

• Intracapsular fractures (e.g., femoral head and neck fractures) have an increased rate of nonunion which leads to AVN
• 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 older adults.

• 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