Hip Fracture

Basics

Description

  • Intracapsular
    • Femoral neck, subcapital, or transcervical
    • Intracapsular femoral neck fractures may disrupt blood supply, resulting in avascular necrosis (1).
  • Extracapsular
    • Intertrochanteric: fracture between the neck of the femur and the lesser trochanter
    • Subtrochanteric: fracture below the lesser trochanter
  • 90% caused by a low-impact fall or twist on planted foot (2)
  • System(s) affected: musculoskeletal, neurologic, vascular
  • Synonym(s): subcapital fracture; trochanteric fracture; femoral neck fracture

Epidemiology

  • Predominant age: 80% occur in patients ≥60 years.
  • Average age: 80 years
  • 80% of all hip fractures are in women.
  • Hip fractures in men are associated with greater mortality (up to 38% in the 1st year) (3).

Incidence

  • In the United States, 320,000 elderly patients sustain hip fractures annually—this is expected to increase as the population ages (4).
  • In the United States, women >75 years; 1% annual incidence
  • 4.5 million people worldwide are disabled from hip fractures each year with an estimated 21 million people in the next 40 years (5).

Prevalence
Lifetime prevalence: 20% for women; 10% for men (1)

Etiology and Pathophysiology

Increased bone resorption increases risk of osteoporosis and hip fracture.

  • Osteoporosis
  • Direct blunt trauma
  • Pathologic conditions (e.g., bone cancer)
  • Stress fracture caused by overtraining
  • Avascular necrosis

Genetics
No known genetic factor

Risk Factors

  • Age >65 years
  • Female sex
  • Low socioeconomic status
  • History of previous fracture (>50 years) or history of a low-impact fracture
  • Family history of osteoporosis
  • Gait, sensory, or visual impairment
  • Low body mass or deconditioning
  • Sedentary lifestyle (on feet <4 hours a day)
  • Environmental hazards, such as throw rugs, loose cords, or inadequate lighting in the home
  • Foot deformity
  • Cigarette smoking
  • ≥3 alcoholic beverages a day
  • Osteoporosis: low bone mineral density (BMD)
  • Osteoarthritis or rheumatoid arthritis
  • Hyperthyroidism or diabetes mellitus
  • Metastatic bone cancer
  • Severe renal disease with secondary hyperparathyroidism
  • Polypharmacy (use of ≥4 chronic medications)
  • Glucocorticoid use
  • Psychoactive medications (SSRIs, benzodiazepines, anticonvulsants)
  • Long-term proton pump inhibitor therapy (high doses)
  • High-dose levothyroxine
  • Antihypertensives: The first 45 days after initiating treatment in the elderly have the highest risk of orthostatic syncope/fall.

General Prevention

Minimize risk factors:

  • Address disordered eating or overtraining if concern for female athlete triad.
  • Fall prevention
    • Avoid long-acting sedatives and hypnotics in the elderly.
    • Use ambulatory aids (canes or walkers) if patient has unsteady gait.
    • Use sturdy rails in bathrooms, stairs, or ramps; avoid throw rugs and slippery surfaces; ensure adequate lighting. Home safety assessment can reduce falls by 39% (6)[A].
    • Exercise with balance training or tai chi reduces the risk for falls (6)[A].
    • Annual vision exams for elderly
    • Minimize polypharmacy.
  • Prophylactic treatment for osteoporosis (3,4)[C]:
    • Magnesium supplementation improves calcium metabolism.
    • Vitamin D supplementation: 800 to 4,000 IU/day PO decreases hip fracture risk (6)[A].
  • Ultrasound (US) and/or BMD measurements quantitatively assess bone health; at age 65 years (age 60 years if risk factors)
  • Treatment of osteoporosis
    • Treatment with bisphosphonates is successful only if combined with weight-bearing exercise and vitamin D supplementation.
    • Bisphosphonates (adverse effect, esophagitis)
    • Alendronate (Fosamax): 35 (prevention) to 70 mg (management) PO weekly
    • Risedronate (Actonel): 150 mg PO monthly
    • Ibandronate (Boniva): 150 mg PO monthly
    • Zoledronic acid (Reclast): 5 mg IV yearly
    • Estrogen replacement prevents decrease of BMD but has other risks (i.e., increased venous thromboembolism [VTE] and cancer risks).
    • Selective estrogen-receptor modulators decrease risk of vertebral fractures but increases VTE risk.
    • Parathyroid hormone (teriparatide [Forteo]) decreases the risk of vertebral fractures; treatment is limited by long-term safety concerns to 2 years.
    • RANKL inhibitor: denosumab (Prolia) 60 mg SC every 6 months

Commonly Associated Conditions

  • Osteoporosis
  • Metastatic malignancy
  • Impaired cognition
  • Gait instability
  • Female athlete triad—low caloric intake, menstrual dysfunction, decreased BMD (stress fractures)

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