Musculoskeletal · Orthopedics
The facts most likely to be tested
Patients with a femoral neck fracture present with a shortened, externally rotated leg.
Intracapsular hip fractures carry a high risk of avascular necrosis of the femoral head due to disruption of the medial circumflex femoral artery.
Garden classification is used to grade the severity and displacement of femoral neck fractures to guide surgical management.
Intertrochanteric fractures are extracapsular and typically managed with cephalomedullary nail fixation rather than arthroplasty.
Occult hip fractures that are not visible on initial plain radiographs require MRI as the gold standard for definitive diagnosis.
Preoperative regional nerve blocks, specifically the fascia iliaca block, are the preferred method for analgesia to reduce opioid requirements.
Early surgical intervention within 24 to 48 hours of admission significantly reduces mortality and postoperative complications in elderly patients.
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An 82-year-old female is brought to the emergency department after a mechanical fall at home. She complains of severe right hip pain and is unable to bear weight. On physical examination, the right lower extremity is shortened and externally rotated. Initial pelvic radiographs show no obvious fracture, but the patient remains in significant pain with any attempt at hip range of motion. Her medical history is significant for osteoporosis.
What is the most appropriate next step in the management of this patient?
MRI of the hip
The patient's clinical presentation is classic for a hip fracture; when plain radiographs are negative for an occult fracture, MRI is the gold standard for diagnosis.
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Etiology / Epidemiology
Elderly patients with osteoporosis and high-energy trauma in young patients. Falls are the primary mechanism.
Clinical Manifestations
Leg is shortened, abducted, and externally rotated. Classic presentation.
Diagnosis
MRI is the gold standard for occult fractures; X-ray is the initial screening tool.
Treatment
Surgical fixation (ORIF or arthroplasty) within 24-48 hours. Avoid prolonged bed rest.
Prognosis
High 1-year mortality rate of 20-30%. Avascular necrosis is the major complication.
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Epidemiology & Etiology
Predominantly affects the elderly due to age-related bone density loss. Osteoporosis and history of prior falls are the most significant risk factors. In younger populations, high-impact trauma like motor vehicle accidents is the primary cause.
Pertinent Anatomy
Fractures are classified as intracapsular (femoral head/neck) or extracapsular (intertrochanteric/subtrochanteric). Intracapsular fractures disrupt the medial circumflex femoral artery, leading to high risk of ischemia.
Pathophysiology
Low-energy trauma in osteoporotic bone causes structural failure of the proximal femur. The fracture disrupts the blood supply to the femoral head, particularly in displaced intracapsular fractures. This leads to avascular necrosis and non-union if not addressed via urgent surgical intervention.
Clinical Manifestations
Patients present with severe hip pain and inability to bear weight. The limb is classically shortened, abducted, and externally rotated. Neurovascular compromise must be ruled out immediately. Groin pain is the most common site of referred discomfort.
Diagnosis
Initial evaluation requires AP pelvis and lateral hip X-rays. If X-rays are negative but clinical suspicion remains high, MRI is the gold standard for detecting occult fractures. CT scan is an alternative if MRI is contraindicated.
Treatment
Definitive treatment is surgical fixation (ORIF or hemiarthroplasty) performed within 24-48 hours to reduce mortality. Prophylactic anticoagulation is mandatory to prevent DVT/PE. Early physical therapy is critical for functional recovery.
Prognosis
High risk of 1-year mortality (up to 30%) due to complications of immobility. Major long-term risks include avascular necrosis of the femoral head and non-union. Patients require aggressive osteoporosis management post-operatively.
Differential Diagnosis
Femoral neck stress fracture: insidious onset of pain
Hip osteoarthritis: chronic, progressive joint stiffness
Trochanteric bursitis: point tenderness over the greater trochanter
Septic arthritis: fever and elevated inflammatory markers
Pelvic fracture: pain radiating to the perineum or lower back