Hip and Femur Injuries

1. The 2-Minute Kinematics

• High-Energy Trauma: Enormous force is required to fracture an undiseased adult femoral shaft; these injuries are typically the result of high-speed motor vehicle collisions (MVCs), crushing injuries, or falls from significant heights.
• Hip Dislocations: Approximately 90% of hip dislocations are posterior, classically caused by significant force exerted on a flexed hip and knee (e.g., a passenger's knees violently striking the dashboard during an MVC). Anterior dislocations result from forced external rotation of an extended hip, tearing the anterior capsule.
• Low-Energy Trauma: In the elderly population, proximal femur (hip) fractures are highly common following simple ground-level falls, carrying a female-to-male incidence ratio of 4:1.
• Pediatric Kinematics: Children may present with Slipped Capital Femoral Epiphysis (SCFE), which peaks during the rapid growth of puberty, or Perthe disease (avascular necrosis of the femoral head), which peaks at 5 years of age.

2. The Bedside Action Plan

• Immediate Resuscitation: Femoral shaft fractures can result in an average of 1,000 mL of occult blood loss; immediately establish two large-bore IVs, cross-match for transfusion, and initiate fluid resuscitation.
• Traction Splinting: Apply a traction splint (e.g., Hare, Sager, or Kendrick) for suspected closed mid-shaft femur fractures to ease pain, maintain reduction, and limit blood loss. Do not apply traction splints if there are concurrent pelvic fractures, patellar fractures, tibia/fibula fractures, or open fractures with exposed bone (which would pull contaminated bone back into the wound).
• Regional Anesthesia: Systemic opioids can worsen hypotension in polytrauma. Perform an ultrasound-guided femoral nerve block or fascia iliaca compartment block; these are highly valuable, often-underutilized adjuncts that provide excellent localized analgesia.
• Open Fractures: These are orthopedic emergencies requiring immediate IV antibiotics (a first-generation cephalosporin, plus an aminoglycoside for Gustilo Type II or III), tetanus prophylaxis, sterile wet dressings, and emergent operative debridement.

3. The Diagnostic Grid

• Targeted Physical Exam: The classic presentation of a proximal femur fracture is severe pain with the affected limb held in a shortened, abducted, and externally rotated position.
• Mandatory Neurovascular Checks: Assess distal pulses and meticulously evaluate motor and sensory function. Sciatic nerve injury is a critical complication that must be ruled out before and after any manipulation or traction.
• Indications for Advanced Imaging (Occult Fractures): Any patient who is unable to ambulate, or experiences severe pain with ambulation despite negative plain radiographs, must be suspected of having an occult hip fracture. MRI is the gold standard (nearly 100% sensitive) for identifying these lesions; if MRI is unavailable, CT is a reasonable alternative.

4. The Visual Board

• Explicit X-ray Interpretation: Always obtain anteroposterior (AP) and lateral views of the hip, alongside dedicated radiographs of the pelvis, femur, and knee. Femur fractures can easily mask the clinical signs of a concomitant hip dislocation, making broad imaging essential.
• The Rapid MRI Protocol: For radiographically occult fractures (accounting for 2% to 10% of hip fractures), a rapid-sequence MRI protocol utilizing just two sequences (large field of view T1 and inversion recovery/fat saturation T2) takes only 7 to 8 minutes and is highly accurate.
• Frog-Leg Lateral View: If evaluating an adolescent for SCFE, order a frog-leg lateral radiograph, which visualizes the hip in a plane midway between the AP and standard lateral views.

5. The Classification Matrix

• Anatomic Fracture Classification: Hip fractures are strictly classified as intracapsular (femoral head and neck) or extracapsular (trochanteric, intertrochanteric, and subtrochanteric). Accurate classification is critical because intracapsular fractures have a much higher rate of vascular disruption.
• Garden Classification: Used to grade subcapital hip fractures (e.g., Garden IV denotes a completely displaced fracture).
• Gustilo-Anderson Classification: Used for open fractures to guide antibiotic therapy and surgical management (Type I, II, IIIA, IIIB, IIIC).

6. The Danger Zone

• Cognitive Trap (Referred Pain): Pain can be referred from anywhere between the lumbosacral spine and the knee. A classic fatal trap is missing a SCFE because the adolescent patient presents complaining exclusively of knee or distal thigh pain.
• Risk of Avascular Necrosis (AVN): The femoral head has a tenuous retrograde blood supply dependent on the medial/lateral circumflex arteries and the foveal artery (via the ligamentum teres). Hip dislocations inevitably tear the ligamentum teres, and intracapsular fractures shear the circumflex vessels, guaranteeing a massive risk of AVN and requiring emergent orthopedic intervention.
• Under-Resuscitation: Up to 70% of patients with intertrochanteric fractures present with hemodynamic instability due to dehydration and occult blood loss; treating the pain without addressing the volume deficit is a critical error.

7. Mcq Masterclass

• High-Yield "Buzzwords": A leg that is "shortened, abducted, and externally rotated" = Proximal femur fracture. A "dashboard injury" with a flexed knee = Posterior hip dislocation. An "obese adolescent boy with knee pain" = SCFE.
• Associated Nerve Injuries: Posterior hip dislocations and fracture-dislocations classically produce sciatic neurapraxia in 10% to 14% of patients.
• Common Exam Distractors: Applying a traction splint to an open femur fracture with exposed bone is a highly tested distractor; doing so will pull grossly contaminated debris deep into the sterile wound bed.

8. The Boardroom Script

"I am consulting you for a [Patient Age]-year-old [Sex] who sustained a [Mechanism of Injury: e.g., high-speed MVC], resulting in a [Gustilo Grade if open/Garden Classification if subcapital] [Intracapsular/Extracapsular] fracture of the [Left/Right] [Femur/Hip]. On exam, the limb is [Deformity: e.g., shortened and externally rotated], and the neurovascular status is [Intact/Compromised, specifically noting sciatic nerve function]. We have initiated fluid resuscitation for estimated blood loss, administered an ultrasound-guided [Femoral Nerve/Fascia Iliaca] block for analgesia, and applied a [Traction Splint, if indicated and closed]. The patient has been pan-scanned and is ready for your evaluation for definitive operative fixation."