Femur Fractures

Modern Study Review (AI-Generated)

High-Yield Summary

Pediatric femur fractures represent a common and clinically significant injury requiring age-specific management strategies to optimize pain control, function, and growth potential. Treatment varies by age, fracture pattern, and patient factors, balancing non-operative methods like spica casting with operative fixation such as flexible nailing or external fixation. Understanding acceptable alignment parameters and the phenomenon of overgrowth is critical to avoid malunion and limb length discrepancy. Modern care emphasizes minimizing complications such as avascular necrosis (AVN) and ensuring early mobilization.

Key Diagnostic Findings

Anatomy

• The femur is the longest and strongest bone, with a proximal physis critical for growth.
• Pediatric femoral blood supply is vulnerable, especially near the proximal femoral physis, increasing AVN risk with certain surgical approaches.

Clinical Presentation

• Pain, swelling, deformity, and inability to bear weight after trauma.
• In polytrauma, assess for associated injuries (head trauma, floating knee).
• Spasticity may complicate immobilization in head-injured children.

Imaging

• Standard AP and lateral femur radiographs to assess fracture pattern, displacement, and alignment.
• Traction or spica cast application may require follow-up imaging to monitor alignment and callus formation.
• CT/MRI reserved for complex cases or suspected vascular compromise.

Classification Systems

Current Gold Standard Treatment

Non-operative Indications and Treatment

• Age 0-4 years: Early hip spica casting preferred for stable, minimally displaced fractures without significant shortening (>15 mm) or rotation.
• Acceptable Alignment Parameters:
• Rotation: No rotation accepted (rotation does not remodel).
• Shortening: Up to 10-15 mm acceptable due to overgrowth potential.
• Varus/Valgus: Up to 10 degrees (some accept 15 degrees).
• Flexion/Extension: Up to 15 degrees (some accept 20 degrees).
• Initial traction (10-21 days) may be used before casting if shortening is excessive.
• Overgrowth phenomenon can compensate for up to 1-1.5 cm shortening, especially in children 8-10 years old.

Operative Indications and Treatment

• Age 4-10 years: Flexible intramedullary (IM) nailing is preferred for length-stable fractures. External fixation is an alternative for open or complex fractures.
• Age >10 years: Flexible nails or rigid IM nails after proximal femoral physis closure.
• Indications for ORIF:
• Open fractures
• Polytrauma (multi-trauma, floating knee)
• Bilateral femur fractures
• Head trauma with spasticity complicating casting
• Avoid standard locked IM nails in children with open proximal femoral physes due to AVN risk.
• Flexible nails should not be inserted through open fractures in children; external fixation preferred.

Modern Complications & Outcomes

Complications

Outcomes

• Most pediatric femur fractures heal well with restoration of function and minimal long-term disability when managed appropriately.
• Overgrowth compensates for mild shortening, improving outcomes in younger children.
• Early mobilization and weight-bearing with flexible nails improve rehabilitation and reduce hospital stay.
• Long-term follow-up is essential to detect growth disturbances or angular deformities.

Classic Clinical Notes

Femur Fractures

Options by age:

• 0-4 years: early hip spica or hip spica after traction; external fixation
• 4-10 years: flexible nail, external fixation, maybe hip spica
• >10 years: flexible nails, external fixation, IM nail

What is acceptable with closed treatment? These are argued, and the references all quote different numbers. Most agree that rotation is not acceptable.

• no rotation – this will not correct
• 10-15 mm of shortening – will probably correct to a certain degree with overgrowth
• 10 degrees of varus or valgus (some say 15)
• 15 degrees of flexion or extension (some say 20)

You have to use your head – obviously, at a very young age, you could probably accept the upper limit, but at an older age, you better get it pretty close.

Early Spica

• has to be pretty straightforward fracture without excessive shortening – the cast will not correct shortening.
• should try to get it perfect on initial reduction
• initial traction for 10-21 days and waiting until it shows some callus is the other technique and is the bail-out if you don’t think the shortening is acceptable.

Overgrowth

• again, different authors describe different amounts of this phenomenon
• some say age has nothing to do with it, others think it is more prominent in the 8-10 year old range
• others say that overgrowth of the femur is about 1 cm, and of the tibia is about 3 mm. Shapiro thinks that it is independent of age, level of fracture, or position of the fracture at time of healing (short, long, or distracted). Others say that the overgrowth is proportional to shortening at healing.
• it is probably a vascular phenomenon to the entire leg
• in the final analysis, shortening of 1 to 1.5 cm is probably acceptable in closed treatment.

Beware putting flexible nails up through an open fracture – in adults, probably okay, but in kids, it has not yet been sorted out. Better to just go with external fixation.

Do not do a standard locked IM nail until the kid’s proximal femoral physis is closed. You better be pretty wary about doing it even then – the consequences of AVN are just so devastating.

Indications for ORIF

• multi-trauma
• open
• floating knee
• bilateral
• head trauma (they get spasticity which is hard to deal with in a cast)

Last Updated on January 25, 2026 by orthonet