Paediatric Proximal Femur Fracture
CIM Case: Paediatric Proximal Femur Fracture
Clinical Scenario
Patient: 13-year-old boy Presentation: Fall from bicycle at high speed 3 hours ago, unable to weight-bear, right hip pain Relevant history: High-energy mechanism, no head injury, no other injuries identified, previously healthy, no bone disease, no medications Examination findings:
- Right leg shortened and externally rotated
- Unable to actively move hip
- Severe pain with any passive motion
- Swelling around hip region
- No open wound
- Knee and ankle examination limited by hip pain
- Neurovascularly intact distally (palpable dorsalis pedis, normal sensation, able to wiggle toes)
- Abdomen soft, pelvis stable
Investigations Provided
Laboratory Results
| Test | Result | Normal Range | Interpretation |
|---|---|---|---|
| Hb | 115 g/L | 120-150 g/L | ↓ Mild decrease (blood loss) |
| WCC | 12.5 ×10⁹/L | 5-15 ×10⁹/L | Upper normal (stress response) |
| Platelets | 310 ×10⁹/L | 150-400 ×10⁹/L | Normal |
| Group & Screen | O positive | - | Available for transfusion |
| Coagulation | Normal | - | Normal |
Imaging
Image 1: AP Pelvis and Lateral Hip Radiograph
Radiological features:
- Displaced transcervical fracture of right femoral neck
- Basicervical extension with comminution of inferior neck
- No obvious intertrochanteric extension
- Shortening and varus angulation
- Physis open (skeletal immaturity)
- No dislocation of femoral head
- Left hip normal
- No other pelvic fractures
Classification: Delbet Type II (Transcervical) - displaced
Questions & Model Answers
What is the diagnosis and classification, and why is this injury significant?
What is your immediate management plan?
Describe your surgical technique.
What are the complications and how would you monitor for AVN?
The fracture heals but develops coxa vara. How would you manage this?
How do you counsel the parents about prognosis and long-term follow-up?
Key Teaching Points
Pattern Recognition
This pattern suggests Paediatric Femoral Neck Fracture:
- High-energy trauma in a child
- Shortened, externally rotated leg
- Unable to weight-bear
- Severe pain with any hip motion
- X-ray: displaced femoral neck fracture with open physis
Distinguish from SUFE:
| Feature | Femoral Neck Fracture | SUFE |
|---|---|---|
| Mechanism | High-energy trauma | Low/no trauma |
| Onset | Acute | Often insidious |
| Habitus | Any | Often obese |
| X-ray | Visible fracture line | Physeal widening, metaphyseal blanch |
| Treatment | Urgent ORIF | Urgent in situ pinning |
Critical Management Points
- SURGICAL EMERGENCY - reduce and fix within 24 hours (ideally 12 hours)
- Capsulotomy is mandatory - decompress haematoma to improve perfusion
- AVN risk is high - 30-50% for Type II despite optimal treatment
- Delbet classification determines prognosis - Type I worst, Type IV best
- Long-term follow-up essential - minimum 2 years for AVN monitoring
- Document AVN risk discussion - medico-legal importance
Common Examiner Follow-ups
Q: "Why is capsulotomy important?"
The femoral head in children has a tenuous blood supply:
- Intracapsular haematoma increases pressure within the joint capsule
- Tamponade effect compresses the remaining retinacular vessels
- Further ischemia occurs in addition to vessel damage from fracture
- Capsulotomy or aspiration relieves this pressure
Studies show lower AVN rates with capsulotomy, though evidence is limited by small numbers. It is considered standard of care in paediatric femoral neck fractures.
Q: "How do you fix across an open physis?"
Options for fixation crossing the physis:
- Smooth K-wires - least damage, but less stable
- Partially threaded screws - threads stay in epiphysis, smooth portion crosses physis
- Small diameter screws - minimise physeal damage
- Limit number of screws - 2 screws may be better than 3 if crossing physis
Accept some physeal damage for stable fixation - the priority is fracture healing and AVN prevention. Premature physeal closure is a lesser problem than AVN or nonunion.
Q: "This child develops AVN at 6 months. What are your options?"
Management depends on severity and age:
Mild AVN (Ficat I-II, no collapse):
- Protected weight-bearing
- Serial X-rays
- May remodel, especially in younger children
Moderate AVN (early collapse):
- Consider containment (similar to Perthes principles)
- Femoral varus osteotomy to improve coverage
- Pelvic osteotomy if stiff hip
Severe AVN (significant collapse):
- May need salvage procedures when older
- Hip arthrodesis (rare, for young active patient)
- Total hip replacement (after skeletal maturity)
Key Point: Young children have some remodelling potential. Severe AVN in an adolescent has poor prognosis.
Q: "What is the Ratliff classification?"
Ratliff classification is an outcome classification based on final result:
| Type | Outcome |
|---|---|
| I | Good - normal or near-normal hip |
| II | Fair - some abnormality but functional |
| III | Poor - significant disability, AVN, or need for salvage surgery |
It is used to report outcomes in studies but doesn't guide treatment.
Related Topics
- Slipped Upper Femoral Epiphysis
- Perthes Disease
- Paediatric Hip Fracture Fixation
- Avascular Necrosis
- Subtrochanteric Osteotomy
- Paediatric Trauma Principles