What is the recommended treatment for a 14-year-old obese boy with acute right hip pain and suspected fracture or slipped capital femoral epiphysis (SCFE) after a football injury?

Slipped Capital Femoral Epiphysis (SCFE) - Diagnosis and Management

Direct Answer

This 14-year-old obese boy with acute hip pain after trauma most likely has an unstable slipped capital femoral epiphysis (SCFE), which requires emergent surgical fixation to prevent avascular necrosis. 1, 2

Clinical Presentation Analysis

The statement "Treatment involves emergent surgical fixation. Delay in management may result in avascular necrosis" is TRUE for this clinical scenario. 1, 2, 3

Key Diagnostic Features Present:

• Age and obesity: SCFE occurs most commonly in children 8-15 years of age and is strongly associated with obesity 1, 2
• Acute traumatic onset: The acute presentation after being tackled suggests an unstable SCFE, where the physis has been disrupted 1, 2
• Classic physical examination finding: The extremity is typically shortened and externally rotated (NOT externally rotated, flexed, and abducted as stated in the incorrect option) 4, 1

Critical Classification: Stable vs. Unstable SCFE

The distinction between stable and unstable SCFE is the most important clinical decision point because it determines urgency and risk of complications. 1, 2, 3

Unstable SCFE Characteristics:

• Patient cannot bear weight even with crutches due to severe pain 1, 2
• Acute traumatic mechanism (as in this case) 1, 2
• High risk of avascular necrosis (AVN) - up to 47% in some series 3
• Requires emergent surgical stabilization 1, 2

Stable SCFE Characteristics:

• Patient can bear weight with or without crutches 1, 2
• Gradual onset of symptoms 1, 2
• Lower AVN risk (approximately 0-15%) 3
• Urgent but not emergent surgery 1, 2

Immediate Diagnostic Approach

Initial Imaging Protocol:

• Anteroposterior (AP) pelvis view with approximately 15 degrees internal rotation 5, 6
• Cross-table lateral view of the symptomatic hip (NOT frog-leg lateral in unstable SCFE, as this can worsen the slip) 1, 2
• Bilateral hip imaging is essential because 20-40% of patients develop contralateral SCFE 1, 2

Critical Imaging Pitfall:

Never obtain frog-leg lateral views in suspected unstable SCFE, as the positioning required can displace the epiphysis further and worsen the injury. 1, 2 Use cross-table lateral views instead. 1, 2

Treatment Algorithm

For Unstable SCFE (This Patient):

1. Immediate orthopedic consultation - this is a surgical emergency 1, 2
2. Keep patient non-weight bearing 1, 2
3. Emergent in situ screw fixation within hours, not days 1, 2, 3
4. Avoid closed reduction attempts in the emergency department, as this increases AVN risk 3
5. Intraoperative assessment of physeal hemodynamics may help predict AVN risk 3

Surgical Technique:

• Percutaneous in situ fixation with a single 6.5-mm partially threaded cannulated screw remains the gold standard 7, 1, 2
• Screw placement in "center-center" position, stopping 3mm short of articular surface 7
• No attempt at reduction for unstable slips due to high AVN risk 1, 2

Complications of Delayed Treatment

Delay in surgical fixation significantly increases the risk of:

• Avascular necrosis (AVN) - the most devastating complication, occurring in up to 47% of unstable SCFE 3
• Chondrolysis - cartilage destruction leading to painful, stiff hip 1, 2
• Further slip progression - worsening deformity and functional outcomes 1, 2
• Femoroacetabular impingement - long-term complication requiring additional surgery 1

Common Clinical Pitfalls

Missed Diagnosis:

• SCFE is one of the most commonly missed diagnoses in children 1, 2
• Patients often present with knee pain only, leading to delayed hip evaluation 1, 2
• Always obtain hip radiographs in adolescents with knee pain and no obvious knee pathology 1, 2

Physical Examination Error:

• The statement that "the extremity is usually externally rotated, flexed, and abducted" is INCORRECT 4
• Correct presentation: shortened, externally rotated limb with obligate external rotation during passive hip flexion 7, 1

Imaging Errors:

• Obtaining only unilateral hip views misses contralateral involvement 5, 1
• Using frog-leg views in unstable SCFE can worsen the slip 1, 2
• Approximately 10% of fractures are missed on initial radiographs, requiring MRI if clinical suspicion remains high 8, 5

Postoperative Management

• Weight-bearing status depends on slip stability: non-weight bearing for unstable slips initially 7, 1
• Radiographic surveillance of the contralateral hip every 6 months until skeletal maturity 7, 1
• Five-phase rehabilitation protocol for gradual return to activities 1

Prognosis

Treatment outcomes correlate directly with slip stability and timing of intervention. 7, 1 Stable slips treated promptly with in situ fixation have good-to-excellent long-term outcomes. 7 Unstable slips carry significantly higher complication rates, with AVN being the primary concern affecting long-term hip function. 3