Slipped Capital Femoral Epiphysis (SCFE): A Comprehensive, Evidence-Based Guide for Patients, Parents, and Clinicians
Slipped Capital Femoral Epiphysis (SCFE)—also known as Slipped Upper Femoral Epiphysis (SUFE)—is the most common hip disorder in adolescents, affecting approximately 10.8 per 100,000 children annually in the United States alone. Left untreated, it can lead to devastating complications like avascular necrosis, chondrolysis, and early-onset osteoarthritis. Yet, when diagnosed early and managed correctly, most patients achieve excellent long-term outcomes.
This in-depth, medically reviewed guide covers anatomy, risk factors, symptoms, diagnosis, classification, treatment protocols, surgical techniques, complications, prognosis, prevention, and answers to the most frequently asked questions—all grounded in current orthopedic literature and clinical best practices.
What Is SCFE? Understanding the Anatomy
SCFE occurs when the femoral head (the “ball” of the hip joint) slips posteriorly and inferiorly through the growth plate (physis) at the proximal femur.
The growth plate is composed of cartilage, which is biomechanically weaker than bone—especially during rapid growth spurts. Increased shear forces (often from obesity or hormonal changes) cause the femoral neck to displace upward and forward relative to the epiphysis.
This condition almost always affects children aged 8–16 years, with peak incidence at 12–13 years in girls and 13–15 years in boys. It is bilateral in 20–40% of cases, often within 12–18 months of the initial diagnosis.
Key Risk Factors: Who’s Most at Risk?
While the exact etiology remains multifactorial, strong associations include:
- Obesity: BMI >95th percentile is present in 60–70% of cases—the single strongest modifiable risk factor.
- Endocrine disorders: Hypothyroidism, growth hormone deficiency, hypopituitarism, and panhypopituitarism.
- Renal osteodystrophy in children with chronic kidney disease.
- Radiation or chemotherapy for malignancy.
- Genetic syndromes: Down syndrome, Prader-Willi syndrome.
- Ethnicity: Higher incidence in African American, Hispanic, and Pacific Islander populations.
- Family history: Suggests a genetic predisposition.
Symptoms: Recognizing the Signs Early
Symptoms vary based on slip stability and chronicity:
✅ Stable SCFE (90% of cases):
- Insidious onset of hip, groin, anterior thigh, or knee pain.
- Pain worsens with activity, improves with rest.
- Limp with external rotation of the affected leg.
- Limited internal rotation and abduction on exam.
- Child can bear weight, though often with a limp.
⚠️ Unstable SCFE (Orthopedic Emergency):
- Sudden, severe pain after minor trauma (e.g., fall from standing height).
- Inability to bear weight.
- High risk of avascular necrosis (AVN) due to vascular compromise.
- Requires immediate hospitalization and surgical stabilization.
Diagnosis: Imaging That Prevents Disability
Early diagnosis is critical to prevent progression and complications.
1. Plain Radiographs (First-Line)
Bilateral AP and frog-leg lateral views of the pelvis (always image both hips).
- Klein’s Line: Drawn along the superior cortex of the femoral neck—on the affected side, the femoral head lies entirely below this line (Trethowan’s sign).
- Loss of Capener’s triangular sign: Due to posterior displacement.
- Metaphyseal blanch sign: Increased density on AP view from superimposed epiphysis.
Figure 1: Anteroposterior (AP) radiograph demonstrating classic findings of right-sided SCFE, including physeal widening and loss of normal femoral head-neck alignment.
Figure 2: Frog-leg lateral radiograph confirming posterior displacement of the femoral epiphysis in right SCFE—critical for assessing slip severity.
2. MRI (Gold Standard for Pre-Slip or Normal X-rays)
Detects bone marrow edema, physeal widening, and early slip before radiographic changes. Recommended when clinical suspicion is high but X-rays are normal. Essential for evaluating the contralateral asymptomatic hip.
Figure 3: Coronal MRI showing physeal widening and bone marrow edema in the right proximal femur, consistent with early SCFE.
3. CT Imaging
CT provides 3D assessment of slip angle and is used preoperatively in complex cases.
Figure 4: Axial CT scan demonstrating physeal widening and posterior displacement of the femoral epiphysis in right SCFE.
Classification Systems: Grading Severity
| Classification | Criteria | Clinical Implication |
|---|---|---|
| Stable | Patient can bear weight (with/without crutches) | Lower AVN risk |
| Unstable | Cannot bear weight | High AVN risk (up to 50%) |
| Acute | Symptoms <3 weeks, often post-trauma | May be unstable |
| Chronic | Symptoms >3 weeks | Usually stable |
| Acute-on-Chronic | Chronic symptoms + sudden worsening | Often becomes unstable |
Slip Angle (Southwick Angle):
- Mild: <30°
- Moderate: 30–50°
- Severe: >50°
Treatment: Surgical Stabilization Is Mandatory
Non-operative management is obsolete and associated with high complication rates.
✅ Gold Standard: In Situ Percutaneous Pinning
- Procedure: Under fluoroscopic guidance, a single 6.5–7.3 mm cannulated screw is inserted across the physis into the femoral head.
- Goal: Halt progression, allow physeal closure, preserve blood supply.
- Timing: Surgery within 24 hours for stable SCFE; immediate for unstable.
- Weight-bearing: Non-weight-bearing for 4–6 weeks, then gradual progression.
🔁 Contralateral Prophylactic Pinning
Indicated in:
- Endocrine disorders
- Obesity with bilateral risk
- Young age (<10 years)
- Symptomatic contralateral hip
Reduces bilateral slip risk from ~40% to <2%.
🛠️ Advanced Reconstruction (Rare)
- Corrective osteotomy: For severe deformity with FAI (high complication rate).
- Total hip arthroplasty: Reserved for end-stage osteoarthritis in adulthood.
Figure 5: Postoperative AP radiograph showing successful in situ fixation of right SCFE with a single 6.5-mm cannulated screw across the physis.
Figure 6: Lateral view confirming optimal screw placement within the femoral head without joint penetration.
Intraoperative Fluoroscopy
Real-time C-arm imaging ensures accurate screw trajectory and depth.
Figure 7: Intraoperative AP fluoroscopic view during guidewire insertion for cannulated screw fixation of right SCFE.
Figure 8: Intraoperative lateral fluoroscopic view confirming correct screw position within the femoral head epiphysis.
Complications: Long-Term Risks to Monitor
Even with optimal treatment, complications occur in 10–30% of cases:
- Avascular Necrosis (AVN): 10–15% overall; up to 50% in unstable SCFE.
- Chondrolysis: Acute cartilage necrosis (7–10%)—causes global stiffness, pain, and joint space loss.
- Femoroacetabular Impingement (FAI): Due to residual metaphyseal prominence.
- Early Osteoarthritis: Up to 90% by age 50 in severe slips.
- Limb Length Discrepancy: From asymmetric growth arrest.
Recovery & Long-Term Follow-Up
- Hospital stay: 1–2 days post-op.
- Crutches: 6–8 weeks (longer for unstable SCFE).
- Physical therapy: Focus on hip ROM, gait training, and core strengthening.
- Imaging: X-rays every 3–6 months until skeletal maturity (Risser 5).
- Lifelong monitoring: Annual hip exams into adulthood due to osteoarthritis risk.
Prevention: Can SCFE Be Avoided?
While not always preventable, key strategies include:
- Weight management: BMI reduction lowers shear forces across the physis.
- Screening: Children with endocrine disorders should have annual hip exams and X-rays during growth spurts.
- Parental education: Recognize early signs (limp, knee pain, external rotation).
Frequently Asked Questions (FAQs)
A: No. SCFE always progresses without surgical stabilization. Non-operative treatment leads to worsening slip, deformity, and complications.
A: The hip and knee share nerve pathways (obturator nerve). Pain from the hip is often “referred” to the knee—a classic red flag for SCFE.
A: Typically 6–8 weeks for stable SCFE. Unstable cases may require longer non-weight-bearing.
A: Usually no. The screw is buried deep in bone and causes no symptoms. Removal is only considered if it causes pain or interferes with future procedures.
A: Yes—most return to full activity 4–6 months post-op, once X-rays confirm physeal closure and strength is restored.
A: While not directly inherited, familial clustering suggests genetic susceptibility—especially with endocrine disorders.
A: Perthes involves avascular necrosis of the femoral head (no slip), while SCFE is a mechanical slip through the growth plate. X-rays and MRI differentiate them.
Final Thoughts
SCFE is a treatable orthopedic emergency—not a life sentence. With prompt diagnosis, in situ pinning, and dedicated follow-up, most adolescents return to full activity and avoid long-term disability.
At BoneFractures.org, we empower families with accurate, compassionate, and evidence-based care guidance—because every child deserves a strong, pain-free future.
— Written by Dr. Mohamed Attia, Orthopedic Surgery consultant
Published on BoneFractures.org – Trusted fracture care for patients and professionals.
References
- Loder RT, et al. Slipped capital femoral epiphysis: current concepts. J Am Acad Orthop Surg. 2020;28(15):609–618. doi:10.5435/JAAOS-D-19-00587
- Uvodich M, et al. Patterns of Pain in Adolescents with Slipped Capital Femoral Epiphysis. J Pediatr. 2019;206:184–189.e1. doi:10.1016/j.jpeds.2018.10.050
- Wensaas A, et al. Bilateral slipped capital femoral epiphysis: a meta-analysis. Acta Orthop. 2022;93:234–241. doi:10.1080/17453674.2022.2053382
- American Academy of Orthopaedic Surgeons (AAOS). Clinical Practice Guideline: Management of SCFE. 2023.
- Klein A. The radiological diagnosis of slipped capital femoral epiphysis. J Bone Joint Surg Br. 1952;34-B(4):601–603.
- Nemours KidsHealth. Slipped Capital Femoral Epiphysis (SCFE). Reviewed January 2022.
- MSD Manual Professional Version. Slipped Capital Femoral Epiphysis. Updated Sept 2025.
- Radiopaedia.org. Slipped Upper Femoral Epiphysis. Last revised Oct 2024.