Legg Calves Perthes (LCP)

Modern Study Review (AI-Generated)

High-Yield Summary

Legg-Calvé-Perthes Disease (LCPD) is an idiopathic avascular necrosis of the femoral head occurring primarily in children aged 4 to 10 years, with a male predominance. It results from temporary disruption of blood supply to the femoral head, leading to bone necrosis, fragmentation, and eventual reossification. Early diagnosis and management focus on preserving hip motion and containment of the femoral head within the acetabulum to optimize long-term hip function and minimize deformity.

Key Diagnostic Findings

Anatomy

• Femoral head blood supply is vulnerable in children due to tenuous lateral epiphyseal vessels.
• The disease affects the ossific nucleus of the femoral head, leading to ischemic necrosis and subsequent remodeling.

Clinical Presentation

• Age: Typically 4–10 years, predominantly males.
• Symptoms: Insidious onset of hip, groin, or knee pain with limping.
• Physical exam: Limited hip range of motion, especially abduction and internal rotation; development of an adduction contracture is a poor prognostic sign.

Imaging

• Initial: AP pelvis and frog-leg lateral radiographs show sclerosis, fragmentation, and collapse of the femoral head.
• MRI: Useful early to detect ischemia before radiographic changes.
• Radiographic stages: Initial ischemia ? fragmentation ? reossification ? healing.

Classification Systems

Current Gold Standard Treatment

Non-operative

• Indications: Most children <8 years with Herring A or B disease and preserved hip motion.
• Treatment: Activity modification, NSAIDs for pain, physical therapy focusing on maintaining hip range of motion and abduction.
• Containment strategies: Use of abduction braces or orthoses to maintain femoral head coverage in select cases.

Operative

• Indications: Children >8 years old, Herring C classification, or those with progressive femoral head collapse and loss of containment.
• Procedures:
• Femoral or pelvic osteotomies (e.g., varus femoral osteotomy, Salter innominate osteotomy) to improve femoral head containment.
• Surgical hip dislocation and head reshaping in select cases.
• Goal: Restore congruency and containment to prevent secondary osteoarthritis.

Modern Complications & Outcomes

Complications

• Femoral head deformity and collapse leading to incongruent joint surfaces.
• Premature osteoarthritis in early adulthood.
• Leg length discrepancy and gait abnormalities.
• Stiffness and persistent pain if untreated or poorly managed.

Outcomes

• Age at onset is the strongest prognostic factor: <8 years generally have good remodeling potential and favorable outcomes.
• Herring classification correlates with prognosis and guides treatment.
• Early intervention to maintain hip motion and containment improves long-term function and delays or prevents osteoarthritis.
• Modern surgical techniques have improved outcomes in severe cases but require careful patient selection.

Classic Clinical Notes

LCP

Approach to Legg Perthes

• Note the age group: usually 4-10 year olds, predominantly males
• Unproven (but possible) association with clotting abnormalities; thyroid disorders
• Goes through stages: blood supply is injured, ossific nucleus stops growing, cartilage widens, then subchondral fracture, then fragmentation, then resorption and new bone formation (healing)
• The goal is to keep the hip as normal and supple as possible during the course of the disorder

• Consider on the differential: Meyer’s dysplasia, MED, SED, hypothyroidism, Gaucher’s, corticosteroid AVN

• The key on the physical is to note their hip range of motion – can they abduct? The development of an adduction contracture is bad. Check to see what else is limited.

• The number one prognostic factor is their age of onset – less than 8 tend to do well; after 8 tend to do more poorly

• Herring lateral pillar classification: based on an AP pelvis x-ray – most prognostic classification
• A – lateral pillar okay
• B – lateral pillar >50% intact
• C – lateral pillar <50% intact

Last Updated on January 25, 2026 by orthonet