Overview
Definition:
Legg-Calvé-Perthes disease (LCPD) is a childhood hip disorder characterized by transient avascular necrosis of the femoral head
It involves the interruption of blood supply to the epiphysis of the femoral head, leading to bone death, eventual collapse, and potential deformity.
Epidemiology:
It primarily affects children between the ages of 4 and 10 years, with a peak incidence around 6-7 years
Boys are affected 4-5 times more often than girls
Bilateral involvement occurs in approximately 10-15% of cases, usually occurring sequentially rather than simultaneously.
Clinical Significance:
LCPD is crucial for pediatric residents and DNB/NEET SS candidates to recognize due to its potential for causing long-term hip joint dysfunction, pain, stiffness, and early-onset osteoarthritis if not managed appropriately
Understanding imaging findings and management principles is vital for optimal patient outcomes.
Clinical Presentation
Symptoms:
Intermittent limp, often worse with activity and relieved by rest
Pain in the hip, groin, thigh, or knee, which may be mild or absent initially
Limp may be present for weeks or months before medical attention is sought
Limited range of motion in the hip, especially abduction and internal rotation
Muscle wasting in the thigh.
Signs:
Antalgic gait
Tenderness over the hip joint
Restricted hip abduction and internal rotation
Leg length discrepancy may develop later in the disease process
Muscle atrophy of the quadriceps and gluteal muscles.
Diagnostic Criteria:
Diagnosis is primarily clinical and radiological
There are no specific laboratory diagnostic criteria
However, LCPD is characterized by the radiographic findings of avascular necrosis of the femoral head, fragmentation, and eventual remodeling of the epiphysis.
Diagnostic Approach
History Taking:
Detailed history of the onset and progression of limp and pain
Location and character of pain
Aggravating and relieving factors
History of trauma (though usually incidental)
Family history of hip disorders
Previous episodes of hip pain or limping.
Physical Examination:
Observe gait for antalgic pattern or Trendelenburg gait
Palpate the hip joint for tenderness
Assess range of motion of the hip, specifically focusing on abduction and internal rotation, which are typically restricted
Measure leg lengths and assess muscle strength and tone.
Investigations:
Radiographs: Initial anteroposterior (AP) pelvis and frog-leg lateral views of the hips are essential
Early changes may be subtle or absent
Later findings include sclerosis, fragmentation, widening of the joint space, and flattening of the femoral head
MRI: Considered the most sensitive imaging modality for detecting early avascular necrosis and assessing the extent of involvement of the femoral head
It can also identify early signs of subchondral collapse
Ultrasound: Can be useful in younger children to rule out effusions and assess the femoral head, but less sensitive for avascular necrosis itself.
Differential Diagnosis:
Transient synovitis of the hip
Septic arthritis of the hip
Slipped capital femoral epiphysis (SCFE)
Developmental dysplasia of the hip (DDH)
Osteomyelitis of the femur or pelvis
Juvenile idiopathic arthritis
Trauma or occult fracture
Osteosarcoma.
Management
Initial Management:
Pain control with oral analgesics (e.g., acetaminophen, NSAIDs)
Activity modification to limit weight-bearing and painful activities
Referral to a pediatric orthopedic specialist is crucial.
Conservative Management:
The goal is to contain the femoral head within the acetabulum during the necrotic and healing phases to promote spherical remodeling
This is achieved through: Maintaining hip abduction: Using abduction braces (e.g., Petrie casts, Denis-Browne bar, abduction orthoses) to keep the femoral head seated in the acetabulum
This is most effective in younger children and less severe cases
Physical therapy: Gentle range-of-motion exercises to prevent stiffness and maintain hip mobility
Avoidance of high-impact activities.
Surgical Management:
Indications for surgery include older age at onset (>8 years), severe femoral head involvement (e.g., >50% affected), significant collapse, containment failure, or progressive deformity
Surgical goals are to improve containment of the femoral head and/or to realign the femur or acetabulum
Procedures include: Femoral osteotomy (e.g., varus derotation osteotomy, intertrochanteric osteotomy) to realign the femoral head within the acetabulum
Pelvic osteotomy (e.g., Salter osteotomy, Pemberton osteotomy) to improve acetabular coverage of the femoral head
Shelf procedures.
Supportive Care:
Patient and family education about the condition, treatment plan, and prognosis
Monitoring for pain and compliance with activity restrictions and bracing
Nutritional support is generally not a primary concern unless there are other co-morbidities.
Complications
Early Complications:
Subchondral fracture or collapse of the necrotic segment
Secondary synovitis
Irreversible deformation of the femoral head.
Late Complications:
Coxa magna (enlarged femoral head)
Femoral head deformity (flattening, sphericity loss)
Acetabular dysplasia
Osteoarthritis of the hip at an early age
Persistent hip pain and limited range of motion
Leg length discrepancy.
Prevention Strategies:
Timely diagnosis and appropriate management are key to minimizing complications
Maintaining containment of the femoral head during the avascular and reparative phases is crucial for achieving a spherical femoral head
Avoiding premature return to high-impact activities is also important.
Prognosis
Factors Affecting Prognosis:
Age at onset (younger age has better prognosis)
Extent of femoral head involvement (less involvement, better outcome)
Degree of femoral head sphericity achieved during healing
Early and appropriate management
Compliance with treatment.
Outcomes:
With timely and appropriate management, many children achieve a functional hip joint with minimal long-term sequelae
However, significant deformity can lead to early osteoarthritis and chronic pain
Outcomes are generally poorer in older children, those with extensive femoral head involvement, and those who develop significant sphericity loss.
Follow Up:
Regular clinical and radiographic follow-up is essential until skeletal maturity
This includes serial X-rays to monitor the healing process, femoral head shape, and acetabular development
Long-term monitoring for signs of early osteoarthritis may be required.
Key Points
Exam Focus:
LCPD is avascular necrosis of the femoral head epiphysis in children aged 4-10
Key imaging findings: sclerosis, fragmentation, collapse, and remodeling
MRI is most sensitive for early detection
Management aims for containment of the femoral head
Conservative management involves activity modification and bracing
Surgical intervention is considered for older children or severe involvement
Poor sphericity leads to long-term osteoarthritis.
Clinical Pearls:
Always consider LCPD in a child with a persistent limp and hip/groin/knee pain, especially in boys aged 4-10
A normal X-ray in early stages does not rule out LCPD
consider MRI
Maintain abduction to promote sphericity
this is the cornerstone of conservative treatment
Recognize that poor containment and severe femoral head involvement are predictors of poor long-term outcomes.
Common Mistakes:
Misdiagnosing LCPD as transient synovitis and delaying appropriate management
Not performing adequate radiographic views (frog-leg lateral is crucial)
Underestimating the significance of early radiographic findings
Inadequate follow-up leading to missed complications
Premature return to strenuous activity.