Pediatric Orthopedics
Let the child's age name the limp
Developmental dysplasia of the hip
Newborn screening. The Ortolani maneuver relocates a dislocated hip with a palpable clunk in (abduction with the greater trochanter lifted forward), whereas the Barlow maneuver dislocates a reducible hip with a clunk out (adduction with posterior pressure). Risk factors are breech presentation, female sex, firstborn status, family history and oligohydramnios.
Asymmetric thigh skin folds and a positive Galeazzi sign (unequal knee heights with the hips and knees flexed) are extra clues. After about 3 months the dislocation becomes fixed, Ortolani and Barlow turn negative, and limited abduction becomes the key sign; a late diagnosis presents as a painless limp or waddling gait.
Imaging and treatment. Use ultrasound under about 4–6 months, while the femoral head is still cartilage; radiographs take over once the head ossifies, after about 4–6 months. Infants with risk factors such as breech presentation get a screening ultrasound around 6 weeks even with a normal exam. Young infants are treated with a Pavlik harness, which holds the hips flexed and abducted; older infants or harness failures need closed or open reduction with spica casting.
The limping child: hip disorders by age
Age frames the limp. Toddlers suggest DDH and transient synovitis, ages 4–8 Legg-Calvé-Perthes disease, and ages 10–16 slipped capital femoral epiphysis (SCFE). At every age, exclude septic arthritis first, because it can destroy the joint within a day. Hip disease often refers pain to the knee, so examine the hip in any child with knee pain.
| Condition | Typical patient | Key findings | Management |
|---|---|---|---|
| DDH | Newborn or infant; breech, female, firstborn | Ortolani and Barlow; later, limited abduction | Pavlik harness |
| Transient synovitis | Toddler or young child after a viral illness | Well-appearing, bears some weight, Kocher criteria low | Rest, NSAIDs |
| Septic arthritis | Any age | Toxic, high fever, refuses to bear weight, Kocher criteria high | Emergent aspiration, drainage, IV antibiotics |
| Legg-Calvé-Perthes | Boy about 4–10 (classically 4–8) | Insidious painless limp; reduced abduction and internal rotation | Observation or bracing |
| SCFE | Obese adolescent, roughly 10–16 | Hip, groin or knee pain; hip held externally rotated; abnormal Klein line | In-situ surgical pinning |
Legg-Calvé-Perthes disease. This is idiopathic avascular necrosis of the femoral head. Radiographs show a sclerotic, then flattened and fragmented femoral head; early films can be normal, and MRI detects the necrosis sooner. Management is often observation or bracing to keep the head contained in the acetabulum. Younger age at onset predicts a better outcome because more growth remains for the femoral head to remodel.
Slipped capital femoral epiphysis. The epiphysis slips posteriorly off the metaphysis, like ice cream sliding off its cone, usually in an obese adolescent boy. Pain may be felt in the hip, groin or only the knee, with a limp and a hip that rotates externally as it is flexed. A frog-leg lateral X-ray of both hips makes the diagnosis: the Klein line along the superior femoral neck fails to intersect the epiphysis. Stop weight-bearing and treat with in-situ screw pinning; avascular necrosis is the feared complication. Slips can be bilateral, and an atypical patient (young or thin) warrants testing for hypothyroidism and other endocrine causes.
Septic hip versus transient synovitis
Kocher criteria. Four predictors separate a septic hip from transient synovitis: fever over 38.5 °C, non-weight-bearing, ESR over 40 mm/h and WBC over 12,000/µL. Meeting all four makes septic arthritis very likely and mandates joint aspiration.
| Feature | Septic arthritis | Transient synovitis |
|---|---|---|
| Appearance | Toxic, high fever | Well-appearing, often after a viral illness |
| Weight-bearing | Refuses | Usually limps but bears weight |
| ESR and WBC | ESR over 40, WBC over 12,000 | Normal or mildly raised |
| Next step | Aspirate the joint, then surgical drainage and IV antibiotics | Supportive care, NSAIDs |
Workup. Ultrasound confirms a hip effusion and guides aspiration. Purulent fluid requires emergent surgical drainage plus IV antibiotics; S. aureus is the leading organism, and Kingella kingae is common in children under 4. Transient synovitis, the most common cause of acute hip pain in young children, is self-limited.
Knee, elbow and limb alignment
Osgood-Schlatter disease. A traction apophysitis where the patellar tendon inserts on the tibial tubercle, it affects active adolescents during growth spurts, especially in jumping and running sports. Anterior knee pain worsens with activity over a tender, swollen tubercle. It is self-limited; treat with rest or activity modification, ice and NSAIDs.
Nursemaid elbow. Axial traction on a pronated arm, as when a toddler is pulled or lifted by the hand, lets the radial head slip under the annular ligament (radial head subluxation). The child holds the arm pronated and slightly flexed and refuses to use it, with little swelling. No imaging is needed: reduce by supination with flexion or by hyperpronation, and the child typically uses the arm again within minutes.
Limb alignment. Genu varum (bowlegs) is normal under age 2 and genu valgum (knock-knees) around ages 3–5; both usually resolve without treatment. Bowing that is persistent, worsening or asymmetric suggests pathologic tibia vara (Blount disease), which is associated with obesity and early walking; rickets is the other classic cause of pathologic bowing.
Spine and foot
Adolescent idiopathic scoliosis. This lateral spinal curve with vertebral rotation, usually right thoracic, is more common (and more often progressive) in girls. Screen with the Adam forward-bend test, which exposes a rib hump, and a scoliometer; standing radiographs quantify the Cobb angle. Observe small curves, brace curves over about 25° in a still-growing child, and consider surgical fusion over roughly 45–50°.
An atypical left thoracic curve, a painful curve or neurologic findings warrant MRI to exclude an underlying spinal cord lesion.
Clubfoot. Talipes equinovarus is a congenital foot that is adducted, inverted and plantarflexed. First-line treatment is the Ponseti method of serial manipulation and casting, often with a heel-cord (Achilles) tenotomy, followed by bracing; primary surgery is not the first step. Clubfoot can coexist with DDH, so examine the hips.
The growing skeleton: physis, abuse and fragility
The physis fails first. In children the growth plate is weaker than the ligaments, so a mechanism that would sprain an adult fractures the physis instead (Salter-Harris injury). Point tenderness over a growth plate after trauma is treated as a fracture even when X-rays look normal.
Patterns that suggest abuse. Metaphyseal corner (bucket-handle) fractures, posterior rib fractures, long-bone fractures in a non-ambulatory infant, and multiple fractures of different ages should raise concern for non-accidental trauma and prompt a skeletal survey. By contrast, a toddler's fracture (a nondisplaced spiral fracture of the distal tibia in a newly walking child) is usually accidental.
Osteogenesis imperfecta. Most often caused by a type I collagen defect (COL1A1 or COL1A2), it produces recurrent fractures with minor trauma, blue sclerae, hearing loss and dental problems (dentinogenesis imperfecta). It is the key medical mimic of child abuse in a child with multiple fractures.