Summary
Limp is a deviation from the normal age-appropriate gait pattern. Causes range from benign conditions (e.g., soft tissue trauma, transient synovitis) to orthopedic emergencies and serious medical conditions (e.g., septic arthritis, unstable slipped capital femoral epiphysis, malignancy, physical child abuse). Clinical features vary. The patient's age and symptom duration can help determine the most likely cause. The presence of red flag features (e.g., inability to bear weight, constitutional symptoms, nocturnal pain) suggests a serious and/or emergent underlying cause. Evaluation begins with a thorough history and physical examination. Further workup may include laboratory studies (e.g., inflammatory markers, synovial fluid analysis) and/or imaging. Management is based on the underlying cause.
Etiology
Causes of limp vary. The patient's age can help determine the most likely cause.
All ages [1][2]
- Postinfectious inflammatory arthritis, e.g.:
- Trauma, e.g.:
- Muscular contusion
- Fracture (including toddler fracture and stress fracture)
- Foreign body in foot
- Infection
- Leg length discrepancy
- Juvenile idiopathic arthritis (JIA)
- Hemophilia or other coagulopathies [3]
- Vasoocclusive crises [4]
- Charcot-Marie-Tooth disease [2]
- Abdominal causes (e.g., psoas abscess, appendicitis) [5]
Transient synovitis is the most common nontraumatic cause of limp in children. [1]
Children < 3 years of age [1][5]
- Hand, foot, and mouth disease
- Side effect of immunization
- Toddler fracture
- Physical child abuse
- Cerebral palsy
- Congenital conditions
- Developmental dysplasia of the hip (DDH)
- Clubfoot
- Congenital Achilles contracture
- Vertical talus
- Inherited myopathies
Children 3–10 years of age [1]
- Muscle disorders
- Post-infectious myositis
- Dermatomyositis
- Acute lymphoblastic leukemia
- Popliteal (Baker) cyst
- Legg-Calvé-Perthes disease (LCPD)
- Kohler disease
Children > 10 years of age [1][2][5]
- Slipped capital femoral epiphysis (SCFE)
- Gonococcal arthritis
- Joint hypermobility
- Sport injuries and overuse syndromes, e.g.:
- Tarsal coalition
- Subchondral bone necrosis: osteochondritis dissecans
- Bone tumors, e.g.:
Clinical evaluation
Focused history [1]
- Onset, duration, and progression of limp
- Exacerbating or relieving factors
- Associated symptoms
- Relevant past history, e.g.:
- Trauma or repetitive activity
- Recent viral infection
- Risk factors for STIs
- Tick exposure
- History of breech position at delivery
- Relevant family history
Focused physical examination [1][2][5]
- Vital signs, general appearance
- Height and weight
- Developmental milestones
- Pediatric gait assessment
- Hip, knee, ankle, foot, and spine examination (See "Orthopedic examination" for details.)
- Assess for:
- Deformity
- Point tenderness, signs of inflammation and/or injury, mass
- Leg length discrepancy
- Restricted and/or painful range of motion
- Perform relevant maneuvers and tests, including:
- Assess for:
- Neurological assessment of the lower limbs, including assessment for Gowers sign
- Abdominal examination
Pediatric hip pathologies often manifest as referred pain in the knee. Prompt assessment of the hip is indicated in children and adolescents presenting with nonspecific knee pain and no findings that suggest knee pathology.
Red flag features of limp in children [6]
The following features suggest an urgent and/or serious underlying cause:
- Constitutional symptoms
- Neurological symptoms
- Inconsolability or severe pain
- Inability to bear weight
- Clinical features of compartment syndrome after trauma [2]
- Injury inconsistent with reported mechanism
- Nocturnal pain or diurnal symptoms
- Palpable mass
A hip held in flexion, abduction, and external rotation may be a sign of septic arthritis of the hip. [1]
Diagnostics
- Diagnosis may be clinical (e.g., reactive arthritis, soft tissue injury).
- Obtain laboratory studies and/or imaging based on suspected underlying cause.
- Consult or refer to a pediatric specialist (e.g., orthopedics) early if there is concern for septic arthritis or SCFE.
In children with symptoms localized to the hip, consider prediction rules (e.g., Kocher criteria for septic arthritis) to distinguish between transient synovitis and septic arthritis. [1][7][8]
Laboratory studies [1][5]
Order targeted diagnostics based on the suspected etiology, e.g.:
- Infection, inflammation, or malignancy
- Bacterial infection
- Asymmetric arthritis, morning stiffness: diagnostics for JIA
- Features suggesting Lyme arthritis: Lyme serology
- Sexually active patients: gonorrhea testing
Imaging [5][9][10]
Initial imaging
No concern for infection [9]
- Localized symptoms: x-ray area of interest
- Nonlocalized symptoms: x-ray bilateral tibia and fibula (AP and lateral views)
- Hip pathology suspected: x-ray bilateral hip joints (AP and frog-leg lateral view) [1][2]
Concern for infection [8][9]
-
Localized symptoms: ultrasound, x-ray, or MRI area of interest
- Hip: Ultrasound is preferred.
- Lower limbs (excluding hip): MRI is preferred.
- Nonlocalized symptoms: MRI lower extremity
Additional imaging [9]
Consider the following if initial imaging is negative but clinical suspicion for infection persists or in the case of diagnostic uncertainty.
- Ultrasound [8][9]
- MRI
- Bone scintigraphy
X-ray findings are often normal in early stages of septic arthritis, osteomyelitis, nondisplaced fracture (e.g., toddler fracture), and LCPD. [1][9][11]
CT is usually not recommended to evaluate limp in children because of radiation exposure and inferior soft tissue contrast compared with MRI. [9]
Common causes
Common causes of acute limp in children
Acute limp is defined as limp lasting < 6 weeks. [1]
| Common causes of acute limp in children [6][7][12] | ||||
|---|---|---|---|---|
| Disease | Clinical features | Diagnostic findings | Management | |
| Transient synovitis [2][13] |
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| Septic arthritis [1][14] |
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| SCFE [1][16] |
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| Skin or soft tissue injury [1][10] |
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| Fracture [1][2] |
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| Physical child abuse [18][19] |
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| Osteomyelitis in children [1][8] |
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Common causes of chronic limp in children
Chronic limp is defined as limp lasting ≥ 6 weeks. [1]
| Common causes of chronic limp in children [6][7] | ||||
|---|---|---|---|---|
| Disease | Clinical features | Diagnostic findings | Management | |
| LCPD [20][21] |
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| DDH (if untreated during early infancy) [2][23][24][25] |
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| Juvenile idiopathic arthritis [2][27][28] |
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| Osgood-Schlatter disease [31][32][33] |
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| Calcaneal apophysitis [31][35] |
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| Leg length discrepancy [1][36][37] |
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Teleoroentgenogram: length discrepancy [38][39] |
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| Duchenne muscular dystrophy [40] |
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| Malignant bone tumors [41][42][43] |
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Mimics
The following can cause normal variations of gait in toddlers and young children. Persistence of these beyond the period of usual resolution should prompt appropriate evaluation. [2]
- Flexible pes planus [44][45]
- Physiological genu varum or genu valgum [44][46]
- Benign intoeing [46]