Causes of Limp in Children
Children may limp because of pain, weakness, deformity, or even behavioural causes.
The spectrum ranges from benign conditions such as transient synovitis to life-threatening sepsis or malignancy.
Serious causes must always be excluded first.
🚨 Most Urgent Causes
- Septic Arthritis: Sudden severe joint pain, fever, refusal to bear weight. Requires immediate IV antibiotics and usually surgical drainage.
- Osteomyelitis: Bone pain, fever, swelling, tenderness. Needs urgent IV antibiotics ± surgical debridement.
- Slipped Capital Femoral Epiphysis (SCFE): Adolescent with groin/knee pain and limp. Non-weight bearing immediately + urgent surgery to avoid avascular necrosis.
- Fracture: Trauma history, pain, swelling, possible deformity. Prompt immobilisation, reduction, or surgery.
🧾 Other Important Causes
- Transient Synovitis (Irritable Hip): Common post-viral, self-limiting with NSAIDs and rest.
- Legg-Calvé-Perthes Disease: Avascular necrosis of femoral head in boys (4–10 yrs). Causes insidious limp, treated with physiotherapy or surgery.
- Juvenile Idiopathic Arthritis (JIA): Chronic limp, morning stiffness, systemic symptoms in some subtypes. Requires DMARDs ± steroids.
- Developmental Dysplasia of the Hip (DDH): Can present late with limp, leg length discrepancy. Managed with Pavlik harness in infants, surgery later.
🩺 Clinical Assessment
- History: Onset (sudden vs gradual), duration, associated events (viral illness, trauma, new shoes), systemic symptoms.
- General Health: Is the child unwell? Fever = red flag 🚨.
👩⚕️ Examination
- Full systemic exam: temperature, HR, BP.
- Examine all joints and soft tissues, not just the hip.
- Brief neurological assessment (weakness, tone, reflexes).
- Measure leg length; assess pain at rest and on weight-bearing.
🔬 Investigations
- Bloods: FBC, CRP, ESR, blood cultures if febrile.
- Plain pelvic radiographs: AP and frog-lateral views.
- Ultrasound: hip effusion in suspected septic arthritis/transient synovitis.
- MRI: for osteomyelitis, Perthes, or subtle SCFE.
📊 Age-Based Causes
- 1–3 years: Developmental dysplasia of the hip (DDH), septic arthritis.
- 3–10 years: Transient synovitis, Perthes’ disease.
- 11–15 years: Slipped Capital Femoral Epiphysis (SCFE).
📌 Clinical Pearls
✅ Any child who is unwell, febrile, or unable to bear weight must be assumed septic arthritis until proven otherwise.
✅ Always examine the knee when hip pathology is suspected (referred pain is common).
✅ Limp + systemic illness = urgent red flag (think infection or malignancy).
