Limp
Limp is an abnormal pattern of walking with a wide range of causes. Limp is a symptom or an observation but is not a diagnosis.
Limp causes can be broadly categorised by age and whether acute or chronic. The Table below is not a comprehensive list of all causes.
|
Age |
Acute limp |
Chronic and insidious limp – |
|
1–3 years |
Septic arthritis/osteomyelitis (Red Flag). Transient synovitis. Trauma / Non-accidental injury (Red Flag). |
Developmental dysplasia of hip. Neuromuscular disorder (e.g., cerebral palsy). Muscular dystrophy. Unequal leg length (e.g., post physeal injury or untreated inflammatory arthritis). Inflammatory joint and muscle disease. |
|
3–10 years |
Transient synovitis Septic arthritis/osteomyelitis (Red Flag). Trauma. Perthes disease (acute). Malignant disease e.g., leukaemia (Red Flag). Inflammatory joint and muscle disease. |
Perthes disease. Developmental dysplasia of hip. Neuromuscular disorders, e.g., Duchenne muscular dystrophy. Inflammatory joint and muscle disease. |
|
11–16 years |
Slipped upper [Capital] femoral epiphysis (acute). Avascular necrosis of the femoral head. Inflammatory joint and muscle disease. Trauma. Septic arthritis/osteomyelitis (Red Flag). Bone tumours (Red Flag). |
Slipped upper [Capital] femoral epiphysis. Inflammatory joint and muscle disease. Dysplastic hip. |
Chronic or intermittent limp can be more diagnostically challenging than acute limp and includes Orthopaedic conditions (e.g., hip pathology such as Perthes’ disease), Rheumatological conditions (such as Juvenile Idiopathic Arthritis or Juvenile Dermatomyositis), Metabolic conditions (e.g., rickets) and Neurological conditions (e.g., cerebral palsy, muscular dystrophy)
Common pitfalls in making a diagnosis of limp include:
- Ascribing limp to trauma and overlooking features that suggest other causes.
- Referred pain (e.g., from the abdomen [and testes in boys], back or chest and hip pathology manifesting as knee pain).
- Not thinking beyond the hip (!) and examining the child comprehensively.
- Classical clinical features of sepsis may be masked in the immunosuppressed child.
- Labelling children with daytime symptoms as having “growing pains”.
- Medically unexplained limp or physical symptoms warrant specific management and referral (i.e., discharge without a diagnosis and follow up plan is not advised).
- The blood film may be normal in children with malignancy.
- Normal blood tests or Radiographs do NOT exclude arthritis.
