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Acute childhood limp

Dr Rajesh Varma

Acute childhood limp guideline by CKS

Review: Evaluating the child who presents with an acute limp. BMJ 2010

Key points

  1. The term limp refers to an abnormal gait pattern usually caused by pain, weakness, or deformity.

  2. The child may present with hip pain or knee pain (referred from the hip)

  3. Age and trauma/non-trauma are key diagnostic determinants

  4. A delay in the diagnosis of a slipped upper femoral epiphysis may worsen the outcome

  5. Transient synovitis and septic arthritis may be difficult to differentiate so any clinical concern warrants urgent investigation

Causes of acute limp in childhood

The underlying cause varies between age-groups

Age 0-3y

Atraumatic
Septic arthritis
Developmental hip dysplasia


Traumatic
Fracture (including Toddler’s fractures)
Non-accidental injury

Age 3-10y

Atraumatic
Transient synovitis
Septic arthritis
Perthes’ disease

Traumatic
Fracture
Non-accidental injury

Age 10-15y

Atraumatic
Slipped upper femoral epiphysis
Septic arthritis
Perthes’ disease

Traumatic
Fracture
Non-accidental injury

Other diagnoses

  • Haematological disease, such as sickle cell anaemia

  • Infective disease, such as pyomyositis or discitis

  • Metabolic disease, such as rickets

  • Neoplastic disease, such as acute lymphoblastic leukaemia

  • Neuromuscular disease, such as cerebral palsy or muscular dystrophy

  • Primary anatomical abnormality, such as limb length inequality

  • Rheumatological disease, such as juvenile idiopathic arthritis

Red Flag features: Refer for urgent assessment in secondary care

  1. Age < 3yr (septic arthritis is more common than transient synovitis)

  2. >Age 9yr AND pain or restricted movement in the hip

  3. Painful or restricted movements of any joints

  4. Unable to weight bear

  5. Fever (or systemically unwell) (suggests septic arthritis or malignancy)

  6. Presenting with a red, hot, swollen joint AND/OR other joints (suggests juvenile idiopathic arthritis).

    Do you have any pain or stiffness in your joints, muscles or back?

  7. Nocturnal pain

  8. Weight loss or anorexia (suggests malignancy)

  9. Suspected maltreatment

Assessment

  1. Exclude Red Flag features

  2. Identify precipitating factors, such as trauma or preceding illness
    If there is any history of trauma or focal bony tenderness on examination, X-ray(s) should be arranged

  3. Examination

  4. Considering the possibility of child maltreatment (non-accidental injury)

Check for

  • Fever

  • Gait

  • Spine (any curvature)

  • Hip (restricted internal rotation is the most sensitive marker, followed by loss of abduction)

  • Lower limbs: legs equal length

  • Any other swollen joints

  • Abdomen and testicles (testicular torsion can present as acute limp).

Investigations

  1. FBC, CRP, ESR

  2. Radiographs of the site of pain

  3. Ultrasound may be useful to identify a hip effusion

  4. Consider additional blood tests, such as creatine kinase (muscular dystrophy), immunogenic markers (rheumatological disease), and a sickle cell screen in high risk groups.

Use Kocher's criteria to differentiate between transient synovitis and septic arthritis?The gold standard is to aspirate the joint and determine the presence or absence of bacteria. However, this is invasive and impractical given that most cases will not be septic arthritis.

Clinical prediction rule is Kocher's criteria in children with a confirmed hip effusion

Fever >38.5°C
Cannot bear weight
ESR >40mm in the first hour
Serum WCC >12

Management

Children >9yr who present with reduced internal rotation of the hip and pain on extremes of movement- consider Slipped Upper Femoral Epiphysis
and refer for AP/Lateral X-rays and orthopaedic assessment.

Children aged 3–9 years
who are well
afebrile
limping but mobile and weight bearing,
<48hr history of atraumatic limp
may be assumed to have a provisional diagnosis of transient synovitis and can be observed in primary care for a short period of observation with safety netting.

Safety Net: advise parents to attend A&E with their child if his/her symptoms worsen, a fever develops, newly unable to weight bear or unwell in the interim.

The child should be reviewed at 48 hours after the onset of symptoms
If symptoms are improving within 48 hours, arrange follow-up one week from symptom onset to ensure complete resolution of symptoms.
If symptoms worsen (such as development of fever or systemic symptoms), fail to resolve, or there is any doubt about the diagnosis, urgent hospital assessment should be arranged.

Referral to paediatric orthopaedics or a paediatric rheumatology

  1. A well child has a working diagnosis of transient synovitis, and symptoms have either worsened or failed to resolve completely within a week of onset.

  2. A child presents with limp on several different occasions.

  3. A child with a persistent limp and normal initial X-ray(s)

  4. There is uncertainty about the diagnosis.

  5. An underlying rheumatological condition such as juvenile idiopathic arthritis is suspected.

Transient synovitis:
Most common in boys aged 4–8y
May follow a viral infection.
Benign and self-limiting: symptoms settle after 2 weeks
Definitive diagnosis requires demonstration of hip effusion and the exclusion of other potential causes.

Septic arthritis:
Usually Staphylococcus aureus, Haemophilus influenza or Group B Streptococcus.
The hip, knee, ankle and elbow are particularly prone and urgent wash-out and intravenous antibiotics are needed.
Diagnosis is based on positive blood cultures or joint aspirate

Acute leukaemia

Toddler fracture:
Subtle undisplaced spiral fracture of the tibia usually in a preschool child.
Caused by a sudden twist, often an unwitnessed fall.
There may be tenderness over the tibial shaft or distress on gentle tibial strain

Perthes' disease:
Idiopathic avascular necrosis of the developing femoral head.
Typically presents in boys aged 4–8y.
Diagnosed by plain AP radiograph of the pelvis, though in early disease typical changes may be absent.
May initially be mistaken for transient synovitis but symptoms do not settle.

Developmental dysplasia of the hip (DDH):
This may present as a limp if not detected in the neonatal period at routine review or at screening if ultrasound ordered because of pre-existing risk factors.

Slipped upper femoral epiphysis (SUFE)
Relatively rare disorder; 1–7 per 100 000
Age>10yr pubertal children, especially obese, more common in boys.
Bilateral in 20% of cases.

Acute SUFE following trauma
Chronic SUFE, where the slip progresses over weeks to months, is more common and more likely to present to GPs. T

Presents with loss of internal rotation and pain at the extremes of movement.
Diagnosis is with anteroposterior and lateral radiographs of both hips on the same film.
Treatments include surgical fixation.