This article refers mainly to children up to young school age, i.e. children who are too young to reliably localise their symptoms.
Conditions that are suitable to be treated in primary care are minor injuries of toddlers, transient (aseptic) synovitis of the hip in a child of preschool age and usually hairline fractures.
Conditions that must be immediately recognized and referred for specialist care are e.g. bacterial infections of the bone or joint, leukaemia, hip epiphysiolysis and suspicion of physical abuse, as well as all children with bone or joint symptoms who also present with general symptoms.
Clinical history
A history of limping must be differentiated from normal ”growing pains” which do not cause limping or other clinical signs.
The physician will often need to assess the role of normal growth variants (knock knees, bow legs, flat feet, toes pointing inwards; see Structural Anomalies in Children) as the cause of the symptoms.
How did limping start (suddenly, associated with an injury, gradually)?
When does limping occur (continuously, intermittently)?
After rest: joint inflammation, juvenile idiopathic arthritis
During exercise: orthopaedic aetiology
After exercise: stress injury, apophysitis
”Poorly healing” injuries in boys: oligoarticular juvenile idiopathic arthritis (JIA), the initial symptoms of which include enthesitis (an inflammation at a tendon insertion site; see Juvenile Idiopathic Arthritis (Juvenile Rheumatoid Arthritis)).
General symptoms: fever may suggest bacterial infection, and a respiratory infection may precede transient synovitis of the hip.
Morning stiffness: a sign of arthritis, particularly juvenile idiopathic arthritis
Clinical examination
Clinical examination must be carried out in a systematic way because
small children cannot localise pain
referred pain is common
the history given by parents may be misleading.
The systematic approach should always include
an examination of the back
a bilateral examination of hips, knees, lower legs and feet.
The examination should combine orthopaedic, traumatologic, neurologic, paediatric and rheumatologic elements.
Visual inspection will yield the most beneficial information. A lightly clothed small child should be allowed to play in the examination room whilst the parents explain the problem.
An older child is asked to walk normally, on the toes and on the heels and to squat.
If the child does have a limp
the sound of the heels hitting the floor may reveal an asymmetric cadence
he/she will push off with the unaffected leg when climbing stairs
a step taken with the unaffected leg is faster than the one with the affected leg.
Observe to which side the trunk and pelvis tilt during walking (Trendelenburg's sign): ask the child to stand on each leg in turn. When standing on the healthy leg the pelvis rises on the side opposite to the stance leg, but when standing on the affected leg the pelvis drops on the opposite side. This is associated with an abnormal tilt of the trunk towards the affected side.
Spinal mobility and postural defects (compensatory scoliosis) may be checked by inspecting the back from behind as the child bends forward. Any limb-length discrepancy should be noted at the same time.
An abnormal Trendelenburg's test result is suggestive of hip pathology or weakened muscle power at the pelvic region (either neurogenic or muscular).
Inability to walk on the heels or toes is suggestive of foot pain, limited range of motion or reduced muscle power.
Visual inspection should note any swelling or redness of the knees or ankles and possible signs of trauma. Only a few weeks' duration of limited exercise capacity will cause muscle atrophy that is evident on clinical examination. An inspection of the soles of the feet may reveal a foreign body or wart.
The range of motion of the hip, knee and ankle joints, and associated pain, is evaluated by comparing the two sides Articular Status of a Child with Arthritic Symptoms with the child on the carer's lap or on the examination table. If the hip is involved, internal rotation, in particular, will be restricted as compared with the opposite side (picture 1).
Palpation should aim to localise the origin of pain by comparing the affected side with the unaffected one as the child withdraws from pain. Accumulation of fluid (MTP joints, ankle, knee) and differences in skin temperature must also be noted Articular Status of a Child with Arthritic Symptoms. This part of the examination should be carried out last.
Follow-up investigations
If no objective signs are present, immediate follow-up investigations are not necessary and the child may be observed only.
If it is possible to identify a joint as the cause of the problem, a systematic examination of the joint Articular Status of a Child with Arthritic Symptoms should follow in order to diagnose possible arthritis. The urgency of diagnosis is outlined in the article Diagnosis and epidemiology of arthritis in children Arthritis in Children.
Radiological studies are indicated if
a fracture is suspected
a foreign body is suspected (a needle etc.)
the hip joint remains symptomatic for more than seven days or
a hip problem recurs after more than seven days after the first occurrence.
Children over 10 years old with hip symptoms should always be investigated by radiography. In particular, Perthes disease and early epiphysiolysis are difficult to detect.
Ultrasonography is useful in the diagnosis of hip, ankle and knee joint effusion and synovitis (can be carried out in primary care).
Arrangement of care
Patients treated in primary care
Minor injury is the most likely cause in a toddler. In a child of preschool age, transient (aseptic) synovitis of the hip Hip Pain in Children is the most common aetiology.
Hairline fractures (fissures, see Upper Limb Injuries in Children) may be treated in primary care if the trauma mechanism is known and there is no reason to suspect non-accidental injury.