Orthopaedic Problems in Children
From knock-knees to pulled elbows, paediatrician Dr Benjamin Jacobs and orthopaedic surgeon Ms Deborah Eastwood advise on some common paediatric conditions.
Most children start to walk with assistance – for example, with hands held or cruising around furniture – by one year of age. If a child is not walking by 18 months of age, referral to a paediatrician is indicated. Causes include developmental dysplasia of the hip (DDH), cerebral palsy and muscular dystrophies. If there is a family history of bottom shuffling and the child is mobile by this means, then a specialist referral can be deferred until two years of age.
Bowlegs and knock-knees
The shape of a child’s legs often causes considerable concern. All children are bow-legged at birth1. Most have grown out of it by 18 months of age. They may then become knock-kneed by three to four before their legs straighten out again to a normal physiological position of a few degrees of valgus.
The bowed legs often have a slight twist to them as well – tibial torsion – and this combination makes the deformity seem worse. If the child is younger than five, of normal proportions and weight, and the deformity is symmetrical with no history of injury or illness, then there is no cause for concern no matter how bad the legs look.
They are likely to straighten spontaneously. If the history suggests a poor diet, bowel disease, or anticonvulsant drugs that can cause rickets, blood biochemistry should be checked2. An X-ray will also exclude rickets, Blount’s disease, or other orthopaedic rarities.
Children often start to walk with their feet pointing towards each other. This twisting may originate in the foot (metatarsus varus), in the tibia (tibial torsion), or in the femur (persistent anteversion of the femoral neck).
The cause can be detected easily by assessing the child in a prone position with knees flexed. All these conditions are symmetrical, free of pain, and allow normal mobility.
Parents often remark that the toddler frequently trips and falls, but all toddlers do! This is usually more apparent at the end of the day when the child is tired. The child will get better with growth and maturity.
As the leg grows it untwists – in the tibia by three to four years and in the femur by seven to eight years – and with maturity, the child learns to control their foot position better so that tripping and falling become less marked.
Referral to an orthopaedic surgeon has only indicated if the condition is very asymmetric or progressive. Surgical correction of the deformity is rarely indicated and only in later childhood and adolescence.
This abnormality of gait is less common than in-toeing and tends to present in a younger child. It is often a reason for a child being late to walk – that is, they are walking but are reluctant to let go of the furniture or their mother’s hand because the externally rotated foot position is associated with an unstable walk.
It tends to improve with time in the same way that in-toeing does.
This is a common phase in the development of a mature gait pattern. However, a child who did walk on their heels and becomes a toe-walker may have a neuromuscular cause, such as Duchenne’s muscular dystrophy.
Unilateral tiptoeing rings alarm bells for problems such as DDH, limb dysplasia, or hemiplegia. Treatment may be required for the persistent idiopathic toe walker, particularly if the Achilles tendon is tight.
Flat foot (pes planus)
A flat foot is one in which the medial longitudinal arch either rests on the ground or appears closer to the ground than the examiner would accept as normal. If the foot is truly flat the heel will be in a valgus position.
Flexible flat feet are universal in the infant, very common in the toddler and present in 15% of adults. The vast majority of flexible flat feet are asymptomatic in both childhood and adulthood.
The natural history of the condition is not altered by the use of orthotics. However, if the child is uncomfortable when walking or has a limited walking tolerance, and this is considered to be due to the flat feet, then orthotic supports may be beneficial in easing the discomfort.
Orthotics will not change the shape of the foot, though. If there is a true delay in motor development, a neurological cause should be sought. Flat feet are frequently seen in families.
They are associated with another inherited condition called hypermobility, and the simple test of Beighton should be applied in a child presenting with flat feet, though the wide racial variation must be considered.
Jack’s test – the great toe extension test – will show if the foot is flexible. When the great toe is extended, or the child stands on tiptoe, the medial arch appears. Rigid flat feet are pathological and caused by neurological abnormality or conditions such as inflammatory arthritis or a tarsal coalition.
Benign joint hypermobility syndrome
Joint laxity is maximal at birth, declining rapidly during childhood, less rapidly during the teens, and slowly during adult life. Women are laxer jointed than men and there is wide ethnic variation.
Epidemiological studies have shown that hypermobility is seen in up to 10% of individuals in Western populations4. The quick clinical test for joint laxity is helpful. A child who scores five or more is hypermobile. When hypermobility becomes symptomatic, hypermobility syndrome is said to be present. Symptoms include:
- joint and back pains
- occasionally subluxations or frank dislocations
- ligament muscle and tendon injuries after mild trauma
On the other hand, most children are asymptomatic and violinists, flautists, and pianists (of all ages) with lax finger joints suffer less pain than their less flexible peers. Symptomatic children can be helped greatly by experienced physiotherapists.
Children aged one to five can easily sublux the head of the radius at the elbow if pulled suddenly by the hand. They then tend to carry their forearm in a lame position of forearm pronation and elbow flexion.
The function is restored and the pain dramatically relieved by supinating the forearm. A click may be felt and heard at the elbow. The arm is then allowed to rest in a sling for a few days. One in five children suffers recurrences but it is very rare beyond the age of 10 years.
Congenital and infantile scoliosis
Congenital scoliosis is the result of anomalous vertebral formation; infantile scoliosis is defined as a spinal curvature that appears before three years of age. Both must be referred early to an orthopaedic surgeon for investigation and follow-up.
Dr Benjamin Jacobs is consultant paediatrician at Northwick Park and St Mark’s Hospitals, Harrow, Middlesex
Ms Deborah Eastwood is consultant orthopaedic surgeon at the Royal National Orthopaedic Hospital in Stanmore, Middlesex
This article is an extract from Practical Paediatric Problems in Primary Care, published by Oxford University Press, edited by Mr Michael Bannon and Professor Yvonne Carter www.oup.co.uk ISBN 978-0-19-8529224