Pediatric and Congenital Conditions of the Limbs

Pediatric and congenital conditions of the limbs encompass a wide range of disorders that may affect the growth, length, alignment, or function of the arms and legs during childhood and adolescence.

Some deformities are present from birth, while others develop progressively during growth or result from trauma, infections, growth plate abnormalities, or rare skeletal disorders.

In children, the assessment should not be limited to the deformity present at the time of the examination. It is essential to understand how the condition may evolve over the years and what the situation is likely to be at the end of growth.

For this reason, the treatment of pediatric limb deformities is often a long-term process that may include periodic check-ups, growth monitoring, and, when necessary, procedures performed at the most appropriate time.

Limb deformities in children change during growth

This is one of the main differences between pediatric orthopedics and adult orthopedics.

In children, bones continue to grow. A mild deformity may therefore correct spontaneously, remain stable, or progressively worsen. Similarly, a difference in length between the two legs may increase over the years if one limb grows more slowly than the other.

It is therefore not enough to ask:

“What is the situation today?”

We must also try to predict:

“What will this deformity look like at the end of growth?”

This prediction is essential in deciding whether observation is appropriate, when to intervene, and which technique should be used.

Lower-limb length discrepancy: when one leg is shorter than the other

A lower-limb length discrepancy is a difference in length between the two legs. It may be caused by a difference in the length of the femur, the tibia, or both bone segments.

The discrepancy may be congenital or may develop during growth following trauma, infection, growth plate damage, or other conditions.

In children, it is particularly important to determine not only the number of centimeters of difference present at the time of the examination, but also the expected limb-length discrepancy at skeletal maturity.

Depending on the extent of the discrepancy and the amount of remaining growth, treatment may include observation, shoe lifts, growth-modulation procedures, or lengthening of the shorter limb.

Learn more: Lower-limb length discrepancy in children: when one leg is shorter

Knock knees and bow legs in children

During growth, the alignment of the legs changes physiologically. At certain stages of childhood, some degree of bow-leggedness, or genu varum, or knock-knees, or genu valgum, is considered normal.

However, when the deformity is excessive, asymmetrical, progressive, or persists beyond the age at which it should normally resolve, a specialist assessment may be necessary.

It is essential to distinguish a physiological deformity from a pathological one and to determine whether the abnormality originates from the femur, the tibia, or both.

In children who still have significant growth remaining, some deformities can be corrected by harnessing the child’s own growth through guided-growth techniques. More complex cases may require different corrective procedures.

Learn more:

• Knock knees in children: when should they be corrected?
• Bow legs in children: when should they be corrected?

Congenital deformities of the lower limbs

Some abnormalities affecting the length or shape of the limbs are present from birth and result from incomplete or abnormal development of one or more bone segments.

The main congenital conditions that may require orthopedic and reconstructive treatment include:

• fibular hemimelia;
• tibial hemimelia;
• congenital short femur / congenital femoral deficiency;
• complex deformities of the femur, tibia, or foot;
• limb-length discrepancies associated with congenital malformations.

In these children, treatment may require a plan extending over many years of growth and may include deformity correction, joint reconstruction, management of limb-length discrepancies, and, when indicated, limb lengthening.

Rare conditions that may cause deformities and limb-length discrepancies

Some rare skeletal disorders can affect limb growth and cause deformities, differences in length, bone fragility, or impaired bone healing.

Conditions that may require a specialist orthopedic assessment include:

• neurofibromatosis and congenital pseudarthrosis of the tibia;
• hemihyperplasia / limb asymmetry;
• Ollier disease;
• hereditary multiple exostoses;
• osteogenesis imperfecta;
• achondroplasia and other skeletal dysplasias.

Each of these conditions has different characteristics and requires an individualized strategy. In some cases, the primary problem is the deformity; in others, it is the limb-length discrepancy, bone fragility, or the simultaneous presence of several abnormalities.

Learn more: Achondroplasia: diagnosis and treatment

Conditions acquired during growth

Not all pediatric deformities are congenital. A child may develop a difference in limb length or a deformity even after initially normal growth.

The main acquired causes include:

• fractures involving the growth plate;
• major trauma;
• bone or joint infections;
• partial or complete growth arrest of a physis;
• consequences of previous surgical procedures;
• post-traumatic deformities;
• progressive alterations in limb alignment during growth.

When a growth plate is damaged, part of the bone may grow more slowly or stop growing altogether. Over time, this may result in a limb-length discrepancy, an angular deformity, or both.

How is a limb deformity assessed in a child?

The assessment begins with a complete orthopedic examination, during which not only the deformity or difference in length is evaluated, but also the entire limb and the way the child walks.

The assessment may include:

• measurement of limb length;
• analysis of femoral and tibial alignment;
• assessment of the hip, knee, ankle, and foot;
• assessment of limb rotation;
• gait evaluation;
• weight-bearing radiographs of the lower limbs;
• assessment of remaining growth and skeletal maturity;
• comparison with previous examinations.

In children with progressive deformities or limb-length discrepancies, it is particularly important to repeat certain measurements over time, as the growth pattern may completely change the treatment strategy.

Predicting growth is part of the treatment

In pediatric deformities, it is not enough to measure what is present today. It is also necessary to estimate how the femur and tibia will grow over the following years.

This prediction helps determine whether a discrepancy is likely to increase, what the expected difference will be at the end of growth, and the best time for a possible procedure.

Timing is particularly important for procedures that take advantage of remaining growth, such as guided growth and epiphysiodesis.

When is treatment necessary?

Not all pediatric deformities require surgery.

For some children, periodic monitoring is sufficient. In others, treatment may be necessary because the deformity is significant or progressive, causes functional impairment, or may become more difficult to correct at the end of growth.

The decision depends on:

• the child’s age;
• the diagnosis;
• the severity of the deformity;
• its progression over time;
• the amount of remaining growth;
• the presence of a limb-length discrepancy;
• limb function;
• any associated deformities.

What treatments are available?

Treatment options vary considerably depending on the condition and the child’s age.

The main treatments may include:

• observation and periodic check-ups;
• shoe lifts or other forms of compensation, when indicated;
• guided growth;
• epiphysiodesis;
• corrective osteotomies;
• gradual correction of deformities;
• reconstruction of congenital malformations;
• limb lengthening;
• external-fixation techniques and Ilizarov principles in selected cases.

There is therefore no single procedure suitable for every pediatric deformity. Treatment must be selected according to the specific condition and, above all, the stage of growth the child has reached.

Guided growth and epiphysiodesis

One of the most valuable opportunities offered by pediatric orthopedics is the ability to use the child’s growth as part of the treatment.

Guided growth can be used to progressively correct certain angular deformities while the child continues to grow.

Epiphysiodesis, on the other hand, may be used in selected cases of limb-length discrepancy to slow down or stop the growth of the longer limb, allowing the shorter limb to progressively reduce part of the difference through its remaining growth.

In both situations, the timing of the procedure is crucial and requires an accurate assessment of the child’s remaining growth.

Limb lengthening in children and adolescents

When a limb-length discrepancy is significant or results from a complex congenital malformation, it may be necessary to plan lengthening of the shorter limb.

Lengthening may involve the femur, the tibia, or, in certain conditions, other skeletal segments.

In children with significant congenital deformities, treatment may be organized in several stages over the years of growth. The goal is not simply to gain centimeters, but to preserve the joints, alignment, function, and proportions of the limb.

Learn more: Limb lengthening: techniques and indications

Why is choosing the right specialist particularly important for a child?

A pediatric deformity may require monitoring for many years and, in some cases, several stages of treatment until growth is complete.

For this reason, when dealing with congenital conditions, limb-length discrepancies, or progressive deformities, it is not enough simply to choose the center where a possible procedure will be performed.

It is particularly important to choose the doctor who will be able to follow the child throughout the years of growth, understand the child’s clinical history, compare examinations over time, and decide when treatment is truly necessary.

Even a correctly performed procedure may fail to achieve the desired result if it is carried out at the wrong time. Conversely, appropriate planning may make it possible to take advantage of the child’s growth and reduce the complexity of certain treatments.

Continuity of care with the same specialist is therefore a fundamental part of the treatment pathway.

Dr. Daniele Pili and pediatric limb reconstruction

Dr. Daniele Pili, a specialist in Orthopedics and Traumatology, focuses on limb reconstruction, deformity correction, limb-length discrepancies, and limb lengthening.

The assessment of pediatric patients with congenital or acquired deformities is based not only on their current condition, but also on how it is expected to evolve throughout growth.

The aim is to establish a personalized treatment pathway designed, whenever possible, to preserve function, correct the deformity, and achieve the best possible symmetry between the limbs by the end of growth.

When should a specialist assessment be requested?

A specialist assessment is advisable when parents notice:

• one leg is shorter than the other;
• a persistent limp;
• pronounced bow legs or knock knees;
• a deformity that progressively worsens;
• clear asymmetry between the two limbs;
• a deformity present from birth;
• problems developing after a fracture or infection;
• a diagnosis of a rare condition that may affect skeletal growth.

An early diagnosis does not necessarily mean that immediate treatment is required. In many cases, it instead makes it possible to plan appropriately for the future and choose the best time for treatment.

FAQs about pediatric and congenital conditions of the limbs

Do all children with bowed or misaligned legs require treatment?

No. Physiological variations in alignment occur during growth. These situations must be distinguished from pathological, progressive, or asymmetrical deformities.

Can a shorter leg become even shorter relative to the other as the child grows?

Yes. If one limb grows more slowly, the discrepancy may progressively increase. For this reason, it is important to estimate the expected difference at the end of growth.

When can guided growth be used?

Guided growth may be used in some children with angular deformities who still have a sufficient amount of growth remaining. The correct indication and timing of the procedure are essential.

What is epiphysiodesis?

It is a procedure used in selected cases of limb-length discrepancy to slow down or stop the growth of the longer limb, using the remaining growth period to progressively reduce the difference.

Can a child undergo limb lengthening?

Yes, when there is an appropriate indication. Limb lengthening may be used to treat significant limb-length discrepancies and certain congenital conditions. It is planned by considering growth, the condition of the joints, associated deformities, and the individual characteristics of the patient.

Do congenital conditions always require surgery?

No. It depends on the diagnosis and the severity of the condition. Some children mainly require monitoring, while others may need one or more procedures during growth.

How long should a child with a deformity be monitored?

For many conditions, follow-up may continue until skeletal maturity. Growth may progressively alter deformities and limb-length discrepancies, making it necessary to adjust the treatment plan over the years.

Is it more important to choose the center or the doctor?

Both are important, but in progressive pediatric conditions, continuity of care with the specialist who follows the child over time is particularly valuable. The treatment strategy may need to be modified during growth, and certain decisions depend on the precise timing of the procedure.