Orthopaedic Surgery - Calcaneovalgus Foot

Basics

Calcaneovalgus foot is a congenital positional deformity believed to result from abnormal positioning of the fetal foot within the uterus.

The hindfoot is held in valgus, while the entire foot is markedly dorsiflexed.

In pronounced cases, the dorsum of the foot may rest against or nearly touch the anterior surface of the tibia.

Epidemiology

Calcaneovalgus foot is seen in newborn infants.

It occurs more frequently in girls and has an association with breech presentation or delivery.

It is one of the most common congenital foot deformities encountered in the neonatal period.

Prevalence

The condition has been reported in varying degrees in approximately 0.5–30% of births.

The wide range reflects differences in diagnostic criteria and the fact that mild positional deformities may resolve rapidly.

Pathophysiology

Calcaneovalgus foot is primarily a soft-tissue positional deformity rather than a structural bony abnormality.

The Achilles tendon is temporarily stretched because the foot has been held in excessive dorsiflexion.

After birth, the soft tissues gradually regain normal length and balance, and spontaneous correction usually occurs.

Bony Anatomy

There are no primary bony abnormalities in a typical calcaneovalgus foot.

This distinction is important because structural congenital deformities such as vertical talus require different treatment.

Associated Conditions

Infants with calcaneovalgus feet should be examined for other positional abnormalities that may also result from intrauterine positioning.

Important associated conditions include developmental dysplasia of the hip (DDH) and torticollis.

Relationship to Pes Planus

There is no convincing evidence that calcaneovalgus foot predisposes a child to pes planus or flatfoot later in life.

Most affected feet develop normal shape and function.

Diagnosis

Signs and Symptoms

The deformity is present at birth and is generally painless and asymptomatic.

The foot is markedly dorsiflexed, often to the point that its dorsum rests against the anterior tibia.

The hindfoot is positioned in valgus.

Muscle Tightness

Occasionally, there may be temporary contracture or tightness of the anterior compartment muscles and dorsiflexors.

Despite this, the deformity is usually flexible.

Flexibility of the Foot

Most calcaneovalgus feet can be passively brought into plantarflexion without substantial difficulty.

The degree of flexibility is an important diagnostic feature and helps distinguish the condition from fixed structural deformities.

Physical Examination

The appearance of the foot is usually sufficient to establish the diagnosis.

The examiner should assess whether the foot can be passively plantarflexed and supinated.

In some newborns, complete correction may not be achievable immediately, but progressive improvement should occur.

Calcaneal Position

The orientation of the calcaneus is especially important.

In calcaneovalgus foot, the hindfoot is dorsiflexed, and the heel points downward.

This finding helps distinguish the condition from congenital vertical talus.

Imaging

Plain Radiographs

Imaging is not routinely required when the physical examination is typical.

If the diagnosis is uncertain, standard anteroposterior and lateral radiographs of the foot and ankle may be obtained.

Radiographs are primarily used to exclude a structural or bony abnormality.

Differential Diagnosis

The main differential diagnoses include congenital vertical talus, posteromedial bowing of the tibia, and neurologic dorsiflexion deformity caused by L5 weakness.

Careful examination of the hindfoot and tibia usually differentiates these conditions.

Congenital Vertical Talus

Congenital vertical talus, also called convex pes valgus, is a rigid structural foot deformity.

Unlike calcaneovalgus foot, the calcaneus is held in plantarflexion or equinus.

The Achilles tendon is contracted, and the navicular is dorsally dislocated over the talar neck.

Distinguishing Vertical Talus

The direction of the heel is a useful clinical clue.

In congenital vertical talus, the heel is positioned upward because the calcaneus is plantarflexed.

In calcaneovalgus foot, the heel points downward because the calcaneus is dorsiflexed.

Posteromedial Bowing of the Tibia

Posteromedial bowing of the tibia can produce a foot that appears dorsiflexed and everted, similar to calcaneovalgus.

However, the primary abnormality is a bow in the tibia itself, rather than a positional deformity at the foot and ankle.

The bony curvature can usually be palpated on examination.

L5 Paresis

Neurologic weakness involving the L5 nerve root, such as may occur in spina bifida, can produce a fixed dorsiflexed foot because of muscle imbalance.

The presence of neurologic abnormalities and a less flexible deformity helps distinguish this from simple calcaneovalgus.

Treatment

General Measures

The most important aspect of treatment is reassurance of the parents.

Calcaneovalgus foot is a benign positional deformity that usually corrects spontaneously as the infant grows.

Parents may require repeated reassurance because the initial appearance can be dramatic.

Stretching

Gentle stretching exercises may be performed several times each day.

Parents can be taught to gently plantarflex and supinate the foot to encourage correction.

These exercises are optional in mild cases because spontaneous improvement is expected even without treatment.

Serial Casting

Occasionally, when the deformity is more pronounced or correction is slower than expected, serial casting may be used.

Casting can accelerate correction by maintaining the foot in a more neutral position.

Activity

No activity restrictions are necessary.

The deformity usually improves rapidly and does not interfere with normal infant development.

Surgery

Surgical treatment is not required for true calcaneovalgus foot.

The need for surgery should prompt reconsideration of the diagnosis and evaluation for another structural deformity.

Referral

Infants with a marked deformity, an unusually rigid foot, or possible congenital vertical talus should be referred to an orthopaedic specialist.

Referral is also appropriate when the diagnosis is uncertain or expected spontaneous improvement does not occur.

Follow-Up

Most infants require only periodic clinical observation.

Follow-up should document progressive improvement in foot position and confirm that the hindfoot becomes increasingly flexible and normally aligned.

Prognosis

The prognosis is excellent.

The deformity gradually corrects, and affected children generally develop a foot with normal appearance, strength, alignment, and function.

Long-Term Outcome

There is no definite evidence that children with calcaneovalgus foot are more likely to develop flatfoot later in life.

Normal walking and activity are expected.

Complications

Complications are rare.

Occasionally, subluxation of the peroneal tendons may occur.

When present, this problem generally responds to serial casting and resolves without long-term functional impairment.

Patient Monitoring

Parents should observe for progressive spontaneous correction.

Persistent rigidity, failure to improve, worsening deformity, or an abnormal heel position should prompt reassessment to exclude congenital vertical talus or another structural or neurologic disorder.