“Sickled feet” is the descriptive term for metatarsus adductus, a common foot deformity in newborns and infants. This condition involves the forefoot turning or angling inward toward the middle of the body. It is one of the most frequently observed foot irregularities, present at birth and often detected during the first pediatric examination. The condition generally represents a positional irregularity rather than a structural bone defect.
How Sickled Feet Appear
The appearance of a sickled foot is characterized by a distinct curve, which often gives the foot a bean or crescent shape. The forefoot deviates inward from the mid-foot, while the heel and ankle typically maintain a normal alignment. This inward angle creates a concave curve along the inside border of the foot and a convex, rounded curve along the outside border.
One method used to visualize this deviation is by drawing an imaginary line down the center of the heel. On a foot with metatarsus adductus, this line, instead of extending straight out between the second and third toes, will exit closer to the big toe or even off the inside edge of the foot. The big toe may also be visibly separated from the other toes, deviating inward with the rest of the forefoot. This helps medical professionals assess the degree of forefoot angulation.
Understanding the Causes and Severity
The most commonly accepted cause for metatarsus adductus is the positioning of the infant inside the uterus during pregnancy. The foot is thought to be folded or pressed against the uterine wall, which naturally molds the soft structures of the infant’s foot into the inward-curved position. This positional etiology explains why the condition is often seen in first-born children or in cases where the amniotic fluid was low, as these circumstances limit the space available for fetal movement.
Sickled feet are structurally different from other congenital foot deformities, such as clubfoot. Metatarsus adductus is primarily a mid-foot and forefoot issue where the heel remains in a neutral position. Clubfoot is a more complex condition that involves the entire foot and ankle, causing the whole foot to twist inward and downward due to structural changes in the tendons and bones.
The severity of metatarsus adductus is determined by its flexibility, which dictates the management approach. In most cases, the condition is mild and flexible, meaning the forefoot can be easily straightened to a neutral position with gentle pressure. A small percentage of cases are more rigid, indicating a slightly greater concern that may require more active intervention. The condition often resolves spontaneously without specialized treatment.
Diagnosis and Management Approaches
Diagnosis of metatarsus adductus relies on a thorough physical examination of the infant’s foot, which focuses on assessing the degree of flexibility. A medical professional will perform passive manipulation, gently attempting to straighten the forefoot back into alignment with the heel. If the foot corrects easily with this manipulation, it is classified as a flexible deformity, which is the most common presentation.
The primary management approach is observation, as the foot often corrects itself as the child grows and begins bearing weight. Parents may be instructed in gentle stretching exercises to perform several times a day, which involves manually guiding the forefoot outward to encourage proper alignment. These exercises help stimulate the soft tissues to assume a straighter position over time.
If the foot is rigid or the deformity is not improving after several months, the physician may recommend a course of serial casting. This non-surgical treatment involves applying a series of plaster casts that are changed every one to two weeks to gradually stretch the forefoot into a corrected position. Bracing or specialized footwear may also be used following casting to maintain the correction. Surgical intervention is reserved for severe, rigid cases that have failed to respond to all other conservative treatments, though this is rare.