Limb Deformities

At SSM Health Cardinal Glennon Children’s Hospital, we have SLUCare Physician Group specialists with long-standing expertise in treating a wide range of limb deformities.

Pediatric limb deformities can either be caused by a traumatic injury or be present at birth or become noticeable over time.

While some conditions may resolve themselves as a child grows taller and ages, others require treatment ranging from physical therapy to bracing and, potentially surgery.

Limb deformities can be diagnosed in either arms or legs. Aside from trauma, among the most common conditions seen in children are:

Arms & Hands

An estimated 25 percent of all limb deformities seen at SSM Health Cardinal Glennon Children’s Hospital involve the arms.

The most common arm deformities affect one of two bones in the forearm — the radius bone, which sits on the inside of the forearm, or the ulnar bone, which is on the outside of the forearm. Either can be too short or even missing at birth. Fingers also may be missing or only partially developed. In half of all pediatric cases, the deformity affects both hands. In addition to bone, the condition can impact muscles, nerves and tendons in the wrist and arm.

Radial Club Hand – A missing or underdeveloped radius bone will result in a hand bent abnormally toward the thumb side of the forearm. It can be mild or severe depending upon how short the radial bone is or if it is missing. In mild cases, it can be treated with splints and therapy. More severe cases require surgery.
Ulnar Club Hand – This is caused when the ulnar bone is short or missing, causing the wrist to turn almost sideways toward the pinky side of the forearm. It is far less common than radial club hand. A splint may be able to correct mild forms of the condition, but more severe cases will need surgical intervention.

Legs

Deformities in the legs most often are related to abnormal rotation or angle of the bones or developmentally weak muscles, such as in the hips. They can impact the entire leg, from the hips to the feet.

Rotational Conditions

When either the top (femur) or bottom (tibia) leg bones are rotated abnormally, children can be seen with toes turned inward or outward. The anatomy of the hip also can impact how the leg rotates. In toddlers, children with toeing in rotational problems can often be seen sitting in a “W” position, with legs rotated outward from the hips while on the floor, versus sitting cross-legged.

It is important to note that leg rotation at the time of birth is completely normal and often resolves itself as the child grows older and gets involved in activities. Parents should take note of how their child sits and walks and monitor the situation for pain or difficulty in walking or running as their child ages.

Angular Deformities

There are two main types of limb deformities that develop as a result of abnormal angles in how the leg bones are connected to each other.

Genu Valgrum (Knock Knees) - Knees turn inward, sometimes knocking or touching each other even as the ankles remain apart and the feet are pointing forward. In most cases, this corrects itself naturally as a child grows older, but it needs to be monitored for the possibility of intervention. In those cases, orthotics (shoe inserts) or braces may be recommended for a short period of time. In a few cases, surgery also may be needed.
Genus Varum (Bowed Legs) – Legs turn outward at the knees. Parents often notice that their child has bowed legs when they are born or when they start walking. Oftentimes, it’s noticed around the age of 2. In the majority of cases, bowed legs go away as the child ages and the bones grow normally. An evaluation by a pediatric orthopedist is recommended if the condition is still present by kindergarten.
Blount’s Disease – This is a condition in which the growth plate at the top of the shinbone (tibia) is abnormal, causing the leg to turn outward just below the knee joint and look bow-legged. It can occur in one or both legs. In children under the age of two, the condition is difficult to diagnose because its appearance is similar to common bowed leg. While the cause is unknown, several factors may contribute to the development of this condition, including kidney failure, obesity, rickets (vitamin D deficiency) or genetics.

Flat Feet

Flat feet are noticeable in that the foot has little to no arch, causing the foot to remain flat on the floor. This is very common in children, with up to 45 percent of preschool children exhibiting some form of flat feet. It often doesn’t require any treatment other than stretching or, in a small number of cases, orthotics (shoe inserts) unless it results in chronic pain, tight ligaments and/or difficulty in walking.

Limb Length Discrepancies

These occur when one leg is longer than the other. It can be congenital (present at birth) or be the result of a traumatic injury, bone infection or a tumor. It also can be the result of a hip dysfuntion. Intervention and treatment options are based upon the degree of the difference between the two limb lengths.

< 1 cm – An estimated 60% of the population naturally has a one-centimeter or less difference in limb length. In these cases, no intervention or treatment is typically needed.
1-2 cm – Doctors may recommend that a small lift be placed in shoe to correct the discrepancy. Physical therapy also may be recommended for a short period of time to strengthen leg and hip muscles.
>2 cm – If there is a limb length difference greater than two centimeters, doctors may recommend a surgical procedure that either shortens or lengthens one leg. The decision to either shorten or lengthen a leg is based upon the extent of the limb discrepancy. Parents also should consider the length of time to heal after either procedure.

Surgical Interventions

Pediatric orthopedists have three options to correct significant limb length discrepancies.

Shorten the longer leg
Slow down the growth of the longer leg
Lengthen the longer leg

Leg Shortening

For older children whose bones have finished growing and have mild limb discrepancies, doctors can remove a portion of a leg bone in the longer leg to match the shorter one. In these cases, surgeons can remove a portion of the bone in either the thigh or shin bone and then hold the remaining pieces together with metal plates and screws while new bone forms in the break and heals.

Epiphysiodesis

This procedure slows down or stops growth at one of the two growth plates in the leg. It is a minimally invasive procedure during which the doctor makes small incisions and places metal staples in the growth plates of either the shin or thigh bone (or both) to temporarily restrict growth. The staples are removed once the shorter leg has reached the length of the other, longer leg.

Leg Lengthening

For significant limb length discrepancies (> 4 cm), the shorter leg can be increased gradually with either an internal or external fixation device. The process can take months, with bone growth of about one centimeter per month. And doctors typically say that for every centimeter of growth needed, it will take about a month of healing after the procedure is complete. On average, total healing time may take 6 months or longer.

External fixation devices look like a small, circular frame around a child’s leg. It is directly connected during surgery to the bone to be lengthened with wires. During the procedure, the doctor will cut the bone into two pieces, with wires inserted into each piece. After 7-10 days, the family is taught how to turn a dial on the frame several times a day to gradually pull the bone apart. The body will slowly create new bone in the space.

Internal fixation – Instead of an external frame, a surgeon will implant a metal rod directly into the bone to be lengthened. The rod can be lengthened over time by using a magnet or screw, which separates the metal rod and bone. New bone is then created by the body over time to fill the gap. It takes about a month to heal for every centimeter the bone is lengthened. There is a risk of the bone not healing with this procedure and it cannot be performed if the growth plates are still open.