Deandra Rusak

Foot Conditions Database

Leg Length Discrepancy And Running

Overview

Leg length discrepancy is the difference in lengths of an individual?s legs. This difference may be anatomical or may be due to scoliosis, trauma/injury, arthritis, overpronation (collapse) of one foot, bowing of one leg or unequal bowing, surgery (hip or knee replacement), pelvic tilting or ageing. The difference can also be functional caused by differing forces of the soft tissues, such as weakness in muscle tissue on one side, or a weakness/tightness in joint tissue. A difference in leg lengths also results when running on indoor banked tracks, beaches and banked streets and side walks (for drainage). Many people have a measurable difference in their leg lengths which is compensated for by their bodies. As we age this compensation does not work as well. An x-ray and physical measurements will define the discrepancy and the adjustment needed.Leg Length Discrepancy

Causes

Some children are born with absence or underdeveloped bones in the lower limbs e.g., congenital hemimelia. Others have a condition called hemihypertrophy that causes one side of the body to grow faster than the other. Sometimes, increased blood flow to one limb (as in a hemangioma or blood vessel tumor) stimulates growth to the limb. In other cases, injury or infection involving the epiphyseal plate (growth plate) of the femur or tibia inhibits or stops altogether the growth of the bone. Fractures healing in an overlapped position, even if the epiphyseal plate is not involved, can also cause limb length discrepancy. Neuromuscular problems like polio can also cause profound discrepancies, but thankfully, uncommon. Lastly, Wilms? tumor of the kidney in a child can cause hypertrophy of the lower limb on the same side. It is therefore important in a young child with hemihypertrophy to have an abdominal ultrasound exam done to rule out Wilms? tumor. It is important to distinguish true leg length discrepancy from apparent leg length discrepancy. Apparent discrepancy is due to an instability of the hip, that allows the proximal femur to migrate proximally, or due to an adduction or abduction contracture of the hip that causes pelvic obliquity, so that one hip is higher than the other. When the patient stands, it gives the impression of leg length discrepancy, when the problem is actually in the hip.

Symptoms

Children whose limbs vary in length often experience difficulty using their arms or legs. They might have difficulty walking or using both arms to engage in everyday activities.

Diagnosis

The only way to decipher between anatomical and functional leg length inequalities (you can have both) is by a physical measurement and series of biomechanical tests. It is actually a simple process and gets to the true cause of some runner?s chronic foot, knee, hip and back pain. After the muscles are tested and the legs are measured it may be necessary to get a special X-ray that measures both of your thighs (Femurs) and legs (Tibias). The X-ray is read by a medical radiologist who provides a report of the actual difference down to the micrometer leaving zero room for error. Once the difference in leg length is known, the solution becomes clear.

Non Surgical Treatment

Treatment is based on an estimate of how great the difference in leg length will be when the child grows up, Small differences (a half inch or less) do not need treatment. Differences of a half to one inch may require a lift inside the shoe.

Leg Length Discrepancy

how to become tall in one day

Surgical Treatment

The bone is lengthened by surgically applying an external fixation device to the leg. The external fixator, a scaffold-like frame, is connected to the bone with wires, pins, or both. A small crack is made in the bone and the frame creates tension when the patient or family member turns its dial. This is done several times each day. The lengthening process begins approximately five to 10 days after surgery. The bone may lengthen 1 millimeter per day, or approximately 1 inch per month. Lengthening may be slower in a bone that was previously injured. It may also be slower if the leg was operated on before. Bones in patients with potential blood vessel abnormalities, such as cigarette smokers, may also need to be lengthened more slowly. The external fixator is worn until the bone is strong enough to support the patient safely. This usually takes about three months for each inch. Factors such as age, health, smoking and participation in rehabilitation can affect the amount of time needed.