Limb Length Discrepancy Shoe Lift

Overview

Small or mild length leg discrepancies (LLD), i.e., below 3.0 cm, have been considered as enough to cause orthopaedic changes such as lumbar pain, stress fractures and osteoarthritis on lower limbs (LLLL) joints. In addition to the classification by its magnitude, discrepancies can also be categorized according to etiology, being structural when a difference is noted between bone structures' length or functional as a result of mechanical changes on the lower limb, and are found in 65% - 70% of the healthy population.

Causes

A patient?s legs may be different lengths for a number of reasons, including a broken leg bone may heal in a shorter position, particularly if the injury was severe. In children, broken bones may grow faster for a few years after they heal, resulting in one longer leg. If the break was near the growth center, slower growth may ensue. Children, especially infants, who have a bone infection during a growth spurt may have a greater discrepancy. Inflammation of joints, such as juvenile arthritis during growth, may cause unequal leg length. Compensation for spinal or pelvic scoliosis. Bone diseases such as Ollier disease, neurofibromatosis, or multiple hereditary exostoses. Congenital differences.

Symptoms

The most common symptom of all forms of LLD is chronic backache. In structural LLD the sufferer may also experience arthritis within the knee and hip are, flank pain, plantar fasciitis and metatarsalgia all on the side that is longer. Functional LLD sufferers will see similar conditions on the shorter side.

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

Heel lifts Raise the heel on the shorter leg. It is applied either to the heel of the custom orthotic or to the inside of the shoe under the insole at the heel. Generally if the discrepancy is greater than 3/8 of an inch, the modification is applied externally on the footwear. Custom made orthotics help to provide proper support and alignment to the foot, controlling conditions such as over pronation. Orthopedic Footwear, properly fitted, to which a lift might be applied inside or out.



Surgical Treatment

Epiphysiodesis is a surgical option designed to slow down the growth of the long leg over a period of months to years. It is only used in growing children. The operation involves a general anaesthetic. Small incisions are made around the knee near the growth plates of the thigh bone and the shin bone. The growth plates are prevented from growing by the use of small screws and plates (?8 - plates?). The screws are buried beneath the skin and are not visible. Stitches are buried beneath the skin and do not need to be removed. The child is normally in hospital for 2-3 days. The child can weight bear immediately and return back to normal activity within a few weeks. Long term follow up is required to monitor the effects of the surgery. The timing of the surgery is based on the amount of growth predicted for the child. Therefore, this procedure can under- and over-correct the difference in leg length. Occasionally the screws have to be removed to allow growth to continue. This procedure can be used on one half of the growth plate to correct deformity in a limb e.g. knock-knees or bow legs. This is known as hemiepiphysiodesis.