Leg Length Discrepancy Hip Pain Running

Overview

A difference in the length of your lower and/or upper legs is called a leg length discrepancy. This is fairly common, actually. One study reported that 32 percent of 600 individuals had a difference in their leg lengths ranging from one-fifth to three-fifths of an inch. A person might not even notice if one leg is slightly longer than the other. However, if the difference is not minimal, treatment may be required.Leg Length Discrepancy

Causes

LLDs are very common. Sometimes the cause isn?t known. But the known causes of LLD in children include, injury or infection that slows growth of one leg bone. Injury to the growth plate (a soft part of a long bone that allows the bone to grow). Growth plate injury can slow bone growth in that leg. Fracture to a leg bone that causes overgrowth of the bone as it heals. A congenital (present at birth) problem (one whole side of the child?s body may be larger than the other side). Conditions that affect muscles and nerves, such as polio.

Symptoms

The effects vary from patient to patient, depending on the cause of the discrepancy and the magnitude of the difference. Differences of 3 1/2 to 4 percent of the total length of the lower extremity (4 cm or 1 2/3 inches in an average adult), including the thigh, lower leg and foot, may cause noticeable abnormalities while walking and require more effort to walk. Differences between the lengths of the upper extremities cause few problems unless the difference is so great that it becomes difficult to hold objects or perform chores with both hands. You and your physician can decide what is right for you after discussing the causes, treatment options and risks and benefits of limb lengthening, including no treatment at all. Although an LLD may be detected on a screening examination for curvature of the spine (scoliosis), LLD does not cause scoliosis. There is controversy about the effect of LLD on the spine. Some studies indicate that people with an LLD have a greater incidence of low back pain and an increased susceptibility to injuries, but other studies refute this relationship.

Diagnosis

A systematic and well organized approach should be used in the diagnosis of LLD to ensure all relevant factors are considered and no clues are overlooked which could explain the difference. To determine the asymmetry a patient should be evaluated whilst standing and walking. During the process special care should be used to note the extent of pelvic shift from side to side and deviation along the plane of the front or leading leg as well as the traverse deviation of the back leg and abnormal curvature of the spine. Dynamic gait analysis should be conducted during waling where observation of movement on the sagittal, frontal and transverse planes should be noted. Also observe head, neck and shoulder movements for any tilting.

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.

Leg Length

Surgical Treatment

Surgical treatments vary in complexity. Sometimes the goal of surgery is to stop the growth of the longer limb. Other times, surgeons work to lengthen the shorter limb. Orthopedic surgeons may treat children who have limb-length conditions with one or a combination of these surgical techniques. Bone resection. An operation to remove a section of bone, evening out the limbs in teens or adults who are no longer growing. Epiphyseal stapling. An operation to slow the rate of growth of the longer limb by inserting staples into the growth plate, then removing them when the desired result is achieved. Epiphysiodesis. An operation to slow the rate of growth of the longer limb by creating a permanent bony ridge near the growth plate. Limb lengthening. A procedure (also called distraction osteogenesis or the Ilizarov procedure) that involves attaching an internal or external fixator to a limb and gradually pulling apart bone segments to grow new bone between them. There are several ways your doctor can predict the final LLD, and thus the timing of the surgery. The easiest way is the so-called Australian method, popularised by Dr. Malcolm Menelaus, an Australian orthopedic surgeon. According to this method, growth in girls is estimated to stop at age 14, and in boys at age 16 years. The femur grows at the rate of 10 mm. a year, and the upper tibia at the rate of 6 mm. a year. Using simple arithmetic, one can get a fairly good prediction of future growth. This of course, is an average, and the patient may be an average. To cut down the risk of this, the doctor usually measures leg length using special X-ray technique (called a Scanogram) on three occasions over at least one year duration to estimate growth per year. He may also do an X-ray of the left hand to estimate the bone age (which in some cases may differ from chronological age) by comparing it with an atlas of bone age. In most cases, however, the bone age and chronological age are quite close. Another method of predicting final LLD is by using Anderson and Green?s remaining growth charts. This is a very cumbersome method, but was till the 1970?s, the only method of predicting remaining growth. More recently, however, a much more convenient method of predicting LLD was discovered by Dr. Colin Moseley from Montreal. His technique of using straight line graphs to plot growth of leg lengths is now the most widely used method of predicting leg length discrepancy. Whatever method your doctor uses, over a period of one or two years, once he has a good idea of the final LLD, he can then formulate a plan to equalize leg lengths. Epiphyseodesis is usually done in the last 2 to 3 years of growth, giving a maximum correction of about 5 cm. Leg lengthening can be done at any age, and can give corrections of 5 to10 cm., or more.

Write a comment

Comments: 0