Leg Length Discrepancy
Overview
Lengthening is usually done by corticotomy and gradual distraction. This technique can result in lengthenings of 25% or more, but typically lengthening of 15%, or about 6 cm, is recommended. The limits of lengthening depend on patient tolerance, bony consolidation, maintenance of range of motion, and stability of the joints above and below the lengthened limb. Numerous fixation devices are available, such as the ring fixator with fine wires, monolateral fixator with half pins, or a hybrid frame. The choice of fixation device depends on the desired goal. A monolateral device is easier to apply and better tolerated by the patient. The disadvantages of monolateral fixation devices include the limitation of the degree of angular correction that can concurrently be obtained; the cantilever effect on the pins, which may result in angular deformity, especially when lengthening the femur in large patients; and the difficulty in making adjustments without placing new pins. Monolateral fixators appear to have a similar success rate as circular fixators, especially with more modest lengthenings (20%).
Causes
From an anatomical stand point, the LLD could have been from hereditary, broken bones, diseases and joint replacements. Functional LLD can be from over pronating, knee deformities, tight calves and hamstrings, weak IT band, curvature in the spine and many other such muscular/skeletal issues.
Symptoms
Many people walk around with LLD?s of up to 2 cm. and not even know it. However, discrepancies above 2 cm. becomes more noticeable, and a slight limp is present. But even up to 3 cm. a small lift compensates very well, and many patients are quite happy with this arrangement. Beyond 3 cm. however, the limp is quite pronounced, and medical care is often sought at that point. Walking with a short leg gait is not only unsightly, but increases energy expenditure during ambulation. It could also put more stress on the long leg, and causes functional scoliosis. Where the discrepancy is more severe, walking becomes grotesque or virtually impossible.
Diagnosis
A doctor will generally take a detailed medical history of both the patient and family, including asking about recent injuries or illnesses. He or she will carefully examine the patient, observing how he or she moves and stands. If necessary, an orthopedic surgeon will order X-ray, bone age determinations and computed tomography (CT) scans or magnetic resonance imaging (MRI).
Non Surgical Treatment
The way in which we would treat a LLD would depend on whether we have an anatomical or functional difference. To determine which one is causing the LLD you will need to get your legs measured. This is the easiest way to determine if it is anatomical or functional. With a functional LLD we must first determine the cause and treat the cause. Should the cause be one that is not correctable then we may need to treat the LLD as if it were an anatomical or may have to treat the opposite leg to improve one's gait. As for the anatomical LLD, we may start off with a heel lift only in the shoe and follow up to see if we will need to put the lift full sole on the bottom of the shoe. This is determined by the affects that a heel lift in one shoe may have on that knee. Should the LLD be more than 1/4 inch we usually recommend starting between 1/8 inch to 1/4 inch less than the actual amount and let the body adjust to the change and then raise up to the measured amount later.
leg length discrepancy hip pain
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.
Lengthening is usually done by corticotomy and gradual distraction. This technique can result in lengthenings of 25% or more, but typically lengthening of 15%, or about 6 cm, is recommended. The limits of lengthening depend on patient tolerance, bony consolidation, maintenance of range of motion, and stability of the joints above and below the lengthened limb. Numerous fixation devices are available, such as the ring fixator with fine wires, monolateral fixator with half pins, or a hybrid frame. The choice of fixation device depends on the desired goal. A monolateral device is easier to apply and better tolerated by the patient. The disadvantages of monolateral fixation devices include the limitation of the degree of angular correction that can concurrently be obtained; the cantilever effect on the pins, which may result in angular deformity, especially when lengthening the femur in large patients; and the difficulty in making adjustments without placing new pins. Monolateral fixators appear to have a similar success rate as circular fixators, especially with more modest lengthenings (20%).
Causes
From an anatomical stand point, the LLD could have been from hereditary, broken bones, diseases and joint replacements. Functional LLD can be from over pronating, knee deformities, tight calves and hamstrings, weak IT band, curvature in the spine and many other such muscular/skeletal issues.
Symptoms
Many people walk around with LLD?s of up to 2 cm. and not even know it. However, discrepancies above 2 cm. becomes more noticeable, and a slight limp is present. But even up to 3 cm. a small lift compensates very well, and many patients are quite happy with this arrangement. Beyond 3 cm. however, the limp is quite pronounced, and medical care is often sought at that point. Walking with a short leg gait is not only unsightly, but increases energy expenditure during ambulation. It could also put more stress on the long leg, and causes functional scoliosis. Where the discrepancy is more severe, walking becomes grotesque or virtually impossible.
Diagnosis
A doctor will generally take a detailed medical history of both the patient and family, including asking about recent injuries or illnesses. He or she will carefully examine the patient, observing how he or she moves and stands. If necessary, an orthopedic surgeon will order X-ray, bone age determinations and computed tomography (CT) scans or magnetic resonance imaging (MRI).
Non Surgical Treatment
The way in which we would treat a LLD would depend on whether we have an anatomical or functional difference. To determine which one is causing the LLD you will need to get your legs measured. This is the easiest way to determine if it is anatomical or functional. With a functional LLD we must first determine the cause and treat the cause. Should the cause be one that is not correctable then we may need to treat the LLD as if it were an anatomical or may have to treat the opposite leg to improve one's gait. As for the anatomical LLD, we may start off with a heel lift only in the shoe and follow up to see if we will need to put the lift full sole on the bottom of the shoe. This is determined by the affects that a heel lift in one shoe may have on that knee. Should the LLD be more than 1/4 inch we usually recommend starting between 1/8 inch to 1/4 inch less than the actual amount and let the body adjust to the change and then raise up to the measured amount later.
leg length discrepancy hip pain
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.
