Overview
There are generally two kinds of leg length discrepancies. Structural discrepancy occurs when either the thigh (femur) or shin (tibia) bone in one leg is actually shorter than the corresponding bone in the other leg. Functional discrepancy occurs when the leg lengths are equal, but symmetry is altered somewhere above the leg, which in turn disrupts the symmetry of the legs. For example, developmental dislocation of the hip (DDH) can cause a functional discrepancy. In DDH, the top of the leg bone (femur) that is not properly positioned in the hip socket may hang lower than the femur on the other side, giving the appearance and symptoms of a leg length discrepancy.
Causes
Some limb-length differences are caused by actual anatomic differences from one side to the other (referred to as structural causes). The femur is longer (or shorter) or the cartilage between the femur and tibia is thicker (or thinner) on one side. There could be actual deformities in one femur or hip joint contributing to leg length differences from side to side. Even a small structural difference can amount to significant changes in the anatomy of the limb. A past history of leg fracture, developmental hip dysplasia, slipped capital femoral epiphysis (SCFE), short neck of the femur, or coxa vara can also lead to placement of the femoral head in the hip socket that is offset. The end-result can be a limb-length difference and early degenerative arthritis of the hip.
Symptoms
The effects of a short leg depend upon the individual and the extent of discrepancy. The most common manifestation if a lateral deviation of the lumbar spine toward the short side with compensatory curves up the spine that can extend into the neck and even impacts the TMJ. Studies have shown that anterior and posterior curve abnormalities also can result.
Diagnosis
Limb length discrepancy can be measured by a physician during a physical examination and through X-rays. Usually, the physician measures the level of the hips when the child is standing barefoot. A series of measured wooden blocks may be placed under the short leg until the hips are level. If the physician believes a more precise measurement is needed, he or she may use X-rays. In growing children, a physician may repeat the physical examination and X-rays every six months to a year to see if the limb length discrepancy has increased or remained unchanged. A limb length discrepancy may be detected on a screening examination for curvature of the spine (scoliosis). But limb length discrepancy does not cause scoliosis.
Non Surgical Treatment
People with uneven leg lengths may be more prone to pain in their back, hips, and knees; uneven gait; and lower leg and foot problems. Due to its risks, surgery is typically not recommended unless the difference is greater than one inch. In cases where the difference is less than one inch, providing the same support for both feet is the most effective. This can be achieved by getting custom-fitted orthotics for both feet. Orthotics are inserts that you wear in the shoes. Your chiropractor will request to measure your feet and possibly your legs. You can step on a device that will take the measurements or you might have a plaster cast of your feet taken. Orthotics are typically made from plastic and leather, and function biomechanically with your foot. If a leg length discrepancy is not properly corrected with orthotics, your chiropractor may recommend a heel lift, also known as a shoe lift. You simply place it in the back of your shoe along with the orthotic. Typically, you will only wear the heel lift in one shoe to assist the shorter leg.
functional leg length discrepancy treatment
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.
There are generally two kinds of leg length discrepancies. Structural discrepancy occurs when either the thigh (femur) or shin (tibia) bone in one leg is actually shorter than the corresponding bone in the other leg. Functional discrepancy occurs when the leg lengths are equal, but symmetry is altered somewhere above the leg, which in turn disrupts the symmetry of the legs. For example, developmental dislocation of the hip (DDH) can cause a functional discrepancy. In DDH, the top of the leg bone (femur) that is not properly positioned in the hip socket may hang lower than the femur on the other side, giving the appearance and symptoms of a leg length discrepancy.
Causes
Some limb-length differences are caused by actual anatomic differences from one side to the other (referred to as structural causes). The femur is longer (or shorter) or the cartilage between the femur and tibia is thicker (or thinner) on one side. There could be actual deformities in one femur or hip joint contributing to leg length differences from side to side. Even a small structural difference can amount to significant changes in the anatomy of the limb. A past history of leg fracture, developmental hip dysplasia, slipped capital femoral epiphysis (SCFE), short neck of the femur, or coxa vara can also lead to placement of the femoral head in the hip socket that is offset. The end-result can be a limb-length difference and early degenerative arthritis of the hip.
Symptoms
The effects of a short leg depend upon the individual and the extent of discrepancy. The most common manifestation if a lateral deviation of the lumbar spine toward the short side with compensatory curves up the spine that can extend into the neck and even impacts the TMJ. Studies have shown that anterior and posterior curve abnormalities also can result.
Diagnosis
Limb length discrepancy can be measured by a physician during a physical examination and through X-rays. Usually, the physician measures the level of the hips when the child is standing barefoot. A series of measured wooden blocks may be placed under the short leg until the hips are level. If the physician believes a more precise measurement is needed, he or she may use X-rays. In growing children, a physician may repeat the physical examination and X-rays every six months to a year to see if the limb length discrepancy has increased or remained unchanged. A limb length discrepancy may be detected on a screening examination for curvature of the spine (scoliosis). But limb length discrepancy does not cause scoliosis.
Non Surgical Treatment
People with uneven leg lengths may be more prone to pain in their back, hips, and knees; uneven gait; and lower leg and foot problems. Due to its risks, surgery is typically not recommended unless the difference is greater than one inch. In cases where the difference is less than one inch, providing the same support for both feet is the most effective. This can be achieved by getting custom-fitted orthotics for both feet. Orthotics are inserts that you wear in the shoes. Your chiropractor will request to measure your feet and possibly your legs. You can step on a device that will take the measurements or you might have a plaster cast of your feet taken. Orthotics are typically made from plastic and leather, and function biomechanically with your foot. If a leg length discrepancy is not properly corrected with orthotics, your chiropractor may recommend a heel lift, also known as a shoe lift. You simply place it in the back of your shoe along with the orthotic. Typically, you will only wear the heel lift in one shoe to assist the shorter leg.
functional leg length discrepancy treatment
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.