Overview
Leg length discrepancy (LLD) affects about 70% of the general population, and can be either structural - when the difference occurs in bone structures - or functional, because of mechanical changes at the lower limbs. The discrepancy can be also classified by its magnitude into mild, intermediate, or severe. Mild LLD has been particularly associated with stress fracture, low back pain and osteoarthritis, and when the discrepancy occurs in subjects whose mechanical loads are increased by their professional, daily or recreational activities, these orthopaedic changes may appear early and severely. The aim of this study was to analyze and compare ground reaction force (GRF) during gait in runners with and without mild LLD. Results showed that subjects with mild LLD of 0.5 to 2.0 cm presented higher values of minimum vertical GRF (0.57 ? 0.07 BW) at the shorter limb compared to the longer limb (0.56 ? 0.08 BW) Therefore, subjects with mild LLD adopt compensatory mechanisms that cause additional overloads to the musculoskeletal system in order to promote a symmetrical gait pattern as showed by the values of absolute symmetric index of vertical and horizontal GRF variables.
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
As patients develop LLD, they will naturally and even unknowingly attempt to compensate for the difference between their two legs by either bending the longer leg excessively or standing on the toes of the short leg. When walking, they are forced to step down on one side and thrust upwards on the other side, which leads to a gait pattern with an abnormal up and down motion. For many patients, especially adolescents, the appearance of their gait may be more personally troublesome than any symptoms that arise or any true functional deficiency. Over time, standing on one's toes can create a contracture at the ankle, in which the calf muscle becomes abnormally contracted, a condition that can help an LLD patient with walking, but may later require surgical repair. If substantial enough, LLD left untreated can contribute to other serious orthopaedic problems, such as degenerative arthritis, scoliosis, or lower back pain. However, with proper treatment, children with leg length discrepancy generally do quite well, without lingering functional or cosmetic deficiencies.
Diagnosis
Infants, children or adolescents suspected of having a limb-length condition should receive an evaluation at the first sign of difficulty in using their arms or legs. In many cases, signs are subtle and only noticeable in certain situations, such as when buying clothing or playing sports. Proper initial assessments by qualified pediatric orthopedic providers can reduce the likelihood of long-term complications and increase the likelihood that less invasive management will be effective. In most cases, very mild limb length discrepancies require no formal treatment at all.
Non Surgical Treatment
Heel lifts and sole lifts are simple ways Pedorthists can compensate for leg length deficiencies. These small modifications can make a tremendous difference to a person?s comfort, balance and mobility. Although people do not always know if they have LLD if you have any of the symptoms I have mentioned you should consult a Pedorthist as treating your condition early will reduce the development of serious problems later on.
leg length discrepancy symptoms
Surgical Treatment
Bone growth restriction (epiphysiodesis) The objective of this surgical procedure is to slow down growth in the longer leg. During surgery, doctors alter the growth plate of the bone in the longer leg by inserting a small plate or staples. This slows down growth, allowing the shorter leg to catch up over time. Your child may spend a night in the hospital after this procedure or go home the same day. Doctors may place a knee brace on the leg for a few days. It typically takes 2 to 3 months for the leg to heal completely. An alternative approach involves lengthening the shorter bone. We are more likely to recommend this approach if your child is on the short side of the height spectrum.
Leg length discrepancy (LLD) affects about 70% of the general population, and can be either structural - when the difference occurs in bone structures - or functional, because of mechanical changes at the lower limbs. The discrepancy can be also classified by its magnitude into mild, intermediate, or severe. Mild LLD has been particularly associated with stress fracture, low back pain and osteoarthritis, and when the discrepancy occurs in subjects whose mechanical loads are increased by their professional, daily or recreational activities, these orthopaedic changes may appear early and severely. The aim of this study was to analyze and compare ground reaction force (GRF) during gait in runners with and without mild LLD. Results showed that subjects with mild LLD of 0.5 to 2.0 cm presented higher values of minimum vertical GRF (0.57 ? 0.07 BW) at the shorter limb compared to the longer limb (0.56 ? 0.08 BW) Therefore, subjects with mild LLD adopt compensatory mechanisms that cause additional overloads to the musculoskeletal system in order to promote a symmetrical gait pattern as showed by the values of absolute symmetric index of vertical and horizontal GRF variables.
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
As patients develop LLD, they will naturally and even unknowingly attempt to compensate for the difference between their two legs by either bending the longer leg excessively or standing on the toes of the short leg. When walking, they are forced to step down on one side and thrust upwards on the other side, which leads to a gait pattern with an abnormal up and down motion. For many patients, especially adolescents, the appearance of their gait may be more personally troublesome than any symptoms that arise or any true functional deficiency. Over time, standing on one's toes can create a contracture at the ankle, in which the calf muscle becomes abnormally contracted, a condition that can help an LLD patient with walking, but may later require surgical repair. If substantial enough, LLD left untreated can contribute to other serious orthopaedic problems, such as degenerative arthritis, scoliosis, or lower back pain. However, with proper treatment, children with leg length discrepancy generally do quite well, without lingering functional or cosmetic deficiencies.
Diagnosis
Infants, children or adolescents suspected of having a limb-length condition should receive an evaluation at the first sign of difficulty in using their arms or legs. In many cases, signs are subtle and only noticeable in certain situations, such as when buying clothing or playing sports. Proper initial assessments by qualified pediatric orthopedic providers can reduce the likelihood of long-term complications and increase the likelihood that less invasive management will be effective. In most cases, very mild limb length discrepancies require no formal treatment at all.
Non Surgical Treatment
Heel lifts and sole lifts are simple ways Pedorthists can compensate for leg length deficiencies. These small modifications can make a tremendous difference to a person?s comfort, balance and mobility. Although people do not always know if they have LLD if you have any of the symptoms I have mentioned you should consult a Pedorthist as treating your condition early will reduce the development of serious problems later on.
leg length discrepancy symptoms
Surgical Treatment
Bone growth restriction (epiphysiodesis) The objective of this surgical procedure is to slow down growth in the longer leg. During surgery, doctors alter the growth plate of the bone in the longer leg by inserting a small plate or staples. This slows down growth, allowing the shorter leg to catch up over time. Your child may spend a night in the hospital after this procedure or go home the same day. Doctors may place a knee brace on the leg for a few days. It typically takes 2 to 3 months for the leg to heal completely. An alternative approach involves lengthening the shorter bone. We are more likely to recommend this approach if your child is on the short side of the height spectrum.