Overview
Leg length difference (LLD) is primarily when the hips are not level, causing a limp from side to side. Most practitioners divide LLD into anatomical or functional. Anatomical is when there is a true difference in the length of the tibia/fibula or the femur bone, or both. While functional LLD are either the shortening or lengthening of a limb, secondary to joint contracture or muscle imbalances.
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
In addition to the distinctive walk of a person with leg length discrepancy, over time, other deformities may be noted, which help compensate for the condition. Toe walking on the short side to decrease the swaying during gait. The foot will supinate (high arch) on the shorter side. The foot will pronate (flattening of the arch) on the longer side. Excessive pronation leads to hypermobility and instability, resulting in metatarsus primus varus and associated unilateral juvenile hallux valgus (bunion) deformity.
Diagnosis
Asymmetry is a clue that a LLD is present. The center of gravity will shift to the short limb side and patients will try to compensate, displaying indications such as pelvic tilt, lumbar scoliosis, knee flexion, or unilateral foot pronation. Asking simple questions such as, "Do you favor one leg over the other?" or, "Do you find it uncomfortable to stand?" may also provide some valuable information. Performing a gait analysis will yield some clues as to how the patient compensates during ambulation. Using plantar pressure plates can indicate load pressure differences between the feet. It is helpful if the gait analysis can be video-recorded and played back in slow motion to catch the subtle aspects of movement.
Non Surgical Treatment
Treatment of leg length inequality involves many different approaches, such as orthotics, epiphysiodesis, shortening, and lengthening, which can be used alone or combined in an effort to achieve equalization of leg lengths. Leg length inequality of 2 cm or less is usually not a functional problem. Often, leg length can be equalized with a shoe lift, which usually corrects about two thirds of the leg length inequality. Up to 1 cm can be inserted in the shoe. For larger leg length inequalities, the shoe must be built up. This needs to be done for every shoe worn, thus limiting the type of shoe that the patient can wear. Leg length inequalities beyond 5 cm are difficult to treat with a shoe lift. The shoe looks unsightly, and often the patient complains of instability with such a large lift. A foot-in-foot prosthesis can be used for larger leg length inequalities. This is often done as a temporizing measure for young children with significant leg length inequalities. The prosthesis is bulky, and a fixed equinus contracture may result.
leg length discrepancy test
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 difference (LLD) is primarily when the hips are not level, causing a limp from side to side. Most practitioners divide LLD into anatomical or functional. Anatomical is when there is a true difference in the length of the tibia/fibula or the femur bone, or both. While functional LLD are either the shortening or lengthening of a limb, secondary to joint contracture or muscle imbalances.
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
In addition to the distinctive walk of a person with leg length discrepancy, over time, other deformities may be noted, which help compensate for the condition. Toe walking on the short side to decrease the swaying during gait. The foot will supinate (high arch) on the shorter side. The foot will pronate (flattening of the arch) on the longer side. Excessive pronation leads to hypermobility and instability, resulting in metatarsus primus varus and associated unilateral juvenile hallux valgus (bunion) deformity.
Diagnosis
Asymmetry is a clue that a LLD is present. The center of gravity will shift to the short limb side and patients will try to compensate, displaying indications such as pelvic tilt, lumbar scoliosis, knee flexion, or unilateral foot pronation. Asking simple questions such as, "Do you favor one leg over the other?" or, "Do you find it uncomfortable to stand?" may also provide some valuable information. Performing a gait analysis will yield some clues as to how the patient compensates during ambulation. Using plantar pressure plates can indicate load pressure differences between the feet. It is helpful if the gait analysis can be video-recorded and played back in slow motion to catch the subtle aspects of movement.
Non Surgical Treatment
Treatment of leg length inequality involves many different approaches, such as orthotics, epiphysiodesis, shortening, and lengthening, which can be used alone or combined in an effort to achieve equalization of leg lengths. Leg length inequality of 2 cm or less is usually not a functional problem. Often, leg length can be equalized with a shoe lift, which usually corrects about two thirds of the leg length inequality. Up to 1 cm can be inserted in the shoe. For larger leg length inequalities, the shoe must be built up. This needs to be done for every shoe worn, thus limiting the type of shoe that the patient can wear. Leg length inequalities beyond 5 cm are difficult to treat with a shoe lift. The shoe looks unsightly, and often the patient complains of instability with such a large lift. A foot-in-foot prosthesis can be used for larger leg length inequalities. This is often done as a temporizing measure for young children with significant leg length inequalities. The prosthesis is bulky, and a fixed equinus contracture may result.
leg length discrepancy test
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.
