Functional Leg Length Discrepancy Causes
Overview
Leg length discrepancy is an orthopaedic problem that usually appears in childhood, in which one's two legs are of unequal lengths. Often abbreviated as ?LLD,' leg length discrepancy may be caused by or associated with a number of other orthopaedic or medical conditions, but is generally treated in a similar fashion, regardless of cause and depending on severity. Leg length discrepancy is sometimes divided up into 'true LLD' and 'functional LLD.' Functional LLD occurs when the legs are actually equal in length, but some other condition, such as pelvic obliquity (a tilt in the position of the pelvis), creates the appearance of legs of different lengths.
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 patient/athlete may present with an altered gait (such as limping) and/or scoliosis and/or low back pain. Lower extremity disorders are possibly associated with LLD, some of these are increased hip pain and degeneration (especially involving the long leg). Increased risk of: knee injury, ITB syndrome, pronation and plantar fascitis, asymmetrical strength in lower extremity. Increased disc or vertebral degeneration. Symptoms vary between patients, some patients may complain of just headaches.
Diagnosis
A qualified musculoskeletal expert will first take a medical history and conduct a physical exam. Other tests may include X-rays, MRI, or CT scan to diagnose the root cause.
Non Surgical Treatment
Whether or not treatment should be pursued depends on the amount of discrepancy. In general, no treatment (other than a heel life, if desired) should be considered for discrepancies under two centimeters. If the discrepancy measures between two and five centimeters, one might consider a procedure to equalize leg length. Usually, this would involve closure of the growth plate on the long side, thereby allowing the short side to catch up; shortening the long leg; or possibly lengthening the short leg.
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Surgical Treatment
The bone is lengthened by surgically applying an external fixation device to the leg. The external fixator, a scaffold-like frame, is connected to the bone with wires, pins, or both. A small crack is made in the bone and the frame creates tension when the patient or family member turns its dial. This is done several times each day. The lengthening process begins approximately five to 10 days after surgery. The bone may lengthen 1 millimeter per day, or approximately 1 inch per month. Lengthening may be slower in a bone that was previously injured. It may also be slower if the leg was operated on before. Bones in patients with potential blood vessel abnormalities, such as cigarette smokers, may also need to be lengthened more slowly. The external fixator is worn until the bone is strong enough to support the patient safely. This usually takes about three months for each inch. Factors such as age, health, smoking and participation in rehabilitation can affect the amount of time needed.
Leg length discrepancy is an orthopaedic problem that usually appears in childhood, in which one's two legs are of unequal lengths. Often abbreviated as ?LLD,' leg length discrepancy may be caused by or associated with a number of other orthopaedic or medical conditions, but is generally treated in a similar fashion, regardless of cause and depending on severity. Leg length discrepancy is sometimes divided up into 'true LLD' and 'functional LLD.' Functional LLD occurs when the legs are actually equal in length, but some other condition, such as pelvic obliquity (a tilt in the position of the pelvis), creates the appearance of legs of different lengths.
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 patient/athlete may present with an altered gait (such as limping) and/or scoliosis and/or low back pain. Lower extremity disorders are possibly associated with LLD, some of these are increased hip pain and degeneration (especially involving the long leg). Increased risk of: knee injury, ITB syndrome, pronation and plantar fascitis, asymmetrical strength in lower extremity. Increased disc or vertebral degeneration. Symptoms vary between patients, some patients may complain of just headaches.
Diagnosis
A qualified musculoskeletal expert will first take a medical history and conduct a physical exam. Other tests may include X-rays, MRI, or CT scan to diagnose the root cause.
Non Surgical Treatment
Whether or not treatment should be pursued depends on the amount of discrepancy. In general, no treatment (other than a heel life, if desired) should be considered for discrepancies under two centimeters. If the discrepancy measures between two and five centimeters, one might consider a procedure to equalize leg length. Usually, this would involve closure of the growth plate on the long side, thereby allowing the short side to catch up; shortening the long leg; or possibly lengthening the short leg.
shoe lifts for men's shoes
Surgical Treatment
The bone is lengthened by surgically applying an external fixation device to the leg. The external fixator, a scaffold-like frame, is connected to the bone with wires, pins, or both. A small crack is made in the bone and the frame creates tension when the patient or family member turns its dial. This is done several times each day. The lengthening process begins approximately five to 10 days after surgery. The bone may lengthen 1 millimeter per day, or approximately 1 inch per month. Lengthening may be slower in a bone that was previously injured. It may also be slower if the leg was operated on before. Bones in patients with potential blood vessel abnormalities, such as cigarette smokers, may also need to be lengthened more slowly. The external fixator is worn until the bone is strong enough to support the patient safely. This usually takes about three months for each inch. Factors such as age, health, smoking and participation in rehabilitation can affect the amount of time needed.
