Functional Leg Length Discrepancy Measurement
Overview
Have you noticed that your pants always fit a little weird or that you are always leaning to one leg when standing for awhile? If so, one of your legs may be longer than the other. This is known as a leg length discrepancy. There are two main reasons for a leg length discrepancy. One reason is that one of your leg bones (tibia or femur) is longer on one side. This is referred to as a true leg length discrepancy because the actual length of your bones is different. A second reason is that your pelvic bone may be rotated on one side making it appear that one leg is longer than the other. This is referred to as an apparent leg length discrepancy because the actual length of your leg bones is not different. In order to figure out if you have a true or apparent leg length discrepancy, your doctor may take an x-ray to measure the length of your leg bones or a simple measurement from your belly button to your ankle can help determine the reason. Over time, the leg length difference can cause stress on your low back, hips and knees, which may cause pain or discomfort.
Causes
An anatomical short leg is due to several orthopedic or medical condition mechanisms. Often, one leg simply stops growing before the other one does and is called ?congenital?. We often see mother-daughters or father-sons who exhibit virtually the same degree of shortness on the same side. Often it is not known why this occurs, but it seems to account for approximately 25% of the population demonstrating a true LLD. Other causes of a true LLD include trauma or broken bones, surgical repair, joint replacement, radiation exposure, tumors or Legg-Calves-Perthes disease.
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
On standing examination one iliac crest may be higher/lower than the other. However a physiotherapist, osteopath or chiropractor will examine the LLD in prone or supine position and measure it, confirming the diagnosis of structural (or functional) LLD. The LLD should be measured using bony fixed points. X-Ray should be taken in a standing position. The osteopath, physiotherapist or chiropractor will look at femoral head & acetabulum, knee joints, ankle joints.
Non Surgical Treatment
Treatment depends on the amount and cause of the leg length discrepancy as well as the age of your child. Typically, if the difference is less than 2 cm we don?t recommend immediate treatment. We may recommend that your child wear a heel lift in one shoe to make walking and running more comfortable. If the leg length discrepancy is more significant, your doctor may recommend surgery to shorten or lengthen a leg. The procedure used most often to shorten a leg is called epiphysiodesis.
Surgical Treatment
Large leg length inequalities can be treated by staged lengthenings or by simultaneous ipsilateral femoral and tibial lengthenings. Additionally, lengthenings can be combined with appropriately timed epiphysiodesis in an effort to produce leg length equality. Staged lengthenings are often used for congenital deficiencies such as fibular hemimelia, in which 15 cm or more may be needed to produce leg length equality. We typically plan for the final lengthening to be completed by age 13 or 14 years, and allow at least 3 years between lengthenings. Lengthening of both the tibia and femur simultaneously requires aggressive therapy and treatment of soft tissue contractures. Curran et al[57] reported the need for surgical release of soft tissue contractures in 3 of 8 patients treated with simultaneous ipsilateral femoral and tibial lengthenings. Lengthening over an IM nail can be done in an effort to decrease the amount of time the fixator needs to be worn and to prevent angular malalignment. This technique requires that the patient be skeletally mature and it carries a higher risk of osteomyelitis (up to 15%). Additionally, if premature consolidation occurs, a repeat corticotomy is more difficult.
Have you noticed that your pants always fit a little weird or that you are always leaning to one leg when standing for awhile? If so, one of your legs may be longer than the other. This is known as a leg length discrepancy. There are two main reasons for a leg length discrepancy. One reason is that one of your leg bones (tibia or femur) is longer on one side. This is referred to as a true leg length discrepancy because the actual length of your bones is different. A second reason is that your pelvic bone may be rotated on one side making it appear that one leg is longer than the other. This is referred to as an apparent leg length discrepancy because the actual length of your leg bones is not different. In order to figure out if you have a true or apparent leg length discrepancy, your doctor may take an x-ray to measure the length of your leg bones or a simple measurement from your belly button to your ankle can help determine the reason. Over time, the leg length difference can cause stress on your low back, hips and knees, which may cause pain or discomfort.
Causes
An anatomical short leg is due to several orthopedic or medical condition mechanisms. Often, one leg simply stops growing before the other one does and is called ?congenital?. We often see mother-daughters or father-sons who exhibit virtually the same degree of shortness on the same side. Often it is not known why this occurs, but it seems to account for approximately 25% of the population demonstrating a true LLD. Other causes of a true LLD include trauma or broken bones, surgical repair, joint replacement, radiation exposure, tumors or Legg-Calves-Perthes disease.
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
On standing examination one iliac crest may be higher/lower than the other. However a physiotherapist, osteopath or chiropractor will examine the LLD in prone or supine position and measure it, confirming the diagnosis of structural (or functional) LLD. The LLD should be measured using bony fixed points. X-Ray should be taken in a standing position. The osteopath, physiotherapist or chiropractor will look at femoral head & acetabulum, knee joints, ankle joints.
Non Surgical Treatment
Treatment depends on the amount and cause of the leg length discrepancy as well as the age of your child. Typically, if the difference is less than 2 cm we don?t recommend immediate treatment. We may recommend that your child wear a heel lift in one shoe to make walking and running more comfortable. If the leg length discrepancy is more significant, your doctor may recommend surgery to shorten or lengthen a leg. The procedure used most often to shorten a leg is called epiphysiodesis.
Surgical Treatment
Large leg length inequalities can be treated by staged lengthenings or by simultaneous ipsilateral femoral and tibial lengthenings. Additionally, lengthenings can be combined with appropriately timed epiphysiodesis in an effort to produce leg length equality. Staged lengthenings are often used for congenital deficiencies such as fibular hemimelia, in which 15 cm or more may be needed to produce leg length equality. We typically plan for the final lengthening to be completed by age 13 or 14 years, and allow at least 3 years between lengthenings. Lengthening of both the tibia and femur simultaneously requires aggressive therapy and treatment of soft tissue contractures. Curran et al[57] reported the need for surgical release of soft tissue contractures in 3 of 8 patients treated with simultaneous ipsilateral femoral and tibial lengthenings. Lengthening over an IM nail can be done in an effort to decrease the amount of time the fixator needs to be worn and to prevent angular malalignment. This technique requires that the patient be skeletally mature and it carries a higher risk of osteomyelitis (up to 15%). Additionally, if premature consolidation occurs, a repeat corticotomy is more difficult.
