Leg Length Discrepancy Measurements

Overview

Your child has been diagnosed with a leg-length discrepancy. This means that your child?s legs are slightly different lengths, with one leg longer than the other. The difference in lengths can vary widely. The larger the difference in lengths, the more problems that can result as the child gets older. Because of this, your child may be referred to a pediatric orthopedist (doctor specializing in treating bone and joint problems in children) for evaluation and possible treatment.Leg Length Discrepancy

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 effects of limb length discrepancy vary from patient to patient, depending on the cause and size of the difference. Differences of 3 1/2 percent to 4 percent of the total length of the leg (about 4 cm or 1 2/3 inches in an average adult) may cause noticeable abnormalities when walking. These differences may require the patient to exert more effort to walk. There is controversy about the effect of limb length discrepancy on back pain. Some studies show that people with a limb length discrepancy have a greater incidence of low back pain and an increased susceptibility to injuries. Other studies do not support this finding.

Diagnosis

The doctor carefully examines the child. He or she checks to be sure the legs are actually different lengths. This is because problems with the hip (such as a loose joint) or back (scoliosis) can make the child appear to have one shorter leg, even though the legs are the same length. An X-ray of the child?s legs is taken. During the X-ray, a long ruler is put in the image so an accurate measurement of each leg bone can be taken. If an underlying cause of the discrepancy is suspected, tests are done to rule it out.

Non Surgical Treatment

Heel lifts Raise the heel on the shorter leg. It is applied either to the heel of the custom orthotic or to the inside of the shoe under the insole at the heel. Generally if the discrepancy is greater than 3/8 of an inch, the modification is applied externally on the footwear. Custom made orthotics help to provide proper support and alignment to the foot, controlling conditions such as over pronation. Orthopedic Footwear, properly fitted, to which a lift might be applied inside or out.

LLD Insoles

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.

Write a comment

Comments: 0