Trendelenburg Gait Leg Length Discrepancy

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Overview

Have you ever been told or noticed that one of your legs is a bit longer than the other? Do you have incidences of lower back pain? These two things could be related. Most individuals have a small difference in their leg lengths. For some, the discrepancy is small and negligible and will not be a contributor to lower back pain. This is usually the case for people if their leg length is less than 5 millimeters. However, a difference of leg lengths greater than 5 millimeters (1/4 inch) can contribute to lower back pain. If you have a leg length difference of greater than 9 mm, then you have a 6X greater likelihood of having an episode of lower back pain.Leg Length Discrepancy

Causes

A number of causes may lead to leg length discrepancy in children. Differences in leg length frequently follow fractures in the lower extremities in children due to over or under stimulation of the growth plates in the broken leg. Leg length discrepancy may also be caused by a congenital abnormality associated with a condition called hemihypertrophy. Or it may result from neuromuscular diseases such as polio and cerebral palsy. Many times, no cause can be identified. A small leg length discrepancy of a quarter of an inch or less is quite common in the general population and of no clinical significance. Larger leg length discrepancies become more significant. The long-term consequences of a short leg may include knee pain, back pain, and abnormal gait or limp.

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 most accurate method to identify leg (limb) length inequality (discrepancy) is through radiography. It?s also the best way to differentiate an anatomical from a functional limb length inequality. Radiography, A single exposure of the standing subject, imaging the entire lower extremity. Limitations are an inherent inaccuracy in patients with hip or knee flexion contracture and the technique is subject to a magnification error. Computed Tomography (CT-scan), It has no greater accuracy compared to the standard radiography. The increased cost for CT-scan may not be justified, unless a contracture of the knee or hip has been identified or radiation exposure must be minimized. However, radiography has to be performed by a specialist, takes more time and is costly. It should only be used when accuracy is critical. Therefore two general clinical methods were developed for assessing LLI. Direct methods involve measuring limb length with a tape measure between 2 defined points, in stand. Two common points are the anterior iliac spine and the medial malleolus or the anterior inferior iliac spine and lateral malleolus. Be careful, however, because there is a great deal of criticism and debate surrounds the accuracy of tape measure methods. If you choose for this method, keep following topics and possible errors in mind. Always use the mean of at least 2 or 3 measures. If possible, compare measures between 2 or more clinicians. Iliac asymmetries may mask or accentuate a limb length inequality. Unilateral deviations in the long axis of the lower limb (eg. Genu varum,?) may mask or accentuate a limb length inequality. Asymmetrical position of the umbilicus. Joint contractures. Indirect methods. Palpation of bony landmarks, most commonly the iliac crests or anterior iliac spines, in stand. These methods consist in detecting if bony landmarks are at (horizontal) level or if limb length inequality is present. Palpation and visual estimation of the iliac crest (or SIAS) in combination with the use of blocks or book pages of known thickness under the shorter limb to adjust the level of the iliac crests (or SIAS) appears to be the best (most accurate and precise) clinical method to asses limb inequality. You should keep in mind that asymmetric pelvic rotations in planes other than the frontal plane may be associated with limb length inequality. A review of the literature suggest, therefore, that the greater trochanter major and as many pelvic landmarks should be palpated and compared (left trochanter with right trochanter) when the block correction method is used.

Non Surgical Treatment

Treatment depends on what limb has the deformity and the amount of deformity present. For example, there may be loss of function of the leg or arm. Cosmetic issues may also be a concern for the patient and their family. If there are problems with the arms, the goal is to improve the appearance and function of the arm. Treatment of leg problems try to correct the deformity that may cause arthritis as the child gets older. If the problem is leg length, where the legs are not "equal," the goal is equalization (making the legs the same length). Treatment may include the use of adaptive devices, prosthesis, orthotics or shoe lifts. If the problem is more severe and not treatable with these methods, then surgery may be necessary.

LLD Insoles

Surgical Treatment

Your child will be given general anesthetic. We cut the bone and insert metal pins above and below the cut. A metal frame is attached to the pins to support the leg. Over weeks and months, the metal device is adjusted to gradually pull the bone apart to create space between the ends of the bones. New bone forms to fill in the space, extending the length of the bone. Once the lengthening process is completed and the bones have healed, your child will require one more short operation to remove the lengthening device. We will see your child regularly to monitor the leg and adjust the metal lengthening device. We may also refer your child to a physical therapist to ensure that he or she stays mobile and has full range of motion in the leg. Typically, it takes a month of healing for every centimeter that the leg is lengthened.

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