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.Causes
There are many causes of leg length discrepancy. Structural inequality is due to interference of normal bone growth of the lower extremity, which can occur from trauma or infection in a child. Functional inequality has many causes, including Poliomyelitis or other paralytic deformities can retard bone growth in children. Contracture of the Iliotibial band. Scoliosis or curvature of the spine. Fixed pelvic obliquity. Abduction or flexion contraction of the hip. Flexion contractures or other deformities of the knee. Foot deformities.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
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
The way in which we would treat a LLD would depend on whether we have an anatomical or functional difference. To determine which one is causing the LLD you will need to get your legs measured. This is the easiest way to determine if it is anatomical or functional. With a functional LLD we must first determine the cause and treat the cause. Should the cause be one that is not correctable then we may need to treat the LLD as if it were an anatomical or may have to treat the opposite leg to improve one's gait. As for the anatomical LLD, we may start off with a heel lift only in the shoe and follow up to see if we will need to put the lift full sole on the bottom of the shoe. This is determined by the affects that a heel lift in one shoe may have on that knee. Should the LLD be more than 1/4 inch we usually recommend starting between 1/8 inch to 1/4 inch less than the actual amount and let the body adjust to the change and then raise up to the measured amount later.what is a shoe lift?Surgical Treatment
Surgical treatments vary in complexity. Sometimes the goal of surgery is to stop the growth of the longer limb. Other times, surgeons work to lengthen the shorter limb. Orthopedic surgeons may treat children who have limb-length conditions with one or a combination of these surgical techniques. Bone resection. An operation to remove a section of bone, evening out the limbs in teens or adults who are no longer growing. Epiphyseal stapling. An operation to slow the rate of growth of the longer limb by inserting staples into the growth plate, then removing them when the desired result is achieved. Epiphysiodesis. An operation to slow the rate of growth of the longer limb by creating a permanent bony ridge near the growth plate. Limb lengthening. A procedure (also called distraction osteogenesis or the Ilizarov procedure) that involves attaching an internal or external fixator to a limb and gradually pulling apart bone segments to grow new bone between them. There are several ways your doctor can predict the final LLD, and thus the timing of the surgery. The easiest way is the so-called Australian method, popularised by Dr. Malcolm Menelaus, an Australian orthopedic surgeon. According to this method, growth in girls is estimated to stop at age 14, and in boys at age 16 years. The femur grows at the rate of 10 mm. a year, and the upper tibia at the rate of 6 mm. a year. Using simple arithmetic, one can get a fairly good prediction of future growth. This of course, is an average, and the patient may be an average. To cut down the risk of this, the doctor usually measures leg length using special X-ray technique (called a Scanogram) on three occasions over at least one year duration to estimate growth per year. He may also do an X-ray of the left hand to estimate the bone age (which in some cases may differ from chronological age) by comparing it with an atlas of bone age. In most cases, however, the bone age and chronological age are quite close. Another method of predicting final LLD is by using Anderson and Green?s remaining growth charts. This is a very cumbersome method, but was till the 1970?s, the only method of predicting remaining growth. More recently, however, a much more convenient method of predicting LLD was discovered by Dr. Colin Moseley from Montreal. His technique of using straight line graphs to plot growth of leg lengths is now the most widely used method of predicting leg length discrepancy. Whatever method your doctor uses, over a period of one or two years, once he has a good idea of the final LLD, he can then formulate a plan to equalize leg lengths. Epiphyseodesis is usually done in the last 2 to 3 years of growth, giving a maximum correction of about 5 cm. Leg lengthening can be done at any age, and can give corrections of 5 to10 cm., or more.