LEG AND LIMB LENGTHENING DISCREPANCIES FAQsvoxmd2020-12-11T19:38:09+00:00
LLD Condition FAQs
How are Limb Length Discrepancies Diagnosed?
Limb length discrepancy may be diagnosed as an infant, in childhood, or later in life, depending on the cause. With a leg length discrepancy, one leg is shorter than the other when hips are level. Since problems with the hip (such as a loose joint) or back (scoliosis) can make one leg appear shorter – even when both are equal in length – diagnosis relies on a combination of physical examination and x-ray analysis. Although there are differing opinions on how to measure leg length, the standard workup for limb length discrepancy is a thorough physical examination, including watching the patient walk and run. Additionally, the surgeon performs a three-joint standing x-ray analysis or an x-ray scanogram to determine the actual length of the legs. During the x-ray imaging, a long ruler is put in the field of view so an accurate measurement of each leg bone can be taken to determine how big the discrepancy is (or will be if a child is still growing), and this helps determine the best treatment plan. Consult a healthcare professional who specializes in limb length discrepancy >
How are Limb Length Discrepancies Treated?
Treatment for a limb length discrepancy depends on the severity of the discrepancy, the age of the patient, and the cause, if known. Both surgical and non-surgical options are available. While a small limb length discrepancy may not cause problems, a significant difference (more than 2 cm) can cause a noticeable limp and will often require treatment. Non-surgical treatment options include the “wait-and-see” approach for children who are still growing, and the shoe lift, which manages the symptoms but does not correct the discrepancy permanently. There are also surgical methods of treating leg length discrepancy. Each of these techniques produces a permanent correction of the leg lengths. Depending on your condition, you and your surgeon may choose to shorten the long leg or lengthen the short leg. Surgical treatment options are generally used for larger leg length discrepancies and in cases where the patient wants a permanent solution.
Bone growth restriction (epiphysiodesis or growth arrest) is often successful when performed at the right time in adolescence, but may cause short stature.
Bone shortening is more predictable than epiphysiodesis, but has a much longer recovery period.
Leg lengthening surgery allows patients to achieve their full height potential, but external fixators require continual maintenance. Internal fixators produce comparable results with fewer risks.
Some limb length discrepancies may require special treatment, but you and your surgeon can decide what treatment, if any, is best for you (or your child). Any treatment will be planned with the child’s final height and leg lengths in mind, not the current leg lengths. Learn more about treatment options >
What are the Long-term Concerns?
It is generally recommended that if your leg length discrepancy is greater than 1.5 to 2.0 cm (5/8 inch) then it should be treated. The concern is that walking with your pelvis out of alignment can start to cause low back pain, hip pain, or knee pain over time. Walking, or running, relies on constant shifting from one base of support to the other. Limb length discrepancy, or unequal limb lengths, can increase the amount of energy needed to walk and reduce muscular efficiency, making movement more difficult. Although, there are many people who have a small amount of LLD that do not have any pain or discomfort. When lower limbs are not the same length, it causes a limp. With a small difference in limb length (less than ¾ inch), a person can hide his/her limp by tilting the pelvis, causing a slight curve of the spine. If the difference between limbs is greater, the limp is worse, which can cause back pain and significant curve of the spine.Limping causes abnormal pressure on the joints and can lead to painful arthritis of the hip, knee, or ankle, if left untreated. Additionally, unequal limb lengths — of the upper or lower limbs — may cause social problems, especially in children. Some parents are concerned that a leg length discrepancy may cause or contribute to scoliosis. While someone with a leg length discrepancy can appear to have a curvature of the back, it does not cause permanent spine deformity (scoliosis). In the standing position, a leg length discrepancy may cause tilting of the pelvis. The spine will try to compensate for this tilt by curving back in the opposite direction. This curvature is usually flexible and goes away in the sitting position. It is possible to have both a leg length discrepancy and scoliosis at the same time but only as two independent diagnoses. The greater the limb length inequality, and the younger the patient, the more problems can result as the patient grows. Back, hip, and knee problems often occur if the condition is left untreated. The good news is that treatment of LLD often leads to a good outcome, and patients go on to lead healthy, happy lives. Read stories from patients >
LLD Treatment FAQs
How Do You Lengthen a Bone?
Bone is living tissue. It can regenerate itself. This is best illustrated by thinking about a broken bone. Many times, when a patient presents to the surgeon with a broken bone, a cast is placed on the injured arm or leg. Over the next few weeks, the bone repairs itself and heals. The cast is removed and the patient can resume his/her daily activities. This same healing response can be used to lengthen a bone. The surgeon can make a precise surgical break in the bone and then allow it to start to heal. Instead of having the bone heal in its original position, however, the bone is slowly pulled apart (approximately 1mm per day). As the two bone ends gradually separate, the body fills in the gap with new bone. The new bone slowly heals over a few months and creates the additional length in the previously shorter bone.
Does Limb Lengthening Hurt?
Stretching a bone seems like something that should be painful. However, the daily adjustments with the PRECICE internal lengthening device are so small that most patients don’t even feel them. Everyone has a different experience with limb lengthening. In general, the first inch is the easiest, and then it gets a little more difficult. Once the initial discomfort from surgery has passed, many patients don’t require any pain medication during the lengthening process.
How Much Discrepancy Can Leg Lengthening Surgery Correct?
The limitations of leg lengthening surgery mostly depends on the underlying reason for why the bone is to be lengthened in the first place. In general, the longer the lengthening, the more risks are involved, so it’s important to consult with your surgeon to determine how much lengthening is realistic for your specific circumstances.
Am I a Candidate for the PRECICE Internal Lengthening Device?
Contact your surgeon to learn more about the risks of leg lengthening and find out if PRECICE might be right for you. Find a surgeon >