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.
Sometimes the cause of LLD is unknown, yet the pattern or combination of conditions is consistent with a certain abnormality. Examples include underdevelopment of the inner or outer side of the leg (hemimelias) or (partial) inhibition of growth of one side of the body of unknown cause (hemihypertrophy). These conditions are present at birth, but the limb length difference may be too small to be detected. As the child grows, the LLD increases and becomes more noticeable. In hemimelia, one of the two bones between the knee and the ankle (tibia or fibula) is abnormally short. There also may be associated foot or knee abnormalities. Hemihypertrophy or hemiatrophy are rare conditions in which there is a difference in length of both the arm and leg on only one side of the body. There may also be a difference between the two sides of the face. Sometimes no cause can be found. This type of limb length is called idiopathic. While there is a cause, it cannot be determined using currect diagnostic methods.
Often there are few or no symptoms prior to the age of 25-35. The most common symptom is chronic lower back pain, but also is frequently middle and upper back pain. Same-sided and repeated injury or pain to the hip, knee and/or ankle is also a hallmark of a long-standing untreated LLD. It is not uncommon to have buttock or radiating hip pain that is non-dermatomal (not from a disc) and tends to go away when lying down.
Limb length discrepancy can be measured by a physician during a physical examination and through X-rays. Usually, the physician measures the level of the hips when the child is standing barefoot. A series of measured wooden blocks may be placed under the short leg until the hips are level. If the physician believes a more precise measurement is needed, he or she may use X-rays. In growing children, a physician may repeat the physical examination and X-rays every six months to a year to see if the limb length discrepancy has increased or remained unchanged. A limb length discrepancy may be detected on a screening examination for curvature of the spine (scoliosis). But limb length discrepancy does not cause scoliosis.
Non Surgical Treatment
For minor limb length discrepancy in patients with no deformity, treatment may not be necessary. Because the risks may outweigh the benefits, surgical treatment to equalize leg lengths is usually not recommended if the difference is less than 1 inch. For these small differences, the physician may recommend a shoe lift. A lift fitted to the shoe can often improve walking and running, as well as relieve any back pain that may be caused by the limb length discrepancy. Shoe lifts are inexpensive and can be removed if they are not effective.
shoe lifts for height
Leg shortening is employed when LLD is severe and when a patient has already reached skeletal maturity. The actual surgery is called an osteotomy , which entails the removal of a small section of bone in the tibia (shinbone) and sometimes the fibula as well, resulting in the loss of around an inch in total height. Leg lengthening is a difficult third option that has traditionally had a high complication rate. Recently, results have improved somewhat with the emergence of a technique known as callotasis , in which only the outer portion of the bone (the cortex ) is cut, (i.e. a corticotomy ). This allows the bone to be more easily lengthened by an external fixation device that is attached to either side of the cut bone with pins through the skin. The ?ex-fix,' as it is sometimes called, is gradually adjusted by an orthopaedic surgeon, and healing can occur at the same time that the leg is being distracted , or lengthened over time. Unlike epiphysiodesis, leg lengthening procedures can be performed at almost any skeletal or chronological age.