People with leg length discrepancy, when one leg is longer than the other, usually have a waddling-type gait where the hips seem to move up and down during walking as the body tries to compensate for the inequality. There are two types of leg length discrepancy. The first type of leg length discrepancy involves a structural defect, where one bone is longer or shorter than the corresponding bone of the other limb. This can occur within the femur (upper leg bone) or the tibia and fibular (lower leg bones). Functional leg length discrepancy results from altered mechanics due to a malalignment in the spine or lower extremity.
Some causes of leg length discrepancy (other than anatomical). Dysfunction of the hip joint itself leading to compensatory alterations by the joint and muscles that impact on the joint. Muscle mass itself, i.e., the vastus lateralis muscle, pushes the iliotibial band laterally, causing femoral compensations to maintain a line of progression during the gait cycle. This is often misdiagnosed as I-T band syndrome and subsequently treated incorrectly. The internal rotators of the lower limb are being chronically short or in a state of contracture. According to Cunningham's Manual of Practical Anatomy these are muscles whose insertion is lateral to the long axis of the femur. The external rotators of the hip joint are evidenced in the hip rotation test. The iliosacral joint displays joint fixations on the superior or inferior transverse, or the sagittal axes. This may result from many causes including joint, muscle, osseous or compensatory considerations. Short hamstring muscles, i.e., the long head of the biceps femoris muscle. In the closed kinetic chain an inability of the fibula to drop inferior will result in sacrotuberous ligament loading failure. The sacroiliac joint dysfunctions along its right or left oblique axis. Failure or incorrect loading of the Back Force Transmission System (the longitudinal-muscle-tendon-fascia sling and the oblique dorsal muscle-fascia-tendon sling). See the proceedings of the first and second Interdisciplinary World Congress on Low Back Pain. Sacral dysfunction (nutation or counternutation) on the respiratory axis. When we consider the above mentioned, and other causes, it should be obvious that unless we look at all of the causes of leg length discrepancy/asymmetry then we will most assuredly reach a diagnosis based on historical dogma or ritual rather than applying the rules of current differential diagnosis.
LLD do not have any pain or discomfort directly associated with the difference of one leg over the other leg. However, LLD will place stress on joints throughout the skeletal structure of the body and create discomfort as a byproduct of the LLD. Just as it is normal for your feet to vary slightly in size, a mild difference in leg length is normal, too. A more pronounced LLD, however, can create abnormalities when walking or running and adversely affect healthy balance and posture. Symptoms include a slight limp. Walking can even become stressful, requiring more effort and energy. Sometimes knee pain, hip pain and lower back pain develop. Foot mechanics are also affected causing a variety of complications in the foot, not the least, over pronating, metatarsalgia, bunions, hammer toes, instep pain, posterior tibial tendonitis, and many more.
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
The most common solution to rectify the difference in your leg lengths is to compensate for the short fall in your shortest leg, thereby making both of your legs structurally the same length. Surgery is a drastic option and extremely rare, mainly because the results are not guaranteed aswell as the risks associated with surgery, not to mention the inconvenience of waiting until your broken bones are healed. Instead, orthopediatrician's will almost always advise on the use of "heel lifts for leg length discrepancy". These are a quick, simple and costs effective solution. They sit under your heel, inside your shoe and elevate your shorter leg by the same amount as the discrepancy. Most heel lifts are adjustable and come in a range of sizes. Such lifts can instantly correct a leg length discrepancy and prevent the cause of associate risks.
what is a shoe lift?
Surgical lengthening of the shorter extremity (upper or lower) is another treatment option. The bone is lengthened by surgically applying an external fixator to the extremity in the operating room. The external fixator, a scaffold-like frame, is connected to the bone with wires, pins or both. A small crack is made in the bone and tension is created by the frame when it is "distracted" by the patient or family member who turns an affixed dial several times daily. The lengthening process begins approximately five to ten days after surgery. The bone may lengthen one millimeter per day, or approximately one inch per month. Lengthening may be slower in adults overall and in a bone that has been previously injured or undergone prior surgery. Bones in patients with potential blood vessel abnormalities (i.e., cigarette smokers) may also lengthen more slowly. The external fixator is worn until the bone is strong enough to support the patient safely, approximately three months per inch of lengthening. This may vary, however, due to factors such as age, health, smoking, participation in rehabilitation, etc. Risks of this procedure include infection at the site of wires and pins, stiffness of the adjacent joints and slight over or under correction of the bone?s length. Lengthening requires regular follow up visits to the physician?s office, meticulous hygiene of the pins and wires, diligent adjustment of the frame several times daily and rehabilitation as prescribed by your physician.