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True Leg Length Discrepancy Measurement

Overview

Leg length discrepancy is the difference in lengths of an individual?s legs. This difference may be anatomical or may be due to scoliosis, trauma/injury, arthritis, overpronation (collapse) of one foot, bowing of one leg or unequal bowing, surgery (hip or knee replacement), pelvic tilting or ageing. The difference can also be functional caused by differing forces of the soft tissues, such as weakness in muscle tissue on one side, or a weakness/tightness in joint tissue. A difference in leg lengths also results when running on indoor banked tracks, beaches and banked streets and side walks (for drainage). Many people have a measurable difference in their leg lengths which is compensated for by their bodies. As we age this compensation does not work as well. An x-ray and physical measurements will define the discrepancy and the adjustment needed.Leg Length Discrepancy

Causes

There are many causes of leg length discrepancy. Some include, A broken leg bone may lead to a leg length discrepancy if it heals in a shortened position. This is more likely if the bone was broken in many pieces. It also is more likely if skin and muscle tissue around the bone were severely injured and exposed, as in an open fracture. Broken bones in children sometimes grow faster for several years after healing, causing the injured bone to become longer. A break in a child's bone through the growth center near the end of the bone may cause slower growth, resulting in a shorter leg. Bone infections that occur in children while they are growing may cause a significant leg length discrepancy. This is especially true if the infection happens in infancy. Inflammation of joints during growth may cause unequal leg length. One example is juvenile arthritis. Bone diseases may cause leg length discrepancy, as well. Examples are, Neurofibromatosis, Multiple hereditary exostoses, Ollier disease. Other causes include inflammation (arthritis) and neurologic conditions. Sometimes the cause of leg length discrepancy is unknown, particularly in cases involving underdevelopment of the inner or outer side of the leg, or partial overgrowth of one side of the body. These conditions are usually present at birth, but the leg length difference may be too small to be detected. As the child grows, the leg length discrepancy increases and becomes more noticeable. In underdevelopment, one of the two bones between the knee and the ankle is abnormally short. There also may be related foot or knee problems. Hemihypertrophy (one side too big) or hemiatrophy (one side too small) are rare leg length discrepancy conditions. In these conditions, the arm and leg on one side of the body are either longer or shorter than the arm and leg on the other side of the body. There may also be a difference between the two sides of the face. Sometimes no cause can be found. This is known as an "idiopathic" difference.

Symptoms

Faulty feet and ankle structure profoundly affect leg length and pelvic positioning. The most common asymmetrical foot position is the pronated foot. Sensory receptors embedded on the bottom of the foot alert the brain to the slightest weight shift. Since the brain is always trying to maintain pelvic balance, when presented with a long left leg, it attempts to adapt to the altered weight shift by dropping the left medial arch (shortening the long leg) and supinating the right arch to lengthen the short leg.1 Left unchecked, excessive foot pronation will internally rotate the left lower extremity, causing excessive strain to the lateral meniscus and medial collateral knee ligaments. Conversely, excessive supination tends to externally rotate the leg and thigh, creating opposite knee, hip and pelvic distortions.

Diagnosis

A qualified musculoskeletal expert will first take a medical history and conduct a physical exam. Other tests may include X-rays, MRI, or CT scan to diagnose the root cause.

Non Surgical Treatment

Internal heel lifts: Putting a simple heel lift inside the shoe or onto a foot orthotic has the advantage of being transferable to many pairs of shoes. It is also aesthetically more pleasing as the lift remains hidden from view. However, there is a limit as to how high the lift can be before affecting shoe fit. Dress shoes will usually only accommodate small lifts (1/8"1/4") before the heel starts to piston out of the shoe. Sneakers and workboots may allow higher lifts, e.g., up to 1/2", before heel slippage problems arise. External heel lifts: If a lift of greater than 1/2" is required, you should consider adding to the outsole of the shoe. In this way, the shoe fit remains good. Although some patients may worry about the cosmetics of the shoe, it does ensure better overall function. Nowadays with the development of synthetic foams and crepes, such lifts do not have to be as heavy as the cork buildups of the past. External buildups are not transferable and they will wear down over time, so the patient will need to be vigilant in having them repaired. On ladies' high-heel shoes, it may be possible to lower one heel and thereby correct the imbalance.

Leg Length Discrepancy

Surgical Treatment

Surgical operations to equalize leg lengths include the following. Shortening the longer leg. This is usually done if growth is already complete, and the patient is tall enough that losing an inch is not a problem. Slowing or stopping the growth of the longer leg. Growth of the lower limbs take place mainly in the epiphyseal plates (growth plates) of the lower femur and upper tibia and fibula. Stapling the growth plates in a child for a few years theoretically will stop growth for the period, and when the staples were removed, growth was supposed to resume. This procedure was quite popular till it was found that the amount of growth retarded was not certain, and when the staples where removed, the bone failed to resume its growth. Hence epiphyseal stapling has now been abandoned for the more reliable Epiphyseodesis. By use of modern fluoroscopic equipment, the surgeon can visualize the growth plate, and by making small incisions and using multiple drillings, the growth plate of the lower femur and/or upper tibia and fibula can be ablated. Since growth is stopped permanently by this procedure, the timing of the operation is crucial. This is probably the most commonly done procedure for correcting leg length discrepancy. But there is one limitation. The maximum amount of discrepancy that can be corrected by Epiphyseodesis is 5 cm. Lengthening the short leg. Various procedures have been done over the years to effect this result. External fixation devices are usually needed to hold the bone that is being lengthened. In the past, the bone to be lengthened was cut, and using the external fixation device, the leg was stretched out gradually over weeks. A gap in the bone was thus created, and a second operation was needed to place a bone block in the gap for stability and induce healing as a graft. More recently, a new technique called callotasis is being use. The bone to be lengthened is not cut completely, only partially and called a corticotomy. The bone is then distracted over an external device (usually an Ilizarov or Orthofix apparatus) very slowly so that bone healing is proceeding as the lengthening is being done. This avoids the need for a second procedure to insert bone graft. The procedure involved in leg lengthening is complicated, and fraught with risks. Theoretically, there is no limit to how much lengthening one can obtain, although the more ambitious one is, the higher the complication rate.

Does Adult Aquired FlatFeet Necessitate Surgical Teatment ?

Overview Posterior tibial tendon insufficiency (also called posterior tibial tendon dysfunction or adult acquired flatfoot) has been named literally after failure of the posterior tibial tendon. However, the condition is caused not only by the progressive failure of the posterior tibial tendon; it is also failure of associated ligaments and joints on the inner side of the ankle and foot. This results in collapse of the arch of the foot, along with the deformity which most often becomes the debilitating problem in its later stages. While at the beginning the common symptom is pain over the tendon in the inner part of the hindfoot and midfoot, later on it is the deformity that can threaten a person?s ability to walk. Just as the tendon degenerates and loses its function, other soft tissue on the same inner side of the foot - namely the ligaments - degenerate and fail. Ligaments are responsible for holding bones in place, and when they fail, bones shift to places where they shouldn?t; deformity is the result. The deformity causes malalignment, leading to more stress and failure of the ligaments. Flat Feet Causes Causes of an adult acquired flatfoot may include Neuropathic foot (Charcot foot) secondary to Diabetes mellitus, Leprosy, Profound peripheral neuritis of any cause. Degenerative changes in the ankle, talonavicular or tarsometatarsal joints, or both, secondary to Inflammatory arthropathy, Osteoarthropathy, Fractures, Acquired flatfoot resulting from loss of the supporting structures of the medial longitudinal arch. Dysfunction of the tibialis posterior tendon Tear of the spring (calcaneoanvicular) ligament (rare). Tibialis anterior rupture (rare). Painful flatfoot can have other causes, such as tarsal coalition, but as such a patient will not present with a change in the shape of the foot these are not included here. Symptoms Posterior tibial tendon insufficiency is divided into stages by most foot and ankle specialists. In stage I, there is pain along the posterior tibial tendon without deformity or collapse of the arch. The patient has the somewhat flat or normal-appearing foot they have always had. In stage II, deformity from the condition has started to occur, resulting in some collapse of the arch, which may or may not be noticeable. The patient may feel it as a weakness in the arch. Many patients initially present in stage II, as the ligament failure can occur at the same time as the tendon failure and therefore deformity can already be occurring as the tendon is becoming symptomatic. In stage III, the deformity has progressed to the extent where the foot becomes fixed (rigid) in its deformed position. Finally, in stage IV, deformity occurs at the ankle in addition to the deformity in the foot. Diagnosis The diagnosis of posterior tibial tendon dysfunction and AAFD is usually made from a combination of symptoms, physical exam and x-ray imaging. The location of pain, shape of the foot, flexibility of the hindfoot joints and gait all may help your physician make the diagnosis and also assess how advanced the problem is. Non surgical Treatment This condition may be treated with conservative methods. These can include orthotic devices, special shoes, and bracing. Physical therapy, rest, ice, and anti-inflammatory medication may be prescribed to help relieve symptoms. If the condition is very severe, surgical treatment may be needed. Acquired Flat Feet Surgical Treatment For those patients with PTTD that have severe deformity or have not improved with conservative treatments, surgery may be necessary to return them to daily activity. Surgery for PTTD may include repair of the diseased tendon and possible tendon transfer to a nearby healthy tendon, surgery on the surrounding bones or joints to prevent biomechanical abnormalities that may be a contributing factor or both.