Small or mild length leg discrepancies (LLD), i.e., below 3.0 cm, have been considered as enough to cause orthopaedic changes such as lumbar pain, stress fractures and osteoarthritis on lower limbs (LLLL) joints. In addition to the classification by its magnitude, discrepancies can also be categorized according to etiology, being structural when a difference is noted between bone structures' length or functional as a result of mechanical changes on the lower limb, and are found in 65% - 70% of the healthy population.
The causes of LLD may be divided into those that shorten a limb versus those that lengthen a limb, or they may be classified as affecting the length versus the rate of growth in a limb. For example, a fracture that heals poorly may shorten a leg slightly, but does not affect its growth rate. Radiation, on the other hand, can affect a leg's long-term ability to expand, but does not acutely affect its length. Causes that shorten the leg are more common than those that lengthen it and include congenital growth deficiencies (seen in hemiatrophy and skeletal dysplasias ), infections that infiltrate the epiphysis (e.g. osteomyelitis ), tumors, fractures that occur through the growth plate or have overriding ends, Legg-Calve-Perthes disease, slipped capital femoral epiphysis (SCFE), and radiation. Lengthening can result from unique conditions, such as hemihypertrophy , in which one or more structures on one side of the body become larger than the other side, vascular malformations or tumors (such as hemangioma ), which cause blood flow on one side to exceed that of the other, Wilm's tumor (of the kidney), septic arthritis, healed fractures, or orthopaedic surgery. Leg length discrepancy may arise from a problem in almost any portion of the femur or tibia. For example, fractures can occur at virtually all levels of the two bones. Fractures or other problems of the fibula do not lead to LLD, as long as the more central, weight-bearing tibia is unaffected. Because many cases of LLD are due to decreased rate of growth, the femoral or tibial epiphyses are commonly affected regions.
Back pain along with pain in the foot, knee, leg and hip on one side of the body are the main complaints. There may also be limping or head bop down on the short side or uneven arm swinging. The knee bend, hip or shoulder may be down on one side, and there may be uneven wear to the soles of shoes (usually more on the longer side).
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
In an adult, we find that we can add a non compressive silicone heel lift to a shoe in increments of 3-4 mm maximum per week. Were we to give a patient with a 20 mm short leg, 20 mm of lift all at once, their entire body would rebel. The various compensations that the body has made, such as curvatures and shortening of muscles on the convex side of the curve, would make such a dramatic change not just noticeable, but painful. When we get close to balancing a patient by lifting a leg with heel inserts, then we perform another gait analysis and follow up xray. At that point, we can typically write them a final prescription to have their shoe modified. A heel lift is typically fine up to 7 mm. When it gets higher than that, the entire shoe must be modified. There are two reasons for this. The back of the shoe is generally too short to accommodate more than 7-8 mm inserted inside the shoes and a heel lift greater than 7 mm will lead to Achilles tendon shortening, which then creates it?s own panoply of problems.
leg length discrepancy hip pain
Surgery to shorten the longer leg. This is less involved than lengthening the shorter leg. Shortening may be done in one of two ways. Closing the growth plate of the long leg 2-3 years before growth ends (around age 11-13), letting the short leg catch up. This procedure is called an epiphysiodesis. Taking some bone from the longer leg once growth is complete to even out leg lengths. Surgery to lengthen the shorter leg. This surgery is more involved than surgery to shorten a leg. During this surgery, cuts are made in the leg bone. An external metal frame and bar are attached to the leg bone. This frame and bar slowly pull on the leg bone, lengthening it. The frame and bar must be worn constantly for months to years. When the frame and bar are removed, a leg cast is required for several months. This surgery requires careful and continued follow-up with the surgeon to be sure that healing is going well.