Approximately 75% of us present with one leg longer than the other. It?s staggering, literally, that so many people walk about with an imbalance. Yet to have one leg longer than the other doesn?t seem to create pain for everyone but for those that it does it brings pain in a myriad of dysfunction from TMJ, headaches, low back pain, IBS, bladder problems, sexual dysfunction, sacroiliac joint pain, pubis dysfunction, groin strain, gluteal dysfunction as well as the formation of trigger points.
A number of causes may lead to leg length discrepancy in children. Differences in leg length frequently follow fractures in the lower extremities in children due to over or under stimulation of the growth plates in the broken leg. Leg length discrepancy may also be caused by a congenital abnormality associated with a condition called hemihypertrophy. Or it may result from neuromuscular diseases such as polio and cerebral palsy. Many times, no cause can be identified. A small leg length discrepancy of a quarter of an inch or less is quite common in the general population and of no clinical significance. Larger leg length discrepancies become more significant. The long-term consequences of a short leg may include knee pain, back pain, and abnormal gait or limp.
In addition to the distinctive walk of a person with leg length discrepancy, over time, other deformities may be noted, which help compensate for the condition. Toe walking on the short side to decrease the swaying during gait. The foot will supinate (high arch) on the shorter side. The foot will pronate (flattening of the arch) on the longer side. Excessive pronation leads to hypermobility and instability, resulting in metatarsus primus varus and associated unilateral juvenile hallux valgus (bunion) deformity.
Asymmetry is a clue that a LLD is present. The center of gravity will shift to the short limb side and patients will try to compensate, displaying indications such as pelvic tilt, lumbar scoliosis, knee flexion, or unilateral foot pronation. Asking simple questions such as, "Do you favor one leg over the other?" or, "Do you find it uncomfortable to stand?" may also provide some valuable information. Performing a gait analysis will yield some clues as to how the patient compensates during ambulation. Using plantar pressure plates can indicate load pressure differences between the feet. It is helpful if the gait analysis can be video-recorded and played back in slow motion to catch the subtle aspects of movement.
Non Surgical Treatment
Non-surgical treatment can be effective. A shoe lift may be recommended if the leg length difference is less than 1 inch. More significant leg length discrepancies may require a surgical procedure. In children, surgical procedures are available to help make leg lengths more equal.
Surgery is another option. In some cases the longer extremity can be shortened, but a major shortening may weaken the muscles of the extremity. In growing children, lower extremities can also be equalized by a surgical procedure that stops the growth at one or two sites of the longer extremity, while leaving the remaining growth undisturbed. Your physician can tell you how much equalization can be attained by surgically halting one or more growth centers. The procedure is performed under X-ray control through very small incisions in the knee area. This procedure will not cause an immediate correction in length. Instead, the LLD will gradually decrease as the opposite extremity continues to grow and "catch up." Timing of the procedure is critical; the goal is to attain equal length of the extremities at skeletal maturity, usually in the mid- to late teens. Disadvantages of this option include the possibility of slight over-correction or under-correction of the LLD and the patient?s adult height will be less than if the shorter extremity had been lengthened. Correction of significant LLDs by this method may make a patient?s body look slightly disproportionate because of the shorter legs.