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.
An anatomical short leg is due to several orthopedic or medical condition mechanisms. Often, one leg simply stops growing before the other one does and is called ?congenital?. We often see mother-daughters or father-sons who exhibit virtually the same degree of shortness on the same side. Often it is not known why this occurs, but it seems to account for approximately 25% of the population demonstrating a true LLD. Other causes of a true LLD include trauma or broken bones, surgical repair, joint replacement, radiation exposure, tumors or Legg-Calves-Perthes disease.
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.
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
The key to treatment of LLD in a child is to predict what the discrepancy is at maturity. If it is predicted to be less than 2 cm., no treatment is needed. Limb length discrepancies of up to 2 or 2.5 cm. can be compensated very well with a lift in the shoe. Beyond 2.5 cm., it becomes increasingly difficult to compensate with a left in the insole. Building up the shoe becomes uncosmetic and cumbersome, and some other way of compensating for the discrepancy becomes necessary. The treatment of LLD is long-term treatment, and involves the physician and patient?s family working together as a team. The family needs to weigh the various options available. If leg lengthening is decided on, the family needs to understand the commitment necessary to see it through. The treatment takes 6 months to a year for completion, and complications can happen. But when it works, the results are gratifying.
Surgical options in leg length discrepancy treatment include procedures to lengthen the shorter leg, or shorten the longer leg. Your child’s physician will choose the safest and most effective method based on the aforementioned factors. No matter the surgical procedure performed, physical therapy will be required after surgery in order to stretch muscles and help support the flexibility of the surrounding joints. Surgical shortening is safer than surgical lengthening and has fewer complications. Surgical procedures to shorten one leg include removing part of a bone, called a bone resection. They can also include epiphysiodesis or epiphyseal stapling, where the growth plate in a bone is tethered or stapled. This slows the rate of growth in the surgical leg.