Deformities and Limb Lengthening
Differences between the lengths of an arm or leg are called limb length discrepancies. Typically, unless there is an extreme difference, differences in arm lengths cause little to no problems or loss of function. A difference in leg length, however, can cause significant difficulty. There are normal variations in leg length in a given population, but greater differences may require surgical intervention to restore the quality of life.
There are many things that can cause a limb-length discrepancy, including:
- Previous injury to the bone: A shortened limb may occur because a bone healed in a shortened position. Also, in children, a fracture through the growth center near the end of the bone can affect the ability of the bone to grow at a normal rate.
- Bone diseases: There are multiple bone diseases such as neurofibromatosis that can result in a limb-length discrepancy.
- Congenital growth deficiencies: Many skeletal dysplasias and growth abnormalities in children can cause unequal limb length as an adult.
- Bone infections: Infections, especially if these occur in growing children, can cause inflammation in a joint affecting the growth center.
- Other causes: Arthritis and neurologic conditions can also cause a shortening of one limb, but sometimes, the cause of the limb-length discrepancy remains unknown.
Signs and Symptoms
Most arm-length differences go unnoticed, as they cause no functional problems for the patients. The effects of leg-length discrepancies can vary from patient to patient. Typically, slight discrepancies remain unnoticed, but more significant differences can cause difficulty walking, pain (including back pain), and dysfunction. Symptoms of a subtle limb-length discrepancy include overuse injuries (tendonitis, plantar fasciitis, medial tibial stress syndrome, metatarsalgia).
Tests and Diagnosis
Limb lengths are typically measured by a physician with a physical exam as well as with X-rays.
For leg length discrepancy, the physician will measure the level of the hips with the patient standing barefoot. Often, a set of wooden blocks of known thickness is placed under the shortened leg until the hips are level.
X-rays are also used to obtain a more precise measurement, and the entire limb must be visualized on the X-ray. In growing children, X-rays are often repeated at multiple intervals to assess whether any difference is changing.
How We Treat
For minor length discrepancies, surgical treatment may not be necessary. If the difference is less than one inch, the risks likely outweigh the benefits of surgical intervention.
For small leg-length differences, a shoe lift may be worn to improve walking and alleviate any pain that may be caused by the limb-length discrepancy.
In children, legs may be made nearly equal in length surgically if the difference is caught and treated early. This procedure is aimed at slowing the growth of the longer leg at one of the growth sites. The procedures is typically performed through small incisions and can allow the shorter limb to "catch up" to the longer limb.
In adults, surgical lengthening of the shorter leg is an option. The bone is lengthened by the surgeon placing an internal or external fixation device to the leg, which gradually lengthens the bone over time. The bone may lengthen by approximately one mm per day or one inch per month.
Once the desired length is obtained, the bone needs time to strengthen enough to support the patient's weight.
Osseointegration - Osseointegration of the limb is a surgical procedure used for the permanent placement of artificial limbs connected to the human skeleton. A metal implant is inserted into the amputated extremity bone. The connector passes through the skin and attaches to the prosthesis. This procedure is beneficial to patients because it can lead to an improved quality of life, less pain or irritation experienced with socket prosthesis such as sores, chafing, or sweating, longer walking distances and better sitting comfort, and better stability standing or walking.
The evaluation process begins with a clinical pre-screening to determine if you are a candidate for surgery. In-person screening and testing is scheduled based on pre-screening outcomes. After candidate selection, additional baseline testing is planned and you may be sent home with prehabilitation exercises to improve your strength or flexibility. Our surgeons have a variety of device or implant types that can be used for osseointegration. They perform single stage and two stage procedures. This will be discussed at more length during your visit with the surgical team. Implant type, bone quality, and various other factors will help your surgeon determine the best technique and implant for you.
Rehabilitation plays an essential role in osseointegration success. You will meet with our Physical Medicine and Rehab team at your initial consult and again preoperatively. Rehabilitation is individualized and you can expect three weeks of physical therapy with our team following osseointegration. Once home, we will work with your local physical therapist to ensure post-operative plans are executed.
Osseoperception: a more natural feeling; the ability to sense or feel the prosthesis