July 2018

Answer:

Thank you very much for your question. Leg length differences are a common concern that pediatric orthopaedic surgeons address. If the difference is within certain limits once a person is fully grown (< 2 to 2.5 cm), then long term there are few consequences. When the difference becomes greater than that, then people might be able to tell that their gait is “off”. Other people may notice it, creating cosmetic concerns, but functionally, a person might be able to feel that one leg is longer than the other, especially with high level activities such as running. Long term consequences of significant leg length differences (> 2.5 cm) can lead to the potential for low back pain and pain in the higher hip as the muscles in these areas must work harder to stabilize the core, pelvis, and legs with activities. Options for leg length equalization depend on the ultimate difference when a person is full grown. For a difference that your daughter is predicted to have, options include doing nothing and using a shoe lift for comfort, epiphysiodesis timed properly, acute shortening once full grown, and a lengthening intramedullary nail. Doing nothing is safe, and gives a person time to see if they ever develop symptoms, though long term once an adult (10 to 20 years onward) is harder to predict. Epiphysiodesis is tried and true with predicatble results. The goal is to turn the long leg growth plates “off” while there is still growth remaining so the shorter leg can “catch up” to be less than 2 cm at full growth. There are various ways to perform this procedure that are effective and how it is performed is really surgeon dependent. If you are not sure if you want to perform the epiphysiodesis, you can simply wait and see what the difference will be and then if symptoms develop, perform a femoral shortening osteotomy (bone cut) that is usually stabilized with a rod inside the femur. Patients can walk right afterward but shortening the femur can create some bulging and weakness in the thigh muscle requiring some aggressive therapy to resolve. Finally, the newest possibility is lengthening the short leg with an internal growing rod. For smaller differences such as your daughter’s, this option has become more accepted (though more time intensive for the patient) and is a novel approach especially for patients who do not want to lose any of their ultimate height. In regards to the likelihood of future problems, this is difficult to predict and answer. The potential for future issues has a lot to do with a person’s ultimate final height, their body size, their activity level, their ultimate profession in life, etc. With a smaller leg length difference, the possibility is less than if the difference was larger (4 to 5 cm range). From a personal standpoint, with your daughter’s predicted leg length difference and with sufficient growth for correction, an epiphysiodesis is safe, effective, easy to recover from and less invasive than the other surgical options, and thus, I would highly recommend pursuing that option. Thank you again for your question, and I hope I was able to answer it sufficiently!

- Cas - South Dakota (Parent)