Leg Length DiscrepancyThe comprehensive treatment of unequal leg lengths
Assessment of Leg Length Discrepancy (LLD)
The first part of assessing a LLD involves understanding the potential cause of the LLD by taking a thorough history of how the discrepancy came about. This conversation tries to identify any condition such as trauma or infection involving the growth plates of the femur or tibia. Your perception of how the LDD affects your life is extremely important.
A detailed clinical examination is then performed to work out which leg is short (or long) and then which bone is responsible for the discrepancy. You may be asked to stand with one leg on blocks to level the hips in order for this assessment to be made.
Following the clinical exam, X-rays may be requested to try and confirm the findings found on examination. These X-rays need to taken with extreme care to ensure that the results are accurate. It is easy for X-rays to be misinterpreted if they are not taken correctly.
It may be necessary to get a Bone Age assessment in children
It is possible that even with a significant LLD, you are not advised to have this fixed immediately. Adults may find that correcting a LLD is disconcerting, having grown up becoming used to the LLD. In children, monitoring of leg lengths gives valuable information as to how the LLD may progress. We have until adulthood (termed skeletal maturity) to complete the process of equalizing a LLD.
How is a Leg Length Discrepancy fixed?
Options in managing a symptomatic LLD include:
1) Non operative options such as a shoe raise
2) Shortening the longer leg
In a child, this can be done by stopping the longer leg from growing before they finish growing. This is an easy procedure with minimal risk. It is called an Epiphyseodesis.
In an adult, a small section of bone can be removed to allow the leg lengths to be equalised
3) Lengthening the shorter leg
This is much more complicated and has more risks involved. It is possible to grow a bone up to 5 cm in one setting, and potentially even longer if you are prepared to undergo multiple surgeries. Depending on the bone requiring the lengthening and also the presence of other co-existing deformities it is possible to use internal devices such as lenthening nails. If you have a more complicated deformity in the bone, then an external fixation frame may be the more appropriate device for your correction.
It is not uncommon for us to have one leg a bit longer than the other. Most people do not notice any problem if the difference is less than 2cm. It is possible to manage a leg length difference of up to 2cm without surgery however if your difference or discrepancy is greater than this, there is a process of assessment and management that should be undertaken.