You know the saying, “No one is perfect.” And that goes for the length of our legs. Limb length discrepancy is a common condition. It’s estimated that 23% of us have minor differences between the lengths of our legs, averaging about one centimeter -- which is nearly one-half inch.
Limb length discrepancies can occur in both children and adults. Some people are born this way. Others can develop a difference between the length of their legs over time due to injuries or illnesses. Some adults develop the condition after undergoing a hip or knee replacement surgery.
If you’re concerned you, your child, or another loved one has a limb length discrepancy, call Central Massachusetts Podiatry and schedule an appointment to see one of our podiatrists for a comprehensive exam.
What are the symptoms of limb length discrepancy?
The symptoms depend on the length of the discrepancy between the two legs and what caused it.
Typical symptoms include:
- A limp, a change in gait, or difficulty walking -- tends to occur when the discrepancy is approximately one inch or more between the legs
- Pain in the lower back, knee, or the shorter leg
- Differences in feet requiring two different shoe sizes
- Head or one shoulder tilting to one side
- Ankle pain or deformities in only one foot
- In severe cases, stress fractures in the bones of the shorter leg
How is a limb length discrepancy diagnosed?
A history and physical: You’ll have a physical examination by one of our doctors. He’ll also talk with you at length regarding your medical history, and ask you what symptoms you’re experiencing.
An assessment of your gait: Our doctor will conduct a gait analysis to determine how well you’re walking. He’ll observe whether or not your body is compensating for the limb length discrepancy by adjusting knee or foot positions when you walk.
Diagnostic imaging: These can vary, but generally the process starts with X-rays. Other imaging may be done, such as a scanogram, CT scan, or possibly an MRI, to help determine the cause of the limb length discrepancy and the amount of the discrepancy. A scanogram is an X-ray technique that involves taking pictures of the ankle, knee, and hip, and using a ruler to measure and compare them to determine leg length.
After a diagnosis is made, your doctor will recommend a way to treat your limb problem. The treatments for limb length discrepancy range from nonsurgical to surgical.
What are the nonsurgical treatment options?
For patients with a discrepancy of one inch or less without any deformities, the treatment is typically nonsurgical. Nonsurgical treatments include:
- A wait-and-see approach: Observation may be recommended for some patients. This is also an approach used for children who are still growing, as some discrepancies may not change over time, while others can worsen.
- Using Shoe Lifts: A shoe lift can be placed inside the shoe of the shorter leg, to help equalize the length between the two legs. A lift can reduce any discomfort the discrepancy is causing. It can also make walking and running less challenging due to equalizing the legs’ length.
What are the surgical treatments?
There are two different surgical approaches used to correct limb length discrepancies: limb lengthening and limb shortening.
Surgical limb lengthening can be achieved via an external or internal approach. Your doctor will determine which makes more sense for your individual situation.
External limb lengthening: This involves cutting the bone of the shorter leg in two locations, then surgically attaching an external frame-like apparatus that sits on the outside of the leg, known as a fixator, to the two areas of the leg. The fixator is connected to the leg bone with pins and wires. Several days after surgery, the fixator is manually turned from the outside the body, and adjusted daily as per the surgeon’s instructions. Over time, this device gradually lengthens the bone it’s attached to internally.
Internal limb lengthening: This involves the cutting of the bone of the affected leg, then placing a metal rod inside the bone. The lengthening process also occurs slowly over time. However, with this approach the bone lengthening occurs in response to leg movements, and not with manual daily adjustments.
Limb shortening: There are two approaches to slow the growth of the longer leg or shorten its length.
- Epiphysiodesis: This procedure is performed on the growth plate of the longer leg to slow down or stop the leg’s growth.
- Limb-shortening surgery: The surgeon removes a portion of bone from the longer leg. This results in a shorter bone that matches the length of the other leg.
There are pros and cons to any surgery, and all surgeries carry some risk, such as the development of infections or blood clots. If surgery is warranted, our podiatrists will determine the best evidence-based surgical approach, specific to your case, to achieve the optimum outcome for you.