Leg Length Discrepancy
While many people have slight differences in the length of one leg compared to the other, a significant difference between the two legs can cause problems. Leg length discrepancies can disturb the way a person walks, how his or her spine lines up and strain hip joints.
Patients with significant lower limb length discrepancies may walk with a limp, have the appearance of a curved spine (non-structural scoliosis), and experience back pain or fatigue. In addition, clothes may not fit right.
Causes and Risk Factors
Children may have significant differences in limb length as a result of accidents or injuries, infection, birth defects or other causes.
A doctor will generally take a detailed medical history of both the patient and family, including asking about recent injuries or illnesses. He or she will carefully examine the patient, observing how he or she moves and stands. If necessary, an orthopedic surgeon will order X-ray, bone age determinations and computed tomography (CT) scans or magnetic resonance imaging (MRI).
Treatment is based on an estimate of how great the difference in leg length will be when the child grows up:
- Small differences (a half inch or less) do not need treatment
- Differences of a half to one inch may require a lift inside the shoe
- Differences of an inch-and-a-half to two inches may require epiphysiodesis (adjusting the growth of the longer side) or acute shortening of the other side
- Differences greater than 2.5 inches usually require a lengthening procedure. The short bone is cut and an external device is applied. Gradual lengthening is done over months to allow the muscles and nerves accommodate the new length.