Limb length discrepancy
LIMB length discrepancy (LLD) is when there is a difference between the lengths of the arms or legs.
In most cases the difference in arm length does not impact function or require treatment; however in leg length, a relatively small discrepancy can have a big impact.
Different leg lengths are not unusual. One in 30 per cent of the general population has between 1/5th and 3/5th of an inch difference. So this is quite normal and often non-symptomatic. Greater differences may affect an individual.
The main bones in the leg that affect the length of the limb are the thigh bone (femur) and the shin bone (tibia).
Causes of LLD
1. Trauma to a bone such as a break can lead to healing in a shortened position. This is more common if the bone was badly shattered and skin and muscle tissue were involved.
2. Bone infection, especially if it occurs in infancy, can cause LLD.
3. Bone diseases like neurofibromatosis can affect the length of bones.
4. Sometimes we cannot find any cause at all and therefore it is idiopathic.
Symptoms
The symptoms will depend on the cause and the size of the LLD. Patients who have a difference of about four centimetres or more in adulthood may have a limp. They are more likely to experience back pain and tire easily due to the extra effort it takes to walk. Patients may also suffer with osteoarthritis in the knee and hip. They may also have patellar tendonitis, plantar faciitis, metatarsalgia, and a plethora of other associated conditions.
Treatment
Once fully diagnosed, treatment will also depend on the size of the LLD, the age of the patient, and the cause. In young children where the LLD is less than two centimetres, we may just monitor until growth is complete as the condition may correct itself.
Wearing a shoe lift inside or outside a shoe can often improve the patient’s ability to run or walk. This is an inexpensive way of correcting the problem.
Surgical intervention is designed to slow down or stop the growth of the longer limb, shorten the longer limb, or lengthen the shorter limb. The surgery can be very painful with no guarantee so any decision would take careful consultation with an orthopaedic surgeon.
Angela Davis BSc (Hons) DPodM MChS is a podiatrist with offices in Montego Bay (293- 7119), Mandeville (962-2100), Ocho Rios (974-6339), Kingston (978-8392), and Savanna-la-Mar (955-3154). She is a member of the Health and Care Professions Council in the United Kingdom.
