Have you ever been told or noticed that one of your legs is a bit longer than the other? Do you have incidences of lower back pain? These two things could be related. Most individuals have a small difference in their leg lengths. For some, the discrepancy is small and negligible and will not be a contributor to lower back pain. This is usually the case for people if their leg length is less than 5 millimeters. However, a difference of leg lengths greater than 5 millimeters (1/4 inch) can contribute to lower back pain. If you have a leg length difference of greater than 9 mm, then you have a 6X greater likelihood of having an episode of lower back pain.
Some limb-length differences are caused by actual anatomic differences from one side to the other (referred to as structural causes). The femur is longer (or shorter) or the cartilage between the femur and tibia is thicker (or thinner) on one side. There could be actual deformities in one femur or hip joint contributing to leg length differences from side to side. Even a small structural difference can amount to significant changes in the anatomy of the limb. A past history of leg fracture, developmental hip dysplasia, slipped capital femoral epiphysis (SCFE), short neck of the femur, or coxa vara can also lead to placement of the femoral head in the hip socket that is offset. The end-result can be a limb-length difference and early degenerative arthritis of the hip.
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.
A systematic and well organized approach should be used in the diagnosis of LLD to ensure all relevant factors are considered and no clues are overlooked which could explain the difference. To determine the asymmetry a patient should be evaluated whilst standing and walking. During the process special care should be used to note the extent of pelvic shift from side to side and deviation along the plane of the front or leading leg as well as the traverse deviation of the back leg and abnormal curvature of the spine. Dynamic gait analysis should be conducted during waling where observation of movement on the sagittal, frontal and transverse planes should be noted. Also observe head, neck and shoulder movements for any tilting.
Non Surgical Treatment
The non-surgical intervention is mainly usedfor the functional and environmental types of leg length discrepancies. It is also applied to the mild category of limb length inequality. Non-surgical intervention consists of stretching the muscles of the lower extremity. This is individually different, whereby the M. Tensor Fascia latae, the adductors, the hamstring muscles, M. piriformis and M. Iliopsoas are stretched. In this non-surgical intervention belongs also the use of shoe lifts. These shoe lifts consists of either a shoe insert (up to 10-20mm of correction), or building up the sole of the shoe on the shorter leg (up to 30-60mm of correction). This lift therapy should be implemented gradually in small increments. Several studies have examined the treatment of low back pain patients with LLD with shoe lifts. Gofton obtained good results: the patients experienced major or complete pain relief that lasted upon follow-up ranging from 3 to 11 years. Helliwell also observed patients whereby 44% experienced complete pain relief, and 45% had moderate or substantial pain relief. Friberg found that 157 (of 211) patients with LBP, treated with shoe lifts, were symprom-free after a mean follow-up of 18 months.
Limb deformity or leg length problems can be treated by applying an external frame to the leg. The frame consists of metal rings which go round the limb. The rings are held onto the body by wires and metal pins which pass through the skin and are anchored into the bone. During this operation, the bone is divided. Gradual adjustment of the frame results in creation of a new bone allowing a limb to be lengthened. The procedure involves the child having an anaesthetic. The child is normally in hospital for one week. The child and family are encouraged to clean pin sites around the limb. The adjustments of the frame (distractions) are performed by the child and/or family. The child is normally encouraged to walk on the operated limb and to actively exercise the joints above and below the frame. The child is normally reviewed on a weekly basis in clinic to monitor the correction of the deformity. The frame normally remains in place for 3 months up to one year depending on the condition which is being treated. The frame is normally removed under a general anaesthetic at the end of treatment.