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Leg Length Discrepancy

Leg length discrepancies are common in childhood. The causes of leg length discrepancy are extensive.

CLINICAL MANIFESTATIONS AND DIAGNOSIS. Signs and symptoms associated with leg length discrepancy usually are related to the underlying cause. Approximately 65% of the growth of the entire lower extremity comes from the distal femoral (37%) and proximal tibial (28%) physes. Thus, growth disturbances about the knee can have the most adverse effect on leg length. Determination of the skeletal, or bone, age. One leg is shorter than the other.

Children with neuromuscular disorders such as spastic hemiplegia benefit from 1 2 cm of shortening on the involved side to improve the swing phase of gait and increased toe clearance. Only extremities that are neurologically normal should be considered for complete equalization of leg lengths short leg.

Angular deformities and limitation of motion are important considerations in children with unequal leg lengths. This is especially true when lengthening procedures are being considered. A child with a dysplastic acetabulum may subsequently experience a hip dislocation if femoral lengthening.

RADIOGRAPHIC EVALUATION. Radiographic evaluations are the most accurate methods of assessing leg lengths. Four different types of radiographic techniques are available. The teleoroentgenogram is a single exposure of both lower extremities.

TREATMENT. The psychological status of the child as well as the parents is an important consideration in treatment selection. Some equalization techniques are simple and safe, whereas others, especially lengthening procedures, are complex with high complication rates.

Orthotics and Prosthetics. Orthotic devices are generally indicated for discrepancies between 2 3 cm in skeletally mature individuals. A heel lift is frequently all that is necessary to provide the patient with a normal gait. Because of normal pelvic rotation during the gait cycle.

Extremity-Shortening Procedures. Three procedures are used to shorten the longer extremity. Epiphysiodesis is indicated in children who have 5 cm or less predicted discrepancy at maturity, have adequate remaining growth for satisfactory correction, and have a predicted relatively normal, corrected adult height. It requires accurate timing to achieve equalization of the leg lengths at maturity. The disadvantages of epiphysiodesis include shortened stature.

Extremity-Lengthening Procedures. The advantages of lengthening are equalization of significant leg length discrepancies.