Pierre Lascombes, HUG
Deformities of lower limbs in children and adolescent are frequent disorders. In young children, growth leads to frequent spontaneous corrections. Nevertheless, aetiology of abnormal disorders is mandatory: congenital, osteochondrodysplasia, rickets, post trauma, post sepsis… Indeed, the evolution depends widely of the aetiology of the deformity.
A perfect analysis of the deformity gives information on the location of the problem: femur, tibia or both; diaphysis, metaphysis or into the physis. Frontal and lateral angles are compared with normal values described by Dror Paley. As well, the horizontal plane (femoral anteversion and tibial torsion) is also evaluated and compared to normal.
Before the end of growth, mild deformities are treated by a growth modulation technique either by plates (Steven) or by screws (Métaizeau). A knowledge of the bone age and of the residual growth is required before surgery. Implants are removed when the correction is obtained.
In case of a too severe deformity for a growth modulation, and in adolescents around the end of growth, a wedge osteotomy should be considered as far as possible: addition or subtraction osteotomy and fixation with an adapted plate. This technique is the most comfortable method for the patients: early weight-bearing and joint motion allow a prompt recovery.
In severe and complex deformities, a progressive correction with an external fixation leads to few neurological complications and to a perfect 3D correction. In some cases, a bone lengthening can be easily obtained with the Ex Fix. The addition of some flexible intramedullary nails is also an option allowing an earlier Ex Fix removal than without flexible nails.
Finally, a long bone lengthening procedure can be combined with the correction of a mild deformity using some lengthening devices as Precice® or Fitbone® nails.
But the most important remains the planification of each surgical procedure, the location of the CORA (or multiple CORAs), the type of surgery and the quality of the post-operative cares leading to avoid, as far as possible, complications which are still frequent.