Treatment for SED often starts with the hips where pelvic osteotomy and femoral osteotomy are performed in order to get better hip coverage and to prevent deformation of the femoral head. The femoral head cartilage is soft and therefore gradually deforms. The pelvic osteotomy helps mold the femoral head to stay spherical. If this is performed early, there is a better chance to preserve the femoral head. The prognosis in these patients without treatment is arthritis of the hip joint at an early age and eventually hip replacement.
At the knees, varus osteotomies are required frequently of the tibiae and often of the femora. Hemi-epiphysiodesis may have a role, but because of slow growth, it takes a long time to see any correction. This is considered only in very young children when they are growing quickly and are ready to buy some time before osteotomy is performed. Ethical treatment may or may not be required in order to improve the ankle.
Overall, the strategy is to realign the lengths and preserve them. The strategy is not dissimilar from that for Pseudoachondroplasia, which is another dysplasia with soft cartilage. Lastly, multiple epiphyseal dysplasia has similar deformities with less shortening because the spine is not affected.
At the Paley Institute, we have treated many patients with these things very successfully and also combine them with lengthening. They can be achieved from 5 to 7.5 cm per bone. A critical consideration is articulation and spanning joints including hip, knee, and ankle in order to prevent pressure on these joints. This is the secret to success in carrying out lengthening for soft cartilage group of dysplasia, which includes Spondyloepiphyseal Dysplasia, Multiple Epiphyseal Dysplasia, Diastrophic Dwarfism, and Pseudoachondroplasia.
