In harmonious dwarfism, the ratio of the limb to trunk height is proportionate, as in Turner syndrome; the person is small but has a good body proportion.
In dysharmonious dwarfism, the limbs are proportionally shorter than the trunk. Seated, the person will seem of normal stature, but when standing, the person appears quite short. These conditions are attributed to alterations in chromosomes; for example, achondroplasia, hypochondroplasia, dyschondroplasia.
After evaluation, treatment consists first of correcting the joints (if they present with problems), then lengthening the limb bones (thigh, leg, arm) according to an individual's needs.
Hips may present with anomalies such as decreased coverage of the femoral head by the pelvic acetabulum. Too small a socket may cause the ball at the head of the femur to pop out if, during lengthening, the femur puts pressure on the joints through taut soft tissue. In this case, an operation to increase the size of the socket (eg, acetabuloplasty or pelvic osteotomy) may be required prior to the lengthening surgery.
Pictures: Typical deformity of hips with hyper-antetorsion (40°) varus (40°) and flexum (40°). A 3D-correction can be performed before lengthening.
Lengthening can be performed preferably with an intramedullary nail, or with an external fixator.
Lengthening surgery is performed preferably with an internal lengthening nail such as the Guichet® nail or with an external fixator.
Pictures: Patient who gained an additional 16-cm to both femora with the Albizzia® nail after a 10-cm gain on both tibiae with an external fixator.
Picture: Achondroplastic patient who gained a further 13-cm on both femora with the Albizzia® nail after a 12-cm bilateral tibial gain.
Pictures: Achondroplastic patient for whom 6 external fixators were used for lengthening (2 femora, 2 tibiae, 2 humeri). He agreed to a further 10-cm bilateral femoral lengthening with the Albizzia® nail and is willing to continue with further bilateral humeral lengthening with the Albizzia® nail.