Our lengthening for stature program for dwarfism is designed to not only increase height but also correct deformities of the ankle, knee, hip, and elbow and to decrease lumbar hyperlordosis (sway back). The latter reduces the risk of spinal stenosis in adulthood. There are two strategies of treatment depending on the age of the patient at the time of presentation.
Juvenile(young children) strategy
- between the ages of 6 and 10 years
- lengthen both femora (upper leg) and both tibiae (lower leg) a total of 10 cm (6 cm in the femur and 4 cm in the tibia)
- correct bowleg or knock-knee deformity
- average external fixation treatment time = 5 months.
Second, third, and fourth lengthenings
- as for adolescent strategy (below)
Total increase in lower limb length = 30 to 35 cm
Total increase in upper limb length = 10 to 12 cm
- between the ages of 14 and 16 years
- lengthen both femora a total of 10 to 12 cm
- correct flexion deformity of both hips (this corrects the lumbar hyperlordosis)
- correct varus deformity of both hips
- average external fixation treatment time = 10 to 12 months
- between the ages of 12 and 14 years
- lengthen both tibiae a total of 10 to 15 cm (double level lengthening)
- correct the varus deformity of the proximal tibia through proximal osteotomy
- correct the varus deformity of the distal tibia through distal osteotomy
- tighten the lateral collateral ligament at the end of the lengthening
- average external fixation treatment time = 8 to 10 months
- between the ages of 13 and 15 years
- lengthen both humeri (upper arm) a total of 8 to 12 cm
- correct flexion deformity of elbows
- average external fixation treatment time = 6 to 8 months
By lengthening the arms between the two lower limb lengthenings, the legs get a well-needed break from lengthening. The minimal time between lengthenings is 6 months after the device is removed.
For bilateral femoral lengthening, the patient is not able to walk during the lengthening phase. Standing is allowed for transfer only. Ambulation is by wheelchair only during the lengthening phase. During the consolidation phase, more and more weight bearing is permitted, and near the time of removal, free walking is allowed.
For bilateral tibial lengthening, the patient is allowed to bear weight from the start using a walker, crutches, or canes. Longer trips are to be made by wheelchair.
During bilateral humeral lengthening, there are almost no restrictions on activities.
Every 2 weeks during the lengthening process, quantitative sensory nerve testing is performed at the time of the follow-up examination with the doctor. This allows us to detect impending nerve problems even before they are noticed clinically. Nerve problems usually present as referred pain to the foot during tibial lengthening. They are very uncommon with femoral or with humeral lengthening. If left untreated, they could produce dropfoot (paralysis of the nerve controlling the muscles that pull the foot up). If detected early and if the rate of lengthening is slowed, the nerve problem usually subsides and the lengthening is continued at a slower rate. If the nerve problem persists despite slowing, the nerve needs to be surgically decompressed. This procedure is a minor one requiring a 1-in incision and an overnight hospital stay. It is similar to the better known surgery that is performed in the hand for carpal tunnel syndrome.