How Does Limb Lengthening Work?
Short answer
Limb lengthening uses distraction osteogenesis. The surgeon makes a controlled cut in the bone and fixes it with a nail (and, with LON, a frame). After a short rest, the bone ends are moved apart about 1 mm a day. The body fills the gap with new bone, which then hardens. Muscles, nerves and skin stretch along with it, guided by physiotherapy 6 days a week.
The five steps
• 1. Surgery (osteotomy): the bone is cut and the nail (or nail plus frame) is fitted. One operation.
• 2. Latency: the body starts the healing response. 5 to 10 days.
• 3. Distraction: about 1 mm a day of lengthening. About 60 days for 6 cm, about 80 days for 8 cm.
• 4. Regeneration: new bone fills the gap as it widens, during distraction.
• 5. Consolidation: the new bone hardens and gets strong. Several months.
Why 1 mm a day?
Faster lengthening can outpace the soft tissues and nerves. Slower lengthening can let the bone harden too early. About 1 mm a day, split into several small steps, is the established balance. The surgeon adjusts it after each X-ray.
Which bones and how much?
• Femur: up to 8 cm
• Tibia: up to 6 cm
• Quadrilateral (both): 12 to 14 cm in total
Methods
The principle is the same with LON, PRECICE and FITBONE. Only the device that moves the bone apart changes. See Internal vs External Limb Lengthening
Related pages
• Is limb lengthening painful?
• Limb lengthening complications