Robert Rozbruch, MD, Chief of the Limb Lengthening and Complex Reconstruction Service (LLCRS) at the Hospital for Special Surgery (HSS) and Professor of Clinical Orthopaedic Surgery at Weill Cornell Medicine, once the lengthened bone is healed, this new bone is as strong as any other bone in the body and does not weaken or deteriorate over time With this method, the bone is straightened at the time of surgery when the ILN is inserted, and the lengthening is then done gradually over the next several weeks.Īccording to S. With a remote control device, the magnet in the nail is rotated and this gradually elongates the telescopic nail and the bone. The internal lengthening nail (ILN) is a telescopic, motorized intramedullary nail or rod that is inserted into the marrow cavity of the bone. Adjustments to the external fixator can be used to gradually lengthen and straighten the short and malaligned limb. The gradual process of lengthening can be accomplished with either an external fixator or an internal lengthening nail.Įxternal fixation is a frame built on the outside of the limb connected to the bone via pins (rods), screws and wires. The patient gradually puts more weight on the affected limb, and starts walking without any assistance. Note the early new bone formation in the gap.ĭuring the second phase of treatment the bone consolidates and heals. Gradual lengthening (8 cm) was accomplished with an internal lengthening nail to optimize leg lengths. The above X-ray images are of an osteotomy of the femur that was performed through a percutaneous approach.
Early on in this phase, patients walk with the aid of crutches in order to remain mobile. Additional strategies are available to correct any deformity that may be present, such as a misalignment of the bone resulting from trauma or a birth defect.
As the space between the ends of the bone opens up, the body continues to produce new tissue in the gap until the desired length of bone has been generated. Continued growth of new bone tissue is accomplished by distracting or spreading the gap typically four times a day, one quarter millimeter (¼ mm) with each adjustment, for a total of one millimeter (1 mm) a day. In the first, or distraction phase, the bone that has been cut is very gradually pulled apart, in a process that promotes distraction osteogenesis or new bone growth at the site of the osteotomy. The limb (usually the upper or lower leg) is then stabilized using one of several different external and/or internal fixation devices or frames. The process begins with an operation called an osteotomy, in which the orthopedic surgeon cuts the bone to be lengthened. Limb lengthening is achieved using the body's own capacity to regenerate new bone as well as the soft tissues, ligaments, blood vessels, and nerves that surround and support it.
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