Clinical application of the tension-stress effect for limb lengthening.

For 40 years, the author has been developing a system of orthopedics, traumatology, and limb lengthening using a circular transfixion-wire external skeletal fixator, often in combination with biomechanic methods of stimulating the formation of new osseous tissue within a widening osteotomy distraction site. The factors important for neoosteogenesis after osteotomy include: maximum preservation of extraosseous and medullary blood supply; stable external fixation; a delay prior to distraction; a distraction rate of 1 mm per day in frequent small steps; a period of stable neutral fixation after lengthening; and physiologic use of the elongating limb. For a successful fixator application, the apparatus must be applied with consideration given to the number, size, and location of the rings, the placement and tension on the wires, the technique of wire insertion, the effect of soft-tissue transfixion on limb use, and the prevention of bone and joint deformities caused by countertension in soft tissues. Clinical application of the author's techniques permits stature increase in certain forms of dwarfism, correction of deformities and limb-length inequalities, and stump elongation. For many of these applications, motorized distraction can provide continuous limb lengthening while the apparatus is on the patient.