The present attitude toward the biology and technology of limb lengthening

Over the past ten years, many technical innovations and biologic concepts have appeared as they relate to the lengthening of long bones. Each of these has had a substantial influence upon the approach to the treatment of major discrepancies in limb length and angular deformities. It is the purpose of this paper to present these issues as objectively as possible so that the reader can put them into proper perspective, recognizing that there will be some degree of bias in the implementation of some of the technical devices. To appreciate the utility of these techniques, it is necessary to understand the biologic foundation of each method as well as its advantages and disadvantages.