Limb lengthening and angular deformity correction in skeletal dysplasias

Purpose of review: Significant advances have been made in understanding the genetics and molecular mechanisms involved in skeletal dysplasias. Short stature and limb deformities continue to be major skeletal manifestations in patients with skeletal dysplasias. These are often the cause of significant disability in these patients. This article reviews the recent advances in the correction of angular limb deformities and limb lengthening in this group of patients. Recent developments: Surgical techniques continue to evolve and technology continues to improve in the field of deformity correction and limb lengthening. Basic science research is focused on understanding the factors involved in maturation of the regenerate bone formed during distraction osteogenesis. Hydroxyapatite-coated external fixator screws have led to decreased loosening of the screws and increased stability of external fixators. Improvements in techniques of internal fixation have led to the use of intramedullary nails for distraction osteogenesis. Early recognition of complications, especially nerve compression syndromes, and their aggressive treatment have resulted in significant reduction in the morbidity associated with these procedures. With advances in total joint arthroplasty and the availability of custom components as well as modular prostheses, the results of joint replacement in these patients continue to improve. Summary: Our knowledge and understanding of the processes involved in the pathogenesis of skeletal dysplasia continue to improve, as does the technology for intramedullary devices for lengthening. Hydroxyapatite coating of Schanz screws and earlier identification of potentially devastating complications such as nerve injury have resulted in reduced morbidity during limb lengthening and deformity corrections in patients with skeletal dysplasia who are at high risk for complications.