Growth in pediatric orthopaedics.

The mature musculoskeletal system is the end result of a highly ordered, coordinated sequence of cellular and extracellular matrix events initiated early in embryonic life and continued to skeletal maturity. These events include transformation of undifferentiated mesenchymal tissue into bone, cartilage, synovium, tendon, ligaments, and muscle, and integration of these tissues to form the musculoskeletal system (7). Growth is a consequence of microgrowth at the cellular level in the growth plate. Although the histologic structure is the same, each physis has its own characteristics and dynamics. The study of growth as height, weight, and body proportions considers macrogrowth, the culmination of the effects of microgrowth of various body segments and the total individual. One must not loose sight of other aspects of growth, such as the impact of the nervous system. Growth assessment provides a reference for the orthopaedist for normal development and, in abnormal states, a guideline for treatment (13,14). Growth is a volumetric revolution. From birth onwards, height increases 350% and weight, 20-fold. Growth involves changes in proportion. At birth, the lower limbs make up 30% of the standing height in contrast to 48% at skeletal maturity. The infant head makes up 25% of the standing height and only 13% at skeletal maturity. Growth reflects a succession of accelerations and decelerations. Because growth does not occur simultaneously in the same magnitude or rate in varied body segments, it is synchronized to maintain limb and spine relationships (20,34–36). A change in direction of parameters that alters synchronization with other parameters may signal an abnormality, a return to normal, or the onset of a normal phase of growth. For this reason, a sequence of measurements of the important parameters is far superior to a single measurement. Simple measurement tools are required at the time of evaluation: height gauge, weight scales, measuring tape, and bone age atlas. Ten simple questions will guide the orthopaedist to the information that is required. How tall is the child? What is their sitting height? What is their subischial leg length? What are their chronological and bone ages? What is their annual growth? What is the growth remaining in the trunk and lower limbs? Where is the child in their normal development? Where is the child on their pubertal path? Are the proportions of the child normal? What is the child’s weight?