Background: Scoliosis progression during adolescence is closely
related to patient maturity. Maturity has various indicators, including
chronological age, height and weight changes, and skeletal and sexual
maturation. It is not certain which of these indicators correlates most
strongly with scoliosis progression. The purpose of the present study was to
evaluate various maturity measurements and how they relate to scoliosis
progression.
Methods: Physically immature girls with idiopathic scoliosis were
evaluated every six months through their growth spurt with serial spinal
radiographs; hand skeletal ages; Oxford pelvic scores; Risser sign
determinations; height; weight; sexual staging; and serologic studies of the
levels of selected growth factors, estradiol, bone-specific alkaline
phosphatase, and osteocalcin. These measurements were then correlated with the
curve-acceleration phase.
Results: The period and pattern of curve acceleration began during
Risser stage 0 for all patients. Skeletal maturation scores derived with the
use of the Tanner-Whitehouse-III RUS method, particularly those for the
metacarpals and phalanges, were superior to all other indicators of maturity.
Regression of the scores provided good estimates of maturity relative to the
period of curve progression (Pearson r = 0.93). The initiation of this period
occurred simultaneously with digital changes from Tanner-Whitehouse-III stage
F to G. At this stage, curves also separated into rapid, moderate, and
low-acceleration patterns, with specific curve types in the rapid and
moderate-acceleration groups. The low-acceleration group was not confined to a
specific curve type.
Conclusions: The curve-acceleration phase separates curves into
various types of curve progression. The Tanner-Whitehouse-III RUS scores are
highly correlated with timing relative to the curve-acceleration phase and
provide better maturity determination and prognosis determination during
adolescence than the other parameters tested. Accurate skeletal maturity
determination should be used as the primary maturity measurement in girls with
idiopathic scoliosis.
Level of Evidence: Prognostic Level I. See Instructions
to Authors for a complete description of levels of evidence.