Maturity assessment and curve progression in girls with idiopathic scoliosis.

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.

Correlates of the peak height velocity in girls with idiopathic scoliosis.

STUDY DESIGN: Prospective longitudinal. OBJECTIVE: Determine correlates of the peak height velocity (PHV) in girls with idiopathic scoliosis. SUMMARY OF BACKGROUND DATA: Only identifiable retrospectively, the PHV is the most useful known maturity marker in idiopathic scoliosis. Clinically useful correlates are needed to make PHV timing helpful. METHODS: A total of 24 immature girls with idiopathic scoliosis were followed with serial heights, sexual staging, skeletal ages, spinal radiographs, insulin-like growth factor (IGF)-1, IGF binding protein-3, dehydroepiandrosterone sulfate, estradiol, bone-specific alkaline phosphatase, and osteocalcin levels. These markers were correlated to PHV timing. RESULTS: There were 14 girls who had identifiable growth peaks that averaged 10.5 +/- 1.8 cm/y at age 11.7 +/- 1 years. At the PHV, all girls were Risser 0 with open triradiate cartilages. On a skeletal age radiograph, digital uncapped phalangeal epiphyses were indicative of pre-PHV and fused epiphyses of post-PHV. Capped but unfused epiphyses were indeterminate. Tanner stage 1 for breast strongly indicates pre-PHV. Stage 3 for breast and pubic hair occurred at or after the PHV, and stage 4 always occurred after PHV. Higher IGF-1 and estradiol levels after PHV are potentially discriminatory. CONCLUSIONS: The PHV occurs during Risser 0 with open triradiate cartilages. If triradiate cartilages are open, then Tanner stages, IGF-1, estradiol levels, and the appearance of the epiphyses on a skeletal age radiograph are useful in determining status before or after PHV.