Systematic Isolation of Key Parameters for Estimating Skeletal Maturity on Anteroposterior Wrist Radiographs.

BACKGROUND

The ability to make a continuous skeletal maturity estimate from a wrist radiograph would be useful in the treatment of adolescent forearm fractures, scoliosis, and other conditions. We attempted to create a reliable, rapid, and accurate method to do this.

METHODS

Many anteroposterior wrist radiographic parameters from 3 skeletal maturity systems were simplified to 23 based on relevance to the peripubertal age range, univariate correlation with skeletal maturity, and reliability. These 23 parameters were evaluated on serial peripubertal anteroposterior hand-wrist radiographs. We determined the Greulich and Pyle (GP) skeletal age and Sanders hand system (SHS) stage. We used stepwise linear regression and generalized estimating equation (GEE) procedures to identify important radiographic and demographic parameters for estimating skeletal maturity, creating the "Modified Fels wrist skeletal maturity system." Its accuracy predicting skeletal maturity was evaluated and compared with that of 4 other systems: (1) GP system, (2) SHS, (3) GP parameters along with age and sex, and (4) SHS parameters along with age and sex.

RESULTS

Three hundred and seventy-two radiographs of 42 girls (age range, 7 to 15 years) and 38 boys (age range, 9 to 16 years) were included. Fifteen radiographic parameters were excluded from the Modified Fels wrist system by stepwise regression and GEE analyses, leaving age, sex, and 8 radiographic parameters in the final model. Use of the Modified Fels wrist system resulted in more accurate skeletal maturity estimations (0.34-year mean discrepancy with actual skeletal maturity) than all other systems (p < 0.001 for all). The Modified Fels wrist system had a similar rate of outlier skeletal maturity estimations as the age, sex, and SHS model (1.9% versus 3.5%, p = 0.11) and fewer outliers than all other systems (p < 0.05 for all).

CONCLUSIONS

A system that included demographic factors and 8 anteroposterior wrist radiographic parameters estimates skeletal maturity more accurately than the 2 most-used skeletal maturity systems in the United States.

CLINICAL RELEVANCE: The Modified Fels wrist skeletal maturity system may allow for more accurate, reliable, and rapid skeletal maturity estimation than current systems, and also may be used when treating adolescent forearm fractures as it does not require imaging past the metacarpals.

LEVEL OF EVIDENCE: Diagnostic Level III. See Instructions for Authors for a complete description of levels of evidence.